EXHIBIT 10.3

                              EMPLOYMENT AGREEMENT

      This Employment Agreement (this "Agreement") is made and entered into as
of May 12, 1997 by and between Saybolt Netherlands B.V., a private limited
liability company organized under the laws of The Netherlands ("Employer"), and
Frerik Pluimers, a resident of The Netherlands ("Employee").

      WHEREAS, Employee is employed as the Chairman of Saybolt International
B.V. ("Previous Employer");

      WHEREAS, Core Laboratories N.V. ("Core"), Employee and Previous Employer
are parties to a Stock Purchase Agreement dated as of the date hereof whereby
Core will purchase all of the capital stock of Previous Employer, and Previous
Employer will become a wholly owned subsidiary of Core (the "Acquisition");

      WHEREAS, one of the conditions to consummation of the Acquisition is that
Employer and Employee enter into this Agreement;

      WHEREAS, Employer is desirous of employing Employee, and Employee wishes
to be employed by Employer, in accordance with the terms and conditions
contained herein.

      NOW, THEREFORE, in consideration of the premises and of the mutual
representations, warranties, covenants and agreements herein contained, and
other good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the parties hereto agree as follows:

                                    ARTICLE I

                                   EMPLOYMENT

      1.01 Employer hereby employs Employee, effective as of the Closing Date
(as defined in the Stock Purchase Agreement) (the "Effective Date"), and
Employee accepts such employment as of the Effective Date, according to the
terms and conditions set forth in this Agreement.

                                   ARTICLE II

                               TERM OF EMPLOYMENT

      2.01 TERM. The term of this Agreement shall commence on the Effective Date
and, except as provided in Section 7.03, shall continue until the earliest to
occur of the following events: (a) Employee resigns, (b) Employee's service is
terminated pursuant to the provisions of Sections 2.03, 2.04 or 2.05 or (c) the
parties hereto agree in writing to terminate this Agreement.

      2.02 DISABILITY. Employee shall be entitled to disability compensation in
accordance with Dutch law (Wet Arbeidsongeschikheidsverzekering). In addition,
Employer shall continue to provide excess insurance coverage (Aanvullende WAO
verzekering) for the benefit of Employee in the amount it currently provides.

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      2.03 DEATH. This Agreement shall terminate immediately on the date of
Employee's death. Employee's estate shall be entitled only to, and Employer's
obligation under this Agreement shall be limited to, the payment of any unpaid
amount of Employee's base salary accrued under Section 4.01 to the date of
Employee's death and any accrued and unused vacation days.

      2.04 TERMINATION FOR CAUSE. The employment of Employee hereunder may be
terminated "for cause" immediately without prior notice by Employer if Employer
in its discretion determines that Employee shall have:

      (A)   deliberately refused or failed, after reasonable notice in writing
            from the Board of Supervisory Directors of Core (the "Board") or a
            representative of Employer duly authorized by the Board (the
            "Supervising Representative") that such refusal or failure would
            constitute a default hereunder, to carry out any reasonable order of
            the Board or the Supervising Representative;

      (B)   committed a breach of the terms of this Agreement or any other legal
            obligation owed by Employee to Employer;

      (C)   demonstrated gross incompetence, negligence or willful misconduct in
            the execution of Employee's assigned duties;

      (D)   demonstrated moral turpitude to the detriment of Employer or
            violated Employer's policy on the use of alcohol or drugs as in
            effect from time to time; or

      (E)   been convicted of a felony or other serious crime.

      In such cases, Employee shall be entitled only to, and Employer's
obligation under this Agreement shall be limited to, the payment of any unpaid
amount of Employee's base salary accrued under Section 4.01 to the date of such
termination and any accrued and unused vacation days. This Section 2.04 shall in
no way be construed as precluding Employer from terminating Employee without
cause or prior notice or for any reason, as provided in Section 2.05.

      2.05 OTHER TERMINATION. Employee understands and agrees that he may be
terminated from employment with Employer for any reason, without cause, at any
time; PROVIDED, HOWEVER, that for any termination made pursuant to this Section
2.05, Employer shall provide Employee with 30 days prior notice of such
termination. Furthermore, Employer agrees that Employee may terminate his
employment with Employer at any time and for any reason by giving prior written
notice to Employer. In such cases, Employee shall be entitled only to, and
Employer's obligation under this Agreement shall be limited to, the payment of
any unpaid amount of Employee's base salary accrued under Section 4.01 to the
date of such termination and any accrued and unused vacation days.

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                                   ARTICLE III

                              DUTIES AND FUNCTIONS

      3.01 POSITION; DUTIES. Employee agrees to serve as a Managing Director of
Employer, to perform the duties of such office diligently and to the best of his
abilities and to assume such additional duties as may from time to time be
assigned to him consistent with his position.

      3.02 PERFORMANCE; SERVICE. Employee agrees in all respects to carry out
and use his best efforts in carrying out the objectives of Employer and
protecting Employer's interests. Employee agrees to be in the full-time service
of Employer and to devote all of his business time and attention to the duties
assigned to him pursuant to this Agreement; PROVIDED, HOWEVER, that Employee may
(i) continue to serve as the Honorary Consul of Gambia and as director for such
entities he currently serves in such capacity or (ii) assume such additional
directorships as may be approved by the Board.

      3.03 WORK FOR SUBSIDIARIES OR OTHER AFFILIATES. All terms and conditions
set forth in this Agreement between Employer and Employee shall apply whether
Employee carries out his activities in or for Employer or in or for any
subsidiary or other affiliate thereof. Employee shall receive no salary or other
payment for any position he holds with Employer or any subsidiary or other
affiliate thereof other than as set forth in this Agreement.

                                   ARTICLE IV

                                  COMPENSATION

      During the term of employment described in Section 2.01 above while this
Agreement is in effect, Employer shall provide to Employee the following:

      4.01 BASE SALARY. Employer shall pay to Employee an annual gross base
salary in the amount of Three Hundred Fifty Thousand and No/100 Dutch guilders
(NLG 350,000), payable in twelve (12) equal installments on the last day of each
calendar month. Annual cost of living adjustments may be made from time to time
to such base salary (commensurate with increases to senior executives of
Employer on August 1 of each calendar year) as determined by the Board or the
Supervising Representative.

      4.02 BONUS. Employee shall be eligible to receive an annual incentive
bonus on March 31 of each calendar year in accordance with and subject to the
performance criteria approved by the Board or the Supervising Representative and
commensurate with those applicable to senior management of Employer. The amount
of any such incentive bonus shall be limited to 60% of Employee's then base
salary.

      4.03 TAX. All amounts payable by Employer under this Agreement shall be
subject to the prior reduction or withholding by Employer of appropriate taxes
and other required amounts. If a determination is made by any relevant
governmental authority that insufficient withholdings have been made and to the
extent that such withholdings would, if made, have resulted in the Employee

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receiving a lower amount of net remuneration, Employee shall indemnify Employer
for all amounts determined to be so payable as a result of such failure to
withhold any or sufficient amounts.

                                    ARTICLE V

                                EMPLOYEE BENEFITS

      5.01 AUTOMOBILE. During the Employee's term of employment hereunder,
Employer shall provide the automobile-related benefits set forth in ANNEX 1
hereto.

      5.02 PENSION. Employer shall continue for the benefit of Employee the
monthly contribution to his pension plan with Previous Employer that is
maintained in The Netherlands, to the extent such contribution does not (1)
conflict with any applicable law and (2) conflict with the terms of such pension
plan. A copy of the applicable pension plan is attached hereto as ANNEX 2.

      5.03 OTHER EMPLOYEE BENEFITS. Employee shall be entitled to participate in
all health, disability and other employee benefit plans offered by Employer or
required (but only to the extent required) by applicable law under the terms and
conditions of each such plan. With respect to Employer's disability plan,
Employer shall continue to sponsor Employee for his existing benefit amount in
excess of the Employer amount. The cash and expenses of such excess benefit
amount shall be borne by Employee.

                                   ARTICLE VI

                          ADDITIONAL RIGHTS OF EMPLOYEE

      6.01 VACATION. In addition to Dutch public holidays, Employee shall be
entitled to a paid annual vacation of twenty-three (23) business days during
each full calendar year of employment during such times as shall not interfere
with the operations of Employer. Employee's rights shall accrue ratably during
each calendar year and shall be subject to proration for partial calendar years.
In the event that in any calendar year Employee shall fail to use all vacation
days to which he is entitled during such year, Employee shall be entitled to
carry forward five (5) of such vacation days into the next succeeding calendar
year.

      6.02 EXPENSES. Employer shall reimburse, or direct payment of, all
expenses reasonably incurred by Employee in the performance of his duties
hereunder, upon the submission of written evidence of such expenses to the
reasonable satisfaction of Employer, plus a fixed expense allowance in the
amount of Five Hundred Dutch guilders (NLG 500) per month.

      6.03  TERMINATION PAYMENT.

      (A)   Subject to Paragraph (B) below, in the event that Employee's
            employment pursuant to this Agreement is terminated by Employer
            other than "for cause," as described in Section 2.04, or for death,
            Employer shall pay to Employee an amount equal to the annual gross
            base salary specified in Section 4.01 as adjusted for the year in
            which such termination occurs. Employee agrees that this termination
            payment will be in

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            lieu of, and not in addition to, any payment to which he would
            otherwise be entitled on account of termination of his employment
            under any other Employer severance, termination, pay in lieu of
            notice, or similar payment program, plan, policy or agreement.

      (B)   The payment referred to in Section 6.03(A) shall be reduced by any
            statutory or other compensation that Employee may be entitled to
            receive from Employer as a result of such termination, and Employee,
            to the extent permitted by applicable law, hereby waives any and all
            rights and remedies with respect to such termination other than as
            expressly provided herein.

      6.04 LOCATION. Employee's services shall be performed primarily at the
facilities of Employer located in The Netherlands. Employee acknowledges that
worldwide travel shall be required. In the event that the Board or the
Supervising Representative determines in its sole discretion that the duties of
Employee hereunder require that Employee relocate to a country or state other
than as set forth above, the parties agree to enter into good faith negotiations
regarding the terms of such relocation. In the event that, after forty five (45)
days after such negotiations have commenced, the parties have failed to reach an
agreement, Employer shall have the option of suspending its relocation plans or
exercising its rights under Section 2.05 above.

                                   ARTICLE VII

              CONFIDENTIAL INFORMATION AND COVENANT NOT TO COMPETE

      7.01 GENERAL. Employee hereby covenants and agrees with Employer that,
except as otherwise expressly consented to, approved or otherwise permitted by
the Board or the Supervising Representative in writing, during Employee's term
of employment hereunder and for a subsequent period as set forth below, Employee
shall not, in any geographic area or market area or market where Employer or any
of its affiliates conduct any business either on the date of termination of the
employment of Employee or during any of the immediately preceding twelve (12)
months, directly or indirectly, acting alone, by providing material assistance
to the efforts of his spouse or as a member of a partnership or other business
entity or as a holder of any interest in a security of any class of a
corporation or other business entity (other than as a holder of less than one
percent (1%) of the outstanding amount of any security listed on a national
securities exchange or designated as a National Market System security by the
National Association of Securities Dealers, Inc.) or as an officer, director,
partner, employee, consultant, agent or representative of any corporation,
partnership or other business entity:

      (A)   Other than as required in the performance of his assigned duties to
            Employer and other than as required by law, either use or disclose
            to any person, firm or corporation any confidential or proprietary
            information concerning the organization, business, inventions,
            discoveries, customers, suppliers, operations, affairs or trade
            secrets of Employer, Employer's affiliates or Previous Employer that
            Employee may have acquired in the course of, or incident to, his
            employment by Employer, Employer's affiliates or Previous Employer,
            whether or not Employee was aware that such information was
            confidential or proprietary when originally given to or learned by

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            him; PROVIDED, HOWEVER, that such obligations of non-use and
            nondisclosure shall not apply to information that is or becomes a
            part of the public domain without breach by Employee of the
            aforementioned obligations;

      (B)   Engage anywhere in any business, trade, or other enterprise
            substantially similar to, or directly or indirectly in competition
            with, the business of Employer, Employer's affiliates or Previous
            Employer if engaging in such business, trade or other enterprise
            could result in any unauthorized use or disclosure by Employee of
            any confidential or proprietary information of or concerning
            Employer, Employer's affiliates or Previous Employer. Employer and
            Employee agree that Employer currently carries on substantial
            business worldwide. Employer and Employee further agree that
            Employee's engaging in the business of inspection, testing
            analytical services and calibration services of oil and chemicals
            and environmental testing of air, water and soil, would necessarily
            involve the unauthorized use or disclosure by Employee of such
            confidential or proprietary information;

      (C)   Request, induce or attempt to influence any current, future or
            prospective customer or supplier of Employer, Employer's affiliates
            or Previous Employer to limit, curtail or cancel its business with
            Employer; or

      (D)   Request, induce or attempt to influence any current, future or
            prospective officer, director, employee, consultant, agent or
            representative of Employer to (i) terminate his, her or its
            employment or business relationship with Employer or (ii) commit any
            act that, if committed by Employee, would constitute a breach of any
            provision of this Section 7.01.

      7.02 INTENT; SCOPE. Employee and Employer agree that the provisions of
clauses (A), (B), (C) and (D) of Section 7.01 are reasonable and necessary to
protect the legitimate interests of Employer. The provisions of said clauses are
separate and distinct commitments independent of each of the other said clauses.
Employee and Employer further agree that if the scope of any said clauses is
deemed by any administrative agency, arbitrator or court to be overly broad,
such agency, arbitrator or court may reduce the scope thereof to that which it
deems reasonable under the circumstances.

      7.03 TERM. If Employee is terminated for any reason or voluntarily leaves
the employ of Employer, the provisions set forth in this Article VII shall
survive for a period of twelve (12) months following the date of such
termination or cessation of employment.

                                  ARTICLE VIII

                                     PENALTY

      8.01 GENERAL. Employee will forfeit to Employer for each breach of any of
the provisions of Article VII hereof a penalty in the amount of Ten Thousand and
No/100 Dutch guilders (NLG 10,000) for each day that the breach continues,
without prejudice to:

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            (i) Employer's right to claim instead of this penalty the actual
      damage Employer has suffered through this breach; and

            (ii) any other relief to which Employer may be entitled under law or
      equity.

      8.02 GROUNDS FOR TERMINATION. Breach by Employee of the provisions of
Section 7.01 hereof shall also constitute grounds for immediate termination of
Employee's employment and shall be considered a termination "for cause" within
the meaning of Section 2.04.

                                   ARTICLE IX

                            EMPLOYEE REPRESENTATIONS

      9.01 Employee represents that he is free to enter into this Agreement and
is not under any contractual or other restraint which would prohibit the
satisfactory performance of his duties to Employer hereunder. Employee
represents and warrants further that he has read and understands each of the
provisions of this Agreement and that he has sought and obtained the advice of
legal counsel before agreeing to be bound by the terms hereof. Employee
acknowledges and agrees that Employer would not have continued Employee's
employment and entered into this Agreement but for Employee's agreement to be
bound by the covenants contained herein.

                                    ARTICLE X

                                  MISCELLANEOUS

      10.01 ENTIRE AGREEMENT. This Agreement, including the annexes attached
hereto, contains the entire understanding of the parties hereto in respect of
its subject matter. This Agreement supersedes all prior written or oral
agreements and understandings between the parties with respect to the subject
matter hereof.

      10.02 GOVERNING LAW. This Agreement shall be construed under and governed
in accordance with the laws of The Netherlands.

      10.03 NOTICES. Any notice or other communications required or permitted
hereunder shall be sufficiently given if in writing and personally delivered or
sent by airmail, postage prepaid, or by international air courier, telecopier or
telex addressed to Employer or Employee, as the case may be, to the following
address or at such other address for such party as specified by like notice:

            (A)   If to Employer:

                        to:   Saybolt Netherlands B.V.
                              c/o Core Laboratories N.V.
                              424 Herengracht
                              1017 BZ Amsterdam
                              The Netherlands
                              Attention:  Jacobus Schouten
                              Telecopy:  (011) 31-20-627-9886

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                  copies to:  Nauta Dutilh
                              Postbus 1110
                              3000 BC Rotterdam
                              Weena 750
                              3014 DA Rotterdam
                              The Netherlands
                              Attention:  Chris A. Fonteijn
                              Telecopy:   (011) 31-10-414-8444

                              Core Laboratories, Inc.
                              5295 Hollister Road
                              Houston, Texas 77040
                              Attention:  John D. Denson
                              Telecopy:   (713) 690-3947

            (B)   If to Employee:

                        to:   Frerik Pluimers
                              Saybolt Netherlands B.V.
                              Postbus 151
                              3000 AD Rotterdam
                              The Netherlands
                              Telecopy:   (011) 31-10-460-9911

      10.04 CHANGE, MODIFICATION, WAIVER. No change or modification of this
Agreement shall be valid unless it is in writing and signed by each of the
parties hereto. No waiver of any provision of this Agreement shall be valid
unless it is in writing and signed by the party against whom the waiver is
sought to be enforced. The failure of a party to insist upon strict performance
of any provision of this Agreement in any one or more instances shall not be
construed as a waiver or relinquishment of the right to insist upon strict
compliance with such provision in the future. No waiver by any party of the
breach of any term or provision contained in this Agreement, whether by conduct
or otherwise, shall be deemed to be or construed as a further or continuing
waiver of any such breach.

      10.05 ASSIGNMENT. This Agreement shall be binding upon and inure to the
benefit of the parties hereto and their respective successors, heirs and
assigns; PROVIDED, HOWEVER, that Employee shall not directly or indirectly
assign or delegate any of his rights or obligations hereunder in whole or in
part without the prior written consent of Employer, and any such assignment or
delegation without such consent shall be void.

      10.06 HEADINGS DESCRIPTIVE. The headings used herein are included for
reference purposes only and shall not in any way affect the meaning or
interpretation of this Agreement.

      10.07 SAVINGS CLAUSE. Should any valid Dutch or other applicable law or
final determination of any administrative agency, arbitrator or court of
competent jurisdiction affect any provision of this Agreement, the provision or
provisions so affected shall be automatically conformed to the law of
determination and this Agreement shall otherwise continue in full force and
effect.

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    IN WITNESS WHEREOF, Employer and Employee have each executed or caused this
Agreement to be executed on its behalf by its officer thereunto duly authorized,
as applicable, all as of the date first above written.


                                     SAYBOLT NETHERLANDS B.V.

                                     By:_________________________________
                                     Name:
                                     Title:

                                     FRERIK PLUIMERS

                                     By:_________________________________

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                                     ANNEX 1

                           AUTOMOBILE RELATED BENEFITS

    Employer shall reimburse Employee for his mileage. Employer acknowledges
that Employee has outstanding a loan for the purchase of his Mercedes Benz
automobile.

                                     ANNEX 2

                                  PENSION PLAN