EXHIBIT 3.1



                          CERTIFICATE OF INCORPORATION




                        NOBLE HOLDING (U.S.) CORPORATION



                                    ARTICLE I


         The name of the corporation is Noble Holding (U.S.) Corporation (the



                                   ARTICLE II


         The address of the initial registered office of the Corporation in the

State of Delaware is c/o The Corporation Trust Company, 1209 Orange Street,

Wilmington, County of New Castle, Delaware 19801. The name of the initial

registered agent of the Corporation at such address is The Corporation Trust



                                   ARTICLE III


         The purpose for which the Corporation is organized is to engage in any

lawful act or activity for which corporations may be organized under the General

Corporation Law of the State of Delaware ("DGCL").


                                   ARTICLE IV


         The Corporation is to have perpetual existence.


                                    ARTICLE V


         The total number of shares of all classes of stock which the

Corporation shall have authority to issue is 10,000 shares of common stock, par

value of $.01 per share ("Common Stock").


                                   ARTICLE VI


         The number of directors constituting the initial Board of Directors is

three (3). Subject to the provisions of law, the number of the directors of the

Corporation may be increased or decreased from time to time pursuant to the

Bylaws of the Corporation (the "Bylaws"). Each director shall serve until the

annual meeting of stockholders next following his election or until his earlier

death, resignation or removal. The act of a majority of the directors present at

a meeting at which a quorum is present shall be the act of the Board of








                                   ARTICLE VII


         The names and addresses of the persons who are to serve as the initial

directors of the Corporation until their respective successors are duly elected

and qualified, or until the term of office shall have otherwise terminated, are

as follows:




         Name                                                 Mailing Address

         ----                                                 ---------------

<S>                                                           <C>

         Robert D. Campbell                                   13135 South Dairy Ashford, Suite 800

                                                              Sugar Land, Texas 77478


         Mark A. Jackson                                      13135 South Dairy Ashford, Suite 800

                                                              Sugar Land, Texas 77478


         Julie J. Robertson                                   13135 South Dairy Ashford, Suite 800

                                                              Sugar Land, Texas 77478



                                  ARTICLE VIII


         The Board of Directors is expressly authorized and empowered to make,

alter or repeal the Bylaws, subject to the power of the stockholders to alter or

repeal the Bylaws.


                                   ARTICLE IX


         The election of directors need not be by written ballot unless the

Bylaws so provide.


                                    ARTICLE X


         To the fullest extent permitted by the DGCL as the same exists or may

hereafter be amended, a director of the Corporation shall not be personally

liable to the Corporation or its stockholders for monetary damages for breach of

duty as a director. Without limiting the foregoing in any respect, a director of

the Corporation shall not be personally liable to the Corporation or its

stockholders for monetary damages for breach of duty as a director, except for

liability (i) for any breach of the director's duty of loyalty to the

Corporation or its stockholders, (ii) for acts or omissions not in good faith or

which involve intentional misconduct or a knowing violation of law, (iii) under

Section 174 of the DGCL, or (iv) for any transaction from which the director

derived an improper personal benefit. If the DGCL is amended to authorize

corporate action further eliminating or limiting the personal liability of

directors, then the liability of a director of the Corporation shall be

eliminated or limited to the fullest extent permitted by the DGCL, as so



                                   ARTICLE XI


         Any contract or other transaction between the Corporation and one or

more of its directors, between the Corporation and any firm of which one or more

of its directors is a member or of which a director is an employee or in which a

director is otherwise interested, or between the Corporation and any corporation

or association of which one or more of its directors







are stockholders, members, directors, officers or employees or in which they are

interested shall be valid for all purposes. The foregoing shall be true

notwithstanding the presence of such director or directors at the meeting of the

Board of Directors that acts upon or in reference to such contract or

transaction and notwithstanding his or their participation in such action, if

the fact of such interest shall be disclosed or known to the Board of Directors

and the Board of Directors shall nevertheless authorize, approve and ratify such

contract or transaction by vote of a majority.


                                   ARTICLE XII


         The Corporation reserves the right to alter, amend or repeal any

provision contained in this Certificate of Incorporation in the manner now or

hereafter prescribed by the laws of the State of Delaware. All rights herein

conferred are granted subject to this reservation.


                                  ARTICLE XIII


         The powers of the sole incorporator shall terminate upon filing of this

Certificate of Incorporation. The name and address of the sole incorporator are

as follows:




         Name                                        Mailing Address

         ----                                        ---------------

<S>                                                  <C>

         Courtney York                               Baker Botts L.L.P.

                                                     2001 Ross Avenue, Suite 800

                                                     Dallas, Texas 75201



         THE UNDERSIGNED, being the sole incorporator herein named, for the

purpose of forming a corporation pursuant to the DGCL, does make this

Certificate, hereby declaring and certifying that this is her act and deed and

that the facts herein stated are true, and accordingly has hereunto set her hand

as of the 8th day of March 2002.




                                           /s/ Courtney York


                                           Courtney York