FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * DENSON JOHN D   2. Issuer Name and Ticker or Trading Symbol CORE LABORATORIES N V [CLB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) VP, Gen.Counsel & Secretary (Last) (First) (Middle) 6316 WINDFERN 3. Date of Earliest Transaction (Month/Day/Year) 02/28/2005 (Street) HOUSTON, TX 77040 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Shares 02/28/2005   M   10,000 A $ 0 62,283 D   Common Shares 02/28/2005   F   4,000 D $ 28.69 58,283 (1) D   Common Shares               18,575 I Deferred Comp / 401(k) Plan (2)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Performance Shares (3)

$ 0 (4)

02/28/2005

M

10,000

12/31/2004

12/31/2004

Common Shares

10,000

$ 0

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
DENSON JOHN D 6316 WINDFERN HOUSTON, TX 77040			VP, Gen.Counsel & Secretary

Signatures

/s/ John D. Denson		03/01/2005
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Includes 19,708 restricted shares granted pursuant to an Executive Share Matching Agreement. The restricted shares will generally vest three years from the date of grant assuming continued employment, continued ownership of the underlying common shares upon which the grant was based and certain other conditions.
(2)	These Common Shares were acquired pursuant to the Core Laboratories, Inc. Profit Sharing and Retirement Plan (the "401(k) Plan") or pursuant to the Core Laboratories, Inc. Deferred Compensation Plan (the "Deferred Comp Plan"), as the case may be, on various dates at various prices per share. The number of Common Shares shown in column 5 of Table 1 is based on an allocation of the aggregate number of Common Shares acquired by the Trustee under the 401(k) Plan or the Deferred Comp Plan, as the case may be, for the benefit of the plan participants who elected to make intra-plan transfers into the Common Share fund under the 401(k) Plan or the Deferred Comp Plan, as the case may be, at approximately the same time (pro rata, based on the dollar amount of each such participant's intra-plan transfer into the Common Share fund, rounding up or down to the nearest whole share).
(3)	Includes tax withholding right.
(4)	1-for-1

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