Document:

Exhibit 10.84

Exhibit 10.84

TCW ASSET MANAGEMENT COMPANY

865 South Figueroa Street, suite 1800

Los Angeles, California 90017

December 30, 2008

Rio Vista Penny LLC

2601 Northwest Expressway #902E

Oklahoma City, Oklahoma 93112

Attention: Ian Bothwell

	 	 	 	 	 
	 

	 	Re:
	 	Note Purchase Agreement, dated as of November 19, 2007 (as amended,
supplemented or otherwise modified, the “Note Purchase Agreement”), by and among
RIO VISTA PENNY LLC, an Oklahoma limited liability company (“Company”), the
Holders party thereto, and TCW ASSET MANAGEMENT COMPANY, as Administrative
Agent.

Gentlemen:

Reference is made to the Note Purchase Agreement. Terms that are defined in the Note
Purchase Agreement and not otherwise defined herein are used herein with the meanings given
them in the Note Purchase Agreement.

Company has requested that Holders extend the required payments of principal and
accrued interest that are due and payable on the December 2008 Quarterly Payment Date and
also to extend the date to deliver the Engineering Report effective as of November 1, 2008,
in each case to February 28, 2009. Accordingly, in reliance upon the representations,
warranties, covenants, and waivers of the Restricted Persons contained in this Letter, and
subject to the terms and conditions of this Letter, Administrative Agent and Holders hereby
agree that (i) the mandatory principal payment in respect of the Notes due and payable on
the December 2008 Quarterly Payment Date pursuant Section 2.8(a) of the Note Purchase
Agreement is hereby extended to February 28, 2009, (ii) the required payment of accrued
interest in respect of the Notes due and payable on the December 2008 Quarterly Payment Date
is hereby extended to February 28, 2009, and (iii) the delivery of the Engineering Report to
be effective as of November 1, 2008 that was due prior to December 1, 2008 pursuant to
Section 7.2(i) of the Note Purchase Agreement is hereby extended to February 28, 2009.

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

December 30, 2008

Page 2

In order to induce Holder Parties to enter into this Letter, Company represents and
warrants to each Holder Party that the representations and warranties contained in Article V
of the Note Purchase Agreement are true and correct at and as of the time of the
effectiveness hereof, except to the extent such representations and warranties specifically
refer to an earlier date, in which case they are true and correct as of such earlier date.
Company hereby further acknowledges, confirms and agrees that as of the close of business on
December 29, 2008, Company is indebted to Holders in respect of the Loans in the aggregate principal amount of
$24,700,000.00 and in respect of accrued but unpaid interest related thereto in the amount of
$789,027.78. All such Loans, together with interest accrued and accruing thereon, and fees, costs,
expenses and other charges now or hereafter payable by Company to Administrative Agent and Holders
under the Note Documents, are unconditionally owing by Company to Administrative Agent and Holders,
without offset, defense or counterclaim of any kind, nature or description whatsoever. Company (and
each other Restricted Person by execution of the attached Consent and Reaffirmation) hereby
acknowledges, confirms and agrees that Administrative Agent and Holders have and shall continue to
have valid, enforceable and perfected first-priority Liens in the Collateral heretofore granted to
Administrative Agent and Holders pursuant to the Note Documents or otherwise granted to or held by
such Persons.

To induce Holder Parties to enter into this Letter, Company (and each other Restricted Person
by execution of the attached Consent and Reaffirmation) hereby (a) represents and warrants that as
of the date of this Letter there are no claims or offsets against or defenses or counterclaims to
its obligations under the Note Documents, and waives any and all such claims, offsets, defenses,
or counterclaims, whether known or unknown, arising prior to the date of this Letter, (b) releases
and forever discharges the Released Persons from any and all Released Claims, and (c) covenants
not to assert (and not to assist or enable any other Person to assert) any Released Claim against
any Released Person. The Restricted Persons acknowledge and agree that such release is a general
release of any and all Released Claims that constitutes a full and complete satisfaction for all
or any alleged injuries or damages arising out of or in connection with the Released Claims, all
of which are herein compromised and settled. As used in this paragraph, “Released Claims” and
“Released Persons” mean:

“Released Claims” means any and all actions, causes of action, judgments, executions,
suits, debts, claims, demands, controversies, liabilities, obligations, damages and
expenses of any and every character (whether known or unknown, liquidated or unliquidated,
absolute or contingent, acknowledged or disputed, direct or indirect), at law or in equity,
of whatsoever kind or nature (including claims of usury), whether heretofore or hereafter
accruing, for or because of any matter or things done, omitted or suffered to be done by
any of the Released Persons prior to and including the date hereof that in any way directly
or indirectly arise out of or in any way are connected to (a) any of the Note Documents or
any default or event of default thereunder, (b) any negotiation, discussion, enforcement
action, agreement or failure to agree related to any Note Document or any default or event
of default thereunder, or (c) any action, event, occurrence, or omission otherwise related
to the rights, duties, obligations and relationships among the various Restricted Persons
and Holder Parties.

“Released Persons” means Administrative Agent, Holders, and Royalty Owner,
together with their respective employees, agents, attorneys, officers, partners,
shareholders, accountants, consultants, and directors, and their respective successors and
assigns.

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

December 30, 2008 

Page 3

The Note Purchase Agreement and the other Note Documents are hereby ratified and confirmed in
all respects. Except as expressly set forth above, the execution, delivery and effectiveness of
this letter shall not operate as a waiver of any right, power or remedy of Administrative Agent or
Holders under the Note Purchase Agreement or any other Note Document, nor constitute a waiver of
any provision of the Note Purchase Agreement or any other Note Document.

THIS LETTER AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE GOVERNED BY, AND
SHALL BE CONSTRUED AND ENFORCED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT
REGARD TO CONFLICT OF LAWS PRINCIPLES THEREOF.

This Letter may be executed in any number of counterparts, each of which when so executed and
delivered shall be deemed an original, but all such counterparts together shall constitute but one
and the same instrument. This Letter may be executed by facsimile signature and all such
signatures shall be effective as originals.

This Letter is a “Note Document”, as defined in the Note Purchase Agreement, and, except as
expressly provided herein to the contrary, this Letter is subject to all provisions of the Note
Purchase Agreement governing such Note Documents.

Please execute a counterpart of this Letter in the place provided below to evidence your
agreement to the foregoing and your continuing ratification of the Note Purchase Agreement and the
other Note Documents in consideration hereof, whereupon this Letter shall become effective as of
the date first written above.

	 	 	 	 	 
	 	Yours truly,

TCW ASSET MANAGEMENT COMPANY, 

as Administrative Agent

 	 
	 	By:  	
 	 
	 	 	Name:  	 	 
	 	 	Title:  	 	 
	 	 	 
	 	By:  	
 	 
	 	 	Name:  	 	 
	 	 	Title:  	 	 

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

December 30, 2008

Page 4

	 	 	 	 	 	 	 	 	 
	 	 	HOLDERS:
	 
	 	 	 	 	 	 	 	 
	 	 	TCW ENERGY FUND X — NL, L.P.,

a California limited partnership
	 
	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X) LLC, its General Partner:
	 
	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member
	 
	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 
	 

	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:
	 

	 	 	 	 	 	 	 	Title:
	 
	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 
	 

	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:
	 

	 	 	 	 	 	 	 	Title:
	 
	 	 	 	 	 	 	 	 
	 	 	TCW ENERGY FUND XB — NL, L.P.,

a California limited partnership
	 
	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X) LLC, its General Partner:
	 
	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member
	 
	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 
	 

	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:
	 

	 	 	 	 	 	 	 	Title:
	 
	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 
	 

	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:
	 

	 	 	 	 	 	 	 	Title:

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

December 30, 2008

Page 5

	 	 	 	 	 	 	 	 	 
	 	 	TCW ENERGY FUND XC — NL, L.P.,

a California limited partnership
	 
	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X) LLC, its General Partner:
	 
	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member
	 
	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 
	 

	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:
	 

	 	 	 	 	 	 	 	Title:
	 
	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 
	 

	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:
	 

	 	 	 	 	 	 	 	Title:
	 
	 	 	 	 	 	 	 	 
	 	 	TCW ENERGY FUND XD — NL, L.P.,

a California limited partnership
	 
	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X) LLC, its General Partner:
	 
	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member
	 
	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 
	 

	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:
	 

	 	 	 	 	 	 	 	Title:
	 
	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 
	 

	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:
	 

	 	 	 	 	 	 	 	Title:

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

December 30, 2008

Page 6

	 	 	 	 	 
	 	 	TCW ASSET MANAGEMENT COMPANY, a

California corporation, as Investment Manager under the Amended and Restated Investment Management
and Custody Agreement dated as of December 3, 2003 among Ensign Peak Advisors, Inc., TCW Asset
Management Company and Trust Company of the West, a California trust company, as Sub-Custodian
	 
	 	 	 	 
	 

	 	By:	 	 
	 

	 	 	 	 
	 

	 	 	 	Name:
	 

	 	 	 	Title:
	 
	 	 	 	 
	 

	 	By:	 	 
	 

	 	 	 	 
	 

	 	 	 	Name:
	 

	 	 	 	Title:
	 
	 	 	 	 
	 	 	TCW ASSET MANAGEMENT COMPANY, a

California corporation, as Investment Manager under the Amended and Restated Investment Management
and Custody Agreement dated as of December 11, 2003 among Harry L. Bradley, Jr. Partition Trust,
Harry L. Bradley, Jr. Trust, Jane Bradley Uihlien Pettit Partition Trust, Jane Bradley Uihlien
Trust, TCW Asset Management Company and Trust Company of the West, a California trust company, as
Sub-Custodian
	 
	 	 	 	 
	 

	 	By:	 	 
	 

	 	 	 	 
	 

	 	 	 	Name:
	 

	 	 	 	Title:
	 
	 	 	 	 
	 

	 	By:	 	 
	 

	 	 	 	 
	 

	 	 	 	Name:
	 

	 	 	 	Title:

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

December 30, 2008

Page 7

	 	 	 	 	 
	 	 	TCW ASSET MANAGEMENT COMPANY, a

California corporation, as Investment Manager under the Amended and Restated Investment Management
and Custody Agreement dated as of March 18, 2004 among ING Life Insurance and Annuity Company, TCW
Asset Management Company and Trust Company of the West, a California trust company, as
Sub-Custodian
	 
	 	 	 	 
	 

	 	By:	 	 
	 

	 	 	 	 
	 

	 	 	 	Name:
	 

	 	 	 	Title:
	 
	 	 	 	 
	 

	 	By:	 	 
	 

	 	 	 	 
	 

	 	 	 	Name:
	 

	 	 	 	Title:

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

December 30, 2008

Page 8

	 	 	 	 	 
	Accepted and agreed to as of the date first written above:	 	 
	 
	 	 	 	 
	RIO VISTA PENNY LLC	 	 
	 
	 	 	 	 
	By:

	 	/s/ Ian Bothwell	 	 
	 

	 	 	 	 
	 

	 	Ian Bothwell

Manager
	 	 

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

December 30, 2008

Page 9

CONSENT AND REAFFIRMATION

Each of the undersigned hereby (i) consents to the provisions of this Letter Agreement
and the transactions contemplated herein and agrees to the provisions therein related to it as
a Restricted Person, (ii) ratifies and confirms the Management Services Agreement, the
Guaranty dated November 19, 2007, and the other Note Documents, in each case to which it is a
party, (iii) agrees that all of its respective obligations and covenants thereunder shall
remain unimpaired by the execution and delivery of this Letter Agreement, and (iv) agrees that
the Management Services Agreement, such Guaranty, and such other Note Documents shall remain
in full force and effect.

	 	 	 	 	 
	 	RIO VISTA ECO LLC

 	 
	 	By:  	/s/ Ian Bothwell
 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 
	 	RIO VISTA GO LLC

 	 
	 	By:  	/s/ Ian Bothwell
 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 
	 	GO, LLC

 	 
	 	By:  	/s/ Ian Bothwell
 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 
	 	MV PIPELINE COMPANY

 	 
	 	By:  	/s/ Ian Bothwell
 	 
	 	 	Ian Bothwell 	 
	 	 	President 	 

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

December 30, 2008

Page 10

	 	 	 	 	 
	 	RIO VISTA OPERATING LLC

 	 
	 	By:  	/s/ Ian Bothwell
 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 
	 	RIO VISTA ENERGY PARTNERS L.P.

 	 
	 	By:  	Rio Vista GP LLC, its general partner
 	 
	 	 	 
	 	By:  	                                            /s/ Ian Bothwell
 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 

[Letter Agreement]Exhibit 10.85

Exhibit 10.85

TCW ASSET MANAGEMENT COMPANY

865 South Figueroa Street, suite 1800

Los Angeles, California 90017

February 28, 2009

Rio Vista Penny LLC

2601 Northwest Expressway #902E

Oklahoma City, Oklahoma 93112

Attention: Ian Bothwell

	 	 	 	 	 
	 

	 	Re:
	 	Note Purchase Agreement, dated as of November 19, 2007 (as amended,
supplemented or otherwise modified, the “Note Purchase Agreement”), by and among RIO
VISTA PENNY LLC, an Oklahoma limited liability company (“Company”), the Holders party
thereto, and TCW ASSET MANAGEMENT COMPANY, as Administrative
Agent.

Gentlemen:

Reference is made to the Note Purchase Agreement. Terms that are defined in the Note Purchase
Agreement and not otherwise defined herein are used herein with the meanings given them in the Note
Purchase Agreement.

Company has requested that Holders extend the required payments of principal and accrued
interest that are due and payable on February 28, 2009 and also to extend the date to deliver the
Engineering Report effective as of November 1, 2008, in each case to March 23, 2009. Accordingly,
in reliance upon the representations, warranties, covenants, and waivers of the Restricted Persons
contained in this Letter, and subject to the terms and conditions of this Letter, Administrative
Agent and Holders hereby agree that (i) the mandatory principal payment in respect of the Notes due
and payable on the December 2008 Quarterly Payment Date pursuant Section 2.8(a) of the Note
Purchase Agreement is hereby extended to March 23, 2009 (which was previously extended to February
28, 2009 by letter agreement dated December 30, 2008 among the parties hereto), (ii) the required
payment of accrued interest in respect of the Notes due and payable on the December 2008 Quarterly
Payment Date is hereby extended to March 23, 2009 (which was previously extended to February 28,
2009 by letter agreement dated December 30, 2008 among the parties hereto), and (iii) the delivery
of the Engineering Report to be effective as of November 1, 2008 that was due prior to December 1,
2008 pursuant to Section 7.2(i) of the Note Purchase Agreement is hereby extended to March 23, 2009
(which was previously extended to February 28, 2009 by letter agreement dated December 30, 2008
among the parties hereto).

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

February 28, 2009

Page 2

Pursuant to the terms of the Warrant, Warrant Owner is entitled at any time and from time to
time to purchase from Parent common units of Parent (the “Units”) upon the terms and conditions as
set forth therein. Holder Parties and Restricted Persons are engaged in ongoing discussions
relating to various restructuring options with respect to the Obligations. During the
pendency of such discussions, Warrant Owner has agreed to provide certain advance notice prior
to exercising its right to purchase Units. Accordingly, in reliance upon the representations,
warranties, covenants, and waivers of the Restricted Persons contained in this Letter, and subject
to the terms and conditions of this Letter and notwithstanding the terms of the Warrant, Warrant
Owner hereby agrees that it will not exercise its right to purchase more than 400,000 Units
(subject to adjustment as provided for in the Warrant) without providing at least 62 days prior
written notice to Parent.

In order to induce Holder Parties to enter into this Letter, Company represents and warrants
to each Holder Party that the representations and warranties contained in Article V of the Note
Purchase Agreement are true and correct at and as of the time of the effectiveness hereof, except
to the extent such representations and warranties specifically refer to an earlier date, in which
case they are true and correct as of such earlier date. Company hereby further acknowledges,
confirms and agrees that as of the close of business on February 28, 2009, Company is indebted to
Holders in respect of the Loans in the aggregate principal amount of $24,700,000.00 and in respect
of accrued but unpaid interest related thereto in the amount of $1,395,893.06. All such Loans,
together with interest accrued and accruing thereon, and fees, costs, expenses and other charges
now or hereafter payable by Company to Administrative Agent and Holders under the Note Documents,
are unconditionally owing by Company to Administrative Agent and Holders, without offset, defense
or counterclaim of any kind, nature or description whatsoever. Company (and each other Restricted
Person by execution of the attached Consent and Reaffirmation) hereby acknowledges, confirms and
agrees that Administrative Agent and Holders have and shall continue to have valid, enforceable and
perfected first-priority Liens in the Collateral heretofore granted to Administrative Agent and
Holders pursuant to the Note Documents or otherwise granted to or held by such Persons.

To induce Holder Parties to enter into this Letter, Company (and each other Restricted Person
by execution of the attached Consent and Reaffirmation) hereby (a) represents and warrants that as
of the date of this Letter there are no claims or offsets against or defenses or counterclaims to
its obligations under the Note Documents, and waives any and all such claims, offsets, defenses, or
counterclaims, whether known or unknown, arising prior to the date of this Letter, (b) releases and
forever discharges the Released Persons from any and all Released Claims, and (c) covenants not to
assert (and not to assist or enable any other Person to assert) any Released Claim against any
Released Person. The Restricted Persons acknowledge and agree that such release is a general
release of any and all Released Claims that constitutes a full and complete satisfaction for all or
any alleged injuries or damages arising out of or in connection with the Released Claims, all of
which are herein compromised and settled. As used in this paragraph, “Released Claims” and
“Released Persons” mean:

“Released Claims” means any and all actions, causes of action, judgments,
executions, suits, debts, claims, demands, controversies, liabilities, obligations, damages
and expenses of any and every character (whether known or unknown, liquidated or
unliquidated, absolute or contingent, acknowledged or disputed, direct or indirect), at law
or in equity, of whatsoever kind or nature (including claims of usury), whether heretofore
or hereafter accruing, for or because of any matter or things done, omitted or suffered
to be done by any of the Released Persons prior to and including the date hereof that in any
way directly or indirectly arise out of or in any way are connected to (a) any of the Note
Documents or any default or event of default thereunder, (b) any negotiation, discussion,
enforcement action, agreement or failure to agree related to any Note Document or any
default or event of default thereunder, or (c) any action, event, occurrence, or omission
otherwise related to the rights, duties, obligations and relationships among the various
Restricted Persons and Holder Parties.

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

February 28, 2009

Page 3

“Released Persons” means Administrative Agent, Holders, and Royalty Owner,
together with their respective employees, agents, attorneys, officers, partners,
shareholders, accountants, consultants, and directors, and their respective successors and
assigns.

The Note Purchase Agreement and the other Note Documents are hereby ratified and confirmed in
all respects. Except as expressly set forth above, the execution, delivery and effectiveness of
this letter shall not operate as a waiver of any right, power or remedy of Administrative Agent or
Holders under the Note Purchase Agreement or any other Note Document, nor constitute a waiver of
any provision of the Note Purchase Agreement or any other Note Document.

THIS LETTER AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE GOVERNED BY, AND
SHALL BE CONSTRUED AND ENFORCED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT
REGARD TO CONFLICT OF LAWS PRINCIPLES THEREOF.

This Letter may be executed in any number of counterparts, each of which when so executed and
delivered shall be deemed an original, but all such counterparts together shall constitute but one
and the same instrument. This Letter may be executed by facsimile signature and all such
signatures shall be effective as originals.

This Letter is a “Note Document”, as defined in the Note Purchase Agreement, and, except as
expressly provided herein to the contrary, this Letter is subject to all provisions of the Note
Purchase Agreement governing such Note Documents.

Please execute a counterpart of this Letter in the place provided below to evidence your
agreement to the foregoing and your continuing ratification of the Note Purchase Agreement and the
other Note Documents in consideration hereof, whereupon this Letter shall become effective as of
the date first written above.

	 	 	 	 	 
	 	Yours truly,

TCW ASSET MANAGEMENT COMPANY,

 as Administrative Agent

 	 
	 	By:  	 	 
	 	 	Name:  	 	 
	 	 	Title:  	 	 
	 
	 	By:  	
 	 
	 	 	Name:  	 	 
	 	 	Title:  	 	 

 [Letter Agreement]

 

 

 

Rio Vista Penny LLC

February 28, 2009

Page 4

	 	 	 	 	 	 	 	 	 	 	 
	 	 	HOLDERS:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	TCW ENERGY FUND X — NL, L.P.,

a California limited partnership	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X), LLC, its General Partner:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 

Name:

Title:
	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 

Name:

Title:
	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	TCW ENERGY FUND XB — NL, L.P.,

a California limited partnership	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X), LLC, its General Partner:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 

Name:

Title:
	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 

Name:

Title:
	 	 

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

February 28, 2009

Page 5

	 	 	 	 	 	 	 	 	 	 	 
	 	 	TCW ENERGY FUND XC — NL, L.P., 

a California limited partnership	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X), LLC, its General Partner:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 

Name:

Title:
	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 

Name:

Title:
	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	TCW ENERGY FUND XD
— NL, L.P.,

a California limited partnership	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X), LLC, its General Partner:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 

Name:

Title:
	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 

Name:

Title:
	 	 

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

February 28, 2009

Page 6

	 	 	 	 	 
	 	TCW ASSET MANAGEMENT COMPANY, a California
corporation, as Investment Manager under the Amended
and Restated Investment Management and Custody
Agreement dated as of December 3, 2003 among Ensign
Peak Advisors, Inc., TCW Asset Management Company and
Trust Company of the West, a California trust
company, as Sub-Custodian
 
	 
	 	 	 
	 	By:  	 	 
	 	 	Name:  	 	 
	 	 	Title:  	 	 
	 	 	 
	 	By:  	
 	 
	 	 	Name:  	 	 
	 	 	Title:  	 	 
	 
	 	TCW ASSET MANAGEMENT COMPANY, a California
corporation, as Investment Manager under the Amended
and Restated Investment Management and Custody
Agreement dated as of December 11, 2003 among Harry
L. Bradley, Jr. Partition Trust, Harry L. Bradley,
Jr. Trust, Jane Bradley Uihlien Pettit Partition
Trust, Jane Bradley Uihlien Trust, TCW Asset
Management Company and Trust Company of the West, a
California trust company, as Sub-Custodian

 
	 
	 	By:  	 	 
	 	 	Name:  	 	 
	 	 	Title:  	 	 
	 	 	 
	 	By:  	
 	 
	 	 	Name:  	 	 
	 	 	Title:  	 	 

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

February 28, 2009

Page 7

	 	 	 	 	 	 	 	 	 	 	 
	 	 	TCW ASSET MANAGEMENT COMPANY, a California
corporation, as Investment Manager under the Amended
and Restated Investment Management and Custody
Agreement dated as of March 18, 2004 among ING Life
Insurance and Annuity Company, TCW Asset Management
Company and Trust Company of the West, a California
trust company, as Sub-Custodian
	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	By:	 	 	 	 	 	 	 	 
	 	 	 	 	 	 	 
	 

	 	 	 	Name:

Title:	 	 	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	By:	 	 	 	 	 	 	 	 
	 	 	 	 	 	 	 
	 

	 	 	 	Name:

Title:	 	 	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	WARRANT OWNER:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	ENERGY FUNDS X HOLDINGS, L.P.,

a California limited partnership	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X), LLC, its General Partner:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 

Name:

Title:
	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 

Name:

Title:
	 	 

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

February 28, 2009

Page 8

	 	 	 	 	 
	Accepted and agreed to as of the date first written above:

RIO VISTA PENNY LLC	 	 
	 
	 	 	 	 
	By:
	 	 	 	 
	 

	 	 

Ian Bothwell

Manager
	 	 

[Letter Agreement]

 

 

 

 Rio Vista Penny LLC

February 28, 2009

Page 9

CONSENT AND REAFFIRMATION

Each of the undersigned hereby (i) consents to the provisions of this Letter Agreement and the
transactions contemplated herein and agrees to the provisions therein related to it as a Restricted
Person, (ii) ratifies and confirms the Management Services Agreement, the Guaranty dated November
19, 2007, and the other Note Documents, in each case to which it is a party, (iii) agrees that all
of its respective obligations and covenants thereunder shall remain unimpaired by the execution and
delivery of this Letter Agreement, and (iv) agrees that the Management Services Agreement, such
Guaranty, and such other Note Documents shall remain in full force and effect.

	 	 	 	 	 
	 	RIO VISTA ECO LLC

 	 
	 	By:  	 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 
	 	RIO VISTA GO LLC

 	 
	 	By:  	 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 
	 	GO, LLC

 	 
	 	By:  	 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 
	 	MV PIPELINE COMPANY

 	 
	 	By:  	 	 
	 	 	Ian Bothwell 	 
	 	 	President 	 

[Letter Agreement]

 

 

 

Rio Vista Penny LLC

February 28, 2009

Page 10

	 	 	 	 	 
	 	RIO VISTA OPERATING LLC

 	 
	 	By:  	 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 
	 	RIO VISTA ENERGY PARTNERS L.P.

 	 
	 	By: Rio Vista GP LLC, its general partner
 	 
	 	 	 
	 	By:  	
 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 

[Letter Agreement]

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00157-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00157-of-00352.parquet"}]]