THIRD AMENDMENT TO
                     SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN



         WHEREAS,  CORE  LABORATORIES  N.V. and its  participating  affiliates
(the  "Company")  have  theretofore
adopted  the CORE  LABORATORIES  SUPPLEMENTAL  EXECUTIVE  RETIREMENT  PLAN (the
"Plan") for the benefit of certain
employees and independent directors of the Company; and

         WHEREAS, the Company desires to amend the Plan in certain respects;

         NOW, THEREFORE, the Plan shall be amended as follows, effective as of
January 1, 2002:

1.       Section 1.1(3) shall be deleted in its entirety and shall be replaced
with the following:

                  "Cause" shall mean Executive has been convicted of a felony or
                  a misdemeanor involving moral turpitude.

2.       As amended hereby, the Plan is specifically ratified and reaffirmed.

         EXECUTED on this 15th day of April, 2002.


                             CORE LABORATORIES N.V.



                            By:
                                ------------------------------------------------
                                     Jacobus Schouten
                                     Managing Director of
                                     Core Laboratories International B.V.
                                     which is the sole managing director of
                                     Core Laboratories N.V.