Document:

EX-10.1

 Exhibit 10.1 

Execution Version 

SERIES D CUMULATIVE CONVERTIBLE PREFERRED UNIT 

PURCHASE AGREEMENT 
 among

 NUSTAR ENERGY L.P. 
 and

 THE PURCHASERS PARTY HERETO 

June 26, 2018 

 TABLE OF CONTENTS 

 

							
	 	  	 	  	Page	 
	 ARTICLE I DEFINITIONS
	  	 	1	 
			
	 Section 1.01
	  	Definitions	  	 	1	 
	 Section 1.02
	  	Accounting Procedures and Interpretation	  	 	8	 
		
	 ARTICLE II AGREEMENT TO SELL AND PURCHASE
	  	 	9	 
			
	 Section 2.01
	  	Sale and Purchase	  	 	9	 
	 Section 2.02
	  	Closing	  	 	9	 
	 Section 2.03
	  	Mutual Conditions at the Initial Closing	  	 	9	 
	 Section 2.04
	  	Conditions to Each Purchaser’s Obligations at the Initial Closing	  	 	10	 
	 Section 2.05
	  	Conditions to the Partnership’s Obligations at the Initial Closing	  	 	10	 
	 Section 2.06
	  	Deliveries at the Initial Closing	  	 	11	 
	 Section 2.07
	  	Mutual Conditions at the Second Closing	  	 	12	 
	 Section 2.08
	  	Conditions to Each Purchaser’s Obligations at the Second Closing	  	 	13	 
	 Section 2.09
	  	Conditions to the Partnership’s Obligations at the Second Closing	  	 	14	 
	 Section 2.10
	  	Independent Nature of Purchasers’ Obligations and Rights	  	 	15	 
	 Section 2.11
	  	Further Assurances	  	 	15	 
		
	 ARTICLE III REPRESENTATIONS AND WARRANTIES AND COVENANTS RELATED TO THE
PARTNERSHIP
	  	 	15	 
			
	 Section 3.01
	  	Existence	  	 	15	 
	 Section 3.02
	  	Capitalization and Valid Issuance of Units	  	 	16	 
	 Section 3.03
	  	Ownership of the Material Subsidiaries	  	 	18	 
	 Section 3.04
	  	NS SEC Documents	  	 	18	 
	 Section 3.05
	  	Financial Statements	  	 	18	 
	 Section 3.06
	  	Independent Registered Public Accounting Firm	  	 	19	 
	 Section 3.07
	  	No Material Adverse Change	  	 	19	 
	 Section 3.08
	  	No Registration Required	  	 	19	 
	 Section 3.09
	  	No Restrictions or Registration Rights	  	 	19	 
	 Section 3.10
	  	Litigation	  	 	19	 
	 Section 3.11
	  	No Default	  	 	20	 
	 Section 3.12
	  	No Conflicts	  	 	20	 
	 Section 3.13
	  	Authority; Enforceability	  	 	20	 
	 Section 3.14
	  	Approvals	  	 	21	 
	 Section 3.15
	  	Distribution Restrictions	  	 	21	 
	 Section 3.16
	  	MLP Status	  	 	21	 
	 Section 3.17
	  	Investment Company Status	  	 	21	 
	 Section 3.18
	  	Certain Fees	  	 	22	 
	 Section 3.19
	  	Labor and Employment Matters	  	 	22	 
	 Section 3.20
	  	Insurance	  	 	22	 
	 Section 3.21
	  	Internal Controls	  	 	22	 
	 Section 3.22
	  	Disclosure Controls and Procedures	  	 	22	 
	 Section 3.23
	  	Sarbanes-Oxley	  	 	23	 
	 Section 3.24
	  	Listing and Maintenance Requirements	  	 	23	 

  
 i 

							
	 Section 3.25
	  	Environmental Compliance	  	 	23	 
	 Section 3.26
	  	ERISA Compliance	  	 	23	 
	 Section 3.27
	  	Tax Returns; Taxes	  	 	24	 
	 Section 3.28
	  	Permits	  	 	24	 
	 Section 3.29
	  	Required Disclosures and Descriptions	  	 	24	 
	 Section 3.30
	  	Title to Property	  	 	24	 
	 Section 3.31
	  	Rights-of-Way	  	 	25	 
	 Section 3.32
	  	Form S-3 Eligibility	  	 	25	 
	 Section 3.33
	  	FCPA	  	 	25	 
	 Section 3.34
	  	Money Laundering Laws	  	 	26	 
	 Section 3.35
	  	OFAC	  	 	26	 
	 Section 3.36
	  	Related Party Transactions	  	 	26	 
	 Section 3.37
	  	No Side Agreements	  	 	26	 
		
	 ARTICLE IV REPRESENTATIONS AND WARRANTIES AND COVENANTS OF THE PURCHASERS
	  	 	27	 
			
	 Section 4.01
	  	Existence	  	 	27	 
	 Section 4.02
	  	Authorization; Enforceability	  	 	27	 
	 Section 4.03
	  	No Breach	  	 	27	 
	 Section 4.04
	  	Certain Fees	  	 	27	 
	 Section 4.05
	  	Unregistered Securities	  	 	27	 
	 Section 4.06
	  	Sufficient Funds	  	 	29	 
	 Section 4.07
	  	No Prohibited Trading	  	 	29	 
		
	 ARTICLE V COVENANTS
	  	 	29	 
			
	 Section 5.01
	  	Conduct of Business	  	 	29	 
	 Section 5.02
	  	Listing of Units	  	 	30	 
	 Section 5.03
	  	Lock-up Agreement	  	 	30	 
	 Section 5.04
	  	Tax Matters	  	 	31	 
	 Section 5.05
	  	Use of Proceeds	  	 	32	 
		
	 ARTICLE VI INDEMNIFICATION, COSTS AND EXPENSES
	  	 	32	 
			
	 Section 6.01
	  	Indemnification by the Partnership	  	 	32	 
	 Section 6.02
	  	Indemnification by the Purchasers	  	 	32	 
	 Section 6.03
	  	Indemnification Procedure	  	 	33	 
	 Section 6.04
	  	Tax Matters	  	 	34	 
		
	 ARTICLE VII TERMINATION
	  	 	34	 
			
	 Section 7.01
	  	Termination	  	 	34	 
	 Section 7.02
	  	Certain Effects of Termination	  	 	35	 
		
	 ARTICLE VIII MISCELLANEOUS
	  	 	35	 
			
	 Section 8.01
	  	Expenses	  	 	35	 
	 Section 8.02
	  	Interpretation	  	 	35	 
	 Section 8.03
	  	Survival of Provisions	  	 	36	 
	 Section 8.04
	  	No Waiver: Modifications in Writing	  	 	36	 
	 Section 8.05
	  	Binding Effect; Assignment	  	 	37	 

  
 ii 

							
	 Section 8.06
	  	Non-Disclosure	  	 	37	 
	 Section 8.07
	  	Communications	  	 	38	 
	 Section 8.08
	  	Removal of Legend	  	 	38	 
	 Section 8.09
	  	Entire Agreement	  	 	39	 
	 Section 8.10
	  	Governing Law; Submission to Jurisdiction	  	 	39	 
	 Section 8.11
	  	Waiver of Jury Trial	  	 	40	 
	 Section 8.12
	  	Exclusive Remedy	  	 	40	 
	 Section 8.13
	  	No Recourse Against Others	  	 	41	 
	 Section 8.14
	  	No Third-Party Beneficiaries	  	 	41	 
	 Section 8.15
	  	Execution in Counterparts	  	 	41	 

  
 iii 

 SERIES D CUMULATIVE CONVERTIBLE PREFERRED UNIT 

PURCHASE AGREEMENT 
 This
SERIES D CUMULATIVE CONVERTIBLE PREFERRED UNIT PURCHASE AGREEMENT, dated as of June 26, 2018 (this “Agreement”), is entered into by and among NUSTAR ENERGY L.P., a Delaware limited partnership (the
“Partnership”) and the purchasers set forth in Schedule A hereto (the “Purchasers”). 

WHEREAS, the Partnership desires to issue and sell to the Purchasers, and the Purchasers desire to purchase from the Partnership, the
Series D Preferred Units (as defined below), in accordance with the provisions of this Agreement; and 
 WHEREAS, the
Partnership has agreed to provide the Purchasers with certain registration rights with respect to the Series D Preferred Units, the PIK Units (as defined below) and the Conversion Units (as defined below). 

NOW THEREFORE, in consideration of the mutual covenants and agreements set forth herein and for good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows: 
 ARTICLE I 

DEFINITIONS 

Section 1.01 Definitions. Unless otherwise defined in this Agreement, terms shall have the same meaning as in the
Partnership Agreement (as defined below). As used in this Agreement, the following terms have the meanings indicated: 

“Affiliate” means, with respect to any Person, any other Person that directly or indirectly through one or more
intermediaries controls, is controlled by or is under common control with, the Person in question (provided that no portfolio company of such Person shall be considered an Affiliate of such Person). As used herein, the term “control” means
the possession, direct or indirect, of the power to direct or cause the direction of the management and policies of a Person, whether through ownership of voting securities, by contract or otherwise. For the avoidance of doubt, for purposes of this
Agreement, (a) the Partnership Entities, on the one hand, and any Purchaser, on the other, shall not be considered Affiliates and (b) with respect to any Purchaser that is an investment fund, investment account or investment company, any
other investment fund, investment account or investment company that is managed, advised or sub-advised by the same investment advisor as such Purchaser or by an Affiliate of such investment advisor, shall be
considered controlled by, and an Affiliate of, such Purchaser. 
 “Agreement” has the meaning set forth in the
introductory paragraph of this Agreement. 
 “Business Day” means any day other than a Saturday, Sunday, any federal
legal holiday or day on which banking institutions in the State of New York or State of Texas are authorized or required by Law or other governmental action to close. 

“Closing Date” means each of the Initial Closing Date and the Second Funding Closing Date. 

  
 1 

 “Code” has the meaning specified in
Section 3.16. 
 “Committed Investment Amount” means $590 million. 

“Common Equity Market Capitalization” means an amount equal to the product of the number of issued and outstanding
Common Units and the average high and low sales price of the Common Units for the date immediately preceding the date of the Second Closing. 

“Common Units” means common units representing limited partner interests in the Partnership. 

“Confidentiality Agreements” means any confidentiality agreement entered into by the Partnership and any of the
Purchasers or their Affiliates, as applicable, as may be amended from time to time. 
 “Consent” has the meaning
specified in Section 3.14. 
 “Contract” means any contract, agreement, indenture, note,
bond, mortgage, deed of trust, loan, instrument, lease, license, commitment or other arrangement, understanding, undertaking, commitment or obligation, whether written or oral. 

“Conversion Units” means the Common Units issuable upon conversion of the Series D Preferred Units or PIK Units.

 “Delaware LLC Act” means the Delaware Limited Liability Company Act, as amended from time to time. 

“Delaware LP Act” means the Delaware Revised Uniform Limited Partnership Act, as amended from time to time. 

“Disclosure Letter” means the disclosure letter provided by the Partnership to the Purchasers dated as of the date
hereof. 
 “EIG” means collectively, EIG Management Company, LLC and FS/EIG Advisor, LLC. 

“Environmental Laws” means any and all applicable federal, state and local laws and regulations relating to the
protection of human health and safety and the environment or imposing liability or standards of conduct concerning any Hazardous Materials. 

“ERISA” has the meaning specified in Section 3.26. 

“Exchange Act” means the Securities Exchange Act of 1934, as amended from time to time, and the rules and regulations
of the SEC promulgated thereunder. 
 “FCPA” has the meaning specified in Section 3.33.

 “GAAP” means generally accepted accounting principles in the United States of America. 

  
 2 

 “General Partner” means Riverwalk Logistics, L.P., the general partner of
the Partnership. 
 “Governmental Authority” means, with respect to a particular Person, any country, state, county,
city and political subdivision in which such Person or such Person’s Property is located or which exercises valid jurisdiction over any such Person or such Person’s Property, and any court, agency, department, commission, board, bureau,
official or other regulatory authority (including self-regulated organizations or other non-governmental regulatory authorities) or instrumentality of any of them and any monetary authority which exercises
valid jurisdiction over any such Person or such Person’s Property. Unless otherwise specified, all references to Governmental Authority herein with respect to the Partnership mean a Governmental Authority having jurisdiction over the
Partnership Entities or any of their respective Properties. 
 “GP Partnership Agreement” means the First Amended
and Restated Limited Partnership Agreement of the General Partner, dated as of April 16, 2001, as amended from time to time. 

“Hazardous Materials” means (A) any “hazardous substance” as defined in the Comprehensive Environmental
Response, Compensation and Liability Act of 1980, as amended, (B) any “hazardous waste” as defined in the Resource Conservation and Recovery Act, as amended, (C) any petroleum or petroleum product, (D) any polychlorinated
biphenyl and (E) any pollutant or contaminant or hazardous, dangerous or toxic chemical, material, waste or substance regulated under or within the meaning of any other Environmental Law. 

“Incentive Distribution Rights” has the meaning specified in Section 3.02(a). 

“Indemnified Party” has the meaning specified in Section 6.03(b). 

“Indemnifying Party” has the meaning specified in Section 6.03(b). 

“Information Rights Agreement” means the Information Rights Agreement, to be entered into at the Initial Closing,
between the Partnership and EIG, substantially in the form attached hereto as Exhibit D. 
 “Initial
Closing” has the meaning specified in Section 2.02. 
 “Initial Closing Date”
means June 29, 2018, or such other later date as the Partnership and the Purchasers shall agree to in writing. 
 “Initial
Funding Amount” means, with respect to a particular Purchaser, an amount equal to the Series D Preferred Unit Purchase Price multiplied by the number of Series D Preferred Units to be purchased by such Purchaser on the Initial
Closing Date pursuant to Section 2.01(a). 
 “Initial Purchase Price” means
$399,999,992.58. 
 “Knowledge” means, with respect to the NuStar Parties, the actual knowledge of Brad Barron, Tom
Shoaf and Daniel Oliver. 

  
 3 

 “Law” means any statute, law ordinance, regulation, rule, order, code,
governmental restriction, decree, injunction or other requirement of law, or any judicial or administrative interpretation thereof, of any Governmental Authority. 

“Lien” means any mortgage, pledge, lien (statutory or otherwise), encumbrance, security interest, security agreement,
conditional sale, trust receipt, charge or claim or a lease, consignment or bailment, preference or priority, assessment, deed of trust, easement, servitude or other encumbrance upon or with respect to any property of any kind. 

“Mandate Letter” has the meaning specified in Section 3.37. 

“Material Adverse Effect” means any change, effect, event or occurrence that, individually or in the aggregate, has
had or would reasonably be expected to have a material adverse effect on (a) the business, condition (financial or otherwise) or results of operations of the Partnership Entities, taken as a whole or (b) the ability of any of the
Partnership Entities, as applicable, to perform their obligations under the Transaction Documents; provided, however, that any adverse changes, effects, events or occurrences resulting from or due to any of the following shall be disregarded
in determining whether there has been a Material Adverse Effect: (i) changes, effects, events or occurrences generally affecting the United States or global economy, the financial, credit, debt, securities or other capital markets or political,
legislative or regulatory conditions or changes in the industries in which the Partnership Entities operate (including changes, effects, events or occurrences generally affecting the prices of commodities); (ii) changes in any Laws or
regulations applicable to the Partnership Entities or applicable accounting regulations or principles or the interpretation thereof, to the extent not directly and exclusively impacting the Partnership Entities; (iii) acts of war or terrorism
(or the escalation of the foregoing) or natural disasters or other acts of God; (iv) any change in the market price or trading volume of the securities of the Partnership Entities (it being understood and agreed that the foregoing shall not
preclude any other Party to this Agreement from asserting that any facts or occurrences giving rise to or contributing to such change that are not otherwise excluded from the definition of Material Adverse Effect should be deemed to constitute, or
be taken into account in determining whether there has been, or would reasonably be expected to be, a Material Adverse Effect); (v) any failure of any of the Partnership Entities to meet any internal or external projections, forecasts or
estimates of revenues, earnings or other financial or operating metrics for any period (it being understood and agreed that the foregoing shall not preclude any other Party to this Agreement from asserting that any facts or occurrences giving rise
to or contributing to such change that are not otherwise excluded from the definition of Material Adverse Effect should be deemed to constitute, or be taken into account in determining whether there has been, or would reasonably be expected to be, a
Material Adverse Effect); (vi) any legal proceedings commenced by or involving any current or former holder of equity interests in the Partnership (on their own or on behalf of the Partnership) arising out of or relating to this Agreement, the
transactions contemplated hereby, the Merger Agreement or the transactions contemplated thereby; (vii) any nonpayment or nonperformance by Petróleos de Venezuela, S.A. that results in a loss of revenues or increased liabilities to the
Partnership; and (viii) the execution, announcement or pendency of this Agreement or the consummation of the transactions contemplated hereby or of a reduction in the quarterly distribution of the Partnership Entities (it being understood and
agreed that the foregoing shall not preclude any other Party to this Agreement from asserting that any facts or occurrences giving rise to or contributing to such change that are not otherwise excluded from the definition of Material Adverse Effect
should be deemed to constitute, or be taken into account in determining whether there has been, or would reasonably be expected to be, a Material Adverse Effect). 

  
 4 

 “Material Subsidiary Operative Document” has the meaning specified in
Section 3.03. 
 “Material Subsidiaries” means each of the Partnership’s
“significant subsidiaries,” as defined in Rule 1-02(w) of Regulation S-X under the Exchange Act. 

“Merger Agreement” means the Agreement and Plan of Merger dated February 7, 2018 by and among the Partnership,
the General Partner, NuStar GP, Marshall Merger Sub LLC, a Delaware limited liability company and a wholly owned subsidiary of the Partnership, NSH and Riverwalk Holdings, as may be amended from time to time. 

“Money Laundering Laws” has the meaning specified in Section 3.34. 

“National Securities Exchange” means an exchange registered with the SEC under Section 6(a) of the Securities
Exchange Act (or any successor to such Section) and any other securities exchange (whether or not registered with the SEC under Section 6(a) (or successor to such Section) of the Securities Exchange Act) that NuStar GP shall designate as a
National Securities Exchange for purposes of this Agreement. 
 “Non-Solicitation Side
Letter” means the Non-Solicitation Side Letter, to be entered into at the Initial Closing, between the Partnership, EIG and the Purchasers, substantially in the form attached hereto as
Exhibit E. 
 “NS Preferred Units” means the Series A Preferred Units, the
Series B Preferred Units and the Series C Preferred Units. 
 “NS SEC Documents” means the
Partnership’s forms, registration statements, reports, schedules and statements filed (but not furnished) by it under the Exchange Act or the Securities Act, as applicable. 

“NSH” NuStar GP Holdings, LLC, a Delaware limited liability company. 

“NuStar Entities” means, collectively, the Partnership and the Partnership’s Subsidiaries. 

“NuStar GP” means NuStar GP, LLC, the general partner of the General Partner. 

“NuStar GP LLC Agreement” means the limited liability company agreement of NuStar GP, dated as of June 5, 2000,
as amended from to time in accordance with the terms thereof. 
 “NuStar Parties” means, collectively, NuStar GP,
the General Partner and the Partnership. 
 “NYSE” means the New York Stock Exchange. 

“Organizational Documents” means, as applicable, an entity’s agreement or certificate of limited partnership,
limited liability company agreement, certificate of formation, certificate or articles of incorporation, bylaws or other similar organizational documents. 

  
 5 

 “Partnership” has the meaning set forth in the introductory paragraph of
this Agreement. 
 “Partnership Agreement” means the Sixth Amended and Restated Agreement of Limited Partnership of
the Partnership, dated as of November 30, 2017, as amended from time to time in accordance with the terms thereof (including, as the context requires, by the Seventh A&R LPA, as it may be further amended and restated from time to time in
accordance with its terms including in connection with the merger contemplated by the Merger Agreement). 
 “Partnership
Entities” means, collectively, the NuStar Parties and NuStar Entities. 
 “Partnership Related Parties”
has the meaning specified in Section 6.02. 
 “PCAOB” means the Public Company Accounting
Oversight Board of the United States. 
 “Permits” has the meaning specified in
Section 3.28. 
 “Permitted Transferee” has the meaning specified in
Section 5.03. 
 “Person” means any individual, corporation, company, voluntary
association, partnership, joint venture, trust, limited liability company, unincorporated organization, government or any agency, instrumentality or political subdivision thereof or any other form of entity. 

“Piggyback Registration Rights” means the rights described in Section 2.02 of the
Registration Rights Agreement. 
 “PIK Units” means any additional Series D Preferred Units issued by the
Partnership to the Purchasers as in-kind distributions pursuant to the Seventh A&R LPA. 

“Plan” has the meaning specified in Section 3.26. 

“Property” means any interest in any kind of property or asset, whether real, personal or mixed, or tangible or
intangible (including intellectual property rights). 
 “Purchaser Related Parties” has the meaning specified in
Section 6.01. 
 “Purchasers” has the meaning specified in the introductory paragraph of
this Agreement. 
 “Registration Rights Agreement” means the Registration Rights Agreement, to be entered into at
the Initial Closing, between the Partnership the Purchasers, substantially in the form attached hereto as Exhibit C. 

“Reimbursable Expenses” has the meaning specified in Section 8.01. 

“Representatives” means, with respect to a specified Person, the investors, officers, directors, managers, employees,
agents, advisors, counsel, accountants, investment bankers and other representatives of such Person. 
 “Revolving Credit
Agreement” means the Revolving Credit Agreement, dated as of June 28, 2013, among NSH and the lenders party thereto, as amended. 

  
 6 

“Rights-of-Way” has the meaning
specified in Section 3.31. 
 “Riverwalk Holdings” means Riverwalk Holdings, LLC, a
Delaware limited liability company and wholly owned subsidiary of NSH. 
 “Sanctions” has the meaning specified in
Section 3.35. 
 “SEC” means the United States Securities and Exchange Commission. 

“Second Closing” has the meaning specified in Section 2.02. 

“Second Funding Closing Date” means July 13, 2018, or such other later date as the Partnership and the Purchasers
shall agree to in writing. 
 “Second Closing Eligible” means that the Partnership (i) is in compliance with
all covenants contained in its outstanding debt and preferred unit instruments and (ii) has a Common Equity Market Capitalization of at least $1.5 billion. 

“Second Closing Purchase Price” means $189,999,984.42. 

“Second Closing Funding Amount” means, with respect to a particular Purchaser, an amount equal to the Series D
Preferred Unit Purchase Price multiplied by the number of Series D Preferred Second Closing Units to be purchased by such Purchaser on the Second Funding Closing Date pursuant to Section 2.01(b). 

“Securities Act” means the Securities Act of 1933, as amended from time to time, and the rules and regulations of the
SEC promulgated thereunder. 
 “Series A Preferred Units” shall mean the 8.50%
Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units issued by the Partnership. 

“Series B Preferred Units” shall mean the 7.625% Series B Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units issued by the Partnership. 

“Series C Preferred Units” shall mean the 9.00% Series C Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units issued by the Partnership. 

“Series D Preferred Initial Closing Units” has the meaning set forth in
Section 2.01(a). 
 “Series D Preferred Second Closing
Units” has the meaning set forth in Section 2.01(b). 

“Series D Preferred Unit Purchase Price” shall mean $25.38. 

“Series D Preferred Units” means the Series D Cumulative Convertible Preferred
Units to be issued by the Partnership. 
 “Seventh A&R LPA” has the meaning specified in
Section 2.06(a)(ii). 

  
 7 

 “Subsidiary” means, as to any Person, any corporation or other entity of
which: (a) such Person or a Subsidiary of such Person is a general partner or, in the case of a limited liability company, the managing member or manager thereof; (b) at least a majority of the outstanding equity interest having by the
terms thereof ordinary voting power to elect a majority of the board of directors or similar governing body of such corporation or other entity (irrespective of whether or not at the time any equity interest of any other class or classes of such
corporation or other entity shall have or might have voting power by reason of the happening of any contingency) is at the time directly or indirectly owned or controlled by such Person or one or more of its Subsidiaries; or (c) any corporation
or other entity as to which such Person consolidates for accounting purposes. 
 “Tax Return” means any return,
report or similar filing (including the attached schedules) filed or required to be filed with respect to Taxes (and any amendments thereto), including any information return, claim for refund or declaration of estimated Taxes. 

“Taxes” means any and all domestic or foreign, federal, state, local or other taxes of any kind (together with any and
all interest, penalties, additions to tax and additional amounts imposed with respect thereto) imposed by any Governmental Authority, including taxes on or with respect to income, franchises, windfall or other profits, gross receipts, property,
sales, use, capital stock, payroll, employment, unemployment, social security, workers’ compensation or net worth, and taxes in the nature of excise, withholding, ad valorem or value added, and including any liability in respect of any
items described above as a transferee or successor, pursuant to Section 1.1502-6 of the Treasury Regulations (or any similar provisions of state, local or foreign Law), or as an indemnitor, guarantor,
surety or in a similar capacity under any Contract. 
 “Third-Party Claim” has the meaning specified in
Section 6.03(b). 
 “Total Funding Amount” means, with respect to a particular Purchaser,
an amount equal to the sum of (a) the Series D Preferred Unit Purchase Price multiplied by the number of Series D Preferred Initial Closing Units to be purchased by such Purchaser and (b) the Series D Preferred Unit Purchase
Price multiplied by the number of Series D Preferred Second Closing Units to be purchased by such Purchaser. 
 “Trading
Day” means a day on which the principal National Securities Exchange on which the Common Units are listed or admitted to trading is open for the transaction of business or, if such Common Units are not listed or admitted to trading on
any National Securities Exchange, a day on which banking institutions in New York City generally are open. 
 “Transaction
Documents” means, collectively, this Agreement, the Registration Rights Agreement, the Seventh A&R LPA, the Information Rights Agreement, the Non-Solicitation Side Letter and any and all other
agreements or instruments executed and delivered in connection with the Initial Closing. 
 “VWAP” means the volume
weighted average trading price. 
 Section 1.02 Accounting Procedures and Interpretation. Unless otherwise specified
herein, all accounting terms used herein shall be interpreted, all determinations with respect to accounting matters hereunder shall be made, and all financial statements of the Partnership and certificates and reports as to financial matters
required to be furnished to the Purchasers hereunder shall be 

  
 8 

 
prepared, in accordance with GAAP applied on a consistent basis during the periods involved (except as may be indicated in the notes thereto or, in the case of unaudited statements, as permitted
by Form 10-Q promulgated by the SEC) and in compliance as to form in all material respects with applicable accounting requirements and with the published rules and regulations of the SEC with respect
thereto. 
 ARTICLE II 

AGREEMENT TO SELL AND PURCHASE 

Section 2.01 Sale and Purchase. 

(a) Subject to the terms and conditions hereof, at the Initial Closing, each Purchaser hereby agrees, severally and not jointly, to purchase
from the Partnership, and the Partnership hereby agrees to issue and sell to each Purchaser, such Purchaser’s respective Series D Preferred Units, as set forth next to such Purchaser’s name on Schedule A hereto (the
“Series D Preferred Initial Closing Units”), upon receipt by the Partnership of the Initial Purchase Price on the Initial Closing Date; and 

(b) subject to the terms and conditions hereof, at the Second Closing, each Purchaser hereby agrees, severally and not jointly, to purchase
from the Partnership, and the Partnership hereby agrees to issue and sell to each Purchaser, such Purchaser’s respective Series D Preferred Units, as set forth next to such Purchaser’s name on Schedule A
hereto (the “Series D Preferred Second Closing Units”), upon receipt by the Partnership of the Second Closing Purchase Price on the Second Funding Closing Date. 

Section 2.02 Closing. The consummation of each of (i) the purchase and sale of the Series D Preferred
Initial Closing Units (the “Initial Closing”) and (ii) the purchase and sale of the Series D Preferred Second Closing Units (the “Second Closing”) shall take place at the offices of Sidley
Austin LLP, 1000 Louisiana St., Suite 6000, Houston, Texas 77002 (or such other location as agreed to by the Partnership and the Purchasers). 

Section 2.03 Mutual Conditions at the Initial Closing. The respective obligations of each party to consummate the
purchase and sale of the Series D Preferred Initial Closing Units at the Initial Closing shall be subject to the satisfaction, on or prior to the Initial Closing Date, of each of the following conditions (any or all of which may be waived by a
party on behalf of itself in writing, in whole or in part, to the extent permitted by applicable Law): 
 (a) no statute, rule, order, decree
or regulation shall have been enacted or promulgated, and no action shall have been taken, by any Governmental Authority which temporarily, preliminarily or permanently restrains, precludes, enjoins or otherwise prohibits the consummation of the
transactions contemplated hereby or under the other Transaction Documents or makes the transactions contemplated hereby or under the other Transaction Documents illegal; and 

(b) there shall not be pending any suit, action or proceeding by any Governmental Authority seeking to restrain, preclude, enjoin or prohibit
the transactions contemplated by this Agreement or the other Transaction Documents. 

  
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 Section 2.04 Conditions to Each Purchaser’s
Obligations at the Initial Closing. The obligation of a Purchaser to consummate its purchase of Series D Preferred Initial Closing Units shall be subject to the satisfaction on or prior to the Initial Closing Date of each of the
following conditions (any or all of which may be waived by the applicable Purchaser with respect to itself in writing, in whole or in part, to the extent permitted by applicable Law): 

(a) the representations and warranties of the Partnership contained in this Agreement shall be true and correct in all material respects (other
than those representations and warranties contained in Section 3.01, Section 3.02, Section 3.03, Section 3.13,
Section 3.16 or Section 3.18 or other representations and warranties that are qualified by materiality or Material Adverse Effect, which, in each case, shall be true and correct in all respects)
when made and as of the Initial Closing Date (except that representations and warranties made as of a specific date shall be required to be true and correct in all material respects as of such date only); 

(b) the Partnership shall have performed and complied in all material respects with all of the covenants and agreements contained in this
Agreement that are required to be performed or complied with by it on or prior to the Initial Closing Date; 
 (c) the NYSE shall have
authorized, upon official notice of issuance, the listing of the Conversion Units; 
 (d) no notice of delisting from the NYSE shall have
been received by the Partnership with respect to the Common Units; 
 (e) there shall not have occurred a Material Adverse Effect; and 

(f) the Partnership shall have delivered, or caused to be delivered, to the Purchaser the Partnership’s closing deliverables described in
Section 2.06(a), as applicable. 
 Section 2.05 Conditions to the
Partnership’s Obligations at the Initial Closing. The obligation of the Partnership to consummate the sale and issuance of the Series D Preferred Initial Closing Units to each Purchaser shall be subject
to the satisfaction on or prior to the Initial Closing Date of each of the following conditions (any or all of which may be waived by the Partnership in writing, in whole or in part, to the extent permitted by applicable Law): 

(a) the representations and warranties of each Purchaser contained in this Agreement shall be true and correct in all material respects (other
than those representations and warranties that are qualified by materiality, which, in each case, shall be true and correct in all respects) when made and as of the Initial Closing Date (except that representations and warranties made as of a
specific date shall be required to be true and correct in all material respects as of such date only); 
 (b) each Purchaser shall have
performed and complied in all material respects with all of the covenants and agreements contained in this Agreement that are required to be performed or complied with by it on or prior to the Initial Closing Date; and 

(c) each Purchaser shall have delivered, or caused to be delivered, to the Partnership the applicable closing deliverables described in
Section 2.06(b), as applicable. 

  
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 Section 2.06 Deliveries at the Initial Closing. 

(a) Deliveries of the Partnership at the Initial Closing. At the Initial Closing, the Partnership shall deliver, or cause to be
delivered, to the Purchasers: 
 (i) An opinion from Sidley Austin LLP, counsel for the Partnership, in substantially the
form attached hereto as Exhibit A, which shall be addressed to the Purchasers and dated the Initial Closing Date; 

(ii) A fully executed copy of the Seventh Amended and Restated Agreement of Limited Partnership of the Partnership,
substantially in the form attached hereto as Exhibit B (the “Seventh A&R LPA”); 

(iii) An executed counterpart of the Registration Rights Agreement; 

(iv) An executed counterpart of the Non-Solicitation Side Letter; 

(v) An executed counterpart of the Information Rights Agreement; 

(vi) A fully executed “Supplemental Listing Application” approving the Conversion Units for listing by the NYSE, upon
official notice of issuance; 
 (vii) A fully executed waiver of NuStar GP with respect to its rights under Section 5.7
of the Partnership Agreement, in substantially the form attached hereto as Exhibit F; 
 (viii)
Evidence of issuance of the Series D Preferred Initial Closing Units credited to book-entry accounts maintained by the transfer agent of the Partnership, bearing a restrictive notation meeting the requirements of the Partnership Agreement, free
and clear of any Liens, other than transfer restrictions under this Agreement, the Partnership Agreement or the Delaware LP Act and applicable federal and state securities Laws and those created by the Purchasers; 

(ix) A certificate of the Secretary or Assistant Secretary of NuStar GP, on behalf of the Partnership, dated the Initial
Closing Date, certifying as to and attaching (A) the certificate of limited partnership of the Partnership, (B) the Partnership Agreement, (C) board resolutions, or resolutions of a committee thereof, authorizing the execution and
delivery of the Transaction Documents and the consummation of the transactions contemplated thereby, and (D) the incumbency of the officers authorized to execute the Transaction Documents on behalf of the Partnership or NuStar GP, as
applicable, setting forth the name and title and bearing the signatures of such officers; 
 (x) A certificate of the
Secretary of State of each applicable state, dated within ten Business Days prior to the Initial Closing Date, to the effect that each of the Partnership and its Material Subsidiaries (other than NuStar Terminals N.V., a private limited liability
company duly established under the laws of the Netherlands Antilles and validly existing under the laws of the Netherlands and the BES-Islands) is in good standing in its jurisdiction of formation; 

  
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 (xi) A certificate of the Executive Vice President and Chief Financial Officer of
NuStar GP, on behalf of the Partnership, dated the Initial Closing Date, certifying, in such capacity, to the effect that the conditions set forth in Section 2.04(a) and Section 2.04(b) contained
herein have been satisfied; and 
 (xii) A cross-receipt executed by the Partnership and delivered to the Purchasers
certifying as to the amounts that it has received from the Purchasers. 
 (b) Deliveries of the Purchasers at the Initial Closing. At
the Initial Closing, the Purchasers, shall deliver or cause to be delivered to the Partnership: 
 (i) A counterpart of the
Registration Rights Agreement, which shall have been duly executed by each Purchaser; 
 (ii) A counterpart of the Non-Solicitation Side Letter, which shall have been duly executed by each Purchaser and EIG; 

(iii) A cross-receipt executed by each Purchaser and delivered to the Partnership certifying that each Purchaser has received
from the Partnership the number of Series D Preferred Initial Closing Units to be received by such Purchaser in connection with the Initial Closing; 

(iv) a certificate of an authorized officer of each Purchaser, dated the Initial Closing Date, in his or her applicable
capacity, to the effect that the conditions set forth in Section 2.05(a) and Section 2.05(b) have been satisfied; 

(v) Payment of each Purchaser’s Initial Funding Amount payable by wire transfer of immediately available funds to an
account designated in advance of the Initial Closing Date by the Partnership; and 
 (vi) A properly executed Internal
Revenue Service Form W-9 from each Purchaser. 
 Section 2.07 Mutual Conditions
at the Second Closing. The respective obligations of each party to consummate the purchase and sale of the Series D Preferred Second Closing Units at the Second Closing shall be subject to the satisfaction, on or prior to the Second
Funding Closing Date, of each of the following conditions (any or all of which may be waived by a party on behalf of itself in writing, in whole or in part, to the extent permitted by applicable Law): 

(a) no statute, rule, order, decree or regulation shall have been enacted or promulgated, and no action shall have been taken, by any
Governmental Authority which temporarily, preliminarily or permanently restrains, precludes, enjoins or otherwise prohibits the consummation of the transactions contemplated hereby or under the other Transaction Documents or makes the transactions
contemplated hereby or under the other Transaction Documents illegal; and 
 (b) there shall not be pending any suit, action or proceeding
by any Governmental Authority seeking to restrain, preclude, enjoin or prohibit the transactions contemplated by this Agreement or the other Transaction Documents. 

  
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 Section 2.08 Conditions to Each Purchaser’s
Obligations at the Second Closing. The obligation of a Purchaser to consummate its purchase of Series D Preferred Second Closing Units shall be subject to the satisfaction on or prior to the Second Funding Closing Date of each of the
following conditions (any or all of which may be waived by the applicable Purchaser with respect to itself in writing, in whole or in part, to the extent permitted by applicable Law): 

(a) the Partnership is Second Closing Eligible; 

(b) the representations and warranties of the Partnership contained in this Agreement shall be true and correct in all material respects
(other than those representations and warranties contained in Section 3.01, Section 3.02, Section 3.03, Section 3.13,
Section 3.16 or Section 3.18 or other representations and warranties that are qualified by materiality or Material Adverse Effect, which, in each case, shall be true and correct in all respects)
when made and as of the Second Funding Closing Date (except that representations and warranties made as of a specific date shall be required to be true and correct in all material respects as of such date only); 

(c) the Partnership shall have performed and complied in all material respects with all of the covenants and agreements contained in this
Agreement that are required to be performed or complied with by it on or prior to the Second Funding Closing Date; 
 (d) no notice of
delisting from the NYSE shall have been received by the Partnership with respect to the Common Units; 
 (e) there shall not have occurred a
Material Adverse Effect; and 
 (f) the Partnership shall have delivered, or cause to be delivered, to the Purchaser the following
documents: 
 (i) an opinion from Sidley Austin LLP, counsel for the Partnership, in substantially the form attached hereto
as Exhibit A with respect to the Series D Preferred Second Closing Units purchased on the Second Funding Closing Date, which shall be addressed to the Purchasers and dated the Second Funding Closing Date; 

(ii) a fully executed “Supplemental Listing Application” approving the Conversion Units, in respect of the
Series D Preferred Second Closing Units, for listing by the NYSE, upon official notice of issuance, if needed; 
 (iii)
evidence of issuance of the Series D Preferred Second Closing Units credited to book-entry accounts maintained by the transfer agent of the Partnership, bearing a restrictive notation meeting the requirements of the Partnership Agreement, free
and clear of any Liens, other than transfer restrictions under this Agreement, the Partnership Agreement or the Delaware LP Act and applicable federal and state securities Laws and those created by the Purchasers; 

(iv) a certificate of the Secretary or Assistant Secretary of NuStar GP, on behalf of the Partnership, dated the Second Funding
Closing Date, certifying as to and attaching (A) the certificate of limited partnership of the Partnership, (B) the Partnership Agreement, (C) board resolutions, or resolutions of a committee thereof, authorizing the execution and

  
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delivery of the Transaction Documents and the consummation of the transactions contemplated thereby, and (D) the incumbency of the officers authorized to execute the Transaction Documents on
behalf of the Partnership or NuStar GP, as applicable, setting forth the name and title and bearing the signatures of such officers; 

(v) a certificate of the Secretary of State of each applicable state, dated within ten Business Days prior to the Second
Funding Closing Date, to the effect that each of the Partnership and its Material Subsidiaries (other than NuStar Terminals N.V., a private limited liability company duly established under the laws of the Netherlands Antilles and validly existing
under the laws of the Netherlands and the BES-Islands) is in good standing in its jurisdiction of formation; 

(vi) a certificate of the Executive Vice President and Chief Financial Officer of NuStar GP, on behalf of the Partnership,
dated the Second Funding Closing Date, certifying, in such capacity, to the effect that the conditions set forth in Section 2.08(b) and Section 2.08(c) contained herein have been satisfied;
and 
 (vii) a cross-receipt executed by the Partnership and delivered to the Purchasers certifying as to the amounts that it
has received from the Purchasers. 
 Section 2.09 Conditions to the Partnership’s
Obligations at the Second Closing. The obligation of the Partnership to consummate the sale and issuance of the Series D Preferred Second Closing Units to each Purchaser shall be subject to the satisfaction on or prior to the Second
Funding Closing Date of each of the following conditions (any or all of which may be waived by the Partnership in writing, in whole or in part, to the extent permitted by applicable Law): 

(a) the representations and warranties of each Purchaser contained in this Agreement shall be true and correct in all material respects (other
than those representations and warranties that are qualified by materiality, which, in each case, shall be true and correct in all respects) when made and as of the Second Funding Closing Date (except that representations and warranties made as of a
specific date shall be required to be true and correct in all material respects as of such date only); 
 (b) each Purchaser shall have
performed and complied in all material respects with all of the covenants and agreements contained in this Agreement that are required to be performed or complied with by it on or prior to the Second Funding Closing Date; and 

(c) the Purchasers, shall have delivered, or caused to be delivered, to the Partnership the following documents: 

(i) a cross-receipt executed by each Purchaser and delivered to the Partnership certifying that each Purchaser has received
from the Partnership the number of Series D Preferred Second Closing Units to be received by such Purchaser in connection with the Second Closing; 

(ii) a certificate of an authorized officer of each Purchaser, dated the Second Funding Closing Date, in his or her applicable
capacity, to the effect that the conditions set forth in Section 2.09(a) and Section 2.09(b) have been satisfied; and 

  
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 (iii) payment of each Purchaser’s Second Closing Funding Amount payable by
wire transfer of immediately available funds to an account designated in advance of the Second Funding Closing Date by the Partnership. 

Section 2.10 Independent Nature of Purchasers’ Obligations and Rights. The
obligations of each Purchaser under any Transaction Document are several and not joint with the obligations of any other Purchaser, and no Purchaser shall be responsible in any way for the performance of the obligations of any other Purchaser under
any Transaction Document. The failure of any Purchaser to perform, or waiver by the Partnership of such performance, under any Transaction Document shall not excuse performance by any other Purchaser and such waiver shall not excuse performance by
the Partnership with respect to any other Purchaser. Similarly, the waiver by any Purchaser of performance of the Partnership under any Transaction Document shall not excuse performance by the Partnership with respect to any other Purchaser and such
waiver shall not excuse performance by the Purchaser so waiving. Nothing contained herein or in any other Transaction Document, and no action taken by any Purchaser pursuant hereto or thereto, shall be deemed to constitute the Purchasers as a
partnership, an association, a joint venture or any other kind of entity, or create a presumption that the Purchasers are in any way acting in concert or as a group with respect to such obligations or the transactions contemplated by the Transaction
Documents. Each Purchaser shall be entitled to independently protect and enforce its rights, including the rights arising out of this Agreement or out of the other Transaction Documents, and it shall not be necessary for any other Purchaser to be
joined as an additional party in any proceeding for such purpose. 
 Section 2.11 Further Assurances. From time to
time after the date hereof, without further consideration, the Partnership and each Purchaser shall use their commercially reasonable efforts to take, or cause to be taken, all actions necessary or appropriate to consummate the transactions
contemplated by this Agreement. 
 ARTICLE III 

REPRESENTATIONS AND WARRANTIES AND COVENANTS RELATED TO THE PARTNERSHIP 

Except as described in the Disclosure Letter, the Partnership represents and warrants to and covenants with the Purchasers as follows: 

Section 3.01 Existence. 

(a) Each of the Partnership Entities has been duly formed or incorporated, as the case may be, and is validly existing as a corporation,
limited partnership or limited liability company, as the case may be, and is in good standing under the Laws of its jurisdiction of incorporation or formation, as the case may be, with full corporate, limited partnership or limited liability company
power and authority (i) to own, lease and operate its Properties and to conduct its business as described in the NS SEC Documents, (ii) to execute and deliver this Agreement and the other Transaction Documents to which such Partnership
Entity is a party and consummate the transactions contemplated hereby and thereby, (iii) in the case of the Partnership, to issue, sell and deliver the Series D Preferred Units, (iv) in the case of the General Partner, to act as the
general partner of the Partnership and (v) in the case of NuStar GP, to act as the general partner of the General Partner. 

  
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 (b) Each of the Partnership Entities is duly qualified to do business as a foreign limited
partnership or limited liability company, as the case may be, and is in good standing in each jurisdiction where the ownership or lease of its Properties or the conduct of its business requires such qualification, except for any failures to be so
qualified and in good standing that would not, individually or in the aggregate, (i) constitute a Material Adverse Effect or (ii) subject the limited partners of the Partnership to any material liability or disability. 

(c) The Organizational Documents of each of the Partnership Entities have been, and, on each Closing Date, the Seventh A&R LPA will be,
duly authorized, executed and delivered by the Partnership Entities, as applicable, and, assuming the due authorization, valid execution and delivery by the other parties thereto (other than the Partnership Entities), each Organizational Document
is, and, on each Closing Date, the Seventh A&R LPA will be, a valid and legally binding agreement of the Partnership Entities, as applicable, enforceable against such parties in accordance with its terms; provided that, with respect to
each agreement described in this Section 3.01(c), the enforceability thereof may be limited by bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws relating to or affecting
creditors’ rights generally and by general principles of equity (regardless of whether such enforceability is considered in a proceeding in equity or at law); provided further, that the indemnity, contribution and exoneration
provisions contained in any of such agreements may be limited by applicable laws and public policy. 
 Section 3.02
Capitalization and Valid Issuance of Units. 
 (a) As of June 22, 2018, the issued and outstanding limited partner
interests of the Partnership consist of 93,183,445 Common Units, 9,060,000 Series A Preferred Units, 15,400,000 Series B Preferred Units and 6,900,000 Series C Preferred Units, and the incentive distribution rights (as defined in the
Partnership Agreement, the “Incentive Distribution Rights”). All outstanding Common Units, NS Preferred Units, Incentive Distribution Rights and the limited partner interests represented thereby were duly authorized and
validly issued in accordance with the Partnership Agreement and are fully paid (to the extent required under the Partnership Agreement) and non-assessable (except as such
non-assessability may be affected by Sections 17-303, 17-607 and 17-804 of the
Delaware LP Act). As of the date hereof, there are no, and as of the Initial Closing Date, there will be no, limited partner interests of the Partnership that are senior to, in right of distribution or liquidation, the Series D Preferred Units.

 (b) NSH is the sole member of NuStar GP and owns 100% of the issued and outstanding membership interests in NuStar GP; such membership
interests have been duly authorized and validly issued in accordance with the NuStar GP LLC Agreement, and are fully paid (to the extent required under the NuStar GP LLC Agreement) and non-assessable (except
as such nonassessability may be affected by matters described in Sections 18-607 and 18-804 of the Delaware LLC Act); and NSH owns such membership interests free
and clear of all Liens. 
 (c) NuStar GP is the sole general partner of the General Partner with a 0.1% general partner interest in the
General Partner; such general partner interest has been duly authorized and validly issued in accordance with the GP Partnership Agreement; and NuStar GP owns such general partner interest free and clear of all Liens. 

  
 16 

 (d) Riverwalk Holdings is the sole limited partner of the General Partner with a 99.9% limited
partner interest in the General Partner; such limited partner interest has been duly authorized and validly issued in accordance with the GP Partnership Agreement and is fully paid (to the extent required under the GP Partnership Agreement) and non-assessable (except as such nonassessability may be affected by matters described in Sections 17-303, 17-607 and 17-804 of the Delaware LP Act); and the Riverwalk Holdings owns such limited partner interest free and clear of all Liens. 

(e) As of the date hereof, the General Partner is the sole general partner of the Partnership with a 2% general partner interest and 100% of
the Incentive Distribution Rights in the Partnership; such general partner interest and Incentive Distribution Rights have been duly authorized and validly issued in accordance with the Partnership Agreement and, in the case of the Incentive
Distribution Rights, are fully paid (to the extent required under the Partnership Agreement) and non-assessable (except as such nonassessability may be affected by matters described in Sections 17-303, 17-607 and 17-804 of the Delaware LP Act); and the General Partner owns such general partner interest and
Incentive Distribution Rights, in each case, free and clear of all Liens. 
 (f) As of the date hereof, (i) Riverwalk Holdings and
NuStar GP, each a direct wholly owned subsidiary of NSH, own 10,213,894 and 732 Common Units, respectively; and (ii) Riverwalk Holdings and NuStar GP own such limited partner interests free and clear of all Liens, except for Liens arising under
or in connection with the Revolving Credit Agreement. 
 (g) The Series D Preferred Units and the limited partner interests represented
thereby will be duly authorized by the Partnership pursuant to the Partnership Agreement prior to the Initial Closing and, when issued and delivered to the Purchasers against payment therefor in accordance with the terms of this Agreement, will be
validly issued, fully paid (to the extent required by the Partnership Agreement) and non-assessable (except as such nonassessability may be affected by matters described in
Sections 17-303, 17-607 and 17-804 of the Delaware LP Act) and will be free of any and all Liens and restrictions on
transfer, other than (i) restrictions on transfer under the Partnership Agreement, this Agreement or applicable state and federal securities Laws, (ii) with respect to each Purchaser’s Series D Preferred Units and the limited
partner interests represented thereby, such Liens as are created by such Purchaser and (iii) such Liens as arise under the Partnership Agreement or the Delaware LP Act. 

(h) Except for any such preemptive rights that have been waived, there are no persons entitled to statutory, preemptive or other similar
contractual rights to subscribe for the Series D Preferred Units; and, except (i) for the Series D Preferred Units to be issued pursuant to this Agreement, and the PIK Units and the Conversion Units to be issued pursuant to the
Partnership Agreement, (ii) for awards issued pursuant to an equity incentive plan approved by the board of directors of NuStar GP, or (iii) as disclosed in the NS SEC Documents or to the Purchasers in writing, no options, warrants or
other rights to purchase, agreements or other obligations to issue, or rights to convert any obligations into or exchange any securities for, Partnership securities or ownership interests in the Partnership are outstanding. 

  
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 (i) Upon issuance in accordance with this Agreement and the Partnership Agreement, the PIK Units
and the Conversion Units will be duly authorized, validly issued, fully paid (to the extent required by the Partnership Agreement) and non-assessable (except as such nonassessability may be affected by matters
described in Sections 17-303, 17-607 and 17-804 of the Delaware LP Act) and will be free of any and all Liens and
restrictions on transfer, other than (i) restrictions on transfer under the Partnership Agreement, this Agreement or applicable state and federal securities Laws, (ii) with respect to each Purchaser’s PIK Units and Conversion Units,
such Liens as are created by such Purchaser and (iii) such Liens as arise under the Partnership Agreement or the Delaware LP Act. 

Section 3.03 Ownership of the Material Subsidiaries. As of the date hereof, the Partnership owns directly or
indirectly 100% of the outstanding capital stock, membership interests, partnership interests or other equity interests, as the case may be, in each of the Material Subsidiaries; such stock, membership interests, partnership interests or other
equity interests have been duly authorized and validly issued in accordance with the Organizational Documents of each applicable Material Subsidiary, as the case may be (the “Material Subsidiary Operative Document”), and,
except in the case of the general partner interests, are fully paid (to the extent required under the applicable Material Subsidiary Operative Document) and non-assessable (except as such nonassessability may
be affected by matters described in Sections 18-607 and 18-804 of the Delaware LLC Act or Sections 17-303, 17-607 and 17-804 of the Delaware LP Act, as the case may be); and the Partnership and the direct owner, if applicable, owns all such stock, membership interests, partnership
interests or other equity interests, as the case may be, free and clear of all Liens. 
 Section 3.04 NS SEC
Documents. Since January 1, 2017, the NS SEC Documents have been filed on a timely basis. The NS SEC Documents, at the time filed (or in the case of registration statements, solely on the dates of effectiveness), except to the extent
corrected by a subsequent NS SEC Document, (a) did not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in light of the
circumstances under which they were made in the case of any such documents other than a registration statement, not misleading and (b) complied as to form in all material respects with the applicable requirements of the Exchange Act and the
Securities Act, as the case may be. 
 Section 3.05 Financial Statements. 

(a) The historical financial statements (including the related notes and supporting schedule) contained or incorporated by reference in the NS
SEC Documents, (i) comply as to form in all material respects with the applicable accounting requirements under the Securities Act and the Exchange Act, (ii) present fairly in all material respects the financial position, results of
operations and cash flows of the entities purported to be shown thereby on the basis stated therein at the respective dates or for the respective periods and (iii) have been prepared in accordance with GAAP consistently applied throughout the
periods involved, in each case except to the extent disclosed therein. The other financial information of the Partnership Entities, including non-GAAP financial measures, if any, contained or incorporated by
reference in the NS SEC Documents has been derived from the accounting records of the Partnership Entities, and fairly presents in all material respects the information purported to be shown thereby. Nothing has come to the attention of the
Partnership that has caused it to believe that the statistical and market-related data included in the NS SEC Documents is not based on or derived from sources that are reliable and accurate in all material respects as of the date on which the
applicable NS SEC Documents were filed or does not comply in all material respects with Regulation G of the Exchange Act and Item 10 of Regulation S-K of the Securities Act, to the extent applicable.

  
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 (b) Since the date of the most recent balance sheet of the Partnership audited by the
Partnership’s auditor, (i) the interactive data in eXtensible Business Reporting Language included or incorporated by reference in the NS SEC Documents fairly presents the information called for in all material respects and has been
prepared in accordance with the SEC’s rules and guidelines applicable thereto in all material respects and (ii) the Partnership, based on an annual evaluation of disclosure controls and procedures, is not aware of (A) any significant
deficiencies in the design or operation of internal controls over financial reporting that are reasonably likely to adversely affect the ability of the Partnership to record, process, summarize and report financial information, or any material
weaknesses in internal controls over financial reporting of the Partnership or (B) any fraud, whether or not material, that involves management or other employees who have a significant role in the internal controls over financial reporting of
the Partnership. 
 Section 3.06 Independent Registered Public Accounting Firm. KPMG LLP, who has audited certain
financial statements of the Partnership and its consolidated subsidiaries and Navigator Energy Services, LLC and its subsidiaries, whose reports are incorporated by reference in the NS SEC Documents, is an independent registered public accounting
firm as required by the Securities Act, the Rules and Regulations and the PCAOB and was an independent registered public accounting firm as required by the Securities Act, the Rules and Regulations and the PCAOB during the periods covered by the
financial statements on which they reported incorporated by reference in the NS SEC Documents. 
 Section 3.07 No Material
Adverse Change. Since December 31, 2017, except as described in the NS SEC Documents, there has not been any Material Adverse Effect. 

Section 3.08 No Registration Required. Assuming the accuracy of the representations and warranties of the applicable
Purchaser contained in Article IV, the issuance and sale of the Series D Preferred Units to such Purchaser pursuant to this Agreement is exempt from registration requirements of the Securities Act, and neither the Partnership nor, to the
Partnership’s Knowledge, any Person acting on its behalf, has taken nor will take any action hereafter that would cause the loss of such exemption. 

Section 3.09 No Restrictions or Registration Rights. Except as described in the Partnership Agreement, there are no
restrictions upon the voting or transfer of, any equity securities of the Partnership. Except for such rights that will be waived at the Initial Closing or as expressly set forth in the Registration Rights Agreement, neither the offering nor sale of
the Series D Preferred Units as contemplated by this Agreement gives rise to any rights for or relating to the registration of any Series D Preferred Units or other securities of the Partnership. Except as described in the Partnership
Agreement, the Partnership has not granted registration rights to any Person other than the Purchasers that would provide such Person priority over the Purchasers’ rights with respect to any Piggyback Registration Rights. 

Section 3.10 Litigation. Except as described in the NS SEC Documents, there are no legal or governmental proceedings
pending to which any of the Partnership Entities is a party or of which any property or assets of any of the Partnership Entities are subject that, individually or in the 

  
 19 

 
aggregate, if resolved adversely to any Partnership Entity, has had, or would reasonably be expected to have, a Material Adverse Effect, and, to the Knowledge of the NuStar Parties, no such
proceedings are threatened or contemplated by Governmental Authorities or others. 
 Section 3.11 No Default. None
of the Partnership Entities is in (i) violation of the Organizational Documents (including, for the avoidance of doubt, the Seventh A&R LPA), (ii) violation of any statute, law, rule or regulation, or any judgment, order or decrees of any
body having jurisdiction over it or (iii) breach or default (or an event which, with notice or lapse of time or both, would constitute such an event) in the performance of any term, covenant or condition contained in any bond, debenture, note
or any other evidence of indebtedness or in any agreement, indenture, lease or other instrument to which it is a party or by which it or any of its properties is subject, which breach, default or violation, in the case of (ii) and (iii),
individually or in the aggregate, has had, or would, if continued, reasonably be expected to have, a Material Adverse Effect. 

Section 3.12 No Conflicts. None of the offering and sale by the Partnership of the Series D Preferred Units, the
execution, delivery and performance of the Transaction Documents by the NuStar Parties or the consummation of any other transactions contemplated hereby or thereby, including the execution and delivery of the Seventh A&R LPA, (i) conflicts
with or will conflict with, or constitutes or will constitute a violation of, the Organizational Documents of any of the Partnership Entities (including, for the avoidance of doubt, the Seventh A&R LPA), (ii) except as provided in the
Disclosure Letter, conflicts with or will conflict with, or constitutes or will constitute a breach or violation of, or a default (or an event that, with notice or lapse of time or both, would constitute such a default) under, any indenture,
contract, lease, mortgage, deed of trust, note agreement, loan agreement or other agreement, obligation, condition, covenant or instrument to which any of the Partnership Entities is a party or by which any of them are bound or to which any of their
respective properties is subject, (iii) violates or will violate any statute, law, rule or regulation, or any judgment, order or decrees of any Governmental Authority having jurisdiction over any of the Partnership Entities or any of their
properties or assets, or (iv) will result in the creation or imposition of any Lien upon any property or assets of any of the Partnership Entities, except, in the case of clauses (ii), (iii) and (iv), for such conflicts, breaches,
violations, defaults or Liens as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect. 

Section 3.13 Authority; Enforceability. The Partnership has all requisite power and authority under the Partnership
Agreement and the Delaware LP Act to issue, sell and deliver the Series D Preferred Units, in accordance with and upon the terms and conditions set forth in this Agreement and the Partnership Agreement. All limited partnership and limited
liability company action, as the case may be, required to be taken by the Partnership Entities or any of their partners or members for the authorization, issuance, sale and delivery of the Series D Preferred Units, the execution and delivery of
the Transaction Documents and the consummation of the transactions contemplated thereby shall have been validly taken. No approval from the holders of outstanding Common Units is required under the Partnership Agreement or the rules of the NYSE in
connection with the Partnership’s issuance and sale of the Series D Preferred Units to the Purchasers. Each of the Transaction Documents has been duly and validly authorized and has been or, with respect to the Transaction Documents to be
delivered at the Initial Closing, will be, validly executed and delivered by the Partnership or the General Partner, as the case may be, and, to the Knowledge of 

  
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the NuStar Parties, the other parties thereto. Each of the Transaction Documents constitutes, or will constitute, the legal, valid and binding obligations of the Partnership or the General
Partner, as the case may be, and, to the Knowledge of the NuStar Parties, each of the parties thereto, in each case enforceable in accordance with its terms; provided that, with respect to each such agreement, the enforceability thereof may
be limited by applicable bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium or similar Laws from time to time in effect affecting creditors’ rights and remedies generally and by general principles of equity (regardless of
whether such principles are considered in a proceeding in equity or at law) provided further, that the indemnity, contribution and exoneration provisions contained in any of such agreements may be limited by applicable laws and public
policy. 
 Section 3.14 Approvals. No approval, authorization, consent, waiver, license, qualification, written
exemption from, or order of or filing with any Governmental Authority, or of or with any self-regulatory organization or other non-governmental regulatory authority (including, without limitation, the NYSE),
or approval of the security holders of the Partnership (each, a “Consent”), is required in connection with the issuance and sale of the Series D Preferred Units by the Partnership, the execution, delivery and performance
of this Agreement and the other Transaction Documents by the NuStar Parties party hereto or thereto and the consummation by the NuStar Parties of the transactions contemplated hereby or thereby, other than Consents (a) required by the SEC or
NYSE in connection with the Partnership’s obligations under the Registration Rights Agreement, (b) required under the state securities or “Blue Sky” Laws, (c) that have been, or prior to the Initial Closing Date or the
Second Funding Closing Date, as applicable, will be, obtained and (d) Consents, the absence or omission of which would not, individually or in the aggregate, have a Material Adverse Effect. 

Section 3.15 Distribution Restrictions. None of the Partnership Entities is currently prohibited, directly or
indirectly, from paying any dividends or other distributions, as applicable, to the Partnership, from repaying to the Partnership any loans or advances to such Partnership Entity from the Partnership or from transferring any of such Partnership
Entity’s property or assets to the Partnership or any other Partnership Entity of the Partnership, except as (i) described in or contemplated by the Organizational Documents of the Partnership Entities or the NS SEC Documents or the
Disclosure Letter or (ii) with respect to any Partnership Entities pending liquidation on the date hereof, where such prohibition would not have a Material Adverse Effect. 

Section 3.16 MLP Status. Except as provided in the Disclosure Letter, the Partnership is, and has been since its
formation, properly classified for U.S. federal income tax purposes as a partnership and each Subsidiary is, and has been since its formation, properly classified as a partnership or as an entity disregarded as separate from its owner. For the
taxable year including the Partnership’s initial public offering and for each taxable year thereafter, the Partnership has met the gross income requirements of Section 7704(c)(2) of the Internal Revenue Code of 1986, as amended (the
“Code”), and otherwise satisfied the requirements for treatment as a “publicly traded partnership” (within the meaning of Section 7704(b) of the Code). The Partnership expects to meet these requirements for its
current taxable year. 
 Section 3.17 Investment Company Status. None of the Partnership Entities is, and as of each
Closing Date and, immediately after giving effect to the offer and sale of the Series D Preferred Units and the application of the proceeds therefrom, none of them will be, an “investment company” or a company “controlled
by” an “investment company” within the meaning of such term under the Investment Company Act of 1940, as amended. 

  
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 Section 3.18 Certain Fees. No Purchaser is required to pay any broker,
finder or investment banker any brokerage, finder’s or other fee or commission with respect to the sale to such Purchaser of any of the Series D Preferred Units or the consummation of the transactions contemplated by this Agreement as a
result of arrangements made by any Partnership Entities. The Partnership agrees that it will indemnify and hold harmless the Purchasers from and against any and all claims, demands, or liabilities for broker’s, finder’s, placement, or
other similar fees or commissions incurred by the Partnership Entities or alleged to have been incurred by the Partnership Entities in connection with the sale of the Series D Preferred Units or the consummation of the transactions contemplated
by this Agreement. 
 Section 3.19 Labor and Employment Matters. No labor dispute by the employees that are engaged
in the business of any of the Partnership Entities exists or, to the Knowledge of the Partnership, is imminent that, individually or in the aggregate, has had, or would reasonably be expected to have, a Material Adverse Effect. 

Section 3.20 Insurance. The Partnership Entities maintain insurance covering their Properties, operations, personnel
and businesses against such losses and risks and in such amounts as is commercially reasonable for the conduct of their respective businesses and the value of their respective Properties. None of the Partnership Entities has received notice from any
insurer or agent of such insurer that substantial capital improvements or other expenditures will have to be made in order to continue such insurance. The Partnership Entities are in compliance with the terms of such policies in all material
respects, and all such insurance is duly in full force and effect on the date hereof. There are no material claims by the Partnership Entities under any such policy or instrument as to which any insurance company is denying liability or defending
under a reservation of rights clause; and the Partnership Entities have not been notified in writing that they will be denied renewal of their existing insurance coverage as and when such coverage expires or will be unable to obtain similar coverage
from similar insurers as may be necessary to continue their businesses at a cost that would not reasonably be expected to have a Material Adverse Effect. 

Section 3.21 Internal Controls. Except as described in the NS SEC Documents, the Partnership Entities, taken as a
whole, maintain a system of internal accounting controls sufficient to provide reasonable assurance that (a) transactions are executed in accordance with management’s general or specific authorization, (b) transactions are recorded as
necessary to permit preparation of financial statements in conformity with GAAP and to maintain accountability for assets, (c) access to assets is permitted only in accordance with management’s general or specific authorization and
(d) the recorded accountability for assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any differences. 

Section 3.22 Disclosure Controls and Procedures. (a) To the extent required by
Rule 13a-15 under the Exchange Act, the Partnership has established and maintains disclosure controls and procedures (as such term is defined in Rule 13a-15(e)
under the Exchange Act), (b) such disclosure controls and procedures are designed to ensure that the information required to be disclosed by the Partnership in the reports to be filed or submitted under the Exchange Act is accumulated and
communicated to management of the Partnership, including the principal executive officer and 

  
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principal financial officer of NuStar GP, as appropriate, to allow timely decisions regarding required disclosure to be made and (c) to the extent required by
Rule 13a-15 under the Exchange Act, such disclosure controls and procedures are effective in all material respects to perform the functions for which they were established. 

Section 3.23 Sarbanes-Oxley. The Partnership and, to the Partnership’s Knowledge, NuStar GP’s directors or
officers, in their capacities as such, are in compliance in all material respects with all applicable provisions of the Sarbanes-Oxley Act of 2002 and the rules and regulations promulgated in connection therewith. 

Section 3.24 Listing and Maintenance Requirements. The Common Units are listed on the NYSE, and the Partnership has
not received any notice of delisting. The issuance and sale of the Series D Preferred Units, the Conversion Units and the PIK Units do not contravene NYSE rules and regulations. 

Section 3.25 Environmental Compliance. Each of the Partnership Entities (i) is in compliance with Environmental
Laws, (ii) has received all permits, licenses or other approvals required of such entity under applicable Environmental Laws to conduct its businesses, (iii) is in compliance with all terms and conditions of any such permits, licenses or
approvals and (iv) does not have any liability in connection with the release into the environment of any Hazardous Material, except where such noncompliance with Environmental Laws, failure to receive required permits, licenses or approvals,
failure to comply with the terms and conditions of such permits, licenses or approvals or liability in connection with such releases would not, individually or in the aggregate, reasonably be expected to have, a Material Adverse Effect. 

Section 3.26 ERISA Compliance. (i) Each “employee benefit plan” (within the meaning of
Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”)) for which any of the Partnership Entities or any member of the “Controlled Group” (defined as any organization which is
a member of a controlled group of corporations within the meaning of Section 414 of the Code) of any of the Partnership Entities would have any liability (each a “Plan”) has been maintained in all material respects in
compliance with its terms and with the material requirements of all applicable statutes, rules and regulations including ERISA and the Code; (ii) with respect to each Plan subject to Title IV of ERISA (a) no “reportable
event” (within the meaning of Section 4043(c) of ERISA and for which the 30-day reporting requirement has not been waived) has occurred or is reasonably expected to occur, (b) no
“accumulated funding deficiency” (within the meaning of Section 302 of ERISA or Section 412 of the Code), whether or not waived, has occurred or is reasonably expected to occur, (c) the fair market value of the assets under
each Plan exceeds the present value of all benefits accrued under such Plan (determined on an ongoing basis based on those assumptions used to fund such Plan) and (d) none of the Partnership Entities or any member of the Controlled Group of any
of the Partnership Entities has incurred, or reasonably expects to incur, any liability under Title IV of ERISA (other than contributions to the Plan or premiums to the United States Pension Benefit Guaranty Corporation in the ordinary course
and without default) in respect of a Plan (including a “multiemployer plan,” within the meaning of Section 4001(c)(3) of ERISA), in each case that, individually or in the aggregate, has had, or would reasonably be expected to have, a
Material Adverse Effect; and (iii) each Plan that is intended to be qualified under Section 401(a) of the Code and that is an individually designed plan has been determined by the Internal Revenue Service to be so qualified and nothing has
occurred, whether by action or by failure to act, which would cause the loss of such qualification. 

  
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 Section 3.27 Tax Returns; Taxes. Each of the Partnership Entities has
timely filed (taking into account permitted extensions) all federal and state income Tax Returns and all other material Tax Returns and all Taxes owed by the Partnership Entities or for which the Partnership Entities may be liable which are or have
become due have been paid in full, except for Taxes that are being contested in good faith by appropriate proceedings and for which the Partnership Entities have set aside on their books adequate reserves. There is no material claim against the
Partnership and, no material assessment, deficiency, or adjustment has been asserted, proposed or, to the Knowledge of the Partnership Entities, threatened with respect to any Taxes or Tax Returns of or with respect to the Partnership Entities. No
material Tax audits or administrative or judicial proceedings are being conducted, pending or to the knowledge of the Partnership Entities, threatened with respect to the Partnership Entities. 

Section 3.28 Permits. Each of the Partnership Entities has such permits, consents, licenses, franchises, certificates
and authorizations of Governmental Authorities (“Permits”) as are necessary to own its properties and to conduct its businesses in the manner described in the NS SEC Documents, subject to such qualifications as may be set
forth in the NS SEC Documents and except for such permits which, if not obtained, would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect; each of the Partnership Entities has fulfilled and performed all
its material obligations with respect to the Permits which are due to have been fulfilled and performed by such date, and no event has occurred that allows, or after notice or lapse of time would allow, revocation or termination thereof or would
result in any other impairment of the rights of the holder of any such Permits, except for any of the foregoing that would not reasonably be expected to have a Material Adverse Effect; and, except as described in the NS SEC Documents, none of the
Permits contain any restriction that is materially burdensome to the Partnership Entities considered as a whole. 
 Section 3.29
Required Disclosures and Descriptions. There are no legal or governmental proceedings or contracts or other documents of a character required to be described in the NS SEC Documents that are not described and filed as required. 

Section 3.30 Title to Property. Each of the Partnership Entities has good and indefeasible title to all real property
and good and marketable title to all personal property described in the NS SEC Documents as being owned by them, in each case free and clear of all Liens, encumbrances and defects, except (i) such as are described in the NS SEC Documents,
(ii) such as do not materially interfere with the use of such properties taken as a whole as they have been used in the past and are proposed to be used in the future as described, and subject to the limitations contained, in the NS SEC
Documents or (iii) such as would not reasonably be expected to have a Material Adverse Effect; all real property and buildings held under lease or license by the Partnership Entities are held by them under valid and subsisting and enforceable
leases or licenses with such exceptions as do not materially interfere with the use of such properties taken as a whole as they have been used in the past and are expected to be used in the future as described in the NS SEC Documents. For purposes
of this Agreement, the phrase “good and indefeasible title” to all real property shall mean, with respect to any real property interest, and subject to the terms, conditions, and provisions contained in the realty deeds and leases creating
such real property interest, that the ownership, 

  
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rights, possession and title in the jurisdiction and locale where the real property interest is located, is in each case legally sufficient in all material respects to conduct the business and
operations of the Partnership Entities as described in the NS SEC Documents, as such business and operations relate to the location of such real property interest, and is free and clear of all Liens excepting (in each case) permitted encumbrances,
such title defects, and imperfections, limitations, correlative rights, or appurtenant rights or obligations contained in, arising from or created by the instrument under which any of the Partnership Entities hold title to such real property
interest or contained in its chain of title thereto, which do not materially and adversely affect current or intended use or operation of the subject real property interest or which are capable of being routinely addressed, cured, avoided or assumed
in the ordinary course of business and land management of the Partnership Entities. 
 Section 3.31 Rights-of-Way. Each of the Partnership Entities has such consents, easements,
rights-of-way or licenses from any person (“Rights-of-Way”) as are necessary to conduct their business
in the manner described in the NS SEC Documents subject to such qualifications as may be set forth in the NS SEC Documents, and except for such Rights-of-Way which, if
not obtained, would not reasonably be expected to have, individually or in the aggregate, a Material Adverse Effect; each of the Partnership Entities has fulfilled and performed all its material obligations with respect to such Rights-of-Way and no event has occurred which allows, or after notice or lapse of time would allow, revocation or termination thereof or would result in any impairment of the
rights of the holder of any such Rights-of-Way, except for such revocations, terminations and impairments that would not reasonably be expected to have a Material
Adverse Effect; and, except as described in the NS SEC Documents, none of such Rights-of-Way contains any restriction that is materially burdensome to the Partnership
Entities considered as a whole. 
 Section 3.32 Form S-3 Eligibility. The Partnership is eligible to register the Conversion Units and the Series D Preferred Units for resale by the Purchasers under Form S-3
promulgated under the Securities Act. 
 Section 3.33 FCPA. None of the Partnership Entities, nor any director or
officer, nor to the Knowledge of the NuStar Parties, any agent, employee or Affiliate of any of the Partnership Entities is aware of or has taken any action, directly or indirectly, that would result in a violation by such persons of (i) the
Foreign Corrupt Practices Act of 1977, as amended, and the rules and regulations thereunder (the “FCPA”), including, without limitation, making use of the mails or any means or instrumentality of interstate commerce corruptly
in furtherance of an offer, payment, promise to pay or authorization of the payment of any money, or other property, gift, promise to give, or authorization of the giving of anything of value to any “foreign official” (as such term is
defined in the FCPA) or any foreign political party or official thereof or any candidate for foreign political office, in contravention of the FCPA; (ii) the Bribery Act 2010 of the United Kingdom; or (iii) any similar Law of any other
relevant jurisdiction, or the rules or regulations thereunder; and the Partnership Entities have conducted their businesses in compliance with applicable anti-corruption Laws to which they may be subject; and the Partnership Entities and, to the
Knowledge of the NuStar Parties, their Affiliates have instituted and maintain policies and procedures designed to ensure, and which are reasonably expected to continue to ensure, continued compliance therewith. 

  
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 Section 3.34 Money Laundering Laws. The operations of the Partnership
Entities are and have been conducted at all times in compliance in all material respects with applicable financial recordkeeping and reporting requirements and the money laundering statutes of jurisdictions where the Partnership Entities conduct
business and rules and regulations thereunder and any related or similar rules, regulations or guidelines issued, administered or enforced by any Governmental Authority (collectively, the “Money Laundering Laws”), and no
action, suit or proceeding by or before any court or Governmental Authority or any arbitrator involving any of the Partnership Entities with respect to the Money Laundering Laws is pending or, to the Knowledge of the NuStar Parties, threatened. 

Section 3.35 OFAC. None of the Partnership Entities, nor any director or officer, nor to the Knowledge of the NuStar
Parties, any agent, employee or Affiliate of any Partnership Entitles, is the subject of any sanctions administered by the Office of Foreign Assets Control of the U.S. Treasury Department, the United Nations Security Council, the European
Union, Her Majesty’s Treasury, or other relevant sanctions authority (collectively, “Sanctions”) nor are any of the Partnership Entities controlled by an individual or entity that is currently the subject or target of
any Sanctions; and the Partnership will not directly or indirectly use the proceeds of the sale of the Series D Preferred Units, or lend, contribute or otherwise make available such proceeds to any Subsidiary, joint venture partner or other
Person or entity, for the purpose of financing the activities of any Person or entity, or in any country or territory, that at the time of such financing is the subject of any Sanctions. 

Section 3.36 Related Party Transactions. Except as described in the NS SEC Documents, no Partnership Entity has,
directly or indirectly (a) extended credit, arranged to extend credit, or renewed any extension of credit, in the form of a personal loan, to or for any director or executive officer of the General Partner or its Affiliates, or to or for any
family member or Affiliate of any directors or executive officers of the General Partner or its Affiliates or (b) made any material modification to the term of any personal loan to any director or executive officer of the General Partner or its
Affiliates, or any family member or Affiliate of any director or executive officer of the General Partner or its Affiliates. 

Section 3.37 No Side Agreements. As of the date hereof, other than that certain Mandate Letter, dated as of
May 30, 2018, between the Partnership and EIG Management Company, LLC (the “Mandate Letter”), and the Confidentiality Agreement, there are no binding agreements by, among or between (a) the Partnership or any of its
Affiliates, on the one hand, and (b) any Purchaser or any of their respective Affiliates, on the other hand, with respect to the transactions contemplated hereby other than the Transaction Documents, and there are no agreements expressly
modifying, amending or waiving any provision of any of the Transaction Documents. 

  
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 ARTICLE IV 

REPRESENTATIONS AND WARRANTIES AND COVENANTS OF THE 

PURCHASERS 
 Each of the
Purchasers, severally but not jointly, represents and warrants and covenants to the Partnership as follows with respect to itself: 

Section 4.01 Existence. Each Purchaser is duly organized and validly existing and in good standing under the Laws of
its state of formation, with all necessary power and authority to own properties and to conduct its business as currently conducted. 

Section 4.02 Authorization; Enforceability. Each Purchaser has all necessary legal power and authority to enter into,
deliver and perform its obligations under the Transaction Documents to which it is a party. The execution, delivery and performance of such Transaction Documents by such Purchaser and the consummation by it of the transactions contemplated thereby
have been duly and validly authorized by all necessary legal action, and no further consent or authorization of such Purchaser is required. Each of the Transaction Documents to which such Purchaser is a party has been duly executed and delivered by
such Purchaser, where applicable, and constitutes a legal, valid and binding obligation of such Purchaser; provided that, with respect to each such agreement, the enforceability thereof may be limited by applicable bankruptcy, insolvency,
fraudulent transfer, reorganization, moratorium or similar Laws from time to time in effect affecting creditors’ rights and remedies generally and by general principles of equity (regardless of whether such principles are considered in a
proceeding in equity or at law). 
 Section 4.03 No Breach. The execution, delivery and performance of the
Transaction Documents to which such Purchaser is a party by such Purchaser and the consummation by such Purchaser of the transactions contemplated thereby will not (a) conflict with or result in a breach or violation of any of the terms or
provisions of, or constitute a default under, any material agreement to which such Purchaser is a party or by which such Purchaser is bound or to which any of the property or assets of such Purchaser is subject, (b) conflict with or result in
any violation of the provisions of the Organizational Documents of such Purchaser, or (c) violate any Law of any Governmental Authority or body having jurisdiction over such Purchaser or the property or assets of such Purchaser, except in the
case of clauses (a) and (c), for such conflicts, breaches, violations or defaults as would not prevent the consummation of the transactions contemplated by such Transaction Documents. 

Section 4.04 Certain Fees. No fees or commissions are or will be payable by such Purchaser to brokers, finders or
investment bankers with respect to the purchase of any of the Series D Preferred Units or the consummation of the transactions contemplated by this Agreement, except for fees or commissions for which the Partnership is not responsible. Each
Purchaser agrees to indemnify and hold harmless the Partnership from and against any and all claims, demands, or liabilities for broker’s, finder’s, placement, or other similar fees or commissions incurred by such Purchaser, or alleged to
have been incurred by such Purchaser in connection with the purchase of the Series D Preferred Units or the consummation of the transactions contemplated by this Agreement. 

Section 4.05 Unregistered Securities. 

(a) Accredited Investor Status; Sophisticated Purchaser. Such Purchaser is an “accredited investor” within the meaning of
Rule 501 under the Securities Act and is able to bear the risk of its investment in the Series D Preferred Units, the PIK Units and the Conversion Units, as applicable. Such Purchaser has such knowledge and experience in financial and
business matters that it is capable of evaluating the merits and risks of the purchase of the Series D Preferred Units and the Conversion Units, as applicable. 

  
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 (b) Information. Such Purchaser and its Representatives have been furnished with all
materials relating to the business, finances and operations of the Partnership that have been requested and materials relating to the offer and sale of the Series D Preferred Units and Conversion Units that have been requested by such
Purchaser. Such Purchaser and its Representatives have been afforded the opportunity to ask questions of the Partnership. Neither such inquiries nor any other due diligence investigations conducted at any time by such Purchasers and its
Representatives shall modify, amend or affect such Purchasers’ right (i) to rely on the Partnership’s representations and warranties contained in Article III above or (ii) to indemnification or any other remedy based on,
or with respect to the accuracy or inaccuracy of, or compliance with, the representations, warranties, covenants and agreements in any Transaction Document. Such Purchaser understands that its purchase of the Series D Preferred Units involves a
high degree of risk. Such Purchaser has sought such accounting, legal and tax advice as it has considered necessary to make an informed investment decision with respect to its acquisition of the Series D Preferred Units. 

(c) Residency. Such Purchaser shall cooperate reasonably with the Partnership to provide any information necessary for any applicable
securities filings. 
 (d) Legends. Such Purchaser understands that, until such time as the Series D Preferred Units, the PIK
Units and the Conversion Units, as applicable, have been sold pursuant to an effective registration statement under the Securities Act, or the Series D Preferred Units are eligible for resale pursuant to Rule 144 promulgated under the
Securities Act without any restriction as to the number of securities as of a particular date that can then be immediately sold, the Series D Preferred Units will bear a restrictive legend as provided in the Partnership Agreement. 

(e) Purchase Representation. Such Purchaser is purchasing the Series D Preferred Units for its own account and not with a view to
distribution in violation of any Laws. Such Purchaser has been advised and understands that neither the Series D Preferred Units, the PIK Units nor the Conversion Units have been registered under the Securities Act or under the “blue
sky” laws of any jurisdiction and may be resold only if registered pursuant to the provisions of the Securities Act (or if eligible, pursuant to the provisions of Rule 144 promulgated under the Securities Act or pursuant to another
available exemption from the registration requirements of the Securities Act). Such Purchaser has been advised and understands that the Partnership, in issuing the Series D Preferred Units, is relying upon, among other things, the
representations and warranties of such Purchaser contained in this Article IV in concluding that such issuance is a “private offering” and is exempt from the registration provisions of the Securities Act. 

(f) Rule 144. Such Purchaser understands that there is no public trading market for the Series D Preferred
Units or the PIK Units, that none is expected to develop and that the Series D Preferred Units and the PIK Units must be held indefinitely unless and until the Series D Preferred Units, the PIK Units or the Conversion Units, as applicable,
are registered under the Securities Act or an exemption from registration is available. Such Purchaser has been advised of and is aware of the provisions of Rule 144 promulgated under the Securities Act. 

  
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 (g) Reliance by the Partnership. Such Purchaser understands that the Series D
Preferred Units are being offered and sold in reliance on a transactional exemption from the registration requirements of federal and state securities Laws and that the Partnership is relying upon the truth and accuracy of the representations,
warranties, agreements, acknowledgments and understandings of such Purchaser set forth herein in order to determine the applicability of such exemptions and the suitability of such Purchaser to acquire the Series D Preferred Units and the PIK
Units, and the Conversion Units issuable upon conversion thereof. 
 Section 4.06 Sufficient Funds. Such Purchaser
will have available to it (i) at the Initial Closing sufficient funds to enable such Purchaser to pay in full at the Initial Closing the entire amount of such Purchaser’s Initial Funding Amount in immediately available cash funds, and
(ii) at the Second Closing sufficient funds to enable such Purchaser to pay in full at the Second Closing the entire amount of such Purchaser’s Second Closing Funding Amount in immediately available cash funds. 

Section 4.07 No Prohibited Trading. Prior to the date hereof, such Purchaser has not (a) other than to a
Permitted Transferee, offered, sold, contracted to sell, sold any option or contract to purchase, purchased any option or contract to sell, granted any option, right or warrant to purchase, lent, or otherwise transferred or disposed of, directly or
indirectly, any of the Series D Preferred Units, or (b) directly or indirectly engaged in any short sales or other derivative or hedging transactions with respect to the Series D Preferred Units, including by means of any swap or
other transaction or arrangement that transfers or that is designed to, or that might reasonably be expected to, result in the transfer to another, in whole or in part, of any of the economic consequences of ownership of any Series D Preferred
Units, regardless of whether any transaction described in this Section 4.07 is to be settled by delivery of Series D Preferred Units, Common Units or other securities, in cash or otherwise. 

ARTICLE V 
 COVENANTS

 Section 5.01 Conduct of Business. During the period commencing on the date of this Agreement and ending on
the Second Funding Closing Date, except as described in the Disclosure Letter, each of the Partnership Entities will use commercially reasonable efforts to (i) conduct its business in the ordinary course of business (other than as contemplated
by the Merger Agreement) and (ii) preserve intact its existence and business organization, Permits, goodwill and present business relationships with all material customers, suppliers, licensors, distributors and others having significant
business relationships with the Partnership Entities (or any of them), to the extent the Partnership believes in its sole discretion that such relationships are and continue to be beneficial to the Partnership Entities and their businesses;
provided, however, that during such period, the Partnership shall provide reasonably prompt written notice to the Purchasers regarding any material adverse developments in respect of the foregoing. Prior to the Second Closing, none of
the Partnership Entities will (i) modify, amend or waive in any material respect any provision of the Partnership Agreement that is material to (A) the rights of the Partnership or (B) the rights of the Purchasers, in their capacity
as purchasers of the applicable Series D Preferred Units or (ii) authorize, issue or reclassify any (A) equity securities of the Partnership ranking on parity with or senior to the Series D Preferred Units or (B) debt
securities of the Partnership convertible into any of the foregoing, in each case without the prior written consent of the Purchasers possessing the right to acquire not less than a majority of the Series D Preferred Units. 

  
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 Section 5.02 Listing of Units. Prior to the Initial Closing, the
Partnership will use its commercially reasonable efforts to obtain approval for listing, subject to notice of issuance, of the Conversion Units on the NYSE. 

Section 5.03 Lock-up Agreement. Without the prior written consent of the
Partnership, except as specifically provided in this Agreement or as otherwise provided in the Partnership Agreement, each Purchaser of Series D Preferred Units and its Affiliates shall not, (a) during the period commencing on the Initial
Closing Date and ending forty-five (45) days following the Initial Closing Date, offer, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase,
lend, or otherwise transfer or dispose of, directly or indirectly, any Common Units, (b) during the period commencing on the Initial Closing Date and ending on the first anniversary following the Initial Closing Date, offer, sell, contract to
sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any of the Series D Preferred Units,
(c) during the period commencing on the Initial Closing Date and ending on the second anniversary of the Initial Closing Date, directly or indirectly engage in any short sales or other derivative or hedging transactions with respect to any
equity securities of the Partnership, (d) transfer any Series D Preferred Units to any non-U.S. resident individual, non-U.S. corporation or partnership,
or any other non-U.S. entity, including any foreign governmental entity, including by means of any swap or other transaction or arrangement that transfers or that is designed to, or that might reasonably
be expected to, result in the transfer to another, in whole or in part, of any of the economic consequences of ownership of any Series D Preferred Units, regardless of whether any transaction described in clauses (b) through (d) above
is to be settled by delivery of Series D Preferred Units, Common Units or other securities, in cash or otherwise, (e) effect any transfer of Series D Preferred Units or Conversion Units in a manner that violates the terms of the
Partnership Agreement, or (f) transfer any Series D Preferred Units to a competitor (as defined in the Seventh A&R LPA); provided, however, that such Purchaser may pledge all or any portion of its Series D Preferred
Units to any holders of obligations owned by such Purchaser, including to the trustee for, or Representative of, such Purchaser; provided, further, that such Purchaser may transfer any Series D Preferred Units to (i) an
Affiliate of such Purchaser, (ii) any other Purchaser or (iii) any of the Persons listed on Schedule C hereto (each, a “Permitted Transferee”), in each case subject to compliance with
clauses (c), (d), (e) and (f) above and provided that (x) the Partnership is given written notice prior to any said transfer or assignment made prior to the Series D Initial Distribution Date (as defined in the Partnership
Agreement), stating the name and address of each such transferee or assignee and identifying the securities with respect to which such transfer or assignment is being made and (y) such Person agrees to be bound by the provisions of this
Section 5.03. After the first anniversary of the Initial Closing Date, each Purchaser or holder may only transfer Series D Preferred Units involving an underlying value of Common Units in an amount not less than
$50 million based on the closing trading price of Common Units on the date immediately preceding such transfer on the NYSE or other National Securities Exchange on which the Common Units are then listed for trading (or such lesser amount if it
(x) constitutes the remaining holdings of the Purchaser or holder or (y) has been approved by the General Partner, in its sole discretion), subject to compliance with applicable securities Laws, the Partnership Agreement and, for the
avoidance of doubt, clause (c), (d), (e) and (f) above. 

  
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 Section 5.04 Tax Matters. 

(a) The Partnership will (i) treat the conversion of the Series D Preferred Units into Common Units (or payment of Common Units with
respect to the Partnership’s redemption of the Series D Preferred Units) as an exercise of a noncompensatory option within the meaning of Treasury Regulation Section 1.761-3 and the Partnership will
use commercially reasonable efforts to cooperate with the Purchasers to minimize the recognition of the taxable income by the Purchasers on such conversion or redemption (including by providing the information described in
Section 5.04(b) and cooperating with Purchaser to avoid or minimize corrective allocations pursuant to Section 6.2(i) of the Partnership Agreement (or similar allocations of taxable income) in connection with such
conversion or redemption) and (ii) in connection with an acquisition, conveyance, exchange, merger, transfer or other plan which causes the Partnership (or a successor to the Partnership) to be taxable as a corporation for U.S. federal income
tax purposes, use commercially reasonable efforts to cooperate with the Purchasers or Affiliates holding Series D Preferred Units or Common Units issued upon the conversion or redemption of Series D Preferred Units to allow an entity that is
classified as a corporation for U.S. federal income tax purposes that is directly or indirectly owned by a Purchaser or its Affiliate (a “blocker corporation”) to merge into or otherwise combine with the corporation in a tax-deferred transaction; provided such blocker corporation is, at all times since its formation through the date of such merger or combination, a special purpose entity that has held no assets and has had no
other business operations other than directly or indirectly holding Series D Preferred Units or Common Units, and a party reasonably satisfactory to the Partnership provides customary tax and other representations and warranties and indemnities
relating to the blocker corporation and ownership thereof; provided, further, in the case of each of (i) and (ii), any action that would have a material adverse effect on the Partnership or its partners in the aggregate (other
than the Purchasers and their Affiliates) shall be deemed to not be commercially reasonable. 
 (b) The Partnership will after the second
anniversary of the Closing Date, upon written request by any Purchaser, provide each Purchaser, within a commercially reasonable time after the Partnership’s receipt of such request, a good faith estimate (and reasonable supporting
calculations) of whether there is sufficient Unrealized Gain attributable to the Partnership property on the date of such request such that, if any of such Purchaser’s Series D Preferred Units were converted to, or redeemed for, Common Units
and such Unrealized Gain was allocated to such Purchaser pursuant to Section 6.1(d)(xii) of the Partnership Agreement (taking proper account of allocations of higher priority), such Purchaser’s Capital Account in respect of its Common
Units would be equal to the Per Unit Capital Amount for an Initial Common Unit without any need for corrective allocations under Section 6.2(i) of the Partnership Agreement (or similar allocations of taxable income). The Purchasers, together
with their Affiliates, shall not, in the aggregate, be entitled to make a request pursuant to this Section 5.04(b) more than four times per calendar year. Purchaser shall bear and pay all reasonable out-of-pocket costs incurred by the Partnership relating to the third and fourth requests, including costs charged by the Partnership’s accounting firm. 

(c) Absent a change in Law or the issuance of contrary administrative or regulatory guidance from the U.S. Treasury or the Internal Revenue
Service, the Partnership will report Section 707(c) guaranteed payments on the Series D Preferred Units for the taxable year as eligible for the deduction under Section 199A of the Code to the extent the Partnership’s income during
the same taxable year is eligible for the deduction under Section 199A of the Code. 

  
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 Section 5.05 Use of Proceeds. The Partnership shall use the proceeds of
the offering of the Series D Preferred Units to repay indebtedness of the Partnership or for general partnership purposes. 
 ARTICLE
VI 
 INDEMNIFICATION, COSTS AND EXPENSES 

Section 6.01 Indemnification by the Partnership. The Partnership agrees to indemnify each Purchaser and its
Representatives (collectively, “Purchaser Related Parties”) from costs, losses, liabilities, damages or expenses of any kind or nature whatsoever, and hold each of them harmless against, any and all actions, suits,
proceedings (including any investigations, litigation or inquiries), demands and causes of action, and, in connection therewith, promptly upon demand, pay or reimburse each of them for all costs, losses, liabilities, damages, or expenses of any kind
or nature whatsoever (including the reasonable fees and disbursements of counsel and all other reasonable expenses incurred in connection with investigating, defending or preparing to defend any such matter that may be incurred by them or asserted
against or involve any of them), whether or not involving a Third-Party Claim, as a result of, arising out of, or in any way related to (a) the failure of any of the representations or warranties made by the Partnership contained herein to be
true and correct in all material respects (other than those representations and warranties contained in Section 3.01, Section 3.02, Section 3.03,
Section 3.13, Section 3.16 or Section 3.18 or other representations and warranties that are qualified by materiality or Material Adverse Effect, which, in each case, shall
be true and correct in all respects) when made and as of each Closing Date (except for any representations and warranties made as of a specific date, which shall be required to be true and correct in all material respects as of such date only) or
(b) the breach of any covenants of the Partnership contained herein; provided that, in the case of the immediately preceding clause (a), such claim for indemnification is made prior to the expiration of the survival period of such
representation or warranty; provided, further, that for purposes of determining when an indemnification claim has been made, the date upon which a Purchaser Related Party shall have given notice (stating in reasonable detail the basis
of the claim for indemnification) to the Partnership shall constitute the date upon which such claim has been made; and provided, further, that the aggregate liability of the Partnership to each Purchaser and its Representatives
pursuant to this Section 6.01 shall not be greater in amount than such Purchaser’s Total Funding Amount as of the date of the Indemnification notice described in Section 6.03(a), and the
aggregate liability of the Partnership to all Purchasers and their respective Representatives pursuant to this Section 6.01 shall not exceed the sum of the Initial Closing Purchase Price and the Second Closing Purchase
Price. No Purchaser Related Party shall be entitled to recover special, indirect, exemplary, lost profits, speculative or punitive damages under this Section 6.01; provided, however, that such limitation shall
not prevent any Purchaser Related Party from recovering under this Section 6.01 for any such damages to the extent that such damages are payable to a third party in connection with any Third-Party Claims. 

Section 6.02 Indemnification by the Purchasers. Each Purchaser agrees, severally and not jointly, to indemnify the
Partnership, the General Partner, NuStar GP and their respective Representatives (collectively, “Partnership Related Parties”) from, all costs, losses, liabilities, damages, or expenses of any kind or nature whatsoever, and
hold each of them harmless against, any and all actions, suits, proceedings (including any investigations, litigation or inquiries), demands, and causes of action, and, in connection therewith, promptly upon demand, pay or

  
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reimburse each of them for all costs, losses, liabilities, damages, or expenses of any kind or nature whatsoever (including the reasonable fees and disbursements of counsel and all other
reasonable expenses incurred in connection with investigating, defending or preparing to defend any such matter that may be incurred by them or asserted against or involve any of them), whether or not involving a Third-Party Claim, as a result of,
arising out of, or in any way related to (a) the failure of any of the representations or warranties made by such Purchaser contained herein to be true and correct in all material respects as of the date made (except to the extent any
representation or warranty includes the word “material,” Material Adverse Effect or words of similar import, with respect to which such representation or warranty, or applicable portions thereof, must have been true and correct in all
respects) or (b) the breach of any of the covenants or obligations of any such Purchaser contained herein (including failure to deliver payment pursuant to such Purchaser’s Total Funding Amount); provided that, in the case of the
immediately preceding clause (a), such claim for indemnification relating to a breach of any representation or warranty is made prior to the expiration of the survival period of such representation or warranty; and
provided, further, that for purposes of determining when an indemnification claim has been made, the date upon which a Partnership Related Party shall have given notice (stating in reasonable detail the basis of the claim for
indemnification) to such Purchaser shall constitute the date upon which such claim has been made; and provided, further, that the liability of any Purchaser shall not be greater in amount than the sum of such Purchaser’s
Total Funding Amount plus any distributions paid to such Purchaser with respect to the Series D Preferred Units. No Partnership Related Party shall be entitled to recover special, indirect, exemplary, lost profits, speculative or punitive
damages under this Section 6.02; provided, however, that such limitation shall not prevent any Partnership Related Party from recovering under this Section 6.02 for any such
damages to the extent that such damages are payable to a third party in connection with any Third-Party Claims. 
 Section 6.03
Indemnification Procedure. 
 (a) A claim for indemnification for any matter not involving a Third-Party Claim may be asserted
by notice to the party from whom indemnification is sought; provided, however, that failure to so notify the indemnifying party shall not preclude the indemnified party from any indemnification which it may claim in accordance
with this Article VI, except as otherwise provided in Section 6.01 and Section 6.02. 
 (b) Promptly
after any Partnership Related Party or Purchaser Related Party (hereinafter, the “Indemnified Party”) has received notice of any indemnifiable claim hereunder, or the commencement of any action, suit or proceeding by a third
person, which the Indemnified Party believes in good faith is an indemnifiable claim under this Agreement (each a “Third-Party Claim”), the Indemnified Party shall give the indemnitor hereunder (the “Indemnifying
Party”) written notice of such Third-Party Claim, but failure to so notify the Indemnifying Party will not relieve the Indemnifying Party from any liability it may have to such Indemnified Party hereunder except to the extent
that the Indemnifying Party is materially prejudiced by such failure. Such notice shall state the nature and the basis of such Third-Party Claim to the extent then known. The Indemnifying Party shall have the right to defend and settle, at its own
expense and by its own counsel who shall be reasonably acceptable to the Indemnified Party, any such matter as long as the Indemnifying Party pursues the same diligently and in good faith. If the Indemnifying Party undertakes to defend or settle, it
shall promptly, and in no event later than ten (10) days, notify the Indemnified Party of its intention to do so, and the Indemnified Party shall cooperate with the 

  
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Indemnifying Party and its counsel in all commercially reasonable respects in the defense thereof and the settlement thereof. Such cooperation shall include, but shall not be limited to,
furnishing the Indemnifying Party with any books, records and other information reasonably requested by the Indemnifying Party and in the Indemnified Party’s possession or control. Such cooperation of the Indemnified Party shall be at the cost
of the Indemnifying Party. After the Indemnifying Party has notified the Indemnified Party of its intention to undertake to defend or settle any such asserted liability, and for so long as the Indemnifying Party diligently pursues such defense, the
Indemnifying Party shall not be liable for any additional legal expenses incurred by the Indemnified Party in connection with any defense or settlement of such asserted liability; provided, however, that the Indemnified Party shall be
entitled (i) at its expense, to participate in the defense of such asserted liability and the negotiations of the settlement thereof and (ii) if (A) the Indemnifying Party has, within ten (10) Business Days of when the
Indemnified Party provides written notice of a Third-Party Claim, failed (1) to assume the defense or employ counsel reasonably acceptable to the Indemnified Party or (2) to notify the Indemnified Party of such assumption or (B) if
the defendants in any such action include both the Indemnified Party and the Indemnifying Party and counsel to the Indemnified Party shall have concluded that there may be reasonable defenses available to the Indemnified Party that are different
from or in addition to those available to the Indemnifying Party or if the interests of the Indemnified Party reasonably may be deemed to conflict with the interests of the Indemnifying Party, then the Indemnified Party shall have the right to
select a separate counsel and to assume such legal defense and otherwise to participate in the defense of such action, with the expenses and fees of such separate counsel and other expenses related to such participation to be reimbursed by the
Indemnifying Party as incurred. Notwithstanding any other provision of this Agreement, the Indemnifying Party shall not settle any indemnified claim without the consent of the Indemnified Party, unless the settlement thereof imposes no liability or
obligation on, and includes a complete release from liability of, and does not include any admission of wrongdoing or malfeasance by, the Indemnified Party. 

Section 6.04 Tax Matters. All indemnification payments under this Article VI shall be treated as adjustments to
the applicable Purchaser’s Total Funding Amount for all Tax purposes except as otherwise required by applicable Law. 
 ARTICLE VII

 TERMINATION 

Section 7.01 Termination. This Agreement may be terminated at any time prior to the Initial Closing: 

(a) by mutual written consent of the Partnership and the Purchasers possessing the right to acquire not less than majority of the Series D
Preferred Units; 
 (b) by written notice from either the Partnership or the Purchasers possessing the right to acquire not less than
majority of the Series D Preferred Units, if any Governmental Authority with lawful jurisdiction shall have issued a final order, decree or ruling or taken any other final action restraining, enjoining or otherwise prohibiting the transactions
contemplated by the Transaction Documents and such order, decree, ruling or other action is or shall have become final and nonappealable; or 

  
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 (c) by written notice from the Partnership or a Purchaser, with respect to itself but not any
other Purchaser, if the Initial Closing does not occur by 11:59 p.m. on June 29, 2018; provided, however, that no party may terminate this Agreement pursuant to this Section 7.01(c) if such party is,
at the time of providing such written notice, in breach of any of its obligations under this Agreement. 
 Section 7.02
Certain Effects of Termination. In the event that this Agreement is terminated pursuant to Section 7.01: 

(a) except as set forth in Section 7.02 or 8.03, this Agreement shall become null and void and have no
further force or effect, but the parties shall not be released from any liability arising from or in connection with any breach hereof occurring prior to such termination; 

(b) each of the Confidentiality Agreements shall remain in effect until such Confidentiality Agreement expires in accordance with its terms.

 ARTICLE VIII 

MISCELLANEOUS 

Section 8.01 Expenses. At the Initial Closing, the Partnership shall pay the transaction fees to each of the entities
identified on Schedule D for their own accounts in the amounts designated in Schedule D attached hereto. The transaction fees are fully earned and shall be due and payable in full at the Initial Closing. All costs and expenses,
including fees and disbursements of counsel, financial advisors and accountants, incurred in connection with the Transaction Documents and the transactions contemplated thereby shall be paid by the party incurring such costs and expenses;
provided that, if the Initial Closing occurs, promptly following receipt of an invoice therefor containing reasonable supporting detail, the Partnership shall reimburse the Purchasers for all of their reasonable
out-of-pocket transaction fees and expenses, including fees and expenses incurred in respect of the Purchasers’ advisors (including legal advisors), actually
incurred by the Purchasers prior to the Initial Closing in connection with due diligence, negotiation and consummation of the transactions contemplated by the Transaction Documents (such fees and expenses, collectively, the “Reimbursable
Expenses”) up to an amount not to exceed $725,000; provided further that, if (a) the Initial Closing does not occur or (b) this Agreement is terminated pursuant to Section 7.01 for any reason
other than the Purchaser’s failure to perform, then the Partnership shall reimburse the Purchasers for their Reimbursable Expenses up to an amount not to exceed $800,000 upon the Initial Closing Date or the date of such termination of this
Agreement, as applicable; it being understood that the expense caps set forth in this Section 8.01 shall be reduced by any amounts actually paid by the Partnership to the Purchasers in respect of the Reimbursable Expenses
prior to the Initial Closing. 
 Section 8.02 Interpretation. Article, Section, Schedule and Exhibit references in
this Agreement are references to the corresponding Article, Section, Schedule or Exhibit to this Agreement, unless otherwise specified. All Exhibits and Schedules to this Agreement are hereby incorporated and made a part hereof as if set forth in
full herein and are an integral part of this Agreement. All references to instruments, documents, Contracts and agreements are references to such instruments, documents, Contracts and agreements as the same may be amended, supplemented and otherwise
modified from time to time, unless otherwise specified. The word 

  
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“including” shall mean “including but not limited to” and shall not be construed to limit any general statement that it follows to the specific or similar items or matters
immediately following it. Whenever the Partnership has an obligation under the Transaction Documents, the expense of complying with that obligation shall be an expense of the Partnership unless otherwise specified. Any reference in this Agreement to
“$” shall mean U.S. dollars. Whenever any determination, consent or approval is to be made or given by a Purchaser, such action shall be in such Purchaser’s sole discretion, unless otherwise specified in this Agreement. If any
provision in the Transaction Documents is held to be illegal, invalid, not binding or unenforceable, (a) such provision shall be fully severable and the Transaction Documents shall be construed and enforced as if such illegal, invalid, not
binding or unenforceable provision had never comprised a part of the Transaction Documents, and the remaining provisions shall remain in full force and effect, and (b) the parties hereto shall negotiate in good faith to modify the Transaction
Documents so as to effect the original intent of the parties as closely as possible in an acceptable manner in order that the transactions contemplated hereby are consummated as originally contemplated to the greatest extent possible. When
calculating the period of time before which, within which or following which any act is to be done or step taken pursuant to the Transaction Documents, the date that is the reference date in calculating such period shall be excluded. If the last day
of such period is not a Business Day, the period in question shall end on the next succeeding Business Day. Any words imparting the singular number only shall include the plural and vice versa. The words such as “herein,”
“hereinafter,” “hereof” and “hereunder” refer to this Agreement as a whole and not merely to a subdivision in which such words appear unless the context otherwise requires. The provision of a Table of Contents, the
division of this Agreement into Articles, Sections and other subdivisions and the insertion of headings are for convenience of reference only and shall not affect or be utilized in construing or interpreting this Agreement. 

Section 8.03 Survival of Provisions. The representations and warranties set forth in
Section 3.01, Section 3.02, Section 3.03, Section 3.13, Section 3.16, Section 3.18,
Section 4.01, Section 4.02, Section 4.04, Section 4.05(a), Section 4.05(b) and
Section 4.05(e) hereunder shall survive the execution and delivery of this Agreement indefinitely, the representations and warranties set forth in Section 3.27 shall survive until
60 days after the applicable statute of limitations (taking into account any extensions thereof) and the other representations and warranties set forth herein shall survive for a period of 12 months following the Second Funding Closing
Date, regardless of any investigation made by or on behalf of the Partnership, the Purchasers. The covenants made in this Agreement or any other Transaction Document shall survive the Initial Closing and remain operative and in full force and effect
regardless of acceptance of any of the Series D Preferred Units and payment therefor and repayment, conversion or repurchase thereof. Regardless of any purported general termination of this Agreement, the provisions of Article VI and all
indemnification rights and obligations thereunder, Article VII and this Article VIII shall remain operative and in full force and effect, unless the applicable parties execute a writing that expressly (with specific references to the
applicable Section or subsection of this Agreement) terminates such rights and obligations. 
 Section 8.04 No Waiver:
Modifications in Writing. 
 (a) Delay. No failure or delay on the part of any party in exercising any right, power or remedy
hereunder shall operate as a waiver thereof, nor shall any single or partial exercise of any such right, power or remedy preclude any other or further exercise thereof or the exercise of any other right, power or remedy. The remedies provided for
herein are cumulative and are not exclusive of any remedies that may be available to a party at law or in equity or otherwise. 

  
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 (b) Specific Waiver. Except as otherwise provided herein, no amendment, waiver, consent,
modification or termination of any provision of any Transaction Document (except in the case of the Partnership Agreement for amendments adopted pursuant to the provisions thereof) shall be effective unless signed by each of the parties thereto
affected by such amendment, waiver, consent, modification or termination. Any amendment, supplement or modification of or to any provision of any Transaction Document, any waiver of any provision of any Transaction Document and any consent to any
departure by the Partnership from the terms of any provision of any Transaction Document shall be effective only in the specific instance and for the specific purpose for which made or given. Except where notice is specifically required by this
Agreement, no notice to or demand on the Partnership in any case shall entitle the Partnership to any other or further notice or demand in similar or other circumstances. Any investigation by or on behalf of any party shall not be deemed to
constitute a waiver by the party taking such action of compliance with any representation, warranty, covenant or agreement contained herein. 

Section 8.05 Binding Effect; Assignment. 

(a) This Agreement shall be binding upon the parties hereto and their respective successors and permitted assigns. Except as expressly
provided in this Agreement, this Agreement shall not be construed so as to confer any right or benefit upon any Person other than the parties to this Agreement and their respective successors and permitted assigns. 

(b) Subject to Section 5.04, each Purchaser may assign its rights and obligations under this Agreement to any fund,
account or company managed, advised or sub-advised by EIG or any Permitted Transferee; provided that any such assignment shall not relieve such Purchaser of any of its obligations hereunder. 

Section 8.06 Non-Disclosure. 

(a) This Agreement shall not impact the terms and provisions of any of the Confidentiality Agreements. The Confidentiality Agreements shall
continue to be in full force and effect, pursuant to the terms and conditions thereof. 
 (b) Other than filings made by the Partnership
with the SEC, the Partnership and any of its Representatives may disclose the identity of, or any other information concerning, the Purchasers or any of their respective Affiliates only after providing the Purchasers a reasonable opportunity to
review and comment on such disclosure (with such comments being incorporated or reflected, to the extent reasonable, in any such disclosure); provided, however, that nothing in this Section 8.06 shall delay
any required filing or other disclosure with the NYSE or any Governmental Authority or otherwise hinder the NuStar Entities’ or their Representatives’ ability to timely comply with all Laws or rules and regulations of the NYSE or other
Governmental Authority. 
 (c) Notwithstanding anything to the contrary in this Section 8.06, the Partnership and
the General Partner agree that each Purchaser may (i) publicize its ownership in the Partnership, as well as the identity of the Partnership, the size of the investment and its pricing terms with respect to the Series D Preferred Units on
its internet site or in marketing materials, press releases, published “tombstone” announcements or any other print or electronic medium and (ii) display the Partnership’s logo in conjunction with any such reference. 

  
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 (d) Except as described in Section 8.06(b), prior to making any public
statements or issuing any press releases with respect to the transactions contemplated by the Transaction Documents, each party will consult with the other parties hereto and consider in good faith any comments provided by such other parties;
provided that no party will make any public statement or issue any press release that attributes comments to any other party or that indicates the approval of any other party of the contents of any such public statement or press release (or
portion thereof) without the prior written approval of the other parties hereto. 
 Section 8.07 Communications. All
notices and demands provided for hereunder shall be in writing and shall be given by registered or certified mail, return receipt requested, telecopy, electronic mail, air courier guaranteeing overnight delivery or personal delivery to the following
addresses 
  

	 	(a)	If to the Purchasers, to the addresses set forth on Schedule A. 

  

	 	(b)	If to the Partnership, to: 

 NuStar Energy L.P. 

19003 IH-10 West 

San Antonio, Texas 78257 

Attention: Amy L. Perry, Senior Vice President, General Counsel and Corporate 

Secretary 
 with a copy to (which
shall not constitute notice): 
 Sidley Austin LLP 

1000 Louisiana Street 
 Suite 6000

 Houston, TX 77002 

Attention: George J. Vlahakos 

Email: gvlahakos@sidley.com 
 or to such other
address as the Partnership or the Purchasers may designate in writing. All notices and communications shall be deemed to have been duly given: at the time delivered by hand, if personally delivered; upon actual receipt if sent by certified or
registered mail, return receipt requested, or regular mail, if mailed; upon actual receipt of the facsimile, if sent via facsimile; when sent, if sent by electronic mail prior to 5:00 p.m. Houston, Texas time on a Business Day, or on the next
succeeding Business Day, if not; and upon actual receipt when delivered to an air courier guaranteeing overnight delivery. 

Section 8.08 Removal of Legend. In connection with a sale of Series D Preferred Units, PIK Units or Conversion
Units by a Purchaser in reliance on Rule 144 promulgated under the Securities Act, the applicable Purchaser or its broker shall deliver to the Partnership a broker representation letter providing to the Partnership any information the
Partnership deems necessary to determine 

  
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that the sale of such Series D Preferred Units, PIK Units or Conversion Units is made in compliance with Rule 144 promulgated under the Securities Act, including, as may be appropriate,
a certification that the Purchaser is not an affiliate of the Partnership (as defined in Rule 144 promulgated under the Securities Act) and a certification as to the length of time the such units have been held. Upon receipt of such
representation letter, the Partnership shall promptly remove the notation of a restrictive legend in such Purchaser’s book-entry account maintained by the Partnership, including the legend referred to in Section 4.05,
and the Partnership shall bear all costs associated with the removal of such legend in the Partnership’s books. At such time as the Series D Preferred Units, PIK Units or Conversion Units have been sold pursuant to an effective
registration statement under the Securities Act or have been held by any Purchaser for more than one year where such Purchaser is not, and has not been in the preceding three months, an affiliate of the Partnership (as defined in Rule 144
promulgated under the Securities Act), if the book-entry account of such Purchaser still bears the notation of the restrictive legend referred to in Section 4.05, the Partnership agrees, upon request of the Purchaser or its
permitted assignee, to take all steps necessary to promptly effect the removal of the legend described in Section 4.05, and the Partnership shall bear all costs associated with the removal of such legend in the
Partnership’s books, regardless of whether the request is made in connection with a sale or otherwise, so long as such Purchaser or its permitted assignee provides to the Partnership any information the Partnership deems reasonably necessary to
determine that the legend is no longer required under the Securities Act or applicable state Laws, including (if there is no such registration statement) a certification that the holder is not an affiliate of the Partnership (as defined in
Rule 144 promulgated under the Securities Act), a covenant to inform the Partnership if it should thereafter become an affiliate (as defined in Rule 144 promulgated under the Securities Act) and to consent to the notation of an appropriate
restriction, and a certification as to the length of time such units have been held. The Partnership shall cooperate with each Purchaser to effect the removal of the legend referred to in Section 4.05 at any time such
legend is no longer appropriate. 
 Section 8.09 Entire Agreement. This Agreement, the other Transaction Documents,
the Confidentiality Agreements and the other agreements and documents referred to herein are intended by the parties as a final expression of their agreement and intended to be a complete and exclusive statement of the agreement and understanding of
the parties hereto in respect of the subject matter contained herein and therein. There are no restrictions, promises, warranties or undertakings, other than those set forth or referred to in this Agreement, the other Transaction Documents or the
Confidentiality Agreements with respect to the rights granted by the Partnership or any of its Affiliates or the Purchasers or any of their respective Affiliates. This Agreement, the other Transaction Documents, the Confidentiality Agreements and
the other agreements and documents referred to herein or therein supersede all prior agreements and understandings among the parties with respect to such subject matter. 

Section 8.10 Governing Law; Submission to Jurisdiction. This Agreement, and all claims or causes of action (whether in
contract or tort) that may be based upon, arise out of or relate to this Agreement or the negotiation, execution or performance of this Agreement (including any claim or cause of action based upon, arising out of or related to any representation or
warranty made in or in connection with this Agreement), will be construed in accordance with and governed by the Laws of the State of Delaware without regard to principles of conflicts of laws. Any action against any party relating to the foregoing
shall be brought in any federal or state court of competent jurisdiction located within the State of Delaware, and the parties hereto hereby irrevocably submit 

  
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to the non-exclusive jurisdiction of any federal or state court located within the State of Delaware over any such action. The parties hereby irrevocably
waive, to the fullest extent permitted by applicable Law, any objection which they may now or hereafter have to the laying of venue of any such dispute brought in such court or any defense of inconvenient forum for the maintenance of such dispute.
Each of the parties hereto agrees that a judgment in any such dispute may be enforced in other jurisdictions by suit on the judgment or in any other manner provided by Law. 

Section 8.11 Waiver of Jury Trial. THE PARTIES TO THIS AGREEMENT EACH HEREBY WAIVES, AND AGREES TO CAUSE ITS
AFFILIATES TO WAIVE, TO THE FULLEST EXTENT PERMITTED BY LAW, ANY RIGHT TO TRIAL BY JURY OF ANY CLAIM, DEMAND, ACTION OR CAUSE OF ACTION (A) ARISING UNDER THIS AGREEMENT OR (B) IN ANY WAY CONNECTED WITH OR RELATED OR INCIDENTAL TO THE
DEALINGS OF THE PARTIES HERETO IN RESPECT OF THIS AGREEMENT OR ANY OF THE TRANSACTIONS RELATED HERETO, IN EACH CASE WHETHER NOW EXISTING OR HEREAFTER ARISING, AND WHETHER IN CONTRACT, TORT, EQUITY OR OTHERWISE. THE PARTIES TO THIS AGREEMENT EACH
HEREBY AGREES AND CONSENTS THAT ANY SUCH CLAIM, DEMAND, ACTION OR CAUSE OF ACTION SHALL BE DECIDED BY COURT TRIAL WITHOUT A JURY AND THAT THE PARTIES TO THIS AGREEMENT MAY FILE AN ORIGINAL COUNTERPART OF A COPY OF THIS AGREEMENT WITH ANY COURT AS
WRITTEN EVIDENCE OF THE CONSENT OF THE PARTIES HERETO TO THE WAIVER OF THEIR RIGHT TO TRIAL BY JURY. 
 Section 8.12
Exclusive Remedy. 
 (a) Each party hereto hereby acknowledges and agrees that the rights of each party to consummate the
transactions contemplated hereby are special, unique and of extraordinary character and that, if any party violates or fails or refuses to perform any covenant or agreement made by it herein, the non-breaching
party may be without an adequate remedy at law. If any party violates or fails or refuses to perform any covenant or agreement made by such party herein, the non-breaching party subject to the terms hereof and
in addition to any remedy at law for damages or other relief, may (at any time prior to the valid termination of this Agreement pursuant to Article VII) institute and prosecute an action in any court of competent jurisdiction to enforce
specific performance of such covenant or agreement or seek any other equitable relief. 
 (b) The sole and exclusive remedy for any and all
claims arising under, out of, or related to this Agreement or the transactions contemplated hereby, shall be the rights of indemnification set forth in Article VI only, and no Person will have any other entitlement, remedy or recourse,
whether in contract, tort or otherwise, it being agreed that all of such other remedies, entitlements and recourse are expressly waived and released by the parties hereto to the fullest extent permitted by Law. Notwithstanding anything in the
foregoing to the contrary, nothing in this Agreement shall limit or otherwise restrict a fraud claim brought by any party hereto or the right to seek specific performance pursuant to Section 8.12(a). 

  
 40 

 Section 8.13 No Recourse Against Others. 

(a) All claims, obligations, liabilities or causes of action (whether in contract or in tort, in law or in equity, or granted by statute) that
may be based upon, in respect of, arise under, out or by reason of, be connected with or relate in any manner to this Agreement, or the negotiation, execution or performance of this Agreement (including any representation or warranty made in, in
connection with, or as an inducement to, this Agreement), may be made only against (and are expressly limited to) the Partnership and the Purchasers. No Person other than the Partnership or the Purchasers, including no member, partner, stockholder,
Affiliate or Representative thereof, nor any member, partner, stockholder, Affiliate or Representative of any of the foregoing, shall have any liability (whether in contract or in tort, in law or in equity, or granted by statute) for any claims,
causes of action, obligations or liabilities arising under, out of, in connection with or related in any manner to this Agreement or based on, in respect of or by reason of this Agreement or its negotiation, execution, performance or breach; and, to
the maximum extent permitted by Law, each of the Partnership and the Purchasers hereby waives and releases all such liabilities, claims, causes of action and obligations against any such third Person. 

(b) Without limiting the foregoing, to the maximum extent permitted by Law, (i) each of the Partnership and the Purchasers hereby waives
and releases any and all rights, claims, demands or causes of action that may otherwise be available at law or in equity, or granted by statute, to avoid or disregard the entity form of the other or otherwise impose liability of the other on any
third Person in respect of the transactions contemplated hereby, whether granted by statute or based on theories of equity, agency, control, instrumentality, alter ego, domination, sham, single business enterprise, piercing the veil, unfairness,
undercapitalization or otherwise; and (ii) each of the Partnership and the Purchasers disclaims any reliance upon any third Person with respect to the performance of this Agreement or any representation or warranty made in, in connection with
or as an inducement to this Agreement. 
 Section 8.14 No Third-Party Beneficiaries. Except as set forth in
Article VI, nothing in this Agreement, express or implied, is intended to or shall confer upon any Person, other than the Partnership, the Purchasers and, for purposes of Section 8.13 only, any member, partner,
stockholder, Affiliate or Representative of the Partnership or the Purchasers, or any member, partner, stockholder, Affiliate or Representative of any of the foregoing, any right, benefit or remedy of any nature whatsoever under or by reason of this
Agreement. 
 Section 8.15 Execution in Counterparts. This Agreement may be executed in any number of counterparts
and by different parties hereto in separate counterparts, each of which counterparts, when so executed and delivered, shall be deemed to be an original and all of which counterparts, taken together, shall constitute but one and the same agreement.

 [Signature Page Follows] 

  
 41 

 IN WITNESS WHEREOF, the parties hereto execute this Agreement, effective as of the date first
above written. 
  

					
	NUSTAR ENERGY L.P.
	
	 By: RIVERWALK LOGISTICS, L.P., its General Partner

		
		 	By: NUSTAR GP, LLC, its General Partner
			
		 	By:	 	/s/ Thomas R. Shoaf
		 	Name:	 	Thomas R. Shoaf
		 	Title:	 	 Executive Vice President and
 Chief Financial
Officer

 [Signature Page to Purchase Agreement] 

 
			
	EIG NOVA EQUITY AGGREGATOR, L.P.
	
	 By: EIG Nova Equity GP, LLC

        its general partner

	
	 By: EIG Asset Management, LLC
its managing member

  

					
		 	By:	 	/s/ Richard K. Punches, II
		 	Name:	 	Richard K. Punches, II
		 	Title:	 	Managing Director

  

					
		 	By:	 	/s/ Matthew Hartman
		 	Name:	 	Matthew Hartman
		 	Title:	 	Senior Vice President

  

			
	FS ENERGY AND POWER FUND
	
	 By: FS/EI Advisor, LLC,
its Investment Advisor

  

					
		 	By:	 	/s/ Richard K. Punches, II
		 	Name:	 	Richard K. Punches, II
		 	Title:	 	Authorized Person

  

					
		 	By:	 	/s/ Matthew Hartman
		 	Name:	 	Matthew Hartman
		 	Title:	 	Authorized Person

 [Signature Page to Purchase Agreement] 

 Exhibit A 

Form of Opinion of Sidley Austin LLP 

					
	 

	 	 SIDLEY AUSTIN LLP
 1000 LOUISIANA STREET

SUITE 6000
 HOUSTON, TX 77002

+1 713 495 4500
 +1 713 495 7799 FAX

 
 AMERICA • ASIA PACIFIC • EUROPE
	  	

 June [•], 2018 

EIG Nova Equity Aggregator, L.P. 
 c/o EIG Management Company,
LLC 
 333 Clay Street, Suite 3500 
 Houston, Texas 77002 

and 
 FS Energy and Power Fund 

c/o EIG Management Company, LLC 
 1700 Pennsylvania Avenue NW,
Suite 800 
 Washington, DC 20006 
  

	 	Re:	23,246,650 Series D Cumulative Convertible Preferred Units issued by NuStar Energy L.P.  

 Ladies
and Gentlemen: 
 We have acted as special counsel to NuStar Energy L.P., a Delaware limited partnership (the
“Partnership”), in connection with the issuance and sale by the Partnership of 23,246,650 Series D Cumulative Convertible Preferred Units representing limited partner interests in the Partnership (the “Preferred
Units”), convertible into common units representing limited partner interests in the Partnership (“Common Units”), pursuant to the Purchase Agreement, dated June 26, 2018 (the “Purchase Agreement”),
among the Partnership and the purchasers named therein (the “Purchasers”), relating to the issuance and sale by the Partnership to the Purchasers of 15,760,441 Preferred Units (the “Units”). 

We are furnishing this opinion letter to you pursuant to Section 2.06(a) of the Purchase Agreement. 

In rendering the opinions set forth herein, we have examined and relied on originals or copies, certified or otherwise identified to our
satisfaction, of the following: 
 (a) each of the Partnership’s reports that have been filed with the U.S. Securities and Exchange
Commission (the “SEC”) since January 1, 2017 (the “NS SEC Documents”); 
 (b) the Purchase Agreement;

 (c) the Registration Rights Agreement, dated as of June 29, 2018, among the Partnership and the Purchasers (the
“Registration Rights Agreement”); 

 

 
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 (d) the Information Rights Agreement, dated as of June 29, 2018, by and among the
Partnership, and EIG Management Company, LLC and FS/EIG Advisor, LLC (EIG Management Company, LLC and FS/EIG Advisor, LLC are referred to herein, collectively, as (“EIG”)) (the “Information Rights Agreement”); 

(e) the Non-Solicitation Side Letter, dated as of June 29, 2018, by and among the Partnership,
the Purchasers and EIG (the “Non-Solicitation Side Letter”) 
 (f) the Amended and
Restated Certificate of Limited Partnership of the Partnership, dated as of December 31, 2001 and effective as of January 1, 2002, as amended by the Amendment to Certificate of Limited Partnership dated as of March 21, 2007 and
effective as of April 1, 2007, certified by the Secretary of State of the State of Delaware as in effect on June 25, 2018, and certified by the Senior Vice President, General Counsel – Corporate and Commercial Law and Corporate
Secretary (the “Corporate Secretary”) of NuStar GP, LLC, a Delaware limited liability company and the general partner of the General Partner (“NuStar GP”), as in effect on the date of the resolutions described in
paragraph (m), the date of the Purchase Agreement and the date hereof (such Amended and Restated Certificate of Limited Partnership, as so amended and as so certified, being referred to herein as the “NuStar L.P. Certificate of Limited
Partnership”); 
 (g) the Sixth Amended and Restated Agreement of Limited Partnership of the Partnership, dated as of
November 30, 2017, certified by the Corporate Secretary as in effect on the date of the resolutions described in paragraph (m) and the date of the Purchase Agreement (the “Sixth A&R NuStar L.P. Partnership Agreement”);

 (h) the Seventh Amended and Restated Agreement of Limited Partnership of the Partnership, dated as of June 29, 2018, certified by
the Corporate Secretary as in effect on the date hereof (the “NuStar L.P. Partnership Agreement”); 
 (i) the Certificate
of Limited Partnership of Riverwalk Logistics, L.P., a Delaware limited partnership and the general partner of the Partnership (the “General Partner”), dated June 5, 2000, certified by the Secretary of State of the State of
Delaware as in effect on June 25, 2018, and certified by the Corporate Secretary as in effect on the date of the resolutions described in paragraph (m), the date of the Purchase Agreement and the date hereof (such Certificate of Limited
Partnership, as so certified, being referred to herein as the “General Partner Certificate of Limited Partnership”); 
 (j)
the First Amended and Restated Limited Partnership Agreement of the General Partner, dated as of April 16, 2001, certified by the Corporate Secretary as in effect on the date of the resolutions described in paragraph (m), the date of the
Purchase Agreement and the date hereof (such First Amended and Restated Limited Partnership Agreement, as so certified, being referred to herein as the “General Partner Partnership Agreement”); 

 

 
 June [●], 2018 
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 (k) the Certificate of Formation of NuStar GP, dated December 7, 1999, as amended by the
Certificate of Amendment to the Certificate of Formation, dated December 31, 2001, and the Certificate of Amendment to the Certificate of Formation, dated effective as of April 1, 2007, certified by the Secretary of State of the State of
Delaware as in effect on June 25, 2018, and certified by the Corporate Secretary as in effect on the date of the resolutions described in paragraph (m), the date of the Purchase Agreement and the date hereof (such Certificate of Formation, as
so amended and as so certified, being referred to herein as the “NuStar GP Certificate of Formation”); 
 (l) the First
Amended and Restated Limited Liability Company Agreement of NuStar GP, dated as of June 5, 2000, as amended by the First Amendment thereto, dated December 31, 2001, the Second Amendment thereto, dated as of June 1, 2006, and the Third
Amendment thereto, dated July 29, 2016, certified by the Corporate Secretary as in effect on the date of the resolutions described in paragraph (m), the date of the Purchase Agreement and the date hereof (such First Amended and Restated Limited
Liability Company Agreement, as so amended and as so certified, being referred to herein as the “NuStar GP LLC Agreement”); 

(m) resolutions of the (i) Board of Directors of NuStar GP adopted June 13, 2018 and (ii) Pricing Committee designated by the
Board of Directors of NuStar GP adopted on June [26], 2018, each as certified by the Corporate Secretary; 
 (n) the Amended and Restated
Certificate of Limited Partnership of NuStar Logistics, L.P., a Delaware limited partnership (“NuStar Logistics”) effective January 8, 2002, as amended by the Certificate of Amendment to the Amended and Restated Certificate of
Limited Partnership, dated May 30, 2002, the Certificate of Amendment to the Amended and Restated Certificate of Limited Partnership, dated effective as of April 1, 2007, and the Certificate of Amendment to the Amended and Restated
Certificate of Limited Partnership, dated March 18, 2014, certified by the Secretary of State of the State of Delaware as in effect on June 25, 2018, and certified by the Corporate Secretary as in effect on the date of the Purchase
Agreement and the date hereof (such Amended and Restated Certificate of Limited Partnership, as so amended and as so certified, being referred to herein as the “NuStar Logistics Certificate of Limited Partnership”); 

(o) the Second Amended and Restated Agreement of Limited Partnership of NuStar Logistics, dated as of April 16, 2001, as amended by the
First Amendment thereto, dated effective as of April 16, 2001, the Second Amendment thereto, dated January 7, 2002, and the Reorganization Agreement dated as of May 30, 2002, among NuStar Logistics, the Partnership, the General
Partner and NuStar GP, Inc., a Delaware corporation and the general partner of NuStar Logistics (“GP, Inc.”), certified by the Corporate Secretary as in effect on the date of the Purchase Agreement and the date hereof (such Second
Amended and Restated Agreement of Limited Partnership, as so amended and as so certified, being referred to herein as the “NuStar Logistics Partnership Agreement”); 

(p) the Certificate of Incorporation of GP, Inc., dated May 28, 2002, as amended by the Certificate of Amendment to the Certificate of
Incorporation dated effective April 1, 2007, certified by the Secretary of State of the State of Delaware as in effect on June 25, 2018, and certified by the Corporate Secretary, as in effect on the date of the Purchase Agreement and the
date hereof (such Certificate of Incorporation, as so amended and as so certified, being referred to herein as the “GP, Inc. Certificate of Incorporation”); 

 

 
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 (q) the Bylaws of GP, Inc., dated May 29, 2002, certified by the Corporate Secretary as
in effect on the date of the Purchase Agreement and the date hereof (such Bylaws, as so certified, being referred to herein as the “GP, Inc. Bylaws”); 

(r) the Certificate of Limited Partnership of NuStar Pipeline Operating Partnership L.P., a Delaware limited partnership
(“NuPOP”), dated September 12, 1989, as amended by the Certificate of Amendment to the Certificate of Limited Partnership, dated effective as of March 31, 2008, certified by the Secretary of State of the State of Delaware
as in effect on June 25, 2018, and certified by the Corporate Secretary as in effect on the date of the Purchase Agreement and the date hereof (such Certificate of Limited Partnership, as so amended and as so certified, being referred to herein
as the “NuPOP Certificate of Limited Partnership”); 
 (s) the Amended and Restated Agreement of Limited Partnership of
NuPOP, dated September 27, 1989, as amended by the Amendment thereto, dated effective June 30, 2003, certified by the Corporate Secretary as in effect on the date of the Purchase Agreement and the date hereof (such Amended and Restated
Agreement of Limited Partnership, as so amended and as so certified, being referred to herein as the “NuPOP Partnership Agreement”); 

(t) the Certificate of Formation of NuStar Pipeline Company, LLC, a Delaware limited liability company and the general partner of NuPOP and
NuStar Pipeline Partners L.P. (“NuStar Pipeline”), dated June 21, 2001, as amended by the Certificate of Amendment to the Certificate of Formation dated effective as of March 31, 2008, certified by the Secretary of State
of the State of Delaware as in effect on June 25, 2018, and certified by the Corporate Secretary as in effect on the date of the Purchase Agreement and the date hereof (such Certificate of Formation, as so amended and as so certified, being
referred to herein as the “NuStar Pipeline Certificate of Formation”); 
 (u) the Amended and Restated Limited Liability
Company Agreement of NuStar Pipeline, dated July 16, 2001, certified by the Corporate Secretary as in effect on the date of the Purchase Agreement and the date hereof (such Amended and Restated Limited Liability Company Agreement, as so
certified, being referred to herein as the “NuStar Pipeline LLC Agreement”); 
 (v) the Certificate of Limited Partnership
of NuStar Pipeline Partners L.P., a Delaware limited partnership (“NuStar Pipeline Partners”), dated August 2, 1989, as amended by the Certificate of Amendment to the Certificate of Limited Partnership, dated effective as of
March 31, 2008, certified by the Secretary of State of the State of Delaware as in effect on June 25, 2018, and certified by the Corporate Secretary as in effect on the date of the Purchase Agreement and the date hereof (such Certificate
of Limited Partnership, as so amended and so certified, being referred to herein as the “NuStar Pipeline Partners Certificate of Limited Partnership”); 

 

 
 June [●], 2018 
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 (w) the Amended and Restated Agreement of Limited Partnership of NuStar Pipeline Partners,
dated September 18, 1995, as revised July 23, 1998, as amended by the Amendment thereto, dated October 27, 2003, certified by the Corporate Secretary as in effect on the date of the Purchase Agreement and the date hereof (such Amended
and Restated Agreement of Limited Partnership, as so revised and amended and as so certified, being referred to herein as the “NuStar Pipeline Partners Partnership Agreement”); 

(x) the Certificate of Formation of LegacyStar Services, LLC, a Delaware limited liability company and the sole member of NuStar Pipeline
(“LegacyStar”), dated April 9, 2001, as amended by the Certificate of Amendment to the Certificate of Formation dated effective as of March 31, 2008, certified by the Secretary of State of the State of Delaware as in
effect on June 25, 2018, and certified by the Corporate Secretary as in effect on the date of the Purchase Agreement and the date hereof (such Certificate of Formation, as so amended and as so certified, being referred to herein as the
“LegacyStar Certificate of Formation”); 
 (y) the Amended and Restated Limited Liability Company Agreement of LegacyStar,
dated as of June 28, 2001, certified by the Corporate Secretary as in effect on the date of the Purchase Agreement and the date hereof (such Amended and Restated Limited Liability Company Agreement, as so certified, being referred to herein as
the “LegacyStar LLC Agreement”); 
 (z) a certificate dated the date hereof (the “Opinion Support
Certificate”), executed by the Corporate Secretary, a copy of which is attached hereto as Exhibit A; 
 (aa) each of the Applicable
Agreements (as defined below); and 
 (bb) results of uniform commercial code searches each dated June 25, 2018 conducted by Capitol
Services, Inc. and purporting to identify all effective uniform commercial code financing statements on file in the office of the Secretary of State of the State of Delaware, through June 13, 2018, naming NuStar Holdings, NuStar GP, Riverwalk
Holdings or the General Partner as debtor (the “Search Reports”). 
 We have also examined and relied upon originals or
copies, certified or otherwise identified to our satisfaction, of such records of the Partnership Entities and such agreements, certificates of public officials, certificates of officers or other representatives of the Partnership Entities and
others, and such other documents, certificates and records, as we have deemed necessary or appropriate as a basis for the opinions set forth herein. In our examination, we have assumed the legal capacity of all natural persons, the genuineness of
all signatures, the authenticity of all documents submitted to or obtained by us as originals, and the conformity to authentic original documents of all documents submitted to or obtained by us as certified or photostatic copies or by facsimile or
other means of electronic transmission or which we obtained from the SEC’s Electronic Data Gathering, Analysis and Retrieval system (“EDGAR”) 

 

 
 June [●], 2018 
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or other sites on the internet, and the authenticity of the originals of such latter documents. If any document we examined in printed, word processed or similar form has been filed with the SEC
on EDGAR, we have assumed that the document filed on EDGAR is identical to the document we examined, except for EDGAR formatting changes. As to facts and certain other matters and the consequences thereof materially relevant to the opinions
expressed herein and the other statements made herein, we have relied without independent investigation or verification upon, and assumed the accuracy and completeness of, (i) oral or written statements and representations of officers and other
representatives of the Partnership Entities (including without limitation the facts certified in the Opinion Support Certificate), (ii) statements and certifications of public officials and others and (iii) the representations and warranties in
the Purchase Agreement (as to factual matters). 
 As used herein the following terms have the respective meanings set forth below: 

“Applicable Agreements” means those agreements and other instruments identified on Schedule 1 to the Opinion Support
Certificate which have been certified by the Corporate Secretary as being every indenture, mortgage, deed of trust, loan, purchase or credit agreement, lease or other agreement that is material in relation to the business, operations, affairs,
financial condition, assets, or properties of the Partnership and its subsidiaries, considered as a single enterprise. 
 “Incentive
Distribution Rights” has the meaning ascribed to such term under the NuStar L.P. Partnership Agreement. 
 “NuStar
Holdings” means NuStar GP Holdings, LLC, a Delaware limited liability company. 
 “Organizational Documents” means
the NuStar GP Certificate of Formation, the NuStar GP LLC Agreement, the General Partner Certificate of Limited Partnership, the General Partner Partnership Agreement, the NuStar L.P. Certificate of Limited Partnership, the Sixth A&R NuStar L.P.
Partnership Agreement, the NuStar L.P. Partnership Agreement, the NuStar Logistics Certificate of Limited Partnership, the NuStar Logistics Partnership Agreement, the LegacyStar Certificate of Formation, the LegacyStar LLC Agreement, the NuStar
Pipeline Certificate of Formation, the NuStar Pipeline LLC Agreement, the NuStar Pipeline Partners Certificate of Limited Partnership, the NuStar Pipeline Partners Partnership Agreement, the NuPOP Certificate of Limited Partnership, the NuPOP
Partnership Agreement, the GP, Inc. Certificate of Incorporation and the GP, Inc. Bylaws. 
 “Partnership Entities” means
NuStar GP, the General Partner, the Partnership, NuStar Logistics, GP, Inc., LegacyStar, NuStar Pipeline, NuStar Pipeline Partners and NuPOP. 

“Partnership Parties” means the Partnership, the General Partner and NuStar GP. 

“Person” means a natural person or a legal entity organized under the laws of any jurisdiction. 

 

 
 June [●], 2018 
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 “Riverwalk Holdings” means Riverwalk Holdings, LLC, a Delaware limited
liability company. 
 “Transaction Documents” means the Purchase Agreement, the Registration Rights Agreement, the
Information Rights Agreement and the Non-Solicitation Side Letter. 
 Based upon the foregoing and
subject to the limitations, qualifications, exceptions and assumptions set forth herein, we are of the opinion that: 
 1. Each of the
Partnership Parties has been formed under the laws of the State of Delaware. Each of the Partnership Entities is validly existing as a limited partnership, limited liability company or corporation, as applicable, and in good standing under the laws
of the State of Delaware. Each of the Partnership Entities has the limited partnership, limited liability company or corporate power and authority, as the case may be, under the laws of the State of Delaware to carry on its business and own or lease
its properties as described in the NS SEC Documents. 
 2. NuStar Holdings is the sole member of NuStar GP, with a 100% membership interest
in NuStar GP, such membership interest has been duly authorized and validly issued in accordance with the NuStar GP LLC Agreement and is fully paid (to the extent required by the NuStar GP LLC Agreement) and is nonassessable (except as such
nonassessability may be affected by Section 18-607 and 18-804 of the Delaware Limited Liability Company Act (the “Delaware LLC Act”)); and NuStar
Holdings owns such membership interest free and clear of all liens in respect of which a uniform commercial code financing statement naming NuStar Holdings as debtor is on file in the office of the Secretary of State of the State of Delaware as of
June 13, 2018. 
 3. NuStar GP is the sole general partner of the General Partner with a 0.1% general partner interest in the General
Partner; such general partner interest has been duly authorized and validly issued in accordance with the General Partner Partnership Agreement; and NuStar GP owns such general partner interest free and clear of all liens in respect of which a
uniform commercial code financing statement naming NuStar GP as debtor is on file in the office of the Secretary of State of the State of Delaware as of June 13, 2018. 

4. Riverwalk Holdings is the sole limited partner of the General Partner with a 99.9% limited partner interest in the General Partner; such
limited partner interest has been duly authorized and validly issued in accordance with the General Partner Partnership Agreement and is fully paid (to the extent required under the General Partner Partnership Agreement) and nonassessable (except as
such nonassessability may be affected by matters described in Sections 17-303, 17-607 and 17-804 of the Delaware Revised
Uniform Limited Partnership Act (the “Delaware LP Act”)); and Riverwalk Holdings owns such limited partner interest free and clear of all liens in respect of which a uniform commercial code financing statement naming Riverwalk
Holdings as debtor is on file in the office of the Secretary of State of the State of Delaware as of June 13, 2018. 

 

 
 June [●], 2018 
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 5. The General Partner is the sole general partner of the Partnership with a 2% general
partner interest and 100% of the Incentive Distribution Rights in the Partnership; such general partner interest and Incentive Distribution Rights have been duly authorized and validly issued in accordance with the NuStar L.P. Partnership Agreement
and, in the case of the Incentive Distribution Rights, are fully paid (to the extent required under the NuStar L.P. Partnership Agreement) and nonassessable (except as such nonassessability may be affected by matters described in Sections 17-303, 17-607 and 17-804 of the Delaware LP Act); and the General Partner owns such general partner interest and
Incentive Distribution Rights, in each case, free and clear of all liens in respect of which a uniform commercial code financing statement naming the General Partner as debtor is on file in the office of the Secretary of State of the State of
Delaware as of June 13, 2018. 
 6. Riverwalk Holdings and NuStar GP own 10,213,894 and 732 Common Units, respectively, as of the date
hereof; and Riverwalk Holdings and NuStar GP own such Common Units free and clear of all liens in respect of which a uniform commercial code financing statement naming either Riverwalk Holdings or NuStar GP as debtor is on file in the office of the
Secretary of State of the State of Delaware as of June 13, 2018, other than, with respect to Riverwalk Holdings, the uniform commercial code financing statement No. 20132498823 filed on June 28, 2013 and the amendments and
continuation thereto, No. 20163633532 filed on June 16, 2016, No. 20174239270 filed on June 27, 2017, No. 20180400834 filed on January 18, 2018 and No. 20182502777 filed on April 12, 2018 naming Riverwalk
Holdings, as debtor, as to which we were advised by Riverwalk Holdings was filed in connection with the Revolving Credit Agreement, dated as of June 28, 2013, among NuStar Holdings, Riverwalk Holdings and the lenders party thereto, as amended.

 7. Except as described in the NS SEC Documents or the Transaction Documents (i) there are no outstanding options, warrants or other
rights to purchase, or any restrictions upon the voting or transfer of, agreements or other obligations requiring any Partnership Entity to issue or rights to convert any securities into or exchange any securities for any equity interest of any
Partnership Entity, in each case, under any Organizational Document of such Partnership Entity or any Applicable Agreement, (ii) there are no preemptive rights or other similar rights to subscribe for or purchase any equity interest of any
Partnership Entity under any Organizational Document of such Partnership Entity, any Applicable Agreement or the Delaware LP Act and (iii) no Person has the right, which has not been waived, under any Organizational Document or any Applicable
Agreement to require the registration under the Securities Act of 1933, as amended (the “Securities Act”) of any sale of securities issued by the Partnership, by reason of the issuance and sale of the Units as contemplated in the
Purchase Agreement. 
 8. Each of the issuance and sale of the Units and the execution and delivery by the Partnership of the Transaction
Documents has been duly authorized by all necessary limited liability company action of NuStar GP, acting in its capacity as the general partner of the General Partner, acting in its capacity as the general partner of the Partnership. 

 

 
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 9. Each of the Purchase Agreement, Registration Rights Agreement and Information Rights
Agreement has been duly authorized, executed and delivered by the Partnership and constitutes a valid and binding obligation of the Partnership, enforceable against the Partnership in accordance with its terms. 

10. The Units to be purchased by the Purchasers from the Partnership have been duly authorized for issuance and sale to the Purchasers
pursuant to the Purchase Agreement, and the limited partner interests represented thereby, have been duly authorized in accordance with the NuStar L.P. Partnership Agreement and, when issued and delivered to the Purchasers against payment therefor
in accordance with the terms of the Purchase Agreement, will be validly issued, fully paid (to the extent required by the NuStar L.P. Partnership Agreement) and nonassessable (except as such nonassessability may be affected by Sections 17-303, 17-607 and 17-804 of the Delaware LP Act). 

11. The Series D PIK Units (as defined in the NuStar L.P. Partnership Agreement) have been duly authorized pursuant to the NuStar L.P.
Partnership Agreement and, assuming the distribution of the Series D PIK Units, if any, is properly authorized by the General Partner, when such Series D PIK Units are issued in accordance with the terms of the NuStar L.P. Partnership Agreement,
such Series D PIK Units will be duly authorized, validly issued, fully paid (to the extent required by the NuStar L.P. Partnership Agreement) and non nonassessable (except as such nonassessability may be affected by Sections 17-303, 17-607 and 17-804 of the Delaware LP Act). 

12. The Series D Conversion Common Units (as defined in the NuStar L.P. Partnership Agreement) have been duly authorized pursuant to the
NuStar L.P. Partnership Agreement and, when issued upon conversion or redemption of the Units in accordance with the terms of the NuStar L.P. Partnership Agreement, will be duly authorized, validly issued, fully paid (to the extent required by the
NuStar L.P. Partnership Agreement) and non nonassessable (except as such nonassessability may be affected by Sections 17-303, 17-607 and
17-804 of the Delaware LP Act). 
 13. The NuStar L.P. Partnership Agreement has been duly
authorized, executed and delivered by, and constitutes a valid and binding agreement of the General Partner and is enforceable against the General Partner in accordance with its terms. 

14. None of (i) the execution, delivery and performance of the Transaction Documents by the Partnership or the consummation of the
transactions contemplated thereby, (ii) the execution and delivery of the NuStar L.P. Agreement by the General Partner or (iii) the issuance and sale by the Partnership of the Units to the Purchasers pursuant to the Purchase Agreement
(A) violated, violates or will violate the Organizational Documents of the Partnership, (B) resulted, results or will result in a breach of, or a default (or an event which, with notice or lapse of time or both, would constitute such a
default) under, any Applicable Agreement, (C) created, creates or will create any security interest in, or lien upon, any of the property or assets of any Partnership Entity pursuant to any Applicable Agreement, (D) violated,

 

 
 June [●], 2018 
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violates or will violate any terms or provisions of (i) any applicable federal laws of the United States of America, (ii) the Delaware General Corporation Law (“DGCL”),
(iii) the Delaware LP Act, (iv) the Delaware LLC Act or (v) any applicable laws of the State of Texas. 
 15. No Governmental
Approval (as defined below) which has not been obtained or made and is not in full force and effect, was or is required for (i) the execution, delivery and performance of the Transaction Documents by the Partnership or the consummation of the
transactions contemplated thereby, except as may be required in connection with the Partnership’s obligations under the Registration Rights Agreement to register the resale of the Units or the Series D Conversion Common Units under the
Securities Act, or (ii) the issuance and sale of the Units by the Partnership to the Purchasers pursuant to the Purchase Agreement, or performance by the Partnership of its obligations thereunder. As used in this paragraph,
“Governmental Approval” means any consent, approval, license, authorization or order of any executive, legislative, judicial, administrative or regulatory body of the State of Delaware, the State of Texas or the United States of
America, pursuant to (i) the DGCL, (ii) the Delaware LP Act, (iii) the Delaware LLC Act, (iv) applicable federal laws of the United States of America or (v) applicable laws of the State of Texas. 

16. The Partnership is not, and immediately after giving effect to the issuance and sale of the Units and the application of the proceeds
therefrom it will not be, required to be registered as an “investment company” as defined in the Investment Company Act of 1940, as amended (the “40 Act”). 

17. Assuming the accuracy of the representations and warranties of the Purchasers and the Partnership contained in the Purchase Agreement, the
offer, issuance and sale of the Units by the Partnership to the Purchasers in accordance with the Purchase Agreement, including the issuance of the Series D Conversion Common Units to such Purchasers upon conversion of the Units in accordance with
the NuStar L.P. Partnership Agreement (assuming such conversion takes place as of the date hereof), are exempt from the registration requirements of the Securities Act; provided, however, that no opinion is expressed as to any
subsequent sale or resale of the Units or the Series D Conversion Common Units. 
 This letter is limited to matters arising under the
(i) applicable laws of the State of Texas, (ii) applicable federal laws of the United States of America, (iii) Delaware LP Act, (iv) Delaware LLC Act, (v) DGCL and (vi) with respect to the opinions in paragraphs 1, 2,
3, 4, 5 and 6 above, our review of the documents and other items described in paragraphs (i), (ii) and (iii) below. References herein to “applicable laws” mean those laws, rules and regulations that, in our experience, are normally
applicable to transactions of the type contemplated by the Purchase Agreement, without our having made any special investigation as to the applicability of any specific law, rule or regulation, and that are not the subject of a specific opinion
herein referring expressly to a particular law or laws; provided however, that such references (including without limitation those appearing in paragraphs 14 and 15 above) do not include any municipal or other local laws, rules or
regulations, or any antifraud, environmental, labor, securities or blue sky laws, 40 Act, tax, insurance or antitrust, laws, rules or regulations. 

 

 
 June [●], 2018 
 Page 11

  

 Our opinions expressed herein are subject to the following additional assumptions and
qualifications: 
 (i) The opinions set forth in paragraph 1 above as to the formation of the Partnership Parties and the valid existence and
good standing of the Partnership Entities under the laws of the State of Delaware are based solely upon our review of certificates and other communications from the appropriate public officials of the State of Delaware. 

(ii) The opinions in paragraphs 2, 3, 4, 5, 6 and 7(i) above as to the ownership of the issued and outstanding equity interests in the Persons
referred to in such paragraphs are based solely upon our review of, and we have relied solely on, the Organizational Documents of the Persons identified in such paragraphs. We have assumed that such Organizational Documents of each such Person
accurately reflect the ownership of all the issued and outstanding equity interests of each such Person as of the respective dates of such Organizational Documents, and we express no opinion as to (and assume that there has not been) any resale,
transfer or issuance of any equity interest of any such Person subsequent to the respective dates of such Organizational Documents other than with respect to the opinion in paragraph 4 with respect to which we were advised by Riverwalk Holdings that
the limited partner interest referred to therein were transferred to Riverwalk Holdings. 
 (iii) With respect to the opinions expressed in
paragraphs 2, 3, 4, 5 and 6 above, as to whether the ownership of the interests in the Persons referred to in such paragraphs are free and clear of the liens described in such paragraphs, our opinions are based solely upon our review of, and we have
relied solely on the Search Reports, and we have assumed the completeness and accuracy of the Search Reports and that the methodology utilized in generating the Search Reports was effective to disclose all effective uniform commercial code financing
statements naming NuStar Holdings, NuStar GP, Riverwalk Holdings or the General Partner as debtor. Furthermore, we have assumed that any uniform commercial code financing statement filed in the office of the Secretary of State of the State of
Delaware naming NuStar Holdings, NuStar GP, Riverwalk Holdings or the General Partner as debtor on file in the office of the Secretary of State of the State of Delaware would have been properly filed and indexed in the records of the Secretary of
State of the State of Delaware and appear in the Search Reports. We wish to point out that the Search Reports purport to disclose all effective uniform commercial code financing statements name NuStar Holdings, NuStar GP, Riverwalk Holdings or the
General Partner, as debtor, on file in the Office of the Secretary of State of the State of Delaware only through June 13, 2018, and our opinions referred to in the first sentence of this paragraph (iii) are as of that date only. 

(iv) The opinions in paragraphs 9 and 13 above may be: 

(1) limited by applicable bankruptcy, insolvency, reorganization, moratorium, fraudulent conveyance or transfer or other
similar laws relating to or affecting the rights of creditors generally; 

 

 
 June [●], 2018 
 Page 12

  

 (2) subject to the application of general principles of equity (regardless of
whether considered in a proceeding in equity or at law), including, without limitation, the possible unavailability of specific performance, injunctive relief or any other equitable remedy and concepts of materiality, reasonableness and the effect
of the judicial imposition of an implied covenant of good faith and fair dealing; and 
 (3) subject to the effect of
applicable law relating to fiduciary duties and to limitations on rights to indemnity and contribution arising under applicable law or public policy. 

(v) We express no opinion as to the validity, effect or enforceability of any provisions: 

(1) purporting to establish evidentiary standards or limitations periods for suits or proceedings to enforce such documents or
otherwise, to establish certain determinations (including determinations of contracting parties and judgments of courts) as conclusive or conclusive absent manifest error, to commit the same to the discretion of any Person or permit any Person to
act in its sole judgment or to waive rights to notice; 
 (2) relating to severability or separability; 

(3) providing for an increase in an interest rate or the payment of additional interest upon the occurrence of certain defaults
or the failure to perform certain obligations or imposing liquidated damages or penalties; 
 (4) purporting to limit the
liability of, or to exculpate, any Person, including without limitation any provision that purports to waive liability for violation of securities laws; 

(5) purporting to obligate any party to conform to a standard that may not be objectively determinable or employing items that
are vague or have no commonly accepted meaning in the context in which used; 
 (6) purporting to require that all
amendments, waivers and terminations be in writing or the disregard of any course of dealing or usage of trade; 
 (7)
purporting to require disregard of mandatory choice of law principles that could require application of a law other than the law expressly chosen to govern the instrument in which such provisions appear; 

(8) purporting to bind a Person that is not a party to such document; 

(9) purporting to impose transfer restrictions to the extent that a transfer occurs by operation of law; 

 

 
 June [●], 2018 
 Page 13

  

 (10) pursuant to which the any party agrees to agree in the future on any
matter; 
 (11) to the effect that the failure to exercise or delay in exercising rights or remedies will not impair or
operate as a waiver of such rights or remedies; 
 (12) purporting to obligate a party to cause other Persons to act in a
certain way insofar as such provision relates to the actions of such other Persons; 
 (13) regarding any obligation or
agreement to use best efforts, reasonable best efforts or commercially reasonable efforts or any similar obligation or agreement; 

(14) regarding choice of law; 

(15) regarding the grant of any power of attorney; 

(16) requiring any party to take further action or to enter into further agreements or instruments or to provide further
assurances; 
 (17) requiring the payment of attorneys’ fees where such payment is contrary to law or public policy;

 (18) purporting to waive punitive, special or exemplary damages; 

(19) purporting to provide for the survival of representations and warranties beyond the applicable statute of limitations; or

 (20) regarding forum selection. 

(vi) In rendering the opinion expressed in paragraph 13 above, we express no opinion with respect to Section 12.2 or Section 14.5(b)
of the NuStar L.P. Partnership Agreement. 
 (vii) In rendering the opinion expressed in paragraph 13 above, we note that (i) with
respect to Section 12.5 of the NuStar L.P. Partnership Agreement, under the Delaware LP Act, the existence of the Partnership as a separate legal entity shall continue, and the Partnership will not terminate under the Delaware LP Act, until a
certificate of cancellation of the MLP Certificate is filed with the Secretary of State and becomes effective and (ii) in addition to the events of dissolution listing in Section 12.1 of the NuStar L.P. Partnership Agreement, under the
Delaware LP Act, the Partnership may dissolve at any time there are no limited partners of the Partnership, unless the Partnership is continued in accordance with the Delaware L.P. Act. Additionally, we have assumed that the NuStar L.P. Partnership
Agreement constitutes the entire agreement among the parties thereto with respect to the subject matter thereof, including with respect to the admission of partners to, and the formation, operation and termination of, the Partnership. 

 

 
 June [●], 2018 
 Page 14

  

 (viii) We note that the transfer restrictions contained in the Purchase Agreement, the
Registration Rights Agreement and the Information Rights Agreement may be subject to 9-406 and 9-408 of the Delaware Uniform Commercial Code, 6 Del. C. § 1-101, et seq. 
 (ix) In rendering the opinions set forth in paragraph 14(B) above
regarding Applicable Agreements, we express no opinion as to any breach of or default under any financial covenant, any provision requiring a mathematical, accounting or financial computation or determination or any cross default or cross
acceleration provisions triggered by another instrument or agreement. 
 (x) With respect to each instrument or agreement referred to in or
otherwise relevant to the opinions set forth herein (each, an “Instrument”), we have assumed, to the extent relevant to the opinions set forth herein, that (i) each party to such Instrument (if not a natural person) was duly
organized or formed, as the case may be, and was at all relevant times and is validly existing and in good standing under the laws of its jurisdiction of organization or formation, as the case may be, and had at all relevant times and has full
right, power and authority to execute, deliver and perform its obligations under such Instrument and (ii) such Instrument has been duly authorized, executed and delivered by, and was at all relevant times and is a valid, binding and enforceable
agreement or obligation, as the case may be, of, each party thereto; provided that we make no such assumption insofar as any of the foregoing matters relates to any Partnership Party and is expressly covered by our opinions set forth in paragraphs
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13 above. 
 (xi) In rendering our opinion set forth in paragraph 16 above, we have relied as to
all factual matters exclusively on the certificate, dated as of the date of this letter, of Jorge A. del Alamo, Senior Vice President and Controller of NuStar GP, and have assumed that the certifications and representations as to such factual
matters set forth therein were true and correct as of the dates set forth therein, are true and correct on the date hereof and will remain true and correct at all times through and including the date on which the Partnership shall have expended all
of the proceeds from the sale of the Units. 
 This letter is being furnished only to you in connection with the sale of the Units under the
Purchase Agreement and is solely for your benefit and is not to be used, circulated, quoted or otherwise referred to for any other purpose or relied upon by any other Person, including any Person who acquires any Units from or through you or any
subsequent Person who acquires any Units, without our express written permission. The opinions expressed herein are as of the date hereof only and are based on laws, orders, contract terms and provisions, and facts as of such date, and we disclaim
any obligation to update this opinion letter after such date or to advise you of changes of facts stated or assumed herein or any subsequent changes in law. 

 Exhibit B 

Form of Seventh Amended and Restated Agreement of Limited Partnership 

 Exhibit C 

Form of Registration Rights Agreement 

 Exhibit D 

Form of Information Rights Agreement 

 INFORMATION RIGHTS AGREEMENT 

This INFORMATION RIGHTS AGREEMENT, dated as of June 29, 2018 (this “Agreement”), is entered into by and among
NuStar Energy L.P., a Delaware limited partnership (the “Partnership”), and EIG Management Company, LLC and FS/EIG Advisor, LLC (EIG Management Company, LLC and FS/EIG Advisor, LLC are referred to herein, collectively, as
“EIG”), on its own behalf and on behalf of the Purchasers. Capitalized terms used and not otherwise defined herein shall have the meanings ascribed to such terms in the Series D Cumulative Convertible Preferred Unit Purchase
Agreement, dated as of June 26, 2018 (the “Purchase Agreement”), among the Partnership and the Purchasers. 

WHEREAS, pursuant to, and subject to the terms and conditions of, the Purchase Agreement, the Partnership has agreed to issue and sell
Series D Cumulative Convertible Preferred Units representing limited partner interests in the Partnership (the “Preferred Units”) to the Purchasers; 

WHEREAS, the Partnership has agreed to provide EIG with certain information rights pursuant to the terms of this Agreement; and 

WHEREAS, it is a condition to the respective obligations of the parties to consummate the transactions contemplated by the Purchase
Agreement that each of the parties hereto execute and deliver this Agreement, contemporaneously with the initial closing of the transactions contemplated by the Purchase Agreement. 

NOW THEREFORE, in consideration of the mutual covenants and agreements set forth herein and for good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows: 
 Section 1.
Information Rights. For so long as the Purchasers and Affiliates of the Purchasers collectively hold at least a majority of the Preferred Units issued on the Initial Closing Date, the Partnership shall provide to
EIG, subject to appropriate provisions for withholding or redacting information that the Partnership confirms in writing (email will suffice) to EIG is necessary to maintain privilege or comply with confidentiality obligations to third parties: 

(a) a single copy of the same information packets that are provided to (i) the Board of Directors or any similar governing body
(collectively, the “Board”) responsible for managing the business of the Partnership in connection with each meeting of the Board or (ii) a committee or sub-committee of the Board
(other than the Conflicts Committee, as defined in the Partnership Agreement) in connection with a meeting thereof pertaining to the approval of (x) a material project, merger, acquisition or divestiture not previously presented to the Board
and with respect to which the Partnership would be required to file a Current Report on Form 8-K, (y) the Partnership’s annual budget or (z) the Partnership’s long-range strategic plan
(collectively, the matters in (x), (y) and (z) are referred to herein as “Material Matters”); 
 (b) a single
copy of all special notifications delivered to (i) the Board or (ii) any committee or sub-committee of the Board (other than the Conflicts Committee, as defined in the Partnership Agreement)
pertaining to the approval of a Material Matter; 

  
 1 

 (c) a single copy of the minutes from each meeting of (i) the Board or (ii) any
committee or sub-committee of the Board (other than the Conflicts Committee, as defined in the Partnership Agreement) pertaining to the approval of a Material Matter; 

(d) a notification prior to the Partnership entering into any asset acquisitions, divestitures or contributions with a value in excess of
$10 million, other than to or among subsidiaries of the Partnership; 
 (e) the right to a quarterly conference call between EIG and
NuStar GP’s Chief Executive Officer and additional conference calls between EIG and NuStar GP’s Chief Executive Officer as reasonably requested by EIG; and 

(f) the right to participate in discussions with NuStar GP’s management regarding any corporate conversion or similar transaction by the
Partnership. 
 At any time EIG may deliver written notice (an “Opt-Out Notice”) to the
Partnership requesting that EIG no longer receive any information or materials from the Partnership pursuant to this Section 1; provided, however, that, for so long as the Purchasers and Affiliates of the Purchasers
collectively hold at least a majority of the Preferred Units issued on the Initial Closing Date, EIG may later revoke any such Opt-Out Notice in writing. For the avoidance of doubt, nothing in this Agreement
shall provide EIG with the right to attend meetings of the Board, any committee or sub-committee thereof or management. 

Section 2. Confidentiality. 

(a) “Confidential Information” means any and all of the information and materials provided by the Partnership to EIG
and its Representatives (as defined below) pursuant to this Agreement. Such Confidential Information shall consist of any and all tangible and intangible information, whether oral or in writing or in any other medium (including, but not limited to,
computer data), provided by the Partnership or its Representatives to EIG or EIG’s Representatives. The term “Confidential Information” shall not apply to information and data which (i) at the time of disclosure, is generally
available to the public, (ii) after disclosure by the Partnership, becomes published or generally available to the public, other than through any act or omission on the part of EIG or its Representatives in violation of this Agreement,
(iii) was or is developed by EIG or its Representatives without the use of Confidential Information, (iv) was or is acquired by EIG or its Representatives from a source other than the Partnership or its Representatives, provided such
source is not, to EIG’s or such Representative’s knowledge, bound by a confidentiality agreement with the Partnership or its Representatives or otherwise prohibited from transmitting the information to EIG or such Representative by a
contractual obligation, with respect to such information, or (v) is approved for public disclosure by the Partnership or its Representatives. For the purposes of this Agreement “Representatives” shall mean (i) with
respect to the Partnership, the directors, officers, employees, agents, accountants, attorneys, advisors and consultants of the Partnership, its General Partner or its Subsidiaries and (ii) with respect to EIG, the directors, officers and
employees of EIG who have a need to know the Confidential Information in connection with the investment by the Purchasers in the Preferred Units pursuant to the Purchase Agreement or the ownership or disposition of the Preferred Units by the
Purchasers pursuant to the Partnership Agreement. 

  
 2 

 (b) Except to the extent permitted by this Section 2, EIG and its
Representatives shall keep the Confidential Information confidential. EIG may describe Confidential Information to a Purchaser, any of EIG’s Affiliates, any of their respective partners, members, unitholders or investors, and any Permitted
Transferee, if such recipient is subject to a confidentiality agreement with respect to the Confidential Information that is no less restrictive than the terms and conditions of this Agreement. EIG agrees to be responsible for the breach of this
Agreement by any of its Representatives, any Purchaser, any of EIG’s Affiliates, any of their respective partners, members, unitholders or investors, and any Permitted Transferee, except that EIG shall not be liable for breaches by any of its
Representatives, any Purchaser, any of EIG’s Affiliates, any of their respective partners, members, unitholders or investors, and any Permitted Transferee that executes a confidentiality agreement with the Partnership. Notwithstanding anything
to the contrary contained in this Agreement and for the avoidance of doubt, EIG and its Representatives may not share any materials received pursuant to this Agreement or copies thereof. 

(c) EIG hereby acknowledges that it is aware, and that it will advise its Representatives, any Purchaser, any of EIG’s Affiliates, any of
their respective partners, members, unitholders or investors, and any Permitted Transferee who are informed of Confidential Information which is the subject of this Agreement, that the United States securities laws prohibit any person who has
received material, non-public information concerning an issuer from purchasing or selling securities of such issuer or from communicating such information to any other person under the circumstances in which
it is reasonably foreseeable that such person is likely to purchase or sell such securities, and EIG has sufficient policies and procedures in place to abide by the applicable securities laws. 

(d) With regard to Confidential Information, except as otherwise permitted herein, EIG agrees: 

(i) not to use the Confidential Information for any other purpose other than in connection with the investment in the Preferred Units by the
Purchasers pursuant to the Purchase Agreement or the ownership or disposition of the Preferred Units by the Purchasers pursuant to the Partnership Agreement; 

(ii) at any time after the Purchasers and Affiliates of the Purchasers collectively hold less than a majority of the Preferred Units issued on
the Initial Closing Date, promptly after written notice is provided by the Partnership to EIG, except to the extent that complying with such request would be prohibited by law, regulation, litigation, or EIG’s internal document retention
compliance policies, to either return the Confidential Information to the Partnership or to confirm in writing (email will suffice) that the Confidential Information has been destroyed; provided however that EIG may retain Confidential
Information stored in standard archival or computer back-up systems or pursuant to professional accounting obligations, and such information shall remain subject to the confidentiality obligations provided
herein; 
 (iii) to maintain the Confidential Information as confidential by the use of commercially reasonable internal procedures; and

  
 3 

 (iv) to ensure its Representatives to which the Confidential Information may be described are
informed of the confidential nature of the Confidential Information. 
 (e) Notwithstanding anything to the contrary contained herein, for
the purposes of this Agreement, no provision of this Agreement shall be applicable to the direct or indirect portfolio companies of investment funds, accounts or companies advised or managed by EIG or its Affiliates (each, an “Excluded
Entity”), except to the extent, if any, that an Excluded Entity has actually received Confidential Information from or through EIG or its Representatives. Furthermore, the Partnership acknowledges that EIG and its Affiliates’
employees serve as directors and observers of portfolio companies and such portfolio companies will not be deemed to have received Confidential Information solely due to the dual role of any such employees so long as such employee does not provide
any Confidential Information to such portfolio companies. 
 (f) EIG and its Representatives shall be permitted to disclose the Confidential
Information in order to comply with any request or requirement by applicable law, statute, regulation, rule, or any court, governmental, regulatory or administrative agency or authority, or nationally or internationally recognized stock exchange or
other self-regulatory organization; provided, however, that in the event that EIG is required to disclose any part or all of the Confidential Information, EIG shall, to the extent practicable and permitted by law, promptly notify the
Partnership, and EIG will use commercially reasonable efforts to cooperate with the Partnership, at the Partnership’s sole cost, to obtain a protective order or other appropriate remedy to maintain the confidential nature of the Confidential
Information; provided further, that if EIG or such Representative discloses any part of the Confidential Information in compliance with this Section 2(f), EIG or such Representative shall disclose only that portion
of the Confidential Information which it is legally required to disclose (upon the advice of counsel, which may be in-house counsel). Notwithstanding anything to the contrary herein, if EIG or its
Representatives become subject to a routine audit, examination or broad request for information by a governmental, judicial, regulatory or administrative authority or self-regulatory organization that is not specific to the Confidential Information
provided hereunder, they shall be permitted to disclose any and all information (including Confidential Information) EIG deems to be responsive to such request without any notice requirement nor liability hereunder. Notwithstanding anything to the
contrary herein, EIG and its Representatives may disclose and retain Confidential Information to the extent such disclosure or retention is necessary to establish EIG’s rights under this Agreement, EIG’s or its Representatives’
compliance with the terms of this Agreement, or in connection with any dispute arising under this Agreement or in connection with the investment in the Preferred Units by the Purchasers pursuant to the Purchase Agreement or the ownership or
disposition of the Preferred Units by the Purchasers pursuant to the Partnership Agreement. 
 (g) EIG’s and its Representatives’
obligations under this Section 2 shall continue for as long as the Confidential Information remains Confidential Information; provided, that any Confidential Information shall cease to be Confidential Information no
later than two (2) years following such time that the Purchasers and Affiliates of the Purchasers collectively hold less than a majority of the Preferred Units issued on the Initial Closing Date. 

  
 4 

 Section 3. Miscellaneous. 

(a) Communications. All notices and other communications provided for in this Agreement shall be in writing and shall be given as
provided in the Purchase Agreement. 
 (b) Entire Agreement. This Agreement is intended by the parties as a final expression of their
agreement and intended to be a complete and exclusive statement of the agreement and understanding of the parties hereto in respect of the subject matter contained herein. There are no restrictions, promises, warranties or undertakings, other than
those set forth or referred to herein with respect to the rights granted by the parties hereto or any of their respective Affiliates set forth herein. This Agreement supersedes all prior agreements and understandings between the parties with respect
to subject matter hereof. 
 (c) Interpretation. Section references in this Agreement are references to the corresponding Section to
this Agreement, unless otherwise specified. All references to instruments, documents, contracts and agreements are references to such instruments, documents, contracts and agreements as the same may be amended, supplemented and otherwise modified
from time to time, unless otherwise specified. The words “include,” “includes” and “including” or words of similar import shall be deemed to be followed by the words “without limitation.” Whenever any
determination, consent or approval is to be made or given by a party under this Agreement, such action shall be in such party’s sole discretion unless otherwise specified. If any provision in this Agreement is held to be illegal, invalid, not
binding or unenforceable, (i) such provision shall be fully severable and this Agreement shall be construed and enforced as if such illegal, invalid, not binding or unenforceable provision had never comprised a part of this Agreement, and the
remaining provisions shall remain in full force and effect, and (ii) the parties hereto shall negotiate in good faith to modify this Agreement so as to effect the original intent of the parties as closely as possible in an acceptable manner in
order that the transactions contemplated hereby are consummated as originally contemplated to the greatest extent possible. When calculating the period of time before which, within which or following which any act is to be done or step taken
pursuant to this Agreement, the date that is the reference date in calculating such period shall be excluded. If the last day of such period is not a Business Day, the period in question shall end on the next succeeding Business Day. Any words
imparting the singular number only shall include the plural and vice versa. The words such as “herein,” “hereinafter,” “hereof” and “hereunder” refer to this Agreement as a whole and not merely to a
subdivision in which such words appear unless the context otherwise requires. The division of this Agreement into Sections and other subdivisions and the insertion of headings are for convenience of reference only and shall not affect or be utilized
in construing or interpreting this Agreement. 
 (d) Governing Law; Submission to Jurisdiction. This Agreement, and all claims or
causes of action (whether in contract or tort) that may be based upon, arise out of or relate to this Agreement or the negotiation, execution or performance of this Agreement (including any claim or cause of action based upon, arising out of or
related to any representation or warranty made in or in connection with this Agreement), will be construed in accordance with and governed by the Laws of the State of Delaware without regard to principles of conflicts of laws. Any action against any
party relating to the foregoing shall be brought in any federal or state court of competent jurisdiction located within the State of Delaware, and the parties hereto hereby irrevocably submit to the
non-exclusive jurisdiction of any federal or state court located within the State of Delaware over any such action. The parties hereby irrevocably waive, to the fullest

  
 5 

 
extent permitted by applicable Law, any objection which they may now or hereafter have to the laying of venue of any such dispute brought in such court or any defense of inconvenient forum for
the maintenance of such dispute. Each of the parties hereto agrees that a judgment in any such dispute may be enforced in other jurisdictions by suit on the judgment or in any other manner provided by Law. 

(e) Waiver of Jury Trial. THE PARTIES TO THIS AGREEMENT EACH HEREBY WAIVES, AND AGREES TO CAUSE ITS AFFILIATES TO WAIVE, TO THE FULLEST
EXTENT PERMITTED BY LAW, ANY RIGHT TO TRIAL BY JURY OF ANY CLAIM, DEMAND, ACTION OR CAUSE OF ACTION (i) ARISING UNDER THIS AGREEMENT OR (ii) IN ANY WAY CONNECTED WITH OR RELATED OR INCIDENTAL TO THE DEALINGS OF THE PARTIES HERETO IN
RESPECT OF THIS AGREEMENT OR ANY OF THE TRANSACTIONS RELATED HERETO, IN EACH CASE WHETHER NOW EXISTING OR HEREAFTER ARISING, AND WHETHER IN CONTRACT, TORT, EQUITY OR OTHERWISE. THE PARTIES TO THIS AGREEMENT EACH HEREBY AGREES AND CONSENTS THAT ANY
SUCH CLAIM, DEMAND, ACTION OR CAUSE OF ACTION SHALL BE DECIDED BY COURT TRIAL WITHOUT A JURY AND THAT THE PARTIES TO THIS AGREEMENT MAY FILE AN ORIGINAL COUNTERPART OF A COPY OF THIS AGREEMENT WITH ANY COURT AS WRITTEN EVIDENCE OF THE CONSENT OF THE
PARTIES HERETO TO THE WAIVER OF THEIR RIGHT TO TRIAL BY JURY. 
 (f) No Waiver; Modifications in Writing. 

(i) Delay. No failure or delay on the part of any party in exercising any right, power or remedy hereunder shall operate as a waiver
thereof, nor shall any single or partial exercise of any such right, power or remedy preclude any other or further exercise thereof or the exercise of any other right, power or remedy. The remedies provided for herein are cumulative and are not
exclusive of any remedies that may be available to a party at law or in equity or otherwise. 
 (ii) Specific Waiver. Except as
otherwise provided herein, no amendment, waiver, consent, modification or termination of any provision of this Agreement shall be effective unless signed by each of the parties hereto affected by such amendment, waiver, consent, modification or
termination. Any amendment, supplement or modification of or to any provision of this Agreement, any waiver of any provision of this Agreement and any consent to any departure by a party from the terms of any provision of this Agreement shall be
effective only in the specific instance and for the specific purpose for which made or given. Except where notice is specifically required by this Agreement, no notice to or demand on a party in any case shall entitle such party to any other or
further notice or demand in similar or other circumstances. Any investigation by or on behalf of any party shall not be deemed to constitute a waiver by the party taking such action of compliance with any representation, warranty, covenant or
agreement contained herein. 
 (g) Binding Effect. This Agreement shall be binding upon the parties hereto and their respective
successors and permitted assigns. Except as expressly provided in this Agreement, this Agreement shall not be construed so as to confer any right or benefit upon any Person other than the parties to this Agreement and their respective successors and
permitted assigns. 

  
 6 

 (h) Specific Performance. Damages in the event of breach of this Agreement by a party
hereto may be difficult, if not impossible, to ascertain, and it is therefore agreed that each such Person, in addition to and without limiting any other remedy or right it may have, shall have the right to seek an injunction or other equitable
relief in any court of competent jurisdiction, enjoining any such breach, and enforcing specifically the terms and provisions hereof, and each of the parties hereto hereby waives any and all defenses it may have on the ground of lack of jurisdiction
or competence of the court to grant such an injunction or other equitable relief. The existence of this right shall not preclude any such Person from pursuing any other rights and remedies at law or in equity that such Person may have. 

(i) Investment Opportunities. The Partnership acknowledges that, in the ordinary course of business, EIG is engaged through separate
platforms in the origination of loans (including the provision of debt financing for transactions similar to the investment in the Preferred Units pursuant to the Purchase Agreement) and purchase and sale of securities and syndicated bank debt and
that nothing in this Agreement shall restrict such activities of such other platforms, provided that none of the Confidential Information is used in connection therewith. The Partnership further acknowledges that EIG or it Representatives may, in
the ordinary course of its or their business, evaluate investments in the energy industry and is or are actively seeking to invest in energy related projects in a variety of areas. The Partnership understands that EIG and its Representatives will
retain certain mental impressions of the Confidential Information which are indistinguishable from generalized industry knowledge. Accordingly, the Partnership agrees that, subject to the terms of this Agreement, EIG and its Representatives are not
precluded from pursuing such investments solely because of such retained mental impressions. 
 (j) Business Development Company.
Notwithstanding anything to the contrary contained herein, and for the avoidance of doubt, nothing in this Agreement shall prohibit the purchase or sale of debt securities issued by, or loans made to, the Partnership by any closed-end management investment company that (i) has elected to be regulated as a business development company under the Investment Company Act of 1940, as amended, and (ii) is advised by EIG or its
Affiliates. 
 (k) No Third-Party Beneficiaries. Nothing in this Agreement, express or implied, is intended or shall confer upon any
Person, other than the Partnership or EIG, any right, benefit or remedy of any nature whatsoever under or by reason of this Agreement. 

(l) Execution in Counterparts. This Agreement may be executed in any number of counterparts and by different parties hereto in separate
counterparts, each of which counterparts, when so executed and delivered, shall be deemed to be an original and all of which counterparts, taken together, shall constitute but one and the same agreement. 

[Signature pages follow] 

  
 7 

 IN WITNESS WHEREOF, the parties hereto execute this Agreement, effective as of the date first above written. 

 

			
	NUSTAR ENERGY L.P.
		
	By:	 	RIVERWALK LOGISTICS, L.P.,
		 	its General Partner
		
	By:	 	NUSTAR GP, LLC, its General Partner

  

			
	By:	 	 
	Name:	 	
	Title:	 	

 Signature Page to Information Rights Agreement 

 
			
	 EIG MANAGEMENT COMPANY, LLC

FS/EIG ADVISOR, LLC,
 on their own behalf and on behalf of
the Purchasers

	  
 EIG Management Company,
LLC

 
			
		
	By:	 	 
	Name:	 	
	Title:	 	

 
			
		
	By:	 	 
	Name:	 	
	Title:	 	

  

			
	FS/EIG Advisor, LLC
		
	By:	 	 
	Name:	 	
	Title:	 	
		
	By:	 	 
	Name:	 	
	Title:	 	

 Signature Page to Information Rights Agreement 

 Exhibit E 

Form of Non-Solicitation Side Letter 

 June 29, 2018 

EIG Nova Equity Aggregator, L.P. 
 c/o EIG Management Company,
LLC 
 333 Clay Street, Suite 3500 
 Houston, Texas 77002 

Attn: Matthew Hartman 
 With copy to: 

EIG Nova Equity Aggregator, L.P. 
 c/o EIG Management Company,
LLC 
 333 Clay Street, Suite 3500 
 Houston, Texas 77002 

Attn: Austin Pearson 
 and 

FS Energy and Power Fund 
 c/o EIG Management Company, LLC 

1700 Pennsylvania Avenue NW, Suite 
 800 Washington, DC 20006

 Attn: Eric Long 
 with copy to: 

FS Energy and Power Fund 
 c/o EIG Management Company, LLC 

1700 Pennsylvania Avenue NW, Suite 800 
 Washington, DC 20006

 Attn: Andrew P. Jamison 
  

	 	Re:	NuStar Energy L.P. Series D Cumulative Convertible Preferred Units 

 Reference is made
to that certain Series D Cumulative Convertible Preferred Unit Purchase Agreement, dated June 26, 2018 (the “Purchase Agreement”), among NuStar Energy L.P., a Delaware limited partnership (the “Partnership”)
and the Purchasers. Capitalized terms used and not otherwise defined herein shall have the meanings ascribed to such terms in the Purchase Agreement. 

This letter agreement (this “Letter Agreement”) is made by and among the Partnership, the Purchasers and EIG Management
Company, LLC and FS/EIG Advisor, LLC (EIG Management Company, LLC and FS/EIG Advisor, LLC are referred to herein, collectively, as “EIG”), on its own behalf and on behalf of the Purchasers. 

 The Partnership, EIG and each of the Purchasers, severally and not jointly, agree to the
following: 
 1. Non-Solicitation. 

(a) Without the consent of the board of directors of NuStar GP, LLC (the “Partnership Board”) or the board of directors of
NSH (the “NSH Board”) or their respective successor governing bodies, as applicable, or as otherwise recommended by the Partnership Board or the NSH Board or their respective successor governing bodies, as applicable, from and after
the Initial Closing Date until the date on which EIG, the Purchasers and their respective Affiliates (as defined below) (1) do not beneficially own any Series D Preferred Units and (2) beneficially own less than 5% of the Common Units, EIG
and the Purchasers shall not, and shall cause their respective Affiliates not to, directly or indirectly, knowingly or willingly make or in any way participate in any “solicitation” of “proxies” (as such terms are used in Rule
14a-1 of Regulation 14A under the Exchange Act) or written consents to vote, seek to influence, or advise any third party with respect to the voting of any voting securities of the Partnership or NSH in respect of any Proposal. 

“Affiliate” means, with respect to any Person, any other Person that directly or indirectly through one or more intermediaries
Controls, is Controlled by or is under common Control with, the Person in question. 
 “Control” and its derivatives shall mean,
with respect to any Person, the possession, directly or indirectly, through one or more intermediaries, by any Person or group of the power or authority, through ownership of voting securities, by contract or otherwise, to appoint a majority of the
board of directors or similar governing body of such Person. 
 “Proposal” means any proposal or offer from or by a third party
relating to: (i) any direct or indirect acquisition or purchase of all or substantially all of the assets of the Partnership or NSH (in each case, inclusive of their respective subsidiaries); (ii) any direct or indirect acquisition or
purchase (by merger, consolidation or otherwise) of a majority of the voting securities of the Partnership or NSH; (iii) the removal (or approving the removal) of the General Partner as the general partner of the Partnership and/or the election
of a successor general partner of the Partnership; or (iv) the removal of any member of the Partnership Board or the NSH Board or their respective successor governing bodies and/or seeking the election of any person as a director not having
been nominated by the Partnership Board or the NSH Board or their respective successor governing bodies other than in respect of the rights provided to a Series D Preferred Unit holder in connection with a Series D Preferred Unit distribution
default in accordance with the Partnership Agreement. 
 (b) Notwithstanding anything to the contrary contained herein, and for the
avoidance of doubt, nothing in this Agreement shall: 
 (i) prohibit EIG, the Purchasers or their respective Affiliates from
privately communicating with, including making any offer or proposal to, the Partnership Board or the NSH Board; 

 (ii) restrict EIG, the Purchasers or their respective Affiliates from selling or
transferring any of their Partnership Securities (as defined in the Partnership Agreement) subject to any restrictions relating thereto contained in the Partnership Agreement; 

(iii) restrict in any manner how a Purchaser votes its Series D Preferred Units or Common Units subject to any restrictions
relating thereto contained in the Partnership Agreement; 
 (iv) prohibit the purchase or sale of debt securities issued by,
or loans made to, the Partnership, NSH or their respective subsidiaries or Affiliates by any closed-end management investment company that (A) has elected to be regulated as a business development company under the Investment Company Act of
1940, as amended, and (B) is advised by EIG or its Affiliates; or 
 (v) apply to any direct or indirect portfolio
companies of investment funds, accounts or companies advised or managed by EIG or its Affiliates unless such portfolio company (A) otherwise satisfies the definition of “Affiliates” hereunder or (B) is a Purchaser or a Permitted
Transferee of Series D Preferred Units. 
 2. Third Party Proposal. In the event that EIG, any of the Purchasers or any of their
respective Affiliates receives a Proposal from a third party, the recipient of such Proposal shall promptly provide notice thereof to the Partnership and shall not cooperate with such third party. 

3. Communications. Except as provided pursuant to Section 1(b)(i) above, all notices and other communications provided for
in this Agreement shall be in writing and shall be given as provided in the Purchase Agreement. 
 4. Amendment and Waiver. No
amendment, modification, termination or cancellation of this Letter Agreement shall be effective unless it is in writing signed by the Partnership, EIG and the Purchasers. No waiver of any of the provisions of this Letter Agreement shall be deemed
or shall constitute a waiver of any other provision hereof (whether or not similar) and any waiver or any consent to any departure from the terms of any provision of this Letter Agreement shall be effective only in the specific instance and for the
specific purpose for which made or given and shall not constitute a continuing waiver or consent. 
 5. Entire Agreement. This Letter
Agreement is intended by the parties as a final expression of their agreement and intended to be a complete and exclusive statement of the agreement and understanding of the parties hereto in respect of the subject matter contained herein. There are
no restrictions, promises, warranties or undertakings, other than those set forth or referred to herein with respect to the subject matter hereof. This Letter Agreement supersedes all prior agreements and understandings between the parties with
respect to subject matter hereof. 
 6. Specific Performance. Damages in the event of breach of this Letter Agreement by a party
hereto may be difficult, if not impossible, to ascertain, and it is therefore agreed that each such Person, in addition to and without limiting any other remedy or right it may have, shall have the right to seek an injunction or other equitable
relief in any court of competent 

 
jurisdiction, enjoining any such breach, and enforcing specifically the terms and provisions hereof, and each of the parties hereto hereby waives any and all defenses it may have on the ground of
lack of jurisdiction or competence of the court to grant such an injunction or other equitable relief. The existence of this right shall not preclude any such Person from pursuing any other rights and remedies at law or in equity that such Person
may have. 
 7. Governing Law; Submission to Jurisdiction. This Letter Agreement, and all claims or causes of action (whether in
contract or tort) that may be based upon, arise out of or relate to this Letter Agreement or the negotiation, execution or performance of this Letter Agreement (including any claim or cause of action based upon, arising out of or related to any
representation or warranty made in or in connection with this Letter Agreement), will be construed in accordance with and governed by the Laws of the State of Delaware without regard to principles of conflicts of laws. Any action against any party
relating to the foregoing shall be brought in any federal or state court of competent jurisdiction located within the State of Delaware, and the parties hereto hereby irrevocably submit to the non-exclusive jurisdiction of any federal or state court
located within the State of Delaware over any such action. The parties hereby irrevocably waive, to the fullest extent permitted by applicable Law, any objection which they may now or hereafter have to the laying of venue of any such dispute brought
in such court or any defense of inconvenient forum for the maintenance of such dispute. Each of the parties hereto agrees that a judgment in any such dispute may be enforced in other jurisdictions by suit on the judgment or in any other manner
provided by Law. 
 8. Waiver of Jury Trial. THE PARTIES TO THIS LETTER AGREEMENT EACH HEREBY WAIVES, AND AGREES TO CAUSE ITS
AFFILIATES TO WAIVE, TO THE FULLEST EXTENT PERMITTED BY LAW, ANY RIGHT TO TRIAL BY JURY OF ANY CLAIM, DEMAND, ACTION OR CAUSE OF ACTION (i) ARISING UNDER THIS AGREEMENT OR (ii) IN ANY WAY CONNECTED WITH OR RELATED OR INCIDENTAL TO THE
DEALINGS OF THE PARTIES HERETO IN RESPECT OF THIS LETTER AGREEMENT OR ANY OF THE TRANSACTIONS RELATED HERETO, IN EACH CASE WHETHER NOW EXISTING OR HEREAFTER ARISING, AND WHETHER IN CONTRACT, TORT, EQUITY OR OTHERWISE. THE PARTIES TO THIS LETTER
AGREEMENT EACH HEREBY AGREES AND CONSENTS THAT ANY SUCH CLAIM, DEMAND, ACTION OR CAUSE OF ACTION SHALL BE DECIDED BY COURT TRIAL WITHOUT A JURY AND THAT THE PARTIES TO THIS LETTER AGREEMENT MAY FILE AN ORIGINAL COUNTERPART OF A COPY OF THIS LETTER
AGREEMENT WITH ANY COURT AS WRITTEN EVIDENCE OF THE CONSENT OF THE PARTIES HERETO TO THE WAIVER OF THEIR RIGHT TO TRIAL BY JURY. 
 9.
Assignment. This Letter Agreement may not be transferred or assigned (whether by operation of law or otherwise) by the parties without the prior written consent of the other parties and shall not be binding on any third party transferees of
the Purchasers other than Permitted Transferees; provided, however, that, as a condition to acquiring Series D Preferred Units as a Permitted Transferee, each such Permitted Transferee must agree in a writing in the form set forth on
Annex A hereto to be bound by the provisions of this Letter Agreement. 

 10. Severability. In case any one or more of the provisions contained in this Letter
Agreement is for any reason held to be invalid, illegal or unenforceable in any respect, such invalidity, illegality or unenforceability shall not affect any other provision of this Letter Agreement, and such invalid, illegal or unenforceable
provision shall be reformed and construed so that it will be valid, legal and enforceable to the maximum extent permitted by law. 
 11.
Counterparts. This Letter Agreement may be executed in any number of counterparts and by different parties hereto in separate counterparts, including facsimile or .pdf counterparts, each of which counterparts, when so executed and delivered,
shall be deemed to be an original and all of which counterparts, taken together, shall constitute but one and the same Letter Agreement. 

[Signature page follows] 

 If the foregoing correctly sets forth our understanding of the subject matter hereof, please so
indicate by executing this Letter Agreement in the space provided below. 
  

			
	Very truly yours,
	
	NUSTAR ENERGY L.P.
		
	By:	 	Riverwalk Logistics, L.P., its general partner
		
	By:	 	NuStar GP, LLC, its general partner
		
	By:	 	 
	Name:	 	
	Title:	 	

  

					
	Acknowledged and agreed, as of the date first written above:	 	
		
	 EIG MANAGEMENT COMPANY, LLC
 FS/EIG
ADVISOR, LLC,
 on their own behalf and on behalf of the Purchasers
	 	  

		
	EIG Management Company, LLC	 	

					
			
	By:	 	 	 	 
	Name:	 		 	
	Title:	 		 	

							
			
	By:	 	 	 	 	 	 
	Name:	 		 			
	Title:	 		 			
		
	FS/EIG Advisor, LLC	 			

					
			
	By:	 	 	 	 
	Name:	 		 	
	Title:	 		 	

					
			
	By:	 	 	 	 
	Name:	 		 	
	Title:	 		 	

  
 Signature Page to
Letter Agreement 

			
	EIG NOVA EQUITY AGGREGATOR, L.P.
		
	By:	 	EIG Nova Equity GP, LLC,
	its general partner
		
	By:	 	EIG Asset Management, LLC,
	its managing member
		
	By:	 	 
	Name:	 	
	Title:	 	
		
	By:	 	 
	Name:	 	
	Title:	 	
	
	FS ENERGY AND POWER FUND
		
	By:	 	FS/EIG Advisor, LLC
	its Investment Advisor
		
	By:	 	 
	Name:	 	
	Title:	 	

  
 Signature Page to
Letter Agreement 

 Annex A 

Form of Joinder 
 [Date] 

NuStar Energy L.P. 
 19003 IH-10 West 

San Antonio, Texas 78257 
 Ladies and Gentlemen: 

Reference is made to the Letter Agreement, dated as of the          day of
            , 2018 (the “Letter Agreement”) between the Partnership, EIG and the Purchasers. Capitalized terms used but not defined herein shall have the meaning
assigned to such terms in the Letter Agreement. 
 The undersigned, a Permitted Transferee, acknowledges that it: (i) has been given a copy of the
Letter Agreement and (ii) has reviewed all provisions of the Letter Agreement. Accordingly, the undersigned, as a condition to being a Permitted Transferee, agrees to be bound by the provisions of the Letter Agreement as a Purchaser, and to
cause its Affiliates to comply with the provisions of the Letter Agreement, until such time as the undersigned and its Affiliates (1) do not beneficially own any Series D Preferred Units and (2) beneficially own less than 5% of the Common
Units, and all provisions of such Letter Agreement are expressly applicable to Affiliates of the undersigned. 
  

			
	Very truly yours,
	
	Permitted Transferee
		
	By:	 	 
	Name:	 	
	Title:	 	

 Exhibit F 

Form of NuStar GP, LLC Waiver 

June 29, 2018 
 Reference is
hereby made to that certain Series D Cumulative Convertible Preferred Unit Purchase Agreement, dated as of June 26, 2018, by and among NuStar Energy L.P. (the “Partnership”) and each of the Purchasers set forth in Schedule A thereto
(the “Purchase Agreement”), pursuant to which the Partnership has agreed to issue and sell an aggregate of 23,660,386 Series D Preferred Units representing limited partner interests in the Partnership for a cash purchase price of
$590 million. Capitalized terms used but not defined herein shall have the meaning given such terms in the Purchase Agreement. NuStar GP, in its own capacity and in its capacity as the general partner of the General Partner, in its capacity as
the general partner of the Partnership, hereby waives any preemptive rights it may hold pursuant to Section 5.7 of the Partnership Agreement, with respect to the offering, issuance and sale of Series D Preferred Units pursuant to the Purchase
Agreement. 
 IN WITNESS WHEREOF, the undersigned executes this General Partner Waiver, effective as of the date first written above. 

 

			
	NUSTAR GP, LLC
		
	By:	 	 
	Name:	 	
	Title:	 	

 Schedule A 

 

									
	 Purchaser and Address
	  	Series D Preferred
Initial Closing
Units	 	  	Series D
Preferred
Second Closing
Units	 
	 EIG Nova Equity Aggregator, L.P.

c/o EIG Management Company, LLC

333 Clay Street, Suite 3500

Houston, Texas 77002

Attn: Matthew Hartman
	  				  			
	 With a copy to (which shall not constitute notice):
	  	 	11,753,549	 	  	 	5,582,936	 
	 EIG Nova Equity Aggregator, L.P.

c/o EIG Management Company, LLC

333 Clay Street, Suite 3500

Houston, Texas 77002

Attn: Austin Pearson
	  				  			
	 FS Energy and Power Fund

c/o EIG Management Company, LLC

1700 Pennsylvania Avenue NW, Suite 800

Washington, DC 20006

Attn: Eric Long
	  				  			
	 with a copy to (which shall not constitute notice):
	  	 	4,006,892	 	  	 	1,903,273	 
	 FS Energy and Power Fund

c/o EIG Management Company, LLC

1700 Pennsylvania Avenue NW, Suite 800

Washington, DC 20006

Attn: Andrew P. Jamison
	  				  			
		  	  
	  
	 	  	  
	  
	 
	 TOTAL
	  	 	15,760,441	 	  	 	7,486,209	 
		  	  
	  
	 	  	  
	  
	 

 Schedule A-1 

 Schedule B 

Material Subsidiaries 
 NuStar Logistics,
L.P. 
 NuStar Permian Transportation and Storage, LLC 
 NuStar
Pipeline Operating Partnership L.P. 
 NuStar Terminals N.V. 

Shore Terminals LLC 
 St. Linden Terminal, LLC 

Schedule B-1 

 Schedule C 

Permitted Transferees 
 For purposes of
this Purchase Agreement, Permitted Transferees means: (i) Atlantic Trust Company, N.A., (ii) Abu Dhabi Investment Authority, (iii) Anchorage Capital Partners (iv) Goldman Sachs & Co., LLC, (v) Highbridge Capital
Management, LLC, (vi) Magnetar Capital LLC, (vii) Mubadala Investment Company, (viii) TPG Capital, or (ix) an investment fund, investment account or investment company, that is managed, advised or
sub-advised by any of the entities listed in (i) through (viii) above. 
 Schedule C-1 

 Schedule D 

Transaction Fees 
  

					
	 EIG Management Company, LLC
	  	$	15,400,000.00	 
	 FS Energy and Power Fund
	  	$	5,250,000.00	 
		  	  
	  
	 
	 Total Transaction Fees
	  	$	20,650,000.00	 
		  	  
	  
	 

 Reimbursable Expenses 
  

					
	 EIG Management Company, LLC
	  	$	725,000.00	 
		  	  
	  
	 
	 Total Reimbursable Expenses
	  	$	725,000.00	 
		  	  
	  
	 

 Schedule D-1EX-10.2

 Exhibit 10.2 

PURCHASE AGREEMENT 
 among

 NUSTAR ENERGY L.P. 
 and

 WILLIAM E. GREEHEY 

June 26, 2018 

 TABLE OF CONTENTS 

 

							
	 	  	 	  	Page	 
		
	 ARTICLE I DEFINITIONS
	  	 	1	 
			
	 Section 1.01
	  	Definitions	  	 	1	 
	 Section 1.02
	  	Accounting Procedures and Interpretation	  	 	5	 
		
	 ARTICLE II AGREEMENT TO SELL AND PURCHASE
	  	 	5	 
			
	 Section 2.01
	  	Sale and Purchase	  	 	5	 
	 Section 2.02
	  	Closing	  	 	5	 
	 Section 2.03
	  	Mutual Conditions at the Closing	  	 	5	 
	 Section 2.04
	  	Conditions to the Purchaser’s Obligations at the Closing	  	 	5	 
	 Section 2.05
	  	Conditions to the Partnership’s Obligations at the Closing	  	 	6	 
	 Section 2.06
	  	Deliveries at the Closing	  	 	6	 
	 Section 2.07
	  	Further Assurances	  	 	7	 
		
	 ARTICLE III REPRESENTATIONS AND WARRANTIES AND COVENANTS RELATED TO THE
PARTNERSHIP
	  	 	7	 
			
	 Section 3.01
	  	Existence	  	 	7	 
	 Section 3.02
	  	Capitalization and Valid Issuance of Units	  	 	8	 
	 Section 3.03
	  	No Material Adverse Change	  	 	8	 
	 Section 3.04
	  	No Registration Required	  	 	8	 
	 Section 3.05
	  	No Default	  	 	9	 
	 Section 3.06
	  	No Conflicts	  	 	9	 
	 Section 3.07
	  	Authority; Enforceability	  	 	9	 
	 Section 3.08
	  	Listing and Maintenance Requirements	  	 	9	 
		
	 ARTICLE IV REPRESENTATIONS AND WARRANTIES AND COVENANTS OF THE PURCHASER
	  	 	10	 
			
	 Section 4.01
	  	Capacity; Validity of Agreement	  	 	10	 
	 Section 4.02
	  	No Breach	  	 	10	 
	 Section 4.03
	  	Unregistered Securities	  	 	10	 
	 Section 4.04
	  	Sufficient Funds	  	 	11	 
		
	 ARTICLE V COVENANTS
	  	 	11	 
			
	 Section 5.01
	  	Conduct of Business	  	 	11	 
	 Section 5.02
	  	Listing of Units	  	 	12	 
	 Section 5.03
	  	Use of Proceeds	  	 	12	 
		
	 ARTICLE VI INDEMNIFICATION, COSTS AND EXPENSES
	  	 	12	 
			
	 Section 6.01
	  	Indemnification by the Partnership	  	 	12	 
	 Section 6.02
	  	Indemnification by the Purchaser	  	 	12	 
	 Section 6.03
	  	Indemnification Procedure	  	 	13	 
	 Section 6.04
	  	Tax Matters	  	 	14	 

  
 i 

							
	 ARTICLE VII TERMINATION
	  	 	14	 
			
	 Section 7.01
	  	Termination	  	 	14	 
	 Section 7.02
	  	Certain Effects of Termination	  	 	15	 
		
	 ARTICLE VIII MISCELLANEOUS
	  	 	15	 
			
	 Section 8.01
	  	Expenses	  	 	15	 
	 Section 8.02
	  	Interpretation	  	 	15	 
	 Section 8.03
	  	Survival of Provisions	  	 	16	 
	 Section 8.04
	  	No Waiver: Modifications in Writing	  	 	16	 
	 Section 8.05
	  	Binding Effect; Assignment	  	 	16	 
	 Section 8.06
	  	Non-Disclosure	  	 	16	 
	 Section 8.07
	  	Communications	  	 	17	 
	 Section 8.08
	  	Entire Agreement	  	 	18	 
	 Section 8.09
	  	Governing Law; Submission to Jurisdiction	  	 	18	 
	 Section 8.10
	  	Waiver of Jury Trial	  	 	18	 
	 Section 8.11
	  	Exclusive Remedy	  	 	19	 
	 Section 8.12
	  	No Recourse Against Others	  	 	19	 
	 Section 8.13
	  	No Third-Party Beneficiaries	  	 	20	 
	 Section 8.14
	  	Execution in Counterparts	  	 	20	 

  
 ii 

 PURCHASE AGREEMENT 

This PURCHASE AGREEMENT, dated as of June 26, 2018 (this “Agreement”), is entered into by and between
NUSTAR ENERGY L.P., a Delaware limited partnership (the “Partnership”) and WILLIAM E. GREEHEY (the “Purchaser”). 

WHEREAS, the Partnership desires to issue and sell to the Purchaser, and the Purchaser desires to purchase from the Partnership, the
Purchased Common Units (as defined below), in accordance with the provisions of this Agreement. 
 NOW THEREFORE, in consideration of
the mutual covenants and agreements set forth herein and for good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the parties hereby agree as follows: 

ARTICLE I 
 DEFINITIONS

 Section 1.01 Definitions. Unless otherwise defined in this Agreement, terms shall have the same meaning as in
the Partnership Agreement (as defined below). As used in this Agreement, the following terms have the meanings indicated: 

“Affiliate” means, with respect to any Person, any other Person that directly or indirectly through one or more
intermediaries controls, is controlled by or is under common control with, the Person in question. As used herein, the term “control” means the possession, direct or indirect, of the power to direct or cause the direction of the management
and policies of a Person, whether through ownership of voting securities, by contract or otherwise. For the avoidance of doubt, for purposes of this Agreement, the Partnership Entities, on the one hand, and the Purchaser, on the other, shall not be
considered Affiliates. 
 “Agreement” has the meaning set forth in the introductory paragraph of this Agreement.

 “Business Day” means any day other than a Saturday, Sunday, any federal legal holiday or day on which banking
institutions in the State of New York or State of Texas are authorized or required by Law or other governmental action to close. 

“Closing” has the meaning specified in Section 2.02. 

“Closing Date” means June 29, 2018. 

“Common Unit Purchase Price” means $24.17. 

“Common Units” means common units representing limited partner interests in the Partnership. 

“Contract” means any contract, agreement, indenture, note, bond, mortgage, deed of trust, loan, instrument, lease,
license, commitment or other arrangement, understanding, undertaking, commitment or obligation, whether written or oral. 

  
 1 

 “Delaware LP Act” means the Delaware Revised Uniform Limited Partnership
Act. 
 “Exchange Act” means the Securities Exchange Act of 1934, as amended from time to time, and the rules and
regulations of the SEC promulgated thereunder. 
 “Funding Amount” means an amount equal to the Common Unit Purchase
Price multiplied by the number of Purchased Common Units. 
 “GAAP” means generally accepted accounting principles
in the United States of America. 
 “General Partner” means Riverwalk Logistics, L.P., the general partner of the
Partnership. 
 “Governmental Authority” means, with respect to a particular Person, any country, state, county,
city and political subdivision in which such Person or such Person’s Property is located or which exercises valid jurisdiction over any such Person or such Person’s Property, and any court, agency, department, commission, board, bureau,
official or other regulatory authority (including self-regulated organizations or other non-governmental regulatory authorities) or instrumentality of any of them and any monetary authority which exercises
valid jurisdiction over any such Person or such Person’s Property. Unless otherwise specified, all references to Governmental Authority herein with respect to the Partnership mean a Governmental Authority having jurisdiction over the
Partnership Entities or any of their respective Properties. 
 “Indemnified Party” has the meaning specified in
Section 6.03(b). 
 “Indemnifying Party” has the meaning specified in
Section 6.03(b). 
 “Knowledge” means, with respect to the NuStar Parties, the actual
knowledge of Brad Barron and Tom Shoaf. 
 “Law” means any statute, law ordinance, regulation, rule, order, code,
governmental restriction, decree, injunction or other requirement of law, or any judicial or administrative interpretation thereof, of any Governmental Authority. 

“Lien” means any mortgage, pledge, lien (statutory or otherwise), encumbrance, security interest, security agreement,
conditional sale, trust receipt, charge or claim or a lease, consignment or bailment, preference or priority, assessment, deed of trust, easement, servitude or other encumbrance upon or with respect to any property of any kind. 

“Material Adverse Effect” means any change, effect, event or occurrence that, individually or in the aggregate, has
had or would reasonably be expected to have a material adverse effect on (a) the business, condition (financial or otherwise) or results of operations of the Partnership Entities, taken as a whole or (b) the ability of any of the
Partnership Entities, as applicable, to perform their obligations under this Agreement; provided, however, that any adverse changes, effects, events or occurrences resulting from or due to any of the following shall be disregarded in
determining whether there has been a Material Adverse Effect: (i) changes, effects, events or occurrences generally affecting the United States or global economy, the financial, credit, debt, securities or other capital markets or political,
legislative or regulatory conditions or changes 

  
 2 

 
in the industries in which the Partnership Entities operate (including changes, effects, events or occurrences generally affecting the prices of commodities); (ii) changes in any Laws or
regulations applicable to the Partnership Entities or applicable accounting regulations or principles or the interpretation thereof, to the extent not directly and exclusively impacting the Partnership Entities; (iii) acts of war or terrorism
(or the escalation of the foregoing) or natural disasters or other acts of God; (iv) any change in the market price or trading volume of the securities of the Partnership Entities (it being understood and agreed that the foregoing shall not
preclude any other Party to this Agreement from asserting that any facts or occurrences giving rise to or contributing to such change that are not otherwise excluded from the definition of Material Adverse Effect should be deemed to constitute, or
be taken into account in determining whether there has been, or would reasonably be expected to be, a Material Adverse Effect); (v) any failure of any of the Partnership Entities to meet any internal or external projections, forecasts or
estimates of revenues, earnings or other financial or operating metrics for any period (it being understood and agreed that the foregoing shall not preclude any other Party to this Agreement from asserting that any facts or occurrences giving rise
to or contributing to such change that are not otherwise excluded from the definition of Material Adverse Effect should be deemed to constitute, or be taken into account in determining whether there has been, or would reasonably be expected to be, a
Material Adverse Effect); (vi) any legal proceedings commenced by or involving any current or former holder of equity interests in the Partnership (on their own or on behalf of the Partnership) arising out of or relating to this Agreement, the
transactions contemplated hereby, the Merger Agreement or the transactions contemplated thereby; (vii) any nonpayment or nonperformance by Petróleos de Venezuela, S.A. that results in a loss of revenues or increased liabilities to the
Partnership; and (viii) the execution, announcement or pendency of this Agreement or the consummation of the transactions contemplated hereby or of a reduction in the quarterly distribution of the Partnership Entities (it being understood and
agreed that the foregoing shall not preclude any other Party to this Agreement from asserting that any facts or occurrences giving rise to or contributing to such change that are not otherwise excluded from the definition of Material Adverse Effect
should be deemed to constitute, or be taken into account in determining whether there has been, or would reasonably be expected to be, a Material Adverse Effect). 

“Merger Agreement” means the Agreement and Plan of Merger dated February 7, 2018 by and among the Partnership,
the General Partner, NuStar GP, Marshall Merger Sub LLC, a Delaware limited liability company and a wholly owned subsidiary of the Partnership, NSH and Riverwalk Holdings, as may be amended from time to time. 

“NS SEC Documents” means the Partnership’s forms, registration statements, reports, schedules and statements
filed (but not furnished) by it under the Exchange Act or the Securities Act, as applicable. 
 “NSH” NuStar GP
Holdings, LLC, a Delaware limited liability company. 
 “NuStar Entities” means, collectively, the Partnership and
the Partnership’s Subsidiaries. 
 “NuStar GP” means NuStar GP, LLC, the general partner of the General
Partner. 
 “NuStar Parties” means, collectively, NuStar GP, the General Partner and the Partnership. 

  
 3 

 “NYSE” means the New York Stock Exchange. 

“Organizational Documents” means, as applicable, an entity’s agreement or certificate of limited partnership,
limited liability company agreement, certificate of formation, certificate or articles of incorporation, bylaws or other similar organizational documents. 

“Partnership” has the meaning set forth in the introductory paragraph of this Agreement. 

“Partnership Agreement” means the Sixth Amended and Restated Agreement of Limited Partnership of the Partnership,
dated as of November 30, 2017, as amended from time to time in accordance with the terms thereof. 
 “Partnership
Entities” means, collectively, the NuStar Parties and NuStar Entities. 
 “Partnership Related Parties”
has the meaning specified in Section 6.02. 
 “Permits” means such permits, consents,
licenses, franchises, certificates and authorization of Governmental Authorities. 
 “Person” means any individual,
corporation, company, voluntary association, partnership, joint venture, trust, limited liability company, unincorporated organization, government or any agency, instrumentality or political subdivision thereof or any other form of entity. 

“Property” means any interest in any kind of property or asset, whether real, personal or mixed, or tangible or
intangible (including intellectual property rights). 
 “Purchaser” has the meaning specified in the introductory
paragraph of this Agreement. 
 “Purchaser Related Parties” has the meaning specified in
Section 6.01. 
 “Purchased Common Units” means the 413,736 Common Units purchased by the
Purchaser pursuant to this Agreement. 
 “Representatives” means, with respect to a specified Person, the investors,
officers, directors, managers, employees, agents, advisors, counsel, accountants, investment bankers and other representatives of such Person. 

“Riverwalk Holdings” means Riverwalk Holdings, LLC, a Delaware limited liability company and wholly owned subsidiary
of NSH. 
 “SEC” means the United States Securities and Exchange Commission. 

“Securities Act” means the Securities Act of 1933, as amended from time to time, and the rules and regulations of the
SEC promulgated thereunder. 
 “Third-Party Claim” has the meaning specified in
Section 6.03(b). 

  
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 Section 1.02 Accounting Procedures and Interpretation. Unless otherwise
specified herein, all accounting terms used herein shall be interpreted, all determinations with respect to accounting matters hereunder shall be made, and all financial statements of the Partnership and certificates and reports as to financial
matters required to be furnished to the Purchaser hereunder shall be prepared, in accordance with GAAP applied on a consistent basis during the periods involved (except as may be indicated in the notes thereto or, in the case of unaudited
statements, as permitted by Form 10-Q promulgated by the SEC) and in compliance as to form in all material respects with applicable accounting requirements and with the published rules and regulations of
the SEC with respect thereto. 
 ARTICLE II 

AGREEMENT TO SELL AND PURCHASE 

Section 2.01 Sale and Purchase. Subject to the terms and conditions hereof, at the Closing, the Purchaser hereby
agrees to purchase from the Partnership, and the Partnership hereby agrees to issue and sell to the Purchaser, the Purchased Common Units, upon receipt by the Partnership of the Funding Amount on the Closing Date. 

Section 2.02 Closing. The consummation of the purchase and sale of the Purchased Common Units (the
“Closing”) shall take place at the offices of Sidley Austin LLP, 1000 Louisiana St., Suite 6000, Houston, Texas 77002 (or such other location as agreed to by the Partnership and the Purchaser). 

Section 2.03 Mutual Conditions at the Closing. The respective obligations of each party to consummate the purchase and
sale of the Purchased Common Units at the Closing shall be subject to the satisfaction, on or prior to the Closing Date, of each of the following conditions (any or all of which may be waived by a party on behalf of itself in writing, in whole or in
part, to the extent permitted by applicable Law): 
 (a) no statute, rule, order, decree or regulation shall have been enacted or
promulgated, and no action shall have been taken, by any Governmental Authority which temporarily, preliminarily or permanently restrains, precludes, enjoins or otherwise prohibits the consummation of the transactions contemplated hereby or makes
the transactions contemplated hereby illegal; and 
 (b) there shall not be pending any suit, action or proceeding by any Governmental
Authority seeking to restrain, preclude, enjoin or prohibit the transactions contemplated by this Agreement. 
 Section 2.04
Conditions to the Purchaser’s Obligations at the Closing. The obligation of the Purchaser to consummate its purchase of the Purchased Common Units shall be subject to the satisfaction on or prior to the
Closing Date of each of the following conditions (any or all of which may be waived by the Purchaser in writing, in whole or in part, to the extent permitted by applicable Law): 

(a) the representations and warranties of the Partnership contained in this Agreement shall be true and correct in all material respects
(other than those representations and warranties 

  
 5 

 
contained in Section 3.01, Section 3.02, or Section 3.07, or other representations and warranties that are qualified
by materiality or Material Adverse Effect, which, in each case, shall be true and correct in all respects) when made and as of the Closing Date (except that representations and warranties made as of a specific date shall be required to be true and
correct in all material respects as of such date only); 
 (b) the Partnership shall have performed and complied in all material respects
with all of the covenants and agreements contained in this Agreement that are required to be performed or complied with by it on or prior to the Closing Date; 

(c) the NYSE shall have authorized, upon official notice of issuance, the listing of the Purchased Common Units; 

(d) no notice of delisting from the NYSE shall have been received by the Partnership with respect to the Purchased Common Units; 

(e) there shall not have occurred a Material Adverse Effect; and 

(f) the Partnership shall have delivered, or caused to be delivered, to the Purchaser the Partnership’s closing deliverables described in
Section 2.06(a), as applicable. 
 Section 2.05 Conditions to the
Partnership’s Obligations at the Closing. The obligation of the Partnership to consummate the sale and issuance of the Purchased Common Units to the Purchaser shall be subject to the satisfaction on or prior
to the Closing Date of each of the following conditions (any or all of which may be waived by the Partnership in writing, in whole or in part, to the extent permitted by applicable Law): 

(a) the representations and warranties of the Purchaser contained in this Agreement shall be true and correct in all material respects (other
than those representations and warranties that are qualified by materiality, which, in each case, shall be true and correct in all respects) when made and as of the Closing Date (except that representations and warranties made as of a specific date
shall be required to be true and correct in all material respects as of such date only); 
 (b) the Purchaser shall have performed and
complied in all material respects with all of the covenants and agreements contained in this Agreement that are required to be performed or complied with by him on or prior to the Closing Date; and 

(c) the Purchaser shall have delivered, or caused to be delivered, to the Partnership the applicable closing deliverables described in
Section 2.06(b), as applicable. 
 Section 2.06 Deliveries at the Closing.

 (a) Deliveries of the Partnership at the Closing. At the Closing, the Partnership shall deliver, or cause to be delivered, to the
Purchaser: 
 (i) A fully executed “Supplemental Listing Application” approving the Purchased Common Units for
listing by the NYSE, upon official notice of issuance; 

  
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 (ii) Evidence of issuance of the Purchased Common Units credited to book-entry
accounts maintained by the transfer agent of the Partnership, bearing a restrictive notation meeting the requirements of the Partnership Agreement, free and clear of any Liens, other than transfer restrictions under this Agreement, the Partnership
Agreement or the Delaware LP Act and applicable federal and state securities Laws and those created by the Purchaser; 

(iii) A certificate of the Executive Vice President and Chief Financial Officer of NuStar GP, on behalf of the Partnership,
dated the Closing Date, certifying, in such capacity, to the effect that the conditions set forth in Section 2.04(a) and Section 2.04(b) contained herein have been satisfied; and 

(iv) A cross-receipt executed by the Partnership and delivered to the Purchaser acknowledging the receipt by the Partnership of
the Funding Amount from the Purchaser. 
 (b) Deliveries of the Purchaser at the Closing. At the Closing, the Purchaser, shall
deliver or cause to be delivered to the Partnership: 
 (i) A cross-receipt executed by the Purchaser and delivered to the
Partnership acknowledging the receipt by the Purchaser of the Purchased Common Units from the Partnership; 
 (ii) a
certificate of the Purchaser, dated the Closing Date, to the effect that the conditions set forth in Section 2.05(a) and Section 2.05(b) have been satisfied; and 

(iii) Payment of the Purchaser’s Funding Amount payable by wire transfer of immediately available funds to an account
designated in advance of the Closing Date by the Partnership. 
 Section 2.07 Further Assurances. From time to time
after the date hereof, without further consideration, the Partnership and the Purchaser shall use their commercially reasonable efforts to take, or cause to be taken, all actions necessary or appropriate to consummate the transactions contemplated
by this Agreement. 
 ARTICLE III 

REPRESENTATIONS AND WARRANTIES AND COVENANTS RELATED TO THE PARTNERSHIP 

The Partnership represents and warrants to and covenants with the Purchaser as follows: 

Section 3.01 Existence. 

(a) Each of the Partnership Entities has been duly formed or incorporated, as the case may be, and is validly existing as a corporation,
limited partnership or limited liability company, as the case may be, and is in good standing under the Laws of its jurisdiction of incorporation or formation, as the case may be, with full corporate, limited partnership or limited liability company
power and authority (i) to own, lease and operate its Properties and to conduct its business as described in the NS SEC Documents, (ii) to execute and deliver this Agreement and consummate 

  
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the transactions contemplated hereby, (iii) in the case of the Partnership, to issue, sell and deliver the Purchased Common Units, (iv) in the case of the General Partner, to act as the
general partner of the Partnership and (v) in the case of NuStar GP, to act as the general partner of the General Partner. 
 (b) Each
of the Partnership Entities is duly qualified to do business as a foreign limited partnership or limited liability company, as the case may be, and is in good standing in each jurisdiction where the ownership or lease of its Properties or the
conduct of its business requires such qualification, except for any failures to be so qualified and in good standing that would not, individually or in the aggregate, (i) constitute a Material Adverse Effect or (ii) subject the limited
partners of the Partnership to any material liability or disability. 
 (c) The Organizational Documents of each of the Partnership Entities
have been, and, on the Closing Date, the Partnership Agreement will be, duly authorized, executed and delivered by the Partnership Entities, as applicable, and, assuming the due authorization, valid execution and delivery by the other parties
thereto (other than the Partnership Entities), each Organizational Document is, and, on the Closing Date, the Partnership Agreement will be, a valid and legally binding agreement of the Partnership Entities, as applicable, enforceable against such
parties in accordance with its terms; provided that, with respect to each agreement described in this Section 3.01(c), the enforceability thereof may be limited by bankruptcy, insolvency, fraudulent transfer,
reorganization, moratorium and similar laws relating to or affecting creditors’ rights generally and by general principles of equity (regardless of whether such enforceability is considered in a proceeding in equity or at law); provided
further, that the indemnity, contribution and exoneration provisions contained in any of such agreements may be limited by applicable laws and public policy. 

Section 3.02 Capitalization and Valid Issuance of Units. The Purchased Common Units and the limited partner interests
represented thereby will be duly authorized by the Partnership prior to the Closing and, when issued and delivered to the Purchaser against payment therefor in accordance with the terms of this Agreement, will be validly issued, fully paid (to the
extent required by the Partnership Agreement) and non-assessable (except as such nonassessability may be affected by matters described in Sections 17-303, 17-607 and 17-804 of the Delaware LP Act) and will be free of any and all Liens and restrictions on transfer, other than (i) restrictions on transfer under the
Partnership Agreement, this Agreement or applicable state and federal securities Laws, (ii) such Liens as are created by the Purchaser and (iii) such Liens as arise under the Partnership Agreement or the Delaware LP Act. 

Section 3.03 No Material Adverse Change. Since December 31, 2017, except as described in the NS SEC Documents,
there has not been any Material Adverse Effect. 
 Section 3.04 No Registration Required. Assuming the accuracy of
the representations and warranties of the Purchaser contained in ARTICLE IV, the issuance and sale of the Purchased Common Units to the Purchaser pursuant to this Agreement is exempt from registration requirements of the Securities Act, and
neither the Partnership nor, to the Partnership’s Knowledge, any Person acting on its behalf, has taken nor will take any action hereafter that would cause the loss of such exemption. 

  
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 Section 3.05 No Default. None of the Partnership Entities is in
(i) violation of the Organizational Documents, (ii) violation of any statute, law, rule or regulation, or any judgment, order or decrees of anybody having jurisdiction over it or (iii) breach or default (or an event which, with notice
or lapse of time or both, would constitute such an event) in the performance of any term, covenant or condition contained in any bond, debenture, note or any other evidence of indebtedness or in any agreement, indenture, lease or other instrument to
which it is a party or by which it or any of its properties is subject, which breach, default or violation, in the case of (ii) and (iii), individually or in the aggregate, has had, or would, if continued, reasonably be expected to have, a
Material Adverse Effect. 
 Section 3.06 No Conflicts. As of the Closing Date, none of the offering and sale by the
Partnership of the Purchased Common Units, the execution, delivery and performance of this Agreement by the NuStar Parties or the consummation of any other transactions contemplated hereby (i) conflicts with or will conflict with, or
constitutes or will constitute a violation of, the Organizational Documents of any of the Partnership Entities, (ii) conflicts with or will conflict with, or constitutes or will constitute a breach or violation of, or a default (or an event
that, with notice or lapse of time or both, would constitute such a default) under, any indenture, contract, lease, mortgage, deed of trust, note agreement, loan agreement or other agreement, obligation, condition, covenant or instrument to which
any of the Partnership Entities is a party or by which any of them are bound or to which any of their respective properties is subject, (iii) violates or will violate any statute, law, rule or regulation, or any judgment, order or decrees of
any Governmental Authority having jurisdiction over any of the Partnership Entities or any of their properties or assets, or (iv) will result in the creation or imposition of any Lien upon any property or assets of any of the Partnership
Entities, except, in the case of clauses (ii), (iii) and (iv), for such conflicts, breaches, violations, defaults or Liens as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect. 

Section 3.07 Authority; Enforceability. The Partnership has all requisite power and authority under the Partnership
Agreement and the Delaware LP Act to issue, sell and deliver the Purchased Common Units, in accordance with and upon the terms and conditions set forth in this Agreement and the Partnership Agreement. All limited partnership and limited liability
company action, as the case may be, required to be taken by the Partnership Entities or any of their partners or members for the authorization, issuance, sale and delivery of the Purchased Common Units, the execution and delivery of this Agreement
and the consummation of the transactions contemplated hereby shall have been validly taken. No approval from the holders of outstanding Common Units is required under the Partnership Agreement or the rules of the NYSE in connection with the
Partnership’s issuance and sale of the Purchased Common Units to the Purchaser. This Agreement has been duly and validly authorized, executed and delivered by the Partnership. This Agreement constitutes the legal, valid and binding obligations
of the Partnership, enforceable in accordance with its terms. 
 Section 3.08 Listing and Maintenance Requirements.
The Common Units are listed on the NYSE, and the Partnership has not received any notice of delisting. The issuance and sale of the Purchased Common Units do not contravene NYSE rules and regulations. 

  
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 ARTICLE IV 

REPRESENTATIONS AND WARRANTIES AND COVENANTS OF THE PURCHASER 

The Purchaser represents and warrants and covenants to the Partnership as follows with respect to himself: 

Section 4.01 Capacity; Validity of Agreement. The Purchaser has the requisite legal capacity and authority to enter
into, deliver and perform his obligations under this Agreement. This Agreement has been duly executed and delivered by the Purchaser and constitutes a legal, valid and binding obligation of the Purchaser. 

Section 4.02 No Breach. The execution, delivery and performance of this Agreement by the Purchaser and the
consummation by the Purchaser of the transactions contemplated hereby will not (a) conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, any material agreement to which the
Purchaser is a party or by which the Purchaser is bound or to which any of the property or assets of the Purchaser is subject, or (b) violate any Law of any Governmental Authority or body having jurisdiction over the Purchaser or the property
or assets of the Purchaser, except in the case of clauses (a) and (b), for such conflicts, breaches, violations or defaults as would not prevent the consummation of the transactions hereby. 

Section 4.03 Unregistered Securities. 

(a) Accredited Investor Status; Sophisticated Purchaser. The Purchaser is an “accredited investor” within the meaning of
Rule 501 under the Securities Act and is able to bear the risk of its investment in the Purchased Common Units. The Purchaser has such knowledge and experience in financial and business matters that it is capable of evaluating the merits and
risks of the purchase of the Purchased Common Units. 
 (b) Information. The Purchaser has been furnished with all materials relating
to the business, finances and operations of the Partnership that have been requested and materials relating to the offer and sale of the Purchased Common Units that have been requested by the Purchaser. The Purchaser and its Representatives have
been afforded the opportunity to ask questions of the Partnership. Neither such inquiries nor any other due diligence investigations conducted at any time by the Purchaser and its Representatives shall modify, amend or affect the Purchaser’s
right (i) to rely on the Partnership’s representations and warranties contained in ARTICLE III above or (ii) to indemnification or any other remedy based on, or with respect to the accuracy or inaccuracy of, or compliance with,
the representations, warranties, covenants and agreements in this Agreement. The Purchaser understands that its purchase of the Purchased Common Units involves a high degree of risk. The Purchaser has sought such accounting, legal and tax advice as
it has considered necessary to make an informed investment decision with respect to its acquisition of the Purchased Common Units. 
 (c)
Residency. The Purchaser shall cooperate reasonably with the Partnership to provide any information necessary for any applicable securities filings. 

  
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 (d) Legends. The Purchaser understands that, until such time as the Purchased Common Units
have been sold pursuant to an effective registration statement under the Securities Act, or the Purchased Common Units are eligible for resale pursuant to Rule 144 promulgated under the Securities Act without any restriction as to the number of
securities as of a particular date that can then be immediately sold, the Purchased Common Units will bear a restrictive legend as provided in the Partnership Agreement. 

(e) Purchase Representation. The Purchaser is purchasing the Purchased Common Units for his own account and not with a view to
distribution in violation of any Laws. The Purchaser has been advised and understands that the Purchased Common Units have not been registered under the Securities Act or under the “blue sky” laws of any jurisdiction and may be resold only
if registered pursuant to the provisions of the Securities Act (or if eligible, pursuant to the provisions of Rule 144 promulgated under the Securities Act or pursuant to another available exemption from the registration requirements of the
Securities Act). The Purchaser has been advised and understands that the Partnership, in issuing the Purchased Common Units, is relying upon, among other things, the representations and warranties of the Purchaser contained in this ARTICLE IV
in concluding that such issuance is a “private offering” and is exempt from the registration provisions of the Securities Act. 

(f) Rule 144. The Purchaser has been advised of and is aware of the provisions of Rule 144 promulgated under
the Securities Act. 
 (g) Reliance by the Partnership. The Purchaser understands that the Purchased Common Units are being offered
and sold in reliance on a transactional exemption from the registration requirements of federal and state securities Laws and that the Partnership is relying upon the truth and accuracy of the representations, warranties, agreements, acknowledgments
and understandings of the Purchaser set forth herein in order to determine the applicability of such exemptions and the suitability of the Purchaser to acquire the Purchased Common Units. 

Section 4.04 Sufficient Funds. The Purchaser will have available to him at the Closing sufficient funds to enable the
Purchaser to pay in full at the Closing the Funding Amount in immediately available cash funds. 
 ARTICLE V 

COVENANTS 

Section 5.01 Conduct of Business. Except where failing use such efforts would not have a Material Adverse Effect,
during the period commencing on the date of this Agreement and ending on the Closing Date each of the Partnership Entities will use commercially reasonable efforts to (i) conduct its business in the ordinary course of business (other than as
contemplated by the Merger Agreement) and (ii) preserve intact its existence and business organization, Permits, goodwill and present business relationships with all material customers, suppliers, licensors, distributors and others having
significant business relationships with the Partnership Entities (or any of them), to the extent the Partnership believes in its sole discretion that such relationships are and continue to be beneficial to the Partnership Entities and their
businesses; provided, however, that during such period, the Partnership shall provide reasonably prompt written notice to the Purchaser regarding any material adverse developments in respect of the foregoing. 

  
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 Section 5.02 Listing of Units. Prior to the Closing, the Partnership will
use its commercially reasonable efforts to obtain approval for listing, subject to notice of issuance, of the Purchased Common Units on the NYSE. 

Section 5.03 Use of Proceeds. The Partnership shall use the proceeds of the offering of the Purchased Common Units to
repay indebtedness of the Partnership or for general partnership purposes. 
 ARTICLE VI 

INDEMNIFICATION, COSTS AND EXPENSES 

Section 6.01 Indemnification by the Partnership. The Partnership agrees to indemnify the Purchaser and its
Representatives (collectively, the “Purchaser Related Parties”) from costs, losses, liabilities, damages or expenses of any kind or nature whatsoever, and hold each of them harmless against, any and all actions, suits,
proceedings (including any investigations, litigation or inquiries), demands and causes of action, and, in connection therewith, promptly upon demand, pay or reimburse each of them for all costs, losses, liabilities, damages, or expenses of any kind
or nature whatsoever (including the reasonable fees and disbursements of counsel and all other reasonable expenses incurred in connection with investigating, defending or preparing to defend any such matter that may be incurred by them or asserted
against or involve any of them), whether or not involving a Third-Party Claim, as a result of, arising out of, or in any way related to (a) the failure of any of the representations or warranties made by the Partnership contained herein to be
true and correct in all material respects (other than those representations and warranties contained in Section 3.01, Section 3.02, or Section 3.07, or other
representations and warranties that are qualified by materiality or Material Adverse Effect, which, in each case, shall be true and correct in all respects) when made and as of the Closing Date (except for any representations and warranties made as
of a specific date, which shall be required to be true and correct in all material respects as of such date only) or (b) the breach of any covenants of the Partnership contained herein; provided that, in the case of the immediately
preceding clause (a), such claim for indemnification is made prior to the expiration of the survival period of such representation or warranty; provided, further, that for purposes of determining when an indemnification claim has
been made, the date upon which the Purchaser Related Party shall have given notice (stating in reasonable detail the basis of the claim for indemnification) to the Partnership shall constitute the date upon which such claim has been made; and
provided, further, that the aggregate liability of the Partnership to the Purchaser and its Representatives pursuant to this Section 6.01 shall not be greater in amount than the Funding Amount as of the date
of the Indemnification notice described in Section 6.03(a). No Purchaser Related Party shall be entitled to recover special, indirect, exemplary, lost profits, speculative or punitive damages under this
Section 6.01; provided, however, that such limitation shall not prevent any Purchaser Related Party from recovering under this Section 6.01 for any such damages to the extent that
such damages are payable to a third party in connection with any Third-Party Claims. Notwithstanding anything contained in this Agreement, no provision contained herein shall limit, restrict or otherwise alter the right of the Purchaser to
indemnification by any of the Partnership Entities under any other agreement. 
 Section 6.02 Indemnification by the
Purchaser. The Purchaser agrees to indemnify the Partnership, the General Partner, NuStar GP and their respective Representatives (collectively, the “Partnership Related Parties”) from, all costs, losses, liabilities,
damages, or expenses of any 

  
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kind or nature whatsoever, and hold each of them harmless against, any and all actions, suits, proceedings (including any investigations, litigation or inquiries), demands, and causes of action,
and, in connection therewith, promptly upon demand, pay or reimburse each of them for all costs, losses, liabilities, damages, or expenses of any kind or nature whatsoever (including the reasonable fees and disbursements of counsel and all other
reasonable expenses incurred in connection with investigating, defending or preparing to defend any such matter that may be incurred by them or asserted against or involve any of them), whether or not involving a Third-Party Claim, as a result of,
arising out of, or in any way related to (a) the failure of any of the representations or warranties made by the Purchaser contained herein to be true and correct in all material respects as of the date made (except to the extent any
representation or warranty includes the word “material,” Material Adverse Effect or words of similar import, with respect to which such representation or warranty, or applicable portions thereof, must have been true and correct in all
respects) or (b) the breach of any of the covenants or obligations of any the Purchaser contained herein (including failure to deliver payment pursuant to the Funding Amount); provided that, in the case of the immediately preceding
clause (a), such claim for indemnification relating to a breach of any representation or warranty is made prior to the expiration of the survival period of such representation or warranty; and provided,
further, that for purposes of determining when an indemnification claim has been made, the date upon which a Partnership Related Party shall have given notice (stating in reasonable detail the basis of the claim for indemnification) to the
Purchaser shall constitute the date upon which such claim has been made; and provided, further, that the liability of any Purchaser shall not be greater in amount than the Funding Amount plus any distributions paid to the
Purchaser with respect to the Purchased Common Units. No Partnership Related Party shall be entitled to recover special, indirect, exemplary, lost profits, speculative or punitive damages under this Section 6.02;
provided, however, that such limitation shall not prevent any Partnership Related Party from recovering under this Section 6.02 for any such damages to the extent that such damages are payable to a third
party in connection with any Third-Party Claims. 
 Section 6.03 Indemnification Procedure. 

(a) A claim for indemnification for any matter not involving a Third-Party Claim may be asserted by notice to the party from whom
indemnification is sought; provided, however, that failure to so notify the indemnifying party shall not preclude the indemnified party from any indemnification which it may claim in accordance with this Article VI,
except as otherwise provided in Section 6.01 and Section 6.02. 
 (b) Promptly after any
Partnership Related Party or Purchaser Related Party (hereinafter, the “Indemnified Party”) has received notice of any indemnifiable claim hereunder, or the commencement of any action, suit or proceeding by a third person,
which the Indemnified Party believes in good faith is an indemnifiable claim under this Agreement (each a “Third-Party Claim”), the Indemnified Party shall give the indemnitor hereunder (the “Indemnifying
Party”) written notice of such Third-Party Claim, but failure to so notify the Indemnifying Party will not relieve the Indemnifying Party from any liability it may have to such Indemnified Party hereunder except to the extent that the
Indemnifying Party is materially prejudiced by such failure. Such notice shall state the nature and the basis of such Third-Party Claim to the extent then known. The Indemnifying Party shall have the right to defend and settle, at its own expense
and by its own counsel who shall be reasonably acceptable to the Indemnified Party, any such matter as long as 

  
 13 

 
the Indemnifying Party pursues the same diligently and in good faith. If the Indemnifying Party undertakes to defend or settle, it shall promptly, and in no event later than ten (10) days,
notify the Indemnified Party of its intention to do so, and the Indemnified Party shall cooperate with the Indemnifying Party and its counsel in all commercially reasonable respects in the defense thereof and the settlement thereof. Such cooperation
shall include, but shall not be limited to, furnishing the Indemnifying Party with any books, records and other information reasonably requested by the Indemnifying Party and in the Indemnified Party’s possession or control. Such cooperation of
the Indemnified Party shall be at the cost of the Indemnifying Party. After the Indemnifying Party has notified the Indemnified Party of its intention to undertake to defend or settle any such asserted liability, and for so long as the Indemnifying
Party diligently pursues such defense, the Indemnifying Party shall not be liable for any additional legal expenses incurred by the Indemnified Party in connection with any defense or settlement of such asserted liability; provided,
however, that the Indemnified Party shall be entitled (i) at its expense, to participate in the defense of such asserted liability and the negotiations of the settlement thereof and (ii) if (A) the Indemnifying Party has,
within ten (10) Business Days of when the Indemnified Party provides written notice of a Third-Party Claim, failed (1) to assume the defense or employ counsel reasonably acceptable to the Indemnified Party or (2) to notify the
Indemnified Party of such assumption or (B) if the defendants in any such action include both the Indemnified Party and the Indemnifying Party and counsel to the Indemnified Party shall have concluded that there may be reasonable defenses
available to the Indemnified Party that are different from or in addition to those available to the Indemnifying Party or if the interests of the Indemnified Party reasonably may be deemed to conflict with the interests of the Indemnifying Party,
then the Indemnified Party shall have the right to select a separate counsel and to assume such legal defense and otherwise to participate in the defense of such action, with the expenses and fees of such separate counsel and other expenses related
to such participation to be reimbursed by the Indemnifying Party as incurred. Notwithstanding any other provision of this Agreement, the Indemnifying Party shall not settle any indemnified claim without the consent of the Indemnified Party, unless
the settlement thereof imposes no liability or obligation on, and includes a complete release from liability of, and does not include any admission of wrongdoing or malfeasance by, the Indemnified Party. 

Section 6.04 Tax Matters. All indemnification payments under this Article VI shall be treated as adjustments to
the applicable Purchaser’s Funding Amount for all Tax purposes except as otherwise required by applicable Law. 
 ARTICLE VII

 TERMINATION 

Section 7.01 Termination. This Agreement may be terminated at any time prior to the Closing: 

(a) by mutual written consent of the Partnership and the Purchaser; 

(b) by written notice from either the Partnership or the Purchaser, if any Governmental Authority with lawful jurisdiction shall have issued a
final order, decree or ruling or taken any other final action restraining, enjoining or otherwise prohibiting the transactions contemplated by this Agreement and such order, decree, ruling or other action is or shall have become final and
nonappealable; or 

  
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 (c) by written notice from the Partnership or the Purchaser, if the Closing does not occur by
11:59 p.m. on June 29, 2018; provided, however, that no party may terminate this Agreement pursuant to this Section 7.01(c) if such party is, at the time of providing such written notice, in breach
of any of its obligations under this Agreement. 
 Section 7.02 Certain Effects of Termination. In the event that
this Agreement is terminated pursuant to Section 7.01, except as set forth in Section 7.02 or 8.03, this Agreement shall become null and void and have no further force or effect, but the
parties shall not be released from any liability arising from or in connection with any breach hereof occurring prior to such termination. 

ARTICLE VIII 

MISCELLANEOUS 

Section 8.01 Expenses. All costs and expenses, including fees and disbursements of counsel, financial advisors and
accountants, incurred in connection with this Agreement and the transactions contemplated thereby shall be paid by the party incurring such costs and expenses. 

Section 8.02 Interpretation. Article, Section, Schedule and Exhibit references in this Agreement are references to the
corresponding Article, Section, Schedule or Exhibit to this Agreement, unless otherwise specified. All Exhibits and Schedules to this Agreement are hereby incorporated and made a part hereof as if set forth in full herein and are an integral part of
this Agreement. All references to instruments, documents, Contracts and agreements are references to such instruments, documents, Contracts and agreements as the same may be amended, supplemented and otherwise modified from time to time, unless
otherwise specified. The word “including” shall mean “including but not limited to” and shall not be construed to limit any general statement that it follows to the specific or similar items or matters immediately following it.
Whenever the Partnership has an obligation under this Agreement, the expense of complying with that obligation shall be an expense of the Partnership unless otherwise specified. Any reference in this Agreement to “$” shall mean
U.S. dollars. Whenever any determination, consent or approval is to be made or given by the Purchaser, such action shall be in the Purchaser’s sole discretion, unless otherwise specified in this Agreement. If any provision in this
Agreement is held to be illegal, invalid, not binding or unenforceable, (a) such provision shall be fully severable and this Agreement shall be construed and enforced as if such illegal, invalid, not binding or unenforceable provision had never
comprised a part of this Agreement, and the remaining provisions shall remain in full force and effect, and (b) the parties hereto shall negotiate in good faith to modify this Agreement so as to effect the original intent of the parties as
closely as possible in an acceptable manner in order that the transactions contemplated hereby are consummated as originally contemplated to the greatest extent possible. When calculating the period of time before which, within which or following
which any act is to be done or step taken pursuant to this Agreement, the date that is the reference date in calculating such period shall be excluded. If the last day of such period is not a Business Day, the period in question shall end on the
next succeeding Business Day. Any words imparting the singular number only shall include the plural and vice versa. The words such as “herein,” “hereinafter,” “hereof” and “hereunder” refer to this Agreement
as a whole and not merely to a subdivision in which such words appear unless the context otherwise requires. The provision of a Table of Contents, the division of this Agreement into Articles, Sections and other subdivisions and the insertion of
headings are for convenience of reference only and shall not affect or be utilized in construing or interpreting this Agreement. 

  
 15 

 Section 8.03 Survival of Provisions. The representations and warranties
set forth in Section 3.01, Section 3.02, Section 3.07, Section 4.01, Section 4.03(a),
Section 4.03(b) and Section 4.03(e) hereunder shall survive the execution and delivery of this Agreement indefinitely and the other representations and warranties set forth herein shall
survive for a period of 12 months following the Closing Date, regardless of any investigation made by or on behalf of the Partnership or the Purchaser. The covenants made in this Agreement shall survive the Closing and remain operative and in
full force and effect regardless of acceptance of any of the Purchased Common Units and payment therefor and repayment, conversion or repurchase thereof. Regardless of any purported general termination of this Agreement, the provisions of ARTICLE
VI and all indemnification rights and obligations thereunder, ARTICLE VII and this ARTICLE VIII shall remain operative and in full force and effect, unless the applicable parties execute a writing that expressly (with specific
references to the applicable Section or subsection of this Agreement) terminates such rights and obligations. 
 Section 8.04
No Waiver: Modifications in Writing. 
 (a) Delay. No failure or delay on the part of any party in exercising any
right, power or remedy hereunder shall operate as a waiver thereof, nor shall any single or partial exercise of any such right, power or remedy preclude any other or further exercise thereof or the exercise of any other right, power or remedy. The
remedies provided for herein are cumulative and are not exclusive of any remedies that may be available to a party at law or in equity or otherwise. 

(b) Specific Waiver. Except as otherwise provided herein, no amendment, waiver, consent, modification or termination of any provision
of this Agreement (except in the case of the Partnership Agreement for amendments adopted pursuant to the provisions thereof) shall be effective unless signed by each of the parties. Any amendment, supplement or modification of or to any provision
of this Agreement, any waiver of any provision of this Agreement and any consent to any departure by the Partnership from the terms of any provision of this Agreement shall be effective only in the specific instance and for the specific purpose for
which made or given. Except where notice is specifically required by this Agreement, no notice to or demand on the Partnership in any case shall entitle the Partnership to any other or further notice or demand in similar or other circumstances. Any
investigation by or on behalf of any party shall not be deemed to constitute a waiver by the party taking such action of compliance with any representation, warranty, covenant or agreement contained herein. 

Section 8.05 Binding Effect; Assignment. This Agreement shall be binding upon the parties hereto and their respective
successors and permitted assigns. Except as expressly provided in this Agreement, this Agreement shall not be construed so as to confer any right or benefit upon any Person other than the parties to this Agreement and their respective successors and
permitted assigns. 
 Section 8.06 Non-Disclosure. 

(a) Other than filings made by the Partnership with the SEC, the Partnership and any of its Representatives may disclose the identity of, or
any other information concerning, the Purchaser or any of his respective Affiliates only after providing the Purchaser a reasonable opportunity to review and comment on such disclosure (with such comments being incorporated

  
 16 

 
or reflected, to the extent reasonable, in any such disclosure); provided, however, that nothing in this Section 8.06 shall delay any required filing or
other disclosure with the NYSE or any Governmental Authority or otherwise hinder the NuStar Entities’ or their Representatives’ ability to timely comply with all Laws or rules and regulations of the NYSE or other Governmental Authority.

 (b) Except as described in Section 8.06(a), prior to making any public statements or issuing any press releases
with respect to the transactions contemplated by this Agreement, each party will consult with the other parties hereto and consider in good faith any comments provided by such other parties; provided that no party will make any public
statement or issue any press release that attributes comments to any other party or that indicates the approval of any other party of the contents of any such public statement or press release (or portion thereof) without the prior written approval
of the other parties hereto. 
 Section 8.07 Communications. All notices and demands provided for hereunder shall be
in writing and shall be given by registered or certified mail, return receipt requested, telecopy, electronic mail, air courier guaranteeing overnight delivery or personal delivery to the following addresses 

 

	 	(a)	If to the Purchaser, to: 

 William E. Greehey 

19003 IH-10 West 

San Antonio, Texas 78257 
  

	 	(b)	If to the Partnership, to: 

 NuStar Energy L.P. 

19003 IH-10 West 

San Antonio, Texas 78257 

Attention: Amy L. Perry, Senior Vice President, General Counsel and Corporate 

Secretary 

with a copy to (which shall not constitute notice): 

Sidley Austin LLP 

1000 Louisiana Street 

Suite 6000 

Houston, TX 77002 

Attention: George J. Vlahakos 

Email: gvlahakos@sidley.com 
 or
to such other address as the Partnership or the Purchaser may designate in writing. All notices and communications shall be deemed to have been duly given: at the time delivered by hand, if personally delivered; upon actual receipt if sent by
certified or registered mail, return receipt requested, or regular mail, if mailed; upon actual receipt of the facsimile, if sent via facsimile; when sent, if sent by electronic mail prior to 5:00 p.m. Houston, Texas time on a Business Day, or
on the next succeeding Business Day, if not; and upon actual receipt when delivered to an air courier guaranteeing overnight delivery. 

  
 17 

 Section 8.08 Entire Agreement. This Agreement and the other agreements
and documents referred to herein are intended by the parties as a final expression of their agreement and intended to be a complete and exclusive statement of the agreement and understanding of the parties hereto in respect of the subject matter
contained herein and therein. There are no restrictions, promises, warranties or undertakings, other than those set forth or referred to in this Agreement, with respect to the rights granted by the Partnership or any of its Affiliates or the
Purchaser or any of his Affiliates. This Agreement and the other agreements and documents referred to herein or therein supersede all prior agreements and understandings among the parties with respect to such subject matter. 

Section 8.09 Governing Law; Submission to Jurisdiction. This Agreement, and all claims or causes of action (whether in
contract or tort) that may be based upon, arise out of or relate to this Agreement or the negotiation, execution or performance of this Agreement (including any claim or cause of action based upon, arising out of or related to any representation or
warranty made in or in connection with this Agreement), will be construed in accordance with and governed by the Laws of the State of Delaware without regard to principles of conflicts of laws. Any action against any party relating to the foregoing
shall be brought in any federal or state court of competent jurisdiction located within the State of Delaware, and the parties hereto hereby irrevocably submit to the non-exclusive jurisdiction of any federal
or state court located within the State of Delaware over any such action. The parties hereby irrevocably waive, to the fullest extent permitted by applicable Law, any objection which they may now or hereafter have to the laying of venue of any such
dispute brought in such court or any defense of inconvenient forum for the maintenance of such dispute. Each of the parties hereto agrees that a judgment in any such dispute may be enforced in other jurisdictions by suit on the judgment or in any
other manner provided by Law. 
 Section 8.10 Waiver of Jury Trial. THE PARTIES TO THIS AGREEMENT EACH HEREBY
WAIVES, AND AGREES TO CAUSE ITS AFFILIATES TO WAIVE, TO THE FULLEST EXTENT PERMITTED BY LAW, ANY RIGHT TO TRIAL BY JURY OF ANY CLAIM, DEMAND, ACTION OR CAUSE OF ACTION (A) ARISING UNDER THIS AGREEMENT OR (B) IN ANY WAY CONNECTED WITH OR
RELATED OR INCIDENTAL TO THE DEALINGS OF THE PARTIES HERETO IN RESPECT OF THIS AGREEMENT OR ANY OF THE TRANSACTIONS RELATED HERETO, IN EACH CASE WHETHER NOW EXISTING OR HEREAFTER ARISING, AND WHETHER IN CONTRACT, TORT, EQUITY OR OTHERWISE. THE
PARTIES TO THIS AGREEMENT EACH HEREBY AGREES AND CONSENTS THAT ANY SUCH CLAIM, DEMAND, ACTION OR CAUSE OF ACTION SHALL BE DECIDED BY COURT TRIAL WITHOUT A JURY AND THAT THE PARTIES TO THIS AGREEMENT MAY FILE AN ORIGINAL COUNTERPART OF A COPY OF THIS
AGREEMENT WITH ANY COURT AS WRITTEN EVIDENCE OF THE CONSENT OF THE PARTIES HERETO TO THE WAIVER OF THEIR RIGHT TO TRIAL BY JURY. 

  
 18 

 Section 8.11 Exclusive Remedy. 

(a) Each party hereto hereby acknowledges and agrees that the rights of each party to consummate the transactions contemplated hereby are
special, unique and of extraordinary character and that, if any party violates or fails or refuses to perform any covenant or agreement made by it herein, the non-breaching party may be without an adequate
remedy at law. If any party violates or fails or refuses to perform any covenant or agreement made by such party herein, the non-breaching party subject to the terms hereof and in addition to any remedy at law
for damages or other relief, may (at any time prior to the valid termination of this Agreement pursuant to ARTICLE VII) institute and prosecute an action in any court of competent jurisdiction to enforce specific performance of such covenant
or agreement or seek any other equitable relief. 
 (b) The sole and exclusive remedy for any and all claims arising under, out of, or
related to this Agreement or the transactions contemplated hereby, shall be the rights of indemnification set forth in Article VI only, and no Person will have any other entitlement, remedy or recourse, whether in contract, tort or otherwise,
it being agreed that all of such other remedies, entitlements and recourse are expressly waived and released by the parties hereto to the fullest extent permitted by Law. Notwithstanding anything in the foregoing to the contrary, nothing in this
Agreement shall limit or otherwise restrict a fraud claim brought by any party hereto or the right to seek specific performance pursuant to Section 8.11(a). 

Section 8.12 No Recourse Against Others. 

(a) All claims, obligations, liabilities or causes of action (whether in contract or in tort, in law or in equity, or granted by statute) that
may be based upon, in respect of, arise under, out or by reason of, be connected with or relate in any manner to this Agreement, or the negotiation, execution or performance of this Agreement (including any representation or warranty made in, in
connection with, or as an inducement to, this Agreement), may be made only against (and are expressly limited to) the Partnership and the Purchaser. No Person other than the Partnership or the Purchaser, including no member, partner, stockholder,
Affiliate or Representative thereof, nor any member, partner, stockholder, Affiliate or Representative of any of the foregoing, shall have any liability (whether in contract or in tort, in law or in equity, or granted by statute) for any claims,
causes of action, obligations or liabilities arising under, out of, in connection with or related in any manner to this Agreement or based on, in respect of or by reason of this Agreement or its negotiation, execution, performance or breach; and, to
the maximum extent permitted by Law, each of the Partnership and the Purchaser hereby waives and releases all such liabilities, claims, causes of action and obligations against any such third Person. 

(b) Without limiting the foregoing, to the maximum extent permitted by Law, (i) each of the Partnership and the Purchaser hereby waives
and releases any and all rights, claims, demands or causes of action that may otherwise be available at law or in equity, or granted by statute, to avoid or disregard the entity form of the other or otherwise impose liability of the other on any
third Person in respect of the transactions contemplated hereby, whether granted by statute or based on theories of equity, agency, control, instrumentality, alter ego, domination, sham, single business enterprise, piercing the veil, unfairness,
undercapitalization or otherwise; and (ii) each of the Partnership and the Purchaser disclaims any reliance upon any third Person with respect to the performance of this Agreement or any representation or warranty made in, in connection with or
as an inducement to this Agreement. 

  
 19 

 Section 8.13 No Third-Party Beneficiaries. Except as set forth in
Article VI, nothing in this Agreement, express or implied, is intended to or shall confer upon any Person, other than the Partnership, the Purchaser and, for purposes of Section 8.12 only, any member, partner,
stockholder, Affiliate or Representative of the Partnership, any right, benefit or remedy of any nature whatsoever under or by reason of this Agreement. 

Section 8.14 Execution in Counterparts. This Agreement may be executed in any number of counterparts and by different
parties hereto in separate counterparts, each of which counterparts, when so executed and delivered, shall be deemed to be an original and all of which counterparts, taken together, shall constitute but one and the same agreement. 

[Signature Page Follows] 

  
 20 

 IN WITNESS WHEREOF, the parties hereto execute this Agreement, effective as of the date first
above written. 
  

					
	NUSTAR ENERGY L.P.
		
	By:	 	RIVERWALK LOGISTICS, L.P., its General Partner
			
		 	By:	 	NUSTAR GP, LLC, its General Partner
			
		 	By:	 	/s/ Thomas R. Shoaf
		 	Name: Thomas R. Shoaf
		 	Title: Executive Vice President and Chief Financial Officer

 Signature Page of the Purchase Agreement (Greehey) 

 
	
	WILLIAM E. GREEHEY
	
	/s/ William E. Greehey

 Signature Page of the Purchase Agreement (Greehey)

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