<PAGE>

                                                                  EXHIBIT  10.11
                                    FORM OF
                          CHANGE IN CONTROL AGREEMENT
                          ---------------------------

          THIS AGREEMENT (this "Agreement") is made as of May __, 2000, between
OSCA, Inc., a Delaware corporation (the "Company," and, together with any of its
                                         -------
subsidiaries or successors in interest, including a successor in a Change in
Control (as defined below), the "Employer"), and Steven J. Brading
                                 --------
("Executive").
  ---------

          WHEREAS, Executive provides valuable services to the Company and the
Company has determined that it would be in the Company's interest to provide
Executive certain assurances regarding Executive's treatment in the event of a
Change in Control; and

          WHEREAS, Executive desires to secure such assurances;

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

     1.   Severance Payment.
          -----------------

          (a) If, subject to the conditions set forth in Section 1(b) below,
Executive's employment with the Employer is terminated under the circumstances
contemplated by Section 1(b), Employer shall pay Executive a lump sum severance
payment (the "Severance Payment") equal to [one/two times] Executive's Annual
Compensation as in effect prior to the Change in Control.

          (b) Executive shall only be entitled to the Severance Payment if:  (i)
the Company has undergone a Change in Control prior to the fifth anniversary of
the date of this Agreement; and (ii) Executive makes himself immediately
available for continued employment by the Company's successor in interest in
such Change in Control; and (iii) (A) such successor in interest elects not to
continue Executive's employment in connection with such Change in Control or (B)
                                                                          --
prior to the first anniversary of such Change in Control, Executive's employment
with the Employer is terminated by the Employer without Cause or Executive
resigns from the Employer with Good Reason; and (iv) Executive executes a
general release of the Employer in the form attached hereto as Annex A.  For the
                                                               -------
avoidance of doubt, if Executive's employment with the Employer terminates under
any other circumstances, including by reason of death, disability, retirement,
resignation without Good Reason or termination by the Employer for Cause,
Executive shall not be entitled to any severance payment whatsoever.

          (c) The Employer shall pay  the Severance Payment to Executive in cash
or wire transfer of immediately available funds within 30 days of the
termination of his employment under the circumstances contemplated by Section
1(b).  If Executive dies after such termination but before the Severance Payment
is paid in full, Employer shall pay the Severance Payment to Executive's legal
heir or estate.  The Severance Payment shall be subject to all required tax
withholding by the Employer.
<PAGE>

          (d) In addition to the payment provided under Section 1(a) hereof, if
Executive's employment with the Employer is terminated under the circumstances
contemplated by Section 1(b), all outstanding stock options previously granted
to Executive, and not yet expired, will become fully and immediately vested and
exercisable by Executive on the date of termination of Executive's employment
with Employer and for such period of time thereafter as shall be permitted
pursuant to the applicable stock option plan and stock award agreements.

          2.   No Guarantee of Employment.  Executive hereby acknowledges and
               --------------------------
agrees that nothing in this Agreement constitutes a guarantee or assurance of
continued employment with the Employer and that his only rights under this
Agreement are to payment of the Severance Payment and immediate vesting of stock
options in accordance with the terms of this Agreement.

          3.   Certain Definitions. The following capitalized terms used in this
               -------------------
Agreement have the meanings set forth below:

          (a)  "Annual Compensation" means Executive's annual base salary as in
                -------------------
effect immediately prior to the Change in Control, plus an amount equal to all
other amounts paid to Executive as wages, bonuses, commissions, profit sharing
or other cash  compensation for services rendered during  the twelve month
period immediately prior to the Change in Control.

          (b)  "Cause" means (i) the commission of a felony or other crime
                -----
involving moral turpitude or the commission of any other act or omission
involving dishonesty, disloyalty or fraud with respect to the Employer or any of
its Subsidiaries or any of their customers or suppliers, (ii) reporting to work
under the influence of alcohol or illegal drugs, the use of illegal drugs
(whether or not at the workplace) or other repeated conduct causing the Employer
or any of its Subsidiaries substantial public disgrace or disrepute or economic
harm, or (iii) substantial and repeated failure to perform duties as reasonably
directed by the Employer's Board of Directors.

          (c)  a "Change in Control"  shall be deemed to have occurred if the
                  -----------------
conditions set forth in any one of the following paragraphs shall have been
satisfied:

          (i)  any "person" (as such term is used in Section 13(d) and 14(d) of
     the Securities Exchange Act of 1934, as amended (the "Exchange Act")) other
     than (i) the Company, (ii) a trustee or other fiduciary holding securities
     under an employee benefit plan of the Company, (iii) an underwriter
     temporarily holding securities pursuant to an offering of such securities,
     or (iv) a corporation owned, directly or indirectly, by the stockholders of
     the Company in substantially the same proportions as their ownership of
     shares of the Company (any such person is hereinafter referred to as a
     "Person"), is or becomes the "beneficial owner" (as defined in Rule 13d-3
     under the Exchange Act), directly or indirectly, of securities of the
     Company representing more than 20% of the combined voting power of the
     Company's then outstanding securities (not including in the securities
     beneficially owned by such Person any securities acquired directly from the
     Company), excluding any Person who becomes such a beneficial owner in
     connection with a transaction described in clause (A) of paragraph (ii)
     below;

                                       2
<PAGE>

          (ii)   there is consummated a merger or consolidation of the Company
     or any direct or indirect subsidiary of the Company with or into any other
     corporation, other than (A) a merger or consolidation which results in the
     directors of the Company immediately prior to such merger or consolidation
     continuing to constitute at least a majority of the Board of Directors of
     the Company, the surviving entity or any parent thereof or (B) a merger or
     consolidation effected to implement a recapitalization of the Company (or
     similar transaction) in which no Person is or becomes the beneficial owner,
     directly or indirectly, of securities of the Company (not including in the
     securities beneficially owned by such Person any securities acquired
     directly from the Company) representing 20% or more of the combined voting
     power of the Company's then outstanding securities;

          (iii)  the stockholders of the Company approve any plan or proposal
     for the liquidation or dissolution of the Company or there is consummated
     an agreement for the sale or disposition by the Company of all or
     substantially all the Company's assets, other than a sale or disposition by
     the Company of all or substantially all of the Company's assets to an
     entity, at least a majority of whose directors were directors of the
     Company immediately prior to such sale or disposition; or

          (iv)   during any period of two consecutive years (not including any
     period prior to the date of this Agreement), individuals who at the
     beginning of such period constitute the Board of Directors of the Company
     and any new director (other than a director whose initial assumption of
     office is in connection with an actual or threatened election contest,
     including but not limited to a consent solicitation, relating to the
     election of directors of the Company) whose appointment or election by the
     Board of Directors of the Company or nomination for election by the
     Company's stockholders was approved or recommended by a vote of at least
     two-thirds (2/3) of the directors then still in office who either were
     directors at the beginning of the period or whose appointment, election or
     nomination for election was previously so approved, cease for any reason to
     constitute a majority thereof.

     Where a Change in Control results from a series of related transactions,
the Change in Control shall be deemed to have occurred on the date of the
consummation of the first such transaction.

     Notwithstanding any other provision hereof, a Change in Control shall not
be deemed to have occurred by virtue of the consummation of any transaction or
series of integrated transactions immediately following which the record holders
of the common stock of the Company immediately prior to such transaction or
series of transactions continue to have substantially the same proportionate
ownership in an entity which owns all or substantially all of the assets of the
Company immediately following such transaction or series of transactions.

          (d)    Executive shall be deemed to have terminated his employment
with the Employer with "Good Reason" if, prior to such termination:
                        -----------

          (i)    the Employer has reduced Executive's base salary or rate of
     compensation as in effect immediately prior to the Change in Control; or

                                       3
<PAGE>

          (ii)   the Employer has assigned Executive duties and responsibilities
     substantially different than those in effect immediately prior to the
     Change in Control; or

          (iii)  the Employer requires Executive to change the location of his
     job or office to a location more than 40 miles from the location in effect
     immediately prior to the Change in Control provided that such new location
     is not closer to Executive's primary residence; or

          (iv)   the Employer fails to provide Executive with pension plans,
     401(k) plans, life insurance plans, health, accident or disability plans,
     or other health, welfare and retirement benefits materially equal to those
     in effect immediately prior to the Change in Control.

          (e)    "Subsidiary" means any corporation or other entity of which the
                  ----------
securities or other ownership interests having the voting power to elect a
majority of the board of directors or other governing body are, at the time of
determination, owned by the Employer, directly or through one of more
Subsidiaries.

          4.     Severability.  Whenever possible, each provision of this
                 ------------
Agreement shall be interpreted in such manner as to be effective and valid under
applicable law, but if any provision of this Agreement is held to be invalid,
illegal or unenforceable in any respect under any applicable law or rule in any
jurisdiction, such invalidity, illegality or unenforceability shall not affect
any other provision or any action in any other jurisdiction, but this Agreement
shall be reformed, construed and enforced in such jurisdiction as if such
invalid, illegal or unenforceable provision had never been contained herein.

          5.     Complete Agreement. Subject to any rights of Executive pursuant
                 ------------------
to applicable law, applicable benefit plans and stock award agreements, this
Agreement embodies the complete agreement and understanding among the parties
and supersedes and preempts any prior understandings, agreements or
representations by or among the parties, written or oral, which may have related
to the subject matter hereof in any way (including, without limitation, the
Transition Payment Agreement between the parties hereto, dated __________).

          6.     No Strict Construction.  The language used in this Agreement
                 ----------------------
shall be deemed to be the language chosen by the parties hereto to express their
mutual intent, and no rule of strict construction shall be applied against any
party.

          7.     Counterparts.  This Agreement may be executed in separate
                 ------------
counterparts, each of which is deemed to be an original and all of which taken
together constitute one and the same agreement.

          8.     Successors and Assigns.  This Agreement is intended to bind and
                 ----------------------
inure to the benefit of and be enforceable by Executive, the Company and their
respective heirs, successors and assigns, except that Executive may not assign
his rights or delegate his duties or obligations hereunder without the prior
written consent of the Company.

          9.     Choice of Law.  All issues and questions concerning the
                 -------------
construction, validity, enforcement and interpretation of this Agreement and the
annex attached hereto shall be

                                       4
<PAGE>

governed by, and construed in accordance with, the laws of the State of
Delaware, without giving effect to any choice of law or conflict of law rules or
provisions (whether of the State of Delaware or any other jurisdiction) that
would cause the application of the laws of any jurisdiction other than the State
of Delaware.

          10.  Amendment and Waiver.  The provisions of this Agreement may be
               --------------------
amended or waived only with the prior written consent of the Employer and
Executive, and no course of conduct or course of dealing or failure or delay by
any party hereto in enforcing or exercising any of the provisions of this
Agreement shall affect the validity, binding effect or enforceability of this
Agreement or be deemed to be an implied waiver of any provision of this
Agreement.

                             *    *    *    *    *
<PAGE>

          IN WITNESS WHEREOF, the parties hereto have executed this Change in
Control Agreement as of the date first written above.


                              OSCA, INC.



                              ___________________________________________
                              By:
                              Its:



                              EXECUTIVE



                              ___________________________________________
                              By: Steven J. Brading


                                       6
<PAGE>

                                                                         Annex A

                                GENERAL RELEASE


     I,[_______________], in  consideration of and subject to the performance by
OSCA, Inc., a Delaware corporation or its successor in interest (together with
its subsidiaries, the "Company"), of its material obligations under the Change
                       -------
in Control Agreement, dated as of [___________, 2000] (the "Agreement"), do
                                                            ---------
hereby release and forever discharge as of the date hereof the Company and all
present and former directors, officers, agents, representatives, employees,
successors and assigns or predecessors of the Company and its direct or indirect
owners (collectively, the "Released Parties") to the extent provided below.
                           ----------------

1.   I understand that any payments or benefits paid or granted to me under
     Section 1 of the Agreement represent, in part, consideration for signing
     this General Release and are not salary, wages or benefits to which I was
     already entitled. I understand and agree that I will not receive the
     payments and benefits specified in Section 1 of the Agreement unless I
     execute this General Release and do not revoke this General Release within
     the time period permitted hereafter or breach this General Release.

2.   Except as provided in paragraph 4 below, I knowingly and voluntarily
     release and forever discharge the Company and the other Released Parties
     from any and all claims, controversies, actions, causes of action, cross-
     claims, counter-claims, demands, debts, compensatory damages, liquidated
     damages, punitive or exemplary damages, other damages, claims for costs and
     attorneys' fees, or liabilities of any nature whatsoever in law and in
     equity, both past and present (through the date of this General Release)
     and whether known or unknown, suspected, or claimed against the Company or
     any of the Released Parties which I, my spouse, or any of my heirs,
     executors, administrators or assigns, may have, which arise out of or are
     connected with my employment with, or my separation from, the Company
     (including, but not limited to, any allegation, claim or violation, arising
     under: Title VII of the Civil Rights Act of 1964, as amended; the Civil
     Rights Act of 1991; the Age Discrimination in Employment Act of 1967, as
     amended (including the Older Workers Benefit Protection Act); the Equal Pay
     Act of 1963, as amended; the Americans with Disabilities Act of 1990; the
     Family and Medical Leave Act of 1993; the Civil Rights Act of 1866, as
     amended; the Worker Adjustment Retraining and Notification Act; the
     Employee Retirement Income Security Act of 1974; any applicable Executive
     Order Programs; the Fair Labor Standards Act; or their state or local
     counterparts; or under any other federal, state or local civil or human
     rights law, or under any other local, state, or federal law, regulation or
     ordinance; or under any public policy, contract or tort, or under common
     law; or arising under any policies, practices or procedures of the Company;
     or any claim for wrongful discharge, breach of contract, infliction of
     emotional distress, defamation; or any claim for costs, fees, or other
     expenses, including attorneys' fees incurred in these matters) (all of the
     foregoing collectively referred to herein as the "Claims").
                                                       ------

3.   I represent that I have made no assignment or transfer of any right, claim,
     demand, cause of action, or other matter covered by paragraph 2 above.


                                      A-1
<PAGE>

4.   I agree that this General Release does not waive or release any (i) rights
     or claims that I may have under the Age Discrimination in Employment Act of
     1967 which arise after the date I execute this General Release; or (ii) any
     claims with respect to accrued benefits under employee benefit plans
     maintained by the Company or any claims arising from the Company's
     obligation to provide any benefits (other than severance benefits) to which
     I may be entitled under applicable plan provisions (as amended from time to
     time) based on the date of termination of employment with the Company.  In
     addition, the release of all claims shall not affect currently pending
     workers compensation proceedings or claims, nor the right of either party
     to enforce the terms of the Agreement and this General Release. I
     acknowledge and agree that my separation from employment with the Company
     in compliance with the terms of the Agreement shall not serve as the basis
     for any claim or action (including, without limitation, any claim under the
     Age Discrimination in Employment Act of 1967).

5.   In signing this General Release, I acknowledge and intend that it shall be
     effective as a bar to each and every one of the Claims hereinabove
     mentioned or implied. I expressly consent that this General Release shall
     be given full force and effect according to each and all of its express
     terms and provisions, including those relating to unknown and unsuspected
     Claims (notwithstanding any state statute that expressly limits the
     effectiveness of a general release of unknown, unsuspected and
     unanticipated Claims), if any, as well as those relating to any other
     Claims hereinabove mentioned or implied. I acknowledge and agree that this
     waiver is an essential and material term of this General Release and that
     without such waiver the Company would not have agreed to the terms of the
     Agreement.  I further agree that in the event I should bring a Claim
     seeking damages against the Company, or in the event I should seek to
     recover against the Company in any Claim brought by a governmental agency
     on my behalf, this General Release shall serve as a complete defense to
     such Claims. I further agree that I am not aware of any pending charge or
     complaint of the type described in paragraph 2 as of the execution of this
     General Release.

6.   I agree that neither this General Release, nor the furnishing of the
     consideration for this General Release, shall be deemed or construed at any
     time to be an admission by the Company, any Released Party or myself of any
     improper or unlawful conduct.

7.   I agree that I will forfeit all amounts payable by the Company pursuant to
     the Agreement if I challenge the validity of this General Release. I also
     agree that if I violate this General Release by suing the Company or the
     other Released Parties for claims waived by this General Release, I will
     pay all costs and expenses of defending against the suit incurred by the
     Released Parties, including reasonable attorneys' fees, and return all
     payments received by me pursuant to the Agreement.

8.   I agree that this General Release is confidential and agree not to disclose
     any information regarding the terms of this General Release, except to my
     immediate family and any tax, legal or other counsel I have consulted
     regarding the meaning or effect hereof or as required by law, and I will
     instruct each of the foregoing not to disclose the same to anyone.

                                      A-2
<PAGE>

9.   Any non-disclosure provision in this General Release does not prohibit or
     restrict me (or my attorney) from responding to any inquiry about this
     General Release or its underlying facts and circumstances by the Securities
     and Exchange Commission (SEC), the National Association of Securities
     Dealers, Inc. (NASD), any other self-regulatory organization or
     governmental entity.

10.  I agree to reasonably cooperate with the Company in any internal
     investigation or administrative, regulatory, or judicial proceeding. I
     understand and agree that my cooperation may include, but not be limited
     to, making myself available to the Company upon reasonable notice for
     interviews and factual investigations; appearing at the Company's request
     to give testimony without requiring service of a subpoena or other legal
     process; volunteering to the Company pertinent information; and turning
     over to the Company all relevant documents which are or may come into my
     possession all at times and on schedules that are reasonably consistent
     with my other permitted activities and commitments. I understand that in
     the event the Company asks for my cooperation in accordance with this
     provision, the Company will reimburse me solely for reasonable travel
     expenses, including lodging and meals, upon my submission of receipts.

11.  Notwithstanding anything in this General Release to the contrary, this
     General Release shall not relinquish, diminish, or in any way affect any
     rights or claims arising out of any breach by the Company or by any
     Released Party of the Agreement.

12.  Whenever possible, each provision of this General Release shall be
     interpreted in, such manner as to be effective and valid under applicable
     law, but if any provision of this General Release is held to be invalid,
     illegal or unenforceable in any respect under any applicable law or rule in
     any jurisdiction, such invalidity, illegality or unenforceability shall not
     affect any other provision or any other jurisdiction, but this General
     Release shall be reformed, construed and enforced in such jurisdiction as
     if such invalid, illegal or unenforceable provision had never been
     contained herein.

BY SIGNING THIS GENERAL RELEASE, I REPRESENT AND AGREE THAT:

(a)  I HAVE READ IT CAREFULLY;

(b)  I UNDERSTAND ALL OF ITS TERMS AND KNOW THAT I AM GIVING UP IMPORTANT
     RIGHTS, INCLUDING BUT NOT LIMITED TO, RIGHTS UNDER THE AGE DISCRIMINATION
     IN EMPLOYMENT ACT OF 1967, AS AMENDED, TITLE VII OF THE CIVIL RIGHTS ACT OF
     1964, AS AMENDED; THE EQUAL PAY ACT OF 1963, THE AMERICANS WITH
     DISABILITIES ACT OF 1990; AND THE EMPLOYEE RETIREMENT INCOME SECURITY ACT
     OF 1974, AS AMENDED;

(c)  I VOLUNTARILY CONSENT TO EVERYTHING IN IT;

(d)  I HAVE BEEN ADVISED TO CONSULT WITH AN ATTORNEY BEFORE EXECUTING IT AND I
     HAVE DONE SO OR, AFTER CAREFUL READING AND CONSIDERATION I HAVE CHOSEN NOT
     TO DO SO OF MY OWN VOLITION;

                                      A-3
<PAGE>

(e)  I HAVE HAD AT LEAST 21 DAYS FROM THE DATE OF MY RECEIPT OF THIS RELEASE
     SUBSTANTIALLY IN ITS FINAL FORM ON _______________ __, _____ TO CONSIDER IT
     AND THE CHANGES MADE SINCE THE _______________ __, _____ VERSION OF THIS
     RELEASE ARE NOT MATERIAL AND WILL NOT RESTART THE REQUIRED 21-DAY PERIOD;

(f)  THE CHANGES TO THE AGREEMENT SINCE _______________ ___, _____ EITHER ARE
     NOT MATERIAL OR WERE MADE AT MY REQUEST.

(g)  I UNDERSTAND THAT I HAVE SEVEN DAYS AFTER THE EXECUTION OF THIS RELEASE TO
     REVOKE IT AND THAT THIS RELEASE SHALL NOT BECOME EFFECTIVE OR ENFORCEABLE
     UNTIL THE REVOCATION PERIOD HAS EXPIRED;

(h)  I HAVE SIGNED THIS GENERAL RELEASE KNOWINGLY AND VOLUNTARILY AND WITH THE
     ADVICE OF ANY COUNSEL RETAINED TO ADVISE ME WITH RESPECT TO IT; AND

(i)  I AGREE THAT THE PROVISIONS OF THIS GENERAL RELEASE MAY NOT BE AMENDED,
     WAIVED, CHANGED OR MODIFIED EXCEPT BY AN INSTRUMENT IN WRITING SIGNED BY AN
     AUTHORIZED REPRESENTATIVE OF THE COMPANY AND BY ME.



DATE: ___________ __, ______                  ______________________________


                                      A-4