<PAGE>
                                                                     EXHIBIT 4.5

                      AMENDED AND RESTATED PARENT GUARANTY

         GUARANTY, dated as May 1, 2002, by NOBLE CORPORATION, a Cayman Islands
exempted company limited by shares ("Parent"), NOBLE HOLDING (U.S.) CORPORATION,
a Delaware corporation ("NHC"), and NOBLE DRILLING CORPORATION, a Delaware
corporation ("NDC"; Parent, NHC and NDC each a "Guarantor"), in favor of
JPMORGAN CHASE BANK, successor-by-merger to Chase Bank of Texas, N.A., as
trustee ("Trustee") for the benefit of the Purchasers. All capitalized terms
used herein and not otherwise defined shall have the meanings provided such
terms in the Agreement referred to below.

                                   WITNESSETH:

         WHEREAS, Noble Drilling (Paul Wolff) Ltd. (the "Company") entered into
a Note Purchase Agreement (as heretofore amended, the "Agreement"), dated July
1, 1998, among the Company, the Trustee and the Purchasers, pursuant to which
the Company issued and sold, and the Purchasers purchased, the Notes referred to
therein;

         WHEREAS, NDC guaranteed the Obligations of the Company under the
Agreement and the Notes pursuant to a certain Parent Guaranty dated July 1, 1998
(the "Original Parent Guaranty") by NDC in favor of Trustee;

         WHEREAS, NDC is contemporaneously herewith reorganizing its corporate
structure in order that, immediately after giving effect to such reorganization,
NDC will be a wholly-owned Subsidiary of NHC and NHC will be a wholly-owned
Subsidiary of Parent;

         WHEREAS, the Company is a wholly-owned indirect Subsidiary of NDC, and
each Guarantor will continue to obtain benefits from the holding of the Notes by
the Purchasers, and it is a condition precedent to the consent of Purchasers to
such reorganization that the Original Parent Guaranty be amended and restated,
and that each Guarantor execute and deliver this Guaranty guaranteeing the
Obligations of the Company under the Agreement and the Notes;

         WHEREAS, each Guarantor may reasonably be expected to benefit, either
directly or indirectly, from this Guaranty;

         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, each Guarantor hereby agrees as
follows:

         1. The Guaranty. In order to induce the Purchasers to continue to hold
the Notes and consent to such reorganization, and in recognition of the direct
benefits to be received by each Guarantor therefrom, each Guarantor hereby
jointly and severally unconditionally and irrevocably guarantees, as primary
obligor and not merely as surety the full and prompt payment when due, whether
upon maturity, acceleration or otherwise, of any and all of the (x) Obligations
and (y) all other obligations (including which but for the automatic stay under
Section 362(a) of the Bankruptcy Code, would become due) and liabilities owing
by the Company to the Purchasers under the Agreement (including, without
limitation, indemnities and interest thereon) now existing or hereafter incurred
under arising out of or in connection with the Agreement or any other Credit
Document and the due performance and compliance with the terms of the Credit
Documents by the Company (collectively, the "Guaranteed Obligations"), and
additionally each



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Guarantor hereby jointly and severally unconditionally and irrevocably
guarantees the performance of all obligations and covenants of Noble Drilling
(Nederland) B.V. ("NDNBV"), or an Affiliate thereof, in its capacity as
contractor under that certain Contract No. 101.2.038.97-5 Charter Contract --
Contract for the Charter of Floating Unit with Dynamic Positioning entered into
between Petroleo Brasileiro S.A.-Petrobras, and NDNBV. If any of the Guaranteed
Obligations becomes due and payable hereunder, each Guarantor unconditionally
promises to pay such indebtedness to Secured Creditors, or order, on demand,
together with (without duplication) any and all expenses which may be incurred
by Secured Creditors in collecting any of the Guaranteed Obligations. This
Guaranty is a continuing one and all liabilities to which it applies or may
apply under the terms hereof shall be conclusively presumed to have been created
in reliance hereon. All payments made by any Parent Guarantor hereunder will be
made free and clear of, and without deduction or withholding for, any present or
future Taxes. If any Taxes are so levied or imposed, each Guarantor agrees to
pay the full amount of such Taxes, and such additional amounts, if any, as may
be necessary so that every payment of all amounts due hereunder, after
withholding or deduction for or on account of any Taxes, will not be less than
the amount provided for herein. If any amounts are payable in respect of Taxes
pursuant to the preceding sentence, each Guarantor agrees to reimburse each
Purchaser, upon the written request of such Purchaser, for taxes imposed on or
measured by the net income or net profits of such Purchaser pursuant to the laws
of the jurisdiction in which the principal office or lending office of such
Purchaser is located or under the laws of any political subdivision or taxing
authority of any such jurisdiction in which the principal office or applicable
lending office of such Purchaser is located and for any withholding of taxes as
such Purchaser shall determine are payable by, or withheld from, such Purchaser
in respect of such amounts so paid to or on behalf of such Purchaser pursuant to
the preceding sentence and in respect of any amounts paid to or on behalf of
such Purchaser pursuant to this sentence. Each Guarantor will furnish to the
Trustee within 45 days after the date the payment of any Taxes is due pursuant
to applicable law certified copies of tax receipts evidencing such payment by
such Guarantor. Each Guarantor agrees to indemnify and hold harmless each
Purchaser, and reimburse such Purchaser upon its written request, for the amount
of any Taxes so levied or imposed and paid by such Purchaser. If a claim is ever
made upon any Secured Creditor for repayment or recovery of any amount or
amounts received in payment or on account of any of the Guaranteed Obligations
and any of the aforesaid payees repays all or part of said amount by reason of
(i) any judgment, decree or order of any court or administrative body having
jurisdiction over such payee or any of its property, including, but not limited
to any repayment by reason of a preferential payment or fraudulent transfer or
(ii) any settlement or compromise of any such claim effected by such payee with
any such claimant (including the Company), then and in such event each Guarantor
agrees that any such judgment, decree, order, settlement or compromise shall be
binding upon such Guarantor, notwithstanding any revocation of this Guaranty or
any other instrument evidencing any liability of the Company, and each Guarantor
shall be and remain liable to the aforesaid payees hereunder for the amount so
repaid or recovered to the same extent as if such amount had never originally
been received by any such payee.

         2. Bankruptcy. Additionally, each Guarantor unconditionally and
irrevocably guarantees the payment of any and all of the Guaranteed Obligations
to the Secured Creditors whether or not due or payable by the Company upon the
occurrence in respect of the Company of any of the events specified in Section
8.05 of the Agreement, and unconditionally promises to pay such indebtedness on
demand, in Dollars.



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         3. Nature of Liability. The liability of each Guarantor hereunder is
exclusive and independent of any security for or other guaranty of the
Guaranteed Obligations whether executed by such Guarantor, any other guarantor
or by any other party, and the liability of each Guarantor hereunder is not
affected or impaired by (a) any direction as to application of payment by the
Company or by any other party or (b) any other continuing or other guaranty,
undertaking or maximum liability of a guarantor or of any other party as to the
Guaranteed Obligations or (c) any payment on or in reduction of any such other
guaranty or undertaking or (d) any dissolution, termination or increase,
decrease or change in personnel by the Company.

         4. Absolute and Independent Obligation. No invalidity, irregularity or
unenforceability of all or any part of the Guaranteed Obligations or of any
security therefor shall affect, impair or be a defense to this Guaranty and this
Guaranty shall be primary, absolute and unconditional notwithstanding the
occurrence of any event or the existence of any other circumstances which might
constitute a legal or equitable discharge of a surety or guarantor except
irrevocable payment in full of the Guaranteed Obligations. The obligations of
each Guarantor hereunder are independent of the obligations of the Company, any
other guarantor or any other Person and a separate action or actions may be
brought and prosecuted against any Guarantor whether or not action is brought
against the Company or any such other guarantor or Person and whether or not the
Company, or any such other guarantor or other Person be joined in any such
action or actions. Each Guarantor waives, to the full extent permitted by law,
the benefit of any statute of limitations affecting its liability hereunder or
the enforcement hereof.

         5. Authorization. Each Guarantor authorizes the Secured Creditors
without notice or demand (except as shall be required by applicable statute and
cannot be waived), and without affecting or impairing its liability hereunder,
from time to time to:

         (a) change the manner, place or terms of payment of, and/or change or
         extend the time of payment of, renew, increase, accelerate or alter,
         any of the Guaranteed Obligations (including any increase or decrease
         in the rate of interest thereon), any security therefor, or any
         liability incurred directly or indirectly in respect thereof, and the
         Guaranty herein made shall apply to the Guaranteed Obligations as so
         changed, extended, renewed or altered;

         (b) take and hold security for the payment of the Guaranteed
         Obligations and sell, exchange, release, surrender, realize upon or
         otherwise deal with in any manner and in any order any property by
         whomsoever at any time pledged or mortgaged to secure, or howsoever
         securing, the Guaranteed Obligations or any liabilities (including any
         of those hereunder) incurred directly or indirectly in respect thereof
         or hereof, and/or any offset thereagainst;

         (c) exercise or refrain from exercising any rights against any Credit
         Party or others or otherwise act or refrain from acting;

         (d) release or substitute any one or more endorsers, guarantors, the
         Company or other obligors;

         (e) settle or compromise any of the Guaranteed Obligations, any
         security therefor or any liability (including any of those hereunder)
         incurred directly or indirectly in respect thereof or hereof, and may
         substitute the payment of all or any part thereof to the




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         payment of any liability (whether due or not) of the Company to its
         creditors other than the Secured Creditors;

         (f) apply any sums by whomsoever paid or howsoever realized to any
         liability or liabilities of the Company to the Secured Creditors
         regardless of what liability or liabilities of the Company remain
         unpaid;

         (g) consent to or waive any breach of, or any act, omission or default
         under, this Agreement, any other Credit Document or any of the
         instruments or agreements referred to herein or therein, or otherwise
         amend, modify or supplement this Agreement, any other Credit Document
         or any of such other instruments or agreements; and/or

         (h) take any other action which would, under otherwise applicable
         principles of common law, give rise to a legal or equitable discharge
         of such Guarantor from its liabilities under this Guaranty.

         6. Reliance. It is not necessary for the Secured Creditors to inquire
into the capacity or powers of the Company or the officers, directors, partners
or agents acting or purporting to act on their behalf, and any Guaranteed
Obligations made or created in reliance upon the professed exercise of such
powers shall be guaranteed hereunder.

         7. Subordination. Any of the indebtedness of the Company now or
hereafter owing to any Guarantor is hereby subordinated to the Guaranteed
Obligations. Prior to the transfer by any Guarantor of any note or negotiable
instrument evidencing any of the indebtedness of the Company to any Guarantor,
such Guarantor shall mark such note or negotiable instrument with a legend that
the same is subject to this subordination. Without limiting the generality of
the foregoing, each Guarantor hereby agrees with the Secured Creditors that it
will not exercise any right of subrogation which it may at any time otherwise
have as a result of this Guaranty (whether contractual, under law or otherwise)
until all Guaranteed Obligations have been irrevocably paid in full in cash.

         8. Waiver. (a) Each Guarantor waives any right (except as cannot be
waived under law) to require any Secured Creditor to (i) proceed against the
Company, any other guarantor or any other party, (ii) proceed against or exhaust
any security held from the Company, any other guarantor or any other party or
(iii) pursue any other remedy in any Secured Creditor's power whatsoever. Each
Guarantor waives any defense based on or arising out of any defense of the
Company, any other guarantor or any other party, other than irrevocable payment
in full of the Guaranteed Obligations, based on or arising out of the disability
of the Company, any other guarantor or any other party, or the unenforceability
of the Guaranteed Obligations or any part thereof from any cause, or the
cessation from any cause of the liability of the Company other than irrevocable
payment in full of the Guaranteed Obligations. The Secured Creditors may, at
their election, foreclose on any security held by the Trustee or any other
Secured Creditor by one or more judicial or nonjudicial sales, whether or not
every aspect of any such sale is commercially reasonable (to the extent such
sale is permitted by applicable law), or exercise any other right or remedy the
Secured Creditors may have against the Company or any other party, or any
security, without affecting or impairing in any way the liability of any
Guarantor hereunder except to the extent the Guaranteed Obligations have been
irrevocably paid.



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         (b) Each Guarantor waives all presentments, demands for performance,
protests and notices (except notices expressly provided for in the Credit
Documents to be provided to such Guarantor), including, without limitation,
notices of nonperformance, notices of protest, notices of dishonor, notices of
acceptance of this Guaranty, and notices of the existence, creation or incurring
of new or additional Guaranteed Obligations. Each Guarantor assumes all
responsibility for being and keeping itself informed of the Company's financial
condition and assets, and of all other circumstances, bearing upon the risk of
nonpayment of the Guaranteed Obligations and the nature, scope and extent of the
risks which such Guarantor assumes and incurs hereunder, and agrees that the
Secured Creditors shall have no duty to advise any Guarantor of information
known to them regarding such circumstances or risks.

         (c) Until such time as the Guaranteed Obligations have been irrevocably
paid in full in cash , each Guarantor hereby waives all rights of subrogation
which it may at any time otherwise have as a result of this Guaranty (whether
contractual, under law, or otherwise) to the claims of the Secured Creditors
against the Company or any other guarantor of the Guaranteed Obligations and all
contractual, statutory or common law rights of reimbursement, contribution or
indemnity from the Company or any other guarantor which it may at any time
otherwise have as a result of this Guaranty.

         9. Enforcement. The Secured Creditors agree that this Guaranty may be
enforced only by the action of the Trustee, in each case acting upon the
instructions of the Required Purchasers and no Secured Creditor shall have any
right individually to seek to enforce or to enforce this Guaranty or to realize
upon the security to be granted by the Security Documents, it being understood
and agreed that such rights and remedies may be exercised by the Trustee for the
benefit of the Secured Creditors upon the terms of this Guaranty and the
Security Documents.

         10. Representations, Warranties and Agreements. In order to induce the
Purchasers to accept this Guaranty and to continue to hold the Notes and consent
to the reorganization, each Guarantor makes the following representations and
warranties to, and agreements with, the Purchasers, all of which shall survive
the execution and delivery of this Guaranty:

         (a) Corporate Status. Each Guarantor is a duly organized and validly
         existing corporation in good standing under the laws of the
         jurisdiction of its organization and has the corporate power and
         authority to own its property and assets and to transact the business
         in which it is engaged.

         (b) Corporate Power and Authority. Each Guarantor has the corporate
         power and authority to execute, deliver and carry out the terms and
         provisions hereof and has taken all necessary corporate action to
         authorize the execution, delivery and performance hereof. Each
         Guarantor has duly executed and delivered this Guaranty and such
         Guaranty constitutes the legal, valid and binding obligation of such
         Guarantor enforceable against such Guarantor in accordance with its
         terms, except to the extent that the enforceability thereof may be
         limited by applicable bankruptcy, insolvency, reorganization,
         moratorium or similar laws generally affecting creditors' rights and by
         equitable principles (regardless of whether enforcement is sought in
         equity or at law).

         (c) No Violation. Neither the execution, delivery and performance by
         any Guarantor of this Guaranty nor compliance with the terms and
         provisions hereof, nor the consummation of the transactions
         contemplated herein (i) will contravene any applicable




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         provision of any law, statute, rule, regulation, order, writ,
         injunction or decree of any court or governmental instrumentality ,
         (ii) will result in any breach of any of the terms, covenants,
         conditions or provisions of, or constitute a default under, or result
         in the creation or imposition of (or the obligation to create or
         impose) any Lien upon any of the property or assets of such Guarantor
         pursuant to the terms of, any indenture, mortgage, deed of trust,
         agreement or other instrument to which Parent or any of its
         Subsidiaries is a party or by which they or any of their respective
         property or assets are bound or to which they are subject, or (iii)
         will violate any provision of the Memorandum of Association,
         Certificate of Incorporation, Articles of Association or Bylaws of such
         Guarantor.

         (d) Litigation. There are no actions, suits or proceedings pending or,
         to the knowledge of any Guarantor, after due inquiry, threatened with
         respect to Parent or its Subsidiaries that are reasonably likely to
         have a material adverse effect on the rights or remedies of the
         Purchasers or on the ability of any Guarantor to perform its
         obligations to them hereunder.

         (e) Governmental Approvals. Except for the orders, consents, approvals,
         licenses, authorizations, validations, recordings, registrations and
         exemptions that have already been duly made or obtained and remain in
         full force and effect, no order, consent, approval, license,
         authorization, or validation of, or filing, recording or registration
         with, or exemption by, any foreign or domestic governmental or public
         body or authority, or any subdivision thereof, is required to authorize
         or is required in connection with (i) the execution, delivery and
         performance hereof, or (ii) the legality, validity, binding effect or
         enforceability hereof.

         (f) Investment Company Act. No Guarantor nor any other Credit Party is
         an "investment company" or a company "controlled" by an "investment
         company," within the meaning of the Investment Company Act of 1940, as
         amended.

         (g) Public Utility Holding Company Act. No Guarantor nor any other
         Credit Party is a "holding company," or a "subsidiary company" of a
         "holding company," or an "affiliate" of a "holding company" or of a
         "subsidiary company" of a "holding company," within the meaning of the
         Public Utility Holding Company Act of 1935, as amended.

         (h) True and Complete Disclosure. All information (taken as a whole)
         heretofore or contemporaneously furnished by or on behalf of any
         Guarantor in writing to the Trustee or any Purchaser for purposes of or
         in connection with the Agreement, this Guaranty or any transaction
         contemplated herein is, and all other such information (taken as a
         whole) hereafter furnished by or on behalf of such Guarantor in writing
         to any Purchaser will be, true and accurate in all material respects on
         the date as of which such information is dated or certified and not
         incomplete by omitting to state any material fact necessary to make
         such information (taken as a whole) not misleading at such time in
         light of the circumstances under which such information was provided.
         There is no fact known to any Guarantor which is reasonably likely to
         have a material adverse effect on the rights or remedies of the
         Purchasers or on the ability of any Credit Party to perform its
         respective obligations under any Credit Document to them, which has not
         been disclosed



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         herein or in such other documents, certificates and statements
         furnished to the Trustee and the Purchasers for use in connection with
         the transactions contemplated hereby.

         (i) Financial Condition; Financial Statements. (i) On and as of the
         Effective Date, on a pro forma basis after giving effect to all
         Indebtedness incurred, and to be incurred, by the Credit Parties in
         connection herewith, (x) the sum of the assets, at a fair valuation, of
         each Guarantor on a consolidated basis taken as a whole will exceed its
         debts, (y) each Guarantor on a consolidated basis taken as a whole will
         not have incurred or intended to, or believe that it will, incur debts
         beyond its ability to pay such debts as such debts mature and (z) each
         Guarantor on a consolidated basis taken as a whole will not have
         unreasonably small capital with which to conduct its business.

                  (ii) The consolidated balance sheet of NDC at December 31,
         2001 and the related consolidated statements of operations and cash
         flows of NDC for the fiscal year, as the case may be, ended as of said
         date, which have been examined by PriceWaterhouseCoopers LLP,
         independent certified public accountants, who delivered an unqualified
         opinion in respect thereto, copies of which have heretofore been
         furnished to each Purchaser, present fairly the financial position of
         such entities at the dates of said statements and the results for the
         period covered thereby in accordance with GAAP, except to the extent
         provided in the notes to said financial statements. All such financial
         statements have been prepared in accordance with generally accepted
         accounting principles and practices consistently applied except to the
         extent provided in the notes to said financial statements. Nothing has
         occurred since December 31, 2001 that has had or is reasonably likely
         to have a material adverse effect on the rights or remedies of the
         Purchasers hereunder, or on the ability of any Guarantor to perform its
         obligations to them.

                  (iii) Except as reflected in the financial statements and the
         notes thereto described in clause (ii) above, there were as of the
         Effective Date no liabilities or obligations with respect to any
         Guarantor of a nature (whether absolute, accrued, contingent or
         otherwise and whether or not due) which, either individually or in
         aggregate, would be material to Parent on a consolidated basis and its
         Subsidiaries taken as a whole, except as incurred subsequent to March
         31, 1998 in the ordinary course of business consistent with past
         practices.

         (j) Tax Returns and Payments. Parent and each of its Subsidiaries has
         filed all federal income tax returns and all other material tax
         returns, domestic and foreign, required to be filed by it and has paid
         all material taxes and assessments payable by it which have become due,
         other than those not yet delinquent and except for those contested in
         good faith. Parent and each of its Subsidiaries has paid, or has
         provided adequate reserves (in the good faith judgment of the
         management of Parent) for the payment of, all federal, state and
         foreign income taxes applicable for all prior fiscal years and for the
         current fiscal year to the date hereof.

         (k) Employee Benefit Plans. (i) Neither Parent nor any of its
         Subsidiaries nor any ERISA Affiliate has ever maintained or contributed
         to (or had an obligation to contribute to) any Plan or any Foreign
         Pension Plan where any current or reasonably foreseeable liability of
         Parent or any of its Subsidiaries with respect to such Plan or such
         Foreign Pension Plan would be reasonably likely to have a Material
         Adverse Effect. All



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         contributions required to be made with respect to (x) any employee
         pension benefit plan (as defined in Section 3(2) of ERISA) maintained
         or contributed to by (or to which there is an obligation to contribute
         of) Parent, any of its Subsidiaries or an ERISA Affiliate and (y) any
         Foreign Pension Plan have been timely made except any such failures to
         contribute which would not individually or in the aggregate be
         reasonably likely to have a Material Adverse Effect. Parent and its
         Subsidiaries may cease contributions to or terminate any employee
         benefit plan (within the meaning of Section 3(3) of ERISA) maintained
         or contributed to by (or to which there is an obligation to contribute
         of) them without incurring any liability which, individually or in the
         aggregate would be reasonably likely to have a Material Adverse Effect.

                  (ii) Each Foreign Pension Plan has been maintained in material
         compliance with its terms and with the requirements of any and all
         applicable laws, statutes, rules, regulations and orders and has been
         maintained, where required, in good standing with applicable regulatory
         authorities.

         (l) Pollution and Other Regulations. (i) Parent and its Subsidiaries
         are in compliance with all applicable Environmental Laws governing its
         business for which failure to comply is reasonably likely to have a
         Material Adverse Effect, and neither Parent nor any of its Subsidiaries
         are liable for any material penalties, fines or forfeitures for failure
         to comply with any of the foregoing. All licenses, permits,
         registrations or approvals required for the business of Parent and its
         Subsidiaries, as conducted as of the Effective Date, under any
         Environmental Law have been secured and Parent and its Subsidiaries are
         in compliance therewith, except such licenses, permits, registrations
         or approvals the failure to secure or to comply therewith is not likely
         to have a Material Adverse Effect. Parent and its Subsidiaries are not
         in any respect in noncompliance with, breach of or default under any
         applicable writ, order, judgment, injunction, or decree to which Parent
         or any such Subsidiary is a party or which would affect the ability of
         Parent and its Subsidiaries to operate the Vessel or any facility and
         no event has occurred and is continuing which, with the passage of time
         or the giving of notice or both, would constitute noncompliance, breach
         of or default thereunder, except in each such case, such noncompliance,
         breaches or defaults as are not likely to, in the aggregate, have a
         Material Adverse Effect. There are as of the Effective Date no
         Environmental Claims pending or, to the knowledge, after due inquiry,
         of Parent, threatened, against Parent or any of its Subsidiaries
         wherein an unfavorable decision, ruling or finding would be reasonably
         likely to have a Material Adverse Effect. There are no facts,
         circumstances, conditions or occurrences on any real property, drilling
         rig or facility owned or operated by Parent or any of its Subsidiaries
         that is reasonably likely (x) to form the basis of an Environmental
         Claim against Parent, the Vessel or facility owned by any Credit Party,
         or (y) to cause the Vessel or facility to be subject to any
         restrictions on its ownership, occupancy, use or transferability under
         any Environmental Law, except in each such case, such Environmental
         Claims or restrictions that individually or in the aggregate are not
         reasonably likely to have a Material Adverse Effect.

                  (ii) Hazardous Materials have not at any time been (x)
         generated, used, treated or stored on, or transported to or from, any
         drilling rig or facility including the Vessel at any time owned or
         operated by Parent or any of its Subsidiaries or (y) released on or
         from any such drilling rig or facility, in each case where, to Parent's
         knowledge, after



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<PAGE>

         due inquiry, such occurrence or event individually or in the aggregate
         is reasonably likely to have a Material Adverse Effect.

         (m) Properties. Parent and its Subsidiaries have title to all material
         properties owned by them, free and clear of all Liens, other than
         Permitted Liens.

         (n) Labor Relations. Neither Parent nor any of its Subsidiaries is
         engaged in any unfair labor practice that is reasonably likely to have
         a Material Adverse Effect. There is (i) no unfair labor practice
         complaint pending against Parent or any of its Subsidiaries or
         threatened against Parent or any of its Subsidiaries, before the
         National Labor Relations Board, and no grievance or arbitration
         proceeding arising out of or under any collective bargaining agreement
         is pending against Parent or any of its Subsidiaries or, to Parent's
         knowledge, after due inquiry, threatened against any of them, (ii) no
         strike, labor dispute, slowdown or stoppage is pending against Parent
         or any of its Subsidiaries or, to Parent's knowledge, after due
         inquiry, threatened against Parent or any of its Subsidiaries and (iii)
         no union representation petition existing with respect to the employees
         of Parent or its Subsidiaries and no union organizing activities are
         taking place, except with respect to any matter specified in clause
         (i), (ii) or (iii) above, either individually or in the aggregate, such
         as is not reasonably likely to have a Material Adverse Effect.

         (o) Rig Classification. The Vessel is classified in the highest class
         available for rigs of its age and type with the American Bureau of
         Shipping, Inc, Bureau Veritas, Det Norske Veritas, Lloyd's Register of
         Shipping, or another internationally recognized classification society
         reasonably acceptable to the Trustee, free of any material requirements
         or recommendations.

         (p) Patents, etc. Parent and its Subsidiaries have obtained all
         patents, trademarks, service marks, trade names, copyrights, licenses
         and other rights, free from burdensome restrictions, that are necessary
         for the operation of its business taken as a whole as presently
         conducted, and Parent knows of no such rights the absence of which
         would be reasonably likely to have a Material Adverse Effect.

         (q) Representations In Mortgages. Each Guarantor hereby confirms each
         representation and warranty of the Company set forth in the Mortgage.

         11. Affirmative Covenants. Parent covenants and agrees that for so long
as this Agreement is in effect and until the Notes (together with interest),
Fees and all other Obligations incurred hereunder, are irrevocably paid in full:

         (a) Information Covenants. Parent will furnish to the Trustee (with
         sufficient copies for each of the Purchasers, and the Trustee will
         promptly forward to each of the Purchasers):

                  (i) Annual Financial Statements. Within 120 days after the
         close of each fiscal year of Parent, the consolidated balance sheet of
         Parent and its Subsidiaries, as at the end of such fiscal year and the
         related consolidated statements of income and retained earnings and of
         cash flows for such fiscal year, in each case setting forth comparative
         consolidated figures for the preceding fiscal year, and examined by
         independent certified public accountants of recognized national
         standing whose opinion shall



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<PAGE>

         not be qualified as to the scope of audit and as to the status of
         Parent and its Subsidiaries as a going concern shall state that such
         financial statements present fairly, in all material respects, the
         financial position of the companies being reported upon and their
         results of operations and cash flows and have been prepared in
         conformity with GAAP, and that the examination of such accountants in
         connection with such financial statements has been made in accordance
         with generally accepted auditing standards, and that such audit
         provides a reasonable basis for such opinion in the circumstances. Such
         opinion shall be accompanied by a certificate of such accountants
         stating that they have reviewed this Agreement and stating further
         whether, in making their audit, they have become aware of any condition
         or event that then constitutes a Default or an Event of Default, and,
         if they are aware that any such condition or event then exists,
         specifying the nature and period of the existence thereof (it being
         understood that such accountants shall not be liable, directly or
         indirectly, for any failure to obtain knowledge of any Default or Event
         of Default unless such accountants should have obtained knowledge
         thereof in making an audit in accordance with GAAP or did not make such
         an audit),

                  (ii) Quarterly Financial Statements. As soon as available and
         in any event within 60 days after the close of each of the first three
         quarterly accounting periods in each fiscal year, the consolidated
         balance sheet of Parent and its Subsidiaries, as at the end of such
         quarterly period and the related consolidated statements of income and
         retained earnings and of cash flows for such quarterly period and for
         the elapsed portion of the fiscal year ended with the last day of such
         quarterly period, in each case setting forth comparative consolidated
         figures for the related period in the prior fiscal year, subject to
         changes resulting from audit and normal year-end audit adjustments.

                  (iii) Compliance Certificate. At the time of the delivery of
         the financial statements provided for in clauses (i) and (ii) above, a
         certificate of Parent signed by its Senior Vice President-Finance,
         Controller or other Authorized Officer setting forth the calculations
         required to establish whether Parent was in compliance with the
         provisions of Section 12 hereof as at the end of such fiscal period or
         year, as the case may be.

                  (iv) Notices. Promptly, and in any event (i) within ten
         Business Days after Parent obtains knowledge thereof, notice of the
         commencement of or any significant development in any litigation or
         governmental proceeding pending against Parent or any of its
         Subsidiaries which is likely to have a Material Adverse Effect or (ii)
         within five days after Parent obtains knowledge thereof, notice of any
         Default or Event of Default or a default or event of default hereunder.

                  (v) Other Information. From time to time, such other
         information or documents (financial or otherwise) as the Trustee or any
         Purchaser may reasonably request.

         (b) Books, Records, Inspection. Parent will, upon reasonable notice to
         the Senior Vice President-Finance, Controller or any other Authorized
         Officer of Parent, permit officers and designated representatives of
         the Trustee (at the expense of the Trustee, but after the occurrence
         and during the continuance of a Default or any Event of Default, at the
         expense of Parent) or any Purchaser (at the expense of such Purchaser
         but after the occurrence and during the continuance of a Default or an
         Event of Default at the expense of Parent), to the extent necessary, to
         examine the books of account of Parent and its



                                       10
<PAGE>

         Subsidiaries and discuss the affairs, finances and accounts of Parent
         and its Subsidiaries with, and be advised as to the same by, its and
         their officers and independent accountants, all at such reasonable
         times and intervals and to such reasonable extent as the Trustee or the
         Purchaser may desire.

         (c) Maintenance of Property; Insurance. There will at all times be
         maintained in full force and effect insurance on the Vessel in such
         amounts with carriers of such insurance industry ratings, covering such
         risks and liabilities and with such deductibles or self-insured
         retentions as are in accordance with normal industry practice for
         similarly situated insureds.

         (d) Payment of Taxes. Parent will and will cause each of its
         Subsidiaries to pay and discharge all material taxes, assessments and
         governmental charges or levies imposed upon it or upon its income or
         profits, or upon any properties belonging to it or its Subsidiaries,
         prior to the date on which penalties attach thereto, and all lawful
         claims which, if unpaid, might become a Lien or charge upon any
         properties of Parent or its Subsidiaries, provided that the Company
         shall not be required to pay any such tax, assessment, charge, levy or
         claim which is being contested in good faith and by proper proceedings
         if it has maintained adequate reserves (in the good faith judgment of
         the management of Parent) with respect thereto.

         (e) Consolidated Corporate Franchises. Parent will do, and will cause
         each Credit Party to do, all things necessary to preserve and keep in
         full force and effect its corporate existence, material rights and
         authority, unless the failure to do so is not reasonably likely to have
         a Material Adverse Effect, provided that any transaction permitted by
         Section 7.02 of the Agreement will not constitute a breach of this
         clause (d).

         (f) Compliance with Statutes, etc. Parent and its Subsidiaries will
         comply with all applicable statutes, regulations and orders of, and all
         applicable restrictions imposed by, all governmental bodies, domestic
         or foreign, in respect of the conduct of their business and the
         ownership of their property other than those the non-compliance with
         which would not have a Material Adverse Effect or would not have a
         material adverse effect on the ability of any Credit Party to perform
         its business or its respective obligations under any Credit Document to
         which it is a party.

         (g) Good Repair. Except in the event the Vessel has been damaged or has
         suffered a casualty as to which (within a reasonable period of time)
         management has not made a determination whether to replace or repair,
         or if the determination to replace or repair has been made, as to which
         such replacement or repairs are being undertaken, subject to
         availability of equipment, materials and/or repair facilities, Parent
         will, and will cause each Credit Party to, keep the Vessel, in
         whomsoever's possession it may be, in good repair, working order and
         condition, normal wear and tear excepted, and, subject to Section 7.02
         of the Agreement, see that from time to time there are made in such
         properties and equipment all needful and proper repairs, renewals,
         replacements, extensions, additions, betterments and improvements
         thereto, (i) to the extent and in the manner useful or customary for
         companies in similar businesses and (ii) to the extent the failure to
         do so is reasonably likely to cause a Material Adverse Effect.



                                       11
<PAGE>

         (h) End of Fiscal Years; Fiscal Quarters. Parent will, for financial
         reporting purposes, cause (i) its and its Subsidiaries fiscal years to
         end on December 31 of each year and (ii) its fiscal quarters to end on
         March 31, June 30, September 30 and December 31 of each year.

         (i) ERISA. As soon as possible and, in any event, within 10 days after
         Parent, any of its Subsidiaries or any ERISA Affiliate knows or has
         reason to know that: (a) a material contribution required to be made
         with respect to (i) any employee pension benefit plan (as defined in
         Section 3(2) of ERISA) maintained or contributed to by (or to which
         there is an obligation to contribute of) Parent, any of its
         Subsidiaries or an ERISA Affiliate or (ii) any Foreign Pension Plan has
         not been timely made or (b) Parent or any of its Subsidiaries may incur
         any material liability pursuant to any employee welfare benefit plan
         (as defined in Section 3(1) of ERISA) that provides benefits to retired
         employees or other former employees (other than as required by Section
         601 of ERISA) or any employee pension benefit plan (as defined in
         Section 3(2) of ERISA), Parent or the Company will deliver to each of
         the Purchasers a certificate of the Senior Vice President-Finance or
         Controller of Parent setting forth details as to such occurrence and
         the action, if any, that Parent, such Subsidiary or such ERISA
         Affiliate is required or proposes to take, together with any notices
         required or proposed to be given to or filed with or by Parent, such
         Subsidiary, the ERISA Affiliate, a plan participant or the plan
         administrator.

         (j) Further Assurances. (i) Parent will, and will cause each other
         Credit Party to, at the expense of such Credit Party, make, execute,
         endorse, acknowledge, file and/or deliver to the Trustee, from time to
         time such vouchers, invoices, schedules, confirmatory assignments,
         conveyances, financing statements, transfer endorsements, power of
         attorney, certificates, real property surveys, reports and other
         assurances or instruments and take such further steps relating to the
         Trustee or any Purchaser may reasonably require.

                  (ii) Parent agrees that each action required above by clause
         (i) shall be completed as soon as possible, but in no event later than
         30 days after such action is requested to be taken by the Trustee or
         the Required Purchasers, provided that in no event shall Parent or any
         of its Subsidiaries be required to take any action, other than using
         its reasonable commercial efforts without any material expenditure, to
         obtain consents or other actions from third parties with respect to its
         compliance with clause (i) above.

         12. Negative Covenants. Parent hereby covenants and agrees that as of
the Effective Date and thereafter for so long as this Guaranty is in effect and
until all Obligations guaranteed hereunder are irrevocably paid in full:

         (a) Changes in Business. Parent Guarantors will not materially alter
         the character of their business taken as a whole from that conducted by
         NDC at the Effective Date.

         (b) Consolidation, Merger, Sale of Assets, etc. Parent will not and
         will not permit any Credit Party to wind up, liquidate or dissolve its
         affairs, or enter into any transaction of merger or consolidation, sell
         or otherwise dispose of all or any part of the Collateral or



                                       12
<PAGE>

         agree to do any of the foregoing at any future time, except that the
         following shall be permitted:

                  (i) NHC or Parent may be merged with each other, NHC or Parent
         may be merged with NDC, so long as NDC is the surviving corporation,
         and the Company may be merged into Parent; and

                  (ii) so long as no Default or Event of Default exists or would
         result therefrom, on or after June 1, 2001 the Company may sell the
         Vessel for cash at fair market value, provided that the proceeds of any
         such disposition shall be applied to prepay the Notes in full in
         accordance with Section 3.01 of the Agreement.

         (c) Interest Coverage Ratio. Parent shall not permit the ratio at the
         end of each fiscal quarter of (i) Adjusted Consolidated EBITDA to (ii)
         Consolidated Interest Expense for the period of the four most recently
         completed consecutive fiscal quarters of the Company to be less than
         3.00:1.00.

         (d) Leverage Ratio. Parent shall not permit the Leverage Ratio as of
         the end of any fiscal quarter to be more than 0.40:1.00.

         (e) Net Worth. Parent shall not permit Consolidated Net Worth as of the
         end of any fiscal quarter to be less than $812,382,000 plus 50% of
         Consolidated Net Income (determined on a cumulative basis) for all
         Cumulative Net Income Periods ending prior to the date of determination
         for which Consolidated Net Income was a positive number.

         13. Miscellaneous.

         (a) Calculations; Computations. The financial statements to be
         furnished to the Purchasers pursuant hereto shall be made and prepared
         in accordance with GAAP consistently applied throughout the periods
         involved (except as set forth in the notes thereto or as otherwise
         disclosed in writing by Parent to the Purchasers), provided that (x)
         except as otherwise specifically provided herein, all computations
         determining compliance with Section 12, including definitions used
         therein, shall utilize accounting principles and policies in effect at
         the time of the preparation of, and in conformity with those used to
         prepare, the December 31, 1997 historical financial statements of NDC
         delivered to the Purchasers pursuant to Section 10(i) as in effect at
         such time, and (y) that if at any time the computations determining
         compliance with Section 12 utilize accounting principles different from
         those utilized in the financial statements furnished to the Purchasers,
         such financial statements shall be accompanied by reconciliation
         work-sheets.

         (b) Notices. All notices and other communications provided for
         hereunder shall be given as set forth in the Agreement (i) to each
         Guarantor at the address set forth below its execution hereof, and (ii)
         to Trustee and/or Purchasers at the addresses set forth in the
         Agreement.

         (c) Benefit of Agreement. This Guaranty shall be binding upon and inure
         to the benefit of and be enforceable by the respective successors and
         assigns of the parties




                                       13
<PAGE>

         hereto, provided that no Guarantor may assign or transfer any of its
         rights or obligations hereunder without the prior written consent of
         the Purchasers.

         (d) Governing Law; Submission to Jurisdiction; Venue; Waiver of Jury
         Trial.

                  (i) THIS GUARANTY AND THE RIGHTS AND OBLIGATIONS OF THE
         PARTIES HEREUNDER AND THEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH
         AND BE GOVERNED BY THE INTERNAL LAW OF THE STATE OF NEW YORK. Any legal
         action or proceeding with respect to this Guaranty may be brought in
         the courts of the state of New York or of the United States for the
         Southern District of New York, and, by execution and delivery of this
         Guaranty, each Guarantor hereby irrevocably accepts for itself and in
         respect of its property, generally and unconditionally, the
         non-exclusive jurisdiction of the aforesaid courts. Each Guarantor
         further irrevocably consents to the service of process out of any of
         the aforementioned courts in any such action or proceeding by the
         mailing of copies thereof by registered or certified mail, postage
         prepaid, to such Guarantor located outside New York City and by hand
         delivery to the Company located within New York City, at its address
         for notices pursuant to Section 13(b) above, such service to become
         effective 7 days after such mailing. Nothing herein shall affect the
         right of the Trustee or any Purchaser to serve process in any other
         manner permitted by law or to commence legal proceedings or otherwise
         proceed against any Guarantor in any other jurisdiction.

                  (ii) Each Guarantor hereby irrevocably waives any objection
         which it may now or hereafter have to the laying of venue of any of the
         aforesaid actions or proceedings arising out of or in connection with
         this Guaranty brought in the courts referred to in clause (i) above and
         hereby further irrevocably waives and agrees not to plead or claim in
         any such court that any such action or proceeding brought in any such
         court has been brought in an inconvenient forum.

                  (iii) Each Guarantor by its acceptance hereof, hereby
         irrevocably waives all right to a trial by jury in any action,
         proceeding or counterclaim arising out of or relating to this Guaranty
         or the transactions contemplated hereby.

         (e) Headings Descriptive. The headings of the several sections and
         subsections of this Guaranty are inserted for convenience only and
         shall not in any way affect the meaning or construction of any
         provision of this Guaranty.

         (f) Amendment/Restatement. This Guaranty amends and restates the
         Original Parent Guaranty in its entirety and is given in replacement
         thereof.

         14. Definitions. As used herein, the following terms shall have the
following meanings (such meanings to be equally applicable to both the singular
and plural forms of the term defined):

                  "Adjusted Consolidated EBITDA" shall mean for any period,
         Consolidated EBITDA for such period, less cash dividends and cash taxes
         paid during such period.

                  "Capital Lease" as applied to any Person shall mean any lease
         of any property (whether real, personal or mixed) by that Person as
         lessee which, in conformity with GAAP, is accounted for as a capital
         lease on the balance sheet of that Person.



                                       14
<PAGE>

                  "Capitalized Lease Obligations" shall mean all obligations
         under Capital Leases of Parent or any of its Subsidiaries in each case
         taken at the amount thereof accounted for as liabilities in accordance
         with GAAP.

                  "Consolidated EBIT" shall mean, for any period, (A) the sum of
         the amounts for such period of (i) Consolidated Net Income, (ii)
         provisions for taxes based on income, (iii) Consolidated Interest
         Expense, (iv) amortization or write-off of deferred financing costs to
         the extent deducted in determining Consolidated Net Income and (v)
         losses on sales of assets (excluding sales in the ordinary course of
         business) and other extraordinary losses less (B) the amount for such
         period of gains on sales of assets (excluding sales in the ordinary
         course of business) and other extraordinary gains, all as determined on
         a consolidated basis in accordance with GAAP.

                  "Consolidated EBITDA" shall mean, for any period, the sum of
         the amounts for such period of (i) Consolidated EBIT, (ii) depreciation
         expense of Parent and its Subsidiaries and (iii) amortization expense
         of Parent and its Subsidiaries, all as determined on a consolidated
         basis in accordance with GAAP.

                  "Consolidated Indebtedness" shall mean, as at any date of
         determination, the aggregate stated balance sheet amount of all
         Indebtedness (including the Notes) of Parent and its Subsidiaries on a
         consolidated basis as determined in accordance with GAAP, excluding all
         Contingent Obligations relating to the Indebtedness of any Person which
         is included in the calculation of Consolidated Indebtedness of Parent
         and its Subsidiaries.

                  "Consolidated Interest Expense" shall mean, for any period,
         total interest expense (including that attributable to Capital Leases)
         of Parent and its Subsidiaries in accordance with GAAP on a
         consolidated basis with respect to all outstanding Indebtedness of
         Parent and its Subsidiaries, provided that for purposes of this
         definition only, "Indebtedness" shall be deemed to include all
         indebtedness of Parent and its Subsidiaries which is otherwise excluded
         pursuant to clause (y) of the proviso contained in the definition of
         "Indebtedness".

                  "Consolidated Net Income" shall mean for any period, the net
         income (or loss) of Parent and its Subsidiaries on a consolidated basis
         for such period taken as a single accounting period determined in
         conformity with GAAP.

                  "Consolidated Net Worth" shall mean, at any time,
         shareholder's equity of Parent and its Subsidiaries on a consolidated
         basis determined in accordance with GAAP.

                  "Contingent Obligations" shall mean as to any Person any
         obligation of such Person guaranteeing or intending to guarantee any
         Indebtedness, leases, dividends or other obligations ("primary
         obligations") of any other Person (the "primary obligor") in any
         manner, whether directly or indirectly, including, without limitation,
         any obligation of such Person, whether or not contingent, (a) to
         purchase any such primary obligation or any property constituting
         direct or indirect security therefor, (b) to advance or supply funds
         (i) for the purchase or payment of any such primary obligation or (ii)
         to maintain working capital or equity capital of the primary obligor or
         otherwise to maintain the net



                                       15
<PAGE>



         worth or solvency of the primary obligor, (c) to purchase property,
         securities or services primarily for the purpose of assuring the owner
         of any such primary obligation of the ability of the primary obligor to
         make payment of such primary obligation or (d) otherwise to assure or
         hold harmless the owner of such primary obligation against loss in
         respect thereof, provided, however, that the term Contingent Obligation
         shall not include endorsements of instruments for deposit or collection
         in the ordinary course of business. The amount of any Contingent
         Obligation shall be deemed to be an amount equal to the stated or
         determinable amount of the primary obligation in respect of which such
         Contingent Obligation is made or, if not stated or determinable, the
         maximum reasonably anticipated liability in respect thereof (assuming
         such Person is required to perform thereunder) as determined by such
         Person in good faith.

                  "Cumulative Net Income Period" shall mean each period
         consisting of a fiscal quarter of the Company ending after March 31,
         1998.

                  "GAAP" shall mean generally accepted accounting principles in
         the United States of America as in effect from time to time.

                  "Indebtedness" of any Person shall mean without duplication
         (i) all indebtedness of such Person for borrowed money, (ii) the
         deferred purchase price of assets or services which in accordance with
         GAAP would be shown on the liability side of the balance sheet of such
         Person, (iii) the face amount of all letters of credit issued for the
         account of such Person and, without duplication, all drafts drawn
         thereunder, (iv) all Indebtedness of a second Person secured by any
         Lien on any property owned by such first Person, whether or not such
         indebtedness has been assumed, (v) all Capitalized Lease Obligations of
         such Person, (vi) all obligations of such Person to pay a specified
         purchase price for goods or services whether or not delivered or
         accepted, (vii) all net obligations of such Person under Interest Rate
         Agreements and (viii) all Contingent Obligations of such Person (other
         than Contingent Obligations arising from the guaranty by such Person of
         Permitted Indebtedness of the Company and/or its Subsidiaries) provided
         that Indebtedness shall not include (x) trade payables and accrued
         expenses, in each case arising in the ordinary course of business and
         (y) indebtedness incurred by non-Credit Party Subsidiaries of Parent
         which is non-recourse to Parent or any other Subsidiary of Parent.

                  "Interest Rate Agreement" shall mean any interest rate swap
         agreement, any interest rate cap agreement, any interest rate collar
         agreement or other similar agreement or arrangement designed to protect
         Parent against interest rate risk.

                  "Leverage Ratio" shall mean, at any date of determination, the
         ratio of Consolidated Indebtedness on such date to Total Capitalization
         on such date.

                  "Non-Recourse Subsidiary" shall mean any Subsidiary of Parent
         which is the obligor with respect to any Indebtedness which is excluded
         from the definition of "Indebtedness" pursuant to clause (y) of the
         proviso contained therein.

                  "Total Capitalization" shall mean, at any time, the sum of
         Consolidated Indebtedness and Consolidated Net Worth at such time.





                                       16
<PAGE>






         IN WITNESS WHEREOF, each Guarantor has caused multiple counterparts of
this Agreement to be duly executed and delivered as of the date first above
written.

                                            NOBLE CORPORATION

                                            By: /s/ MARK A. JACKSON
                                               ---------------------------------
                                               Mark A. Jackson
                                               Senior Vice President-Finance and
                                               Treasurer

                                            NOBLE HOLDING (U.S.) CORPORATION

                                            By: /s/ MARK A. JACKSON
                                               ---------------------------------
                                               Mark A. Jackson
                                               Senior Vice President-Finance and
                                               Treasurer

                                            NOBLE DRILLING CORPORATION

                                            By: /s/ MARK A. JACKSON
                                               ---------------------------------
                                               Mark A. Jackson
                                               Senior Vice President-Finance and
                                               Treasurer
Address for Notices:

13135 South Dairy Ashford, Suite 800
Sugar Land, TX 77478
Attn: Mark Mey
Telephone: (281) 276-6390
Facsimile: (281) 276-6344


                                            Accepted and Agreed to:

                                            JPMORGAN CHASE BANK, as Trustee

                                            By: /s/ MAURI J. COWEN
                                               ---------------------------------
                                               Mauri J. Cowen
                                               Vice President and Trust Officer


                                       17