<PAGE>

                                                                   Exhibit 10.13

                      MASTER LEASE AND SERVICES AGREEMENT
                      -----------------------------------

     This MASTER LEASE AND SERVICES AGREEMENT (the "Agreement") is entered into
and shall be effective this 3/rd/ day of February, 1998, by and between C-PORT,
L.L.C., a Louisiana Limited Liability Company (the "Lessor") and OSCA, INC. a
Delaware corporation (the "Lessee").


                                  WITNESSETH

     WHEREAS, Lessor has entered into certain contracts (the "Contracts of
Lease") with the Greater Lafourche Port Commission (the "Port Commission"),
whereby Lessor has been granted the right to occupy, improve and operate certain
property in furtherance of Lessor's legitimate business enterprise.

     WHEREAS, Lessor owns and operates certain facilities, and provides certain
specific services related to those facilities, in support of the offshore and
petrochemical industries.

     WHEREAS, Lessee desires to lease from Lessor the certain facilities and
services more fully described herein.

     NOW, THEREFORE, in consideration of the terms and conditions set forth
herein, and for other good and valuable consideration hereby acknowledged,
Lessor and Lessee mutually agree as follows:


     1.00      THE PREMISES AND SERVICES
               -------------------------

          Lessee desires to lease from Lessor the facilities and services more
     fully described in Exhibit "A" attached hereto and made a part hereof.
     These facilities and services are herein referred to collectively as the
     "Premises/Services" and/or separately as the "Premises" or "Services."

                                       1
<PAGE>

2.00  TERM OF AGREEMENT
      -----------------

2.01 Base Term

     Subject to the provisions of Section 8 in this Agreement, the initial term
of this Agreement (the "Base Term") shall be for a period of ten (10) years
commencing the 15/th/ day of March 1998 (the "Commencement Date").

2.02 Renewal Term

     As hereinafter set forth, Lessee may request an extension of this Agreement
for a total of no more than five (5) consecutive terms of five (5) years each
(the "Renewal Term"). If Lessee desires to extend this Agreement for a renewal
term, then Lessee must request such extension in writing at least ninety (90)
days prior to expiration of the Base Term or then current Renewal Term. With the
exception of the rental payable under Exhibits "A" and "B," this Agreement will
renew on all of the terms and conditions set forth herein if the renewal request
is accepted by Lessor. Lessor and Lessee further agree that any other term or
condition may be altered in writing only upon mutual agreement of both Lessor
and Lessee. If Lessor does not accept Lessee's request for renewal of this
Agreement, then Lessee shall vacate the Premises not later than the expiration
of the Base Term or then current Renewal Term. Notwithstanding anything
contained in this Section 2 to the contrary, in no event may Lessee renew if it
is in breach of any of its obligations under this Agreement, unless Lessor shall
agree in writing to waive this condition.

                                       2
<PAGE>

3.00      USE OF PREMISES AND RELATIONSHIP OF PARTIES
          -------------------------------------------

     The Premises/Services shall be occupied and used by Lessee solely for
lawful business purposes and the business for which the Premises have been
designed. It is understood that this includes the mooring, loading and
discharging of vessels, the supplying and resupplying of vessels and other
activities which may be permitted by Lessor in its sole discretion.

     Lessee will be obligated to fence its leased area with a cyclone-type
fencing, minimum height six (6') feet.

     Lessee shall be granted exclusive rights to sell high-density brine fluids,
completion and brine based drill-in fluids, dry salts, and blends of these
fluids that are used in the completion and workover of oil and natural gas
wells.

     Completion and workover fluids covered by this exclusivity agreement
include the solids-free solution of chloride, bromide, acetate, or formate salts
used to control downhole pressure after the exchange of the drilling fluid and
during the completion of the well.

These fluids may include:

     1.   Potassium chloride
     2.   Sodium chloride
     3.   Sodium acetate
     4.   Sodium bromide
     5.   Calcium chloride
     6.   Calcium bromide
     7.   Zinc bromide
     8.   Sodium formate
     9.   Cesium formate
     10.  Potassium formate

     Lessee shall have the sole possession and the duty to maintain completion
fluid stock tanks, mixing facilitates, and warehouses for day materials used in
the blending of these solids-free fluids.

                                      3










<PAGE>

     Materials that are not exclusive to completion and workover fluids shall
be excluded from this agreement, including.

     A.   Fluids used in workover operations that are non-brine based;
     B.   Fluid additives common to both drilling and completion fluids; and,
     C.   Non-brine based (drill-in fluids)

     Lessee will have the non-exclusive right to receive and discharge NOW waste
from its facilities. Lessee's services and product sales shall commence not
later than June 1/st/, 1998, and shall continue through the full term of this
lease.

     Lessee shall use all due care to avoid damage to the Premises or other
property of Lessor, the Port Commission, or any other persons or entities.
Lessee expressly assumes full and exclusive care, custody, and control of the
Premises and shall specifically, without limitation, insure that its operations
on and about the Premises are conducted in a safe and workmanlike manner.

     Lessor and Lessee expressly understand and agree that under no
circumstances is Lessee, or any of its employees or contractors or
subcontractors, to be considered agents, representatives or employees of Lessor,
and under no circumstances are any goods or services of Lessee to be considered
the goods or services of Lessor.

4.00      COMPLIANCE WITH LAWS
          --------------------

     Lessee shall observe and comply with all Laws of all federal, state,
parish, municipal, or local governmental or regulatory authorities or agencies
having or claiming jurisdiction over the Premises/Services or any part thereof,
or any activities of Lessee on or about the Premises. This includes, by way of
illustration and without limitation, the United States Coast Guard, the United
States Army Corps of Engineers, the United States Environmental Protection
Agency, and the Louisiana Department of Environmental Quality (each a
"Governmental Authority" and, collectively, "Governmental Authorities"). For
purposes of this Agreement, "laws" means all federal, state, parish, municipal,
or local laws, statutes, ordinances, codes, rules, regulations, and policies now
or

                                       4














<PAGE>

hereafter in effect during the term or any Renewal Term of this Agreement.

     Lessee shall be solely responsible for obtaining at its expense any and all
permits, licenses, financial assurances or like documentation needed to lawfully
carry on Lessee's activities on or about the Premises.

5.00      CONDITION AND IMPROVEMENT OF THE PREMISES
          -----------------------------------------

     Lessee accepts the Premises in their present condition and agrees to
maintain all of its structures, improvements and appurtenances on the Premises
in a good, safe condition throughout the duration of this Agreement. During the
Base Term or any Renewal Term of this Agreement, Lessor shall have the right to
enter and inspect the Premises as often as it deems necessary, provided such
inspection does not unreasonably disrupt Lessee's operations. Said inspection
may include all of the permanent structures, improvements and appurtenances upon
the Premises. Should any of those structures, improvements or appurtenances be
damaged by Lessee beyond normal wear and tear, or not be maintained properly, or
not be in compliance with applicable law, or not maintained to the same standard
as demonstrated by the rest of the C-Port facility, in the reasonable opinion of
Lessor, Lessor shall send Lessee a written list of the items which are damaged
or improperly maintained and the repairs necessary to correct the situation.
Lessee shall then have fifteen (15) days from the receipt of the aforementioned
list to respond to Lessor's allegations. Thereafter, the repairs will be
performed by Lessor, at its option, and at the sole expense of Lessee. Should
Lessee disagree with the claims and allegations of Lessor, it shall so state in
writing to Lessor within the notice provision stated above. Thereafter, Lessor
may perform the necessary repairs and pursue Lessee for damages or any other
rights or recourse it may have under this Agreement.

     Subject to Lessor's prior written consent and approval, Lessee shall have
the right during the Base Term or any Renewal Term hereof to make, at its
sole expense, improvements to any additions upon the Premises. Lessee shall have
the right to remove any of its

                                    5
<PAGE>

improvements or additions which are not, or have not become, immovable property,
all at Lessee's sole cost and expense. Any other improvements and/or additions
may at the sole option of Lessor, upon the expiration or earlier termination of
this Agreement, become the property of Lessor without compensation to Lessee.
However, Lessee shall, at the option of Lessor, remove any such improvements
and/or additions at Lessee's sole cost and expense. In the event Lessee removes
any improvements and/or additions, Lessee then shall restore the Premises to its
original condition (ordinary wear and tear excepted) at Lessee's sole cost and
expense. Lessee shall keep and maintain the Premises in a neat and orderly
condition and shall not allow the accumulation of waste, trash, debris or any
hazardous waste, material, pollutant or contaminant thereon. If any Governmental
Authority determines that any of the Premises constitute a hazard or otherwise
prohibited condition, then Lessee shall remedy said condition at Lessee's sole
cost and expense.

6.00     INGRESS AND EGRESS
         ------------------

     Lessee shall be afforded ingress and egress to the Premises at such points
as Lessor, in its sole and absolute discretion, may designate. Such ingress and
egress shall not, under any circumstances, constitute or be deemed to constitute
a servitude burdening the Premises, the other property of Lessor, the property
of the Port Commission or the property of any other person. The rights granted
to Lessee under this Section are personal to Lessee; are not assignable or
transferable without Lessor's specific written consent; and, shall terminate
upon the expiration or earlier termination of this Agreement.

7.00     RENTALS AND INVOICING
         ---------------------

7.01  Base Rental

     The rental payable for the Premises and Services shall be as set forth in
Exhibit "A." This rental shall be payable thirty (30) days, in advance, with the
first payment being due on the Commencement

                                       6
<PAGE>

Date. The rental is to be payable without any offset, withholding or deduction.

7.02  Additional Rental

     Lessee shall have the right to request certain specific services in
addition to those set forth in Exhibit "A." Those additional services, and the
costs thereof, are as set forth in Exhibit "B" which is attached hereto and made
a part hereof.

7.03  Taxes and Contributions

     Lessee assumes full and exclusive responsibility and liability for
withholding and paying as may be required by law, all Federal, State and local
taxes, workers' compensation, unemployment insurance and other contributions
with respect to, assessed against, or measured by, Lessee's earnings hereunder
or sales, wages, salaries or other contributions paid to Lessee's subcontractors
and employees. Lessee shall be responsible for all sales and use taxes, and any
and all other taxes or contributions applicable to the Premises/Services herein
or the activities of Lessee thereon. Lessee shall be responsible for all returns
and/or reports required in connection with any and all such laws, taxes and
contributions. Further, Lessee shall pay and be solely responsible for any taxes
assessed against its personal property located on or about or used in connection
with the Premises.

7.04  Invoicing

     Payment for the additional services set forth in Exhibit "B" shall be
invoiced weekly by Lessor, for the services performed the preceding week. Lessee
shall pay such invoices within thirty (30) days of receipt. Should Lessee fail
to tender payment timely, Lessor at its option may, in addition to any and all
other rights set forth in this Agreement, refuse to provide or continue any of
the additional services set forth in Exhibit "B."

7.05  Delinquent Payments

     Any rent payable under either Exhibit "A" or Exhibit "B" shall be deemed
delinquent if not received by Lessor on the date due. All delinquent amounts
shall bear interest at the rate of one and one-half (1.5) percent per month, or
the highest rate permitted by law, whichever is less, from the date due until
paid. Payment by Lessee of any delinquent amount plus the interest stated herein
shall not

                                       7


<PAGE>

deprive Lessor of any and all other rights it may have under this Agreement.

8.00     TERMINATION
         -----------

8.01     Default

     The following events constitute a "Default" by Lessee:
     (i)    If Lessee fails to pay when due the amounts due under Exhibit "A" or
            Exhibit "B," plus any interest which may also then be due;

     (ii)   Except as otherwise stated at paragraphs (v) and (vi) below, if
            Lessee fails to perform any of its obligations under this Agreement,
            or violates any of the terms and conditions of this Agreement, and
            such failure or violation continues for thirty (30) days after
            Lessor gives notice to Lessee of such failure or violation. Lessor
            is not required to give Lessee notification of any such failure or
            violation which could not reasonably be cured by Lessee within
            thirty (30) days of receiving notification;

     (iii)  If Lessee abandons the Premises for a period of thirty (30)
            consecutive days. Lessee shall be considered to have abandoned the
            Premises if it vacates the Premises or fails to request the Services
            set forth in Exhibits "A" and "B";

     (iv)   If Lessee is adjudicated bankrupt or insolvent by a Court of
            competent jurisdiction, or such Court enters an Order, Judgment, or
            Decree approving a Petition against Lessee seeking reorganization,
            liquidation, dissolution, or similar relief, or if a receiver,
            trustee, or liquidator is appointed for all or substantially all of
            Lessee's assets, or if Lessee seeks or consents to any other relief
            hereinabove enumerated in this subpart, or files a voluntary
            Petition in bankruptcy or insolvency or makes an assignment of all
            or substantially all of its assets for the benefit of its creditors,
            or admits in writing of its inability to pay its debts generally as
            they

                                       8
<PAGE>

become due, or if Lessee's interests under this Agreement are sold under an
execution, attachment, or decree of Court to satisfy a debt or any liens against
Lessee's interests;

     (v)    If Lessee uses the Premises/Services for any purpose not expressly
            authorized in Section 3.0; and

     (vi)   If Lessee attempts to assign this Agreement or attempts to sublet
            the Premises, in whole or in part, without the prior written consent
            of Lessor.

8.02        Consequences of Default

     If a default occurs, Lessor is entitled, at Lessor's sole option, to
exercise any one or more of the following remedies:

     (i)    Lessor may terminate this Agreement and immediately expel Lessee
            from the Premises. However, such action shall not be deemed to waive
            Lessor's right to collect all rent due for the period up to the time
            Lessor regains possession of the Premises, together with liquidated
            damages (not as a penalty) in the amount of three (3) months rent,
            calculated at the rate payable under this Agreement at the time of
            default. Lessee hereby assents to the foregoing and expressly waives
            all legal notice to vacate the Premises, including, without
            limitation, any notice requirements contained in the Louisiana Code
            of Civil Procedure.

     (ii)   Lessor may accelerate the rent and declare all unpaid installments
            of rent for the Base Term or the then current Renewal Term, as the
            case may be, at once due and owing, in which event all such unpaid
            amounts shall be immediately payable. Additionally, all other sums
            due hereunder become payable as and when Lessor ascertains the
            amount thereof with reasonable certainty.

     (iii)  Lessor may, in the event Lessee abandons the Premises, reenter and
            retake possession of the Premises without

                                       9

<PAGE>

     legal proceedings as agent for Lessee, and may relet the Premises on such
     terms and conditions as Lessor may determine in its sole discretion, all
     without incurring any liability to Lessee and without being deemed to have
     terminated this Agreement, evicted Lessee, or relieved Lessee of any of its
     obligations under this Agreement. Lessor shall in no way be responsible or
     liable for any failure, nor shall Lessor have any obligation, to relet the
     Premises. Lessor expressly reserves the right to collect and receive all
     rents arising from such reletting. Lessee will be entitled to credit for
     such rents actually received by Lessor against the rent payable hereunder,
     which credit will apply after Lessor has deducted from such rents: 1) all
     expenses Lessor may incur in reentering the Premises, putting the Premises
     in proper repair, and protecting and preserving the Premises; and 2) all
     expenses of reletting the Premises, including without limitation,
     attorneys' fees and expenses, brokerage, leasing, and management
     commissions, and all other reasonable expenses that Lessor may incur in
     connection with such reletting.

          No such reletting shall be construed as an election by Lessor to
     terminate this Agreement unless a notice of such intention to terminate is
     given to Lessee by Lessor. No such reletting without termination shall
     preclude Lessor from thereafter terminating this Agreement for Lessee's
     abandonment of the Premises.

(iv) Lessor may exercise any other remedy or method of redress accorded to it
     under Louisiana law.

                                      10
<PAGE>

8.03 Termination For Other Than Default

     Lessor shall have the right, at its option, to terminate this Agreement as
set forth below:

     (i)    If any governmental or public authority refuses to grant or revokes
            any permit or revokes the Contacts of Lease, or if any person,
            governmental or public authority successfully enjoins the exercise
            of any rights of Lessor or Lessee hereunder, or if Lessor's rights
            to possess and operate the facilities upon which the
            Premises/Services are located are otherwise impaired, then Lessor
            may, at its option, terminate this Agreement effective as of the
            date Lessor's rights in connection with the Premises are so
            impaired.

     (ii)   Lessor and Lessee may by mutual consent, given in writing, terminate
            this Agreement upon such terms and conditions as they deem
            appropriate.

9.00     LIABILITY AND INDEMNIFICATION
         -----------------------------

     Lessee agrees to defend, indemnify and hold Lessor and the Port Commission
(hereinafter "Indemnitees") harmless from and against any and all loss, damage,
liability, cost, expense (including reasonable attorney fees), lien or claimed
lien, fine, penalty and/or claim of any nature whatsoever (including, without
limitation, claims by Governmental or public authorities), on account of injury
to, death or illness of persons or damage to or loss of or loss of use of
property (including, without limitation, diminution in the value of the Premises
or any other property), arising out of or in any way directly or indirectly
related to Lessee's presence upon or use of the Premises or any adjacent
property, or any improvements, works or facilities constructed by, for, or at
the instance of Lessee, or any

                                      11
<PAGE>

products or materials or services of Lessee, and any operation or services
performed under this Agreement, or the exercise of any rights granted by this
Agreement, regardless of the cause or causes thereof, and regardless of whether
or not caused or contributed to, in whole or in part, by any negligence, fault
or strict liability of Indemnitees, or the unseaworthiness of any vessel for
which Indemnitees are or might be held responsible.

10.00  HAZARDOUS SUBSTANCE
       -------------------

10.01 Hazardous Substance Defined

     "Hazardous Substance" as used throughout this Agreement means any product,
substance or material:

     (i)     the presence of which requires investigation or remediation under
             any present or future applicable law;

     (ii)    which is or becomes defined as a hazardous waste, hazardous
             material, pollutant, or contaminant under any law including,
             without limitation, the Comprehensive Environmental Response
             Compensation and Liability Act (42 USC (S)9601, et seq.), the
             Resource Conservation and Recovery Act (42 USC (S)6901, et seq.),
             Federal Water Pollution Act of 1990 (33 USC (S)1251, et seq.) or
             the Oil Pollution Control Act (33 USC (S)2701, et seq.), and
             specifically including, without limitation, petroleum, crude oil,
             natural gas, natural gas liquids, liquified natural gas, synthetic
             gas and/or any mixture, fraction or waste thereof;

     (iii)   which is toxic, explosive, corrosive, flammable, infectious,
             radioactive, carcinogenic, or otherwise hazardous and is, or
             becomes, regulated by any Governmental Authority; or

     (iv)    the presence of which on the Premises or adjacent areas causes or
             threatens to cause a nuisance upon the

                                      12


<PAGE>

          Premises or adjacent areas, or poses or threatens to pose a hazard to
          the health or safety of persons on or about the Premises and any
          adjacent property.

10.02     Hazardous Substance Indemnification

     Lessee agrees to defend, indemnify and hold Lessor and the Port Commission
(hereinafter "Indemnitees") harmless from and against any and all loss
(including, without limitation, diminution in the value of the Premises or any
other property) liabilities, judgments, damages, penalties, fines, costs,
expenses and claims of any nature whatsoever (including, without limitation, any
claims by Governmental or public authorities) to either persons or property
(including, without limitation, cost of clean up, remediation, removal,
restoration, replacement or monitoring required by any federal, state, local or
responsible authority) any claims by Governmental or public authorities) which
are caused in whole or in part by, or which in any way directly or indirectly
arise out of the transportation, transfer, sale, generation, use, storage,
maintenance, handling, loading, unloading, disposal, release, threatened
release, presence or discharge of any Hazardous Substance by Lessee and/or its
subcontractors and/or its vessels (whether owned or chartered), and/or any other
person at the Premises or its adjacent property providing or receiving services
of any nature to or from Lessee, regardless of the cause or causes thereof, and
regardless of whether or not caused or contributed to, in whole or in part, by
any negligence, fault or strict liability of Indemnitees or the unseaworthiness
of any vessel for which Indemnitees are or might be held responsible.

                                      13
<PAGE>

10.03     Expiration/Termination Requirements

     Upon the expiration or earlier termination of this Agreement, Lessee shall
at its sole cost and expense (a) cause all Hazardous Substances previously
owned, stored or used by Lessee, and/or any other person at the Premises or its
adjacent property receiving or providing services of any nature from or to
Lessee, to be removed and disposed of in accordance with applicable provisions
of any Hazardous Substance laws, regulations, recommendations or requirements;
(b) remove any above ground or underground storage tanks or any other piping or
container installed by Lessee to store and/or transport and/or contain any
Hazardous Substances, and repair any damage caused by such removal; and, (c)
perform any other act required by applicable Hazardous Substance laws,
regulations, recommendations or requirements.


11.00     INSURANCE
          ---------

     Throughout the Base Term and any Renewal Term of this Agreement, Lessee
agrees to maintain, at its sole cost and expense, the insurance and insuring
terms as set forth in Exhibit "C" which is attached hereto and made a part
hereof.


12.00     ASSIGNMENT AND SUBLEASE
          -----------------------

     Lessee shall not assign this Agreement or sublease the Premises in whole or
in part without the prior written consent of Lessor. If Lessor consents to any
such assignment or sublease, Lessee shall remain solidarily bound with the
assignee or sublessee for the performance of all obligations under this
Agreement. The granting by Lessor of its consent to any assignment of this

                                      14
<PAGE>

Agreement or any sublease of the Premises shall not constitute the granting of
consent to any subsequent assignment or sublease, and in each instance the
written consent of Lessor must specifically be obtained.


13.00     PAYMENT OF ATTORNEY FEES
          ------------------------

     If Lessor employs one or more attorneys to enforce the payment of rent, or
the obligations of Lessee or rights of Lessor under this Agreement, then Lessee
hereby agrees to pay the fees of such attorney or attorneys, and Lessee further
agrees to pay all court costs and other related expenses, and such fees, costs,
and expenses will be deemed to be rent payable by Lessee upon demand of Lessor
and subject to the provisions of Section 7.07 of this Agreement.

14.00     REMEDIES CUMULATIVE
          -------------------

     Each right and remedy of Lessor provided for in this Agreement shall be
cumulative and in addition to every other right or remedy provided for in this
Agreement or now or hereafter existing at law or in equity or by statute or
otherwise; and the exercise or beginning of the exercise by Lessor of any one or
more of such rights or remedies shall not preclude the simultaneous or later
exercise by Lessor of any or all other rights or remedies provided for in this
Agreement or now or hereafter existing at law or in equity or by statute or
otherwise.


15.00     WAIVER
          ------

     The waiver by Lessor of any breach of any term, covenant or condition
herein contained shall not be deemed to be a waiver of

                                      15
<PAGE>

such term, covenant or condition or any subsequent breach of the same or any
other term, covenant or condition herein contained. The subsequent acceptance of
rent hereunder by Lessor shall not be deemed to be a waiver of any preceding
breach of Lessee of any term, covenant or condition of this Agreement, other
than the failure of Lessee to pay the particular rent so accepted, regardless of
Lessor's knowledge of such preceding breach at the time of acceptance of such
rent. No covenant, term or condition of this Agreement shall be deemed to have
been waived by Lessor unless such waiver be in writing by Lessor.


16.00     AGREEMENT SUBJECT TO CONTRACTS OF LEASE
          ---------------------------------------

     Lessee agrees that this Agreement is subject to the terms and conditions of
the Contracts of Lease in effect between Lessor and the Port Commission. If the
Contracts of Lease with the Port Commission are terminated during the Term of
this Agreement, then this Agreement shall terminate as of that same date. Unless
otherwise expressly provided for herein, no provision of the Contracts of Lease
with the Port Commission shall be deemed to confer any greater rights upon
either Lessor or Lessee than as are set forth in this Agreement. Lessee shall
not take, or fail to take any action that would result in a breach of the
Contracts of Lease.


17.00     FORCE MAJEURE
          -------------

     Each party to this Agreement shall be excused from complying with certain
obligations of this Agreement, except for the payment of rent, services or other
monies due, if and only to the extent that performance of such obligations is
prevented by acts of God,

                                      16

<PAGE>

hurricanes (designated as such by the U.S. Weather Bureau), cyclones, strikes or
industrial disputes (except for strikes and industrial disputes involving
Lessor's personnel), restraints or prohibitions by any government or division
thereof having jurisdiction over the parties hereto or by any act or cause which
is reasonably beyond the control of such party (herein referred to in this
Agreement as 'Force Majeure'). Rain, snow, ice or other adverse weather except
as provided above shall not be considered a Force Majeure cause enumerated
above.

     It is agreed that any party claiming Force Majeure shall give full notice
and details of the Force Majeure in writing to the other party as promptly as
possible after its occurrence. In such cases only, the obligations which are
incapable of performance because of the Force Majeure shall be suspended during
the continuance the Force Majeure. Should any act of Force Majeure causing the
suspension of operations hereunder continue for a period of at least six (6)
months from the commencement of the Force Majeure, either party shall have the
right to terminate this Agreement at any time thereafter (unless normal
operations have been resumed) by giving the other written notice ten (10) days
in advance of the effective date of termination, subject to payments due under
the Agreement.


18.00     NOTICES
          -------

     All notices required by or provided for in this Agreement shall be given to
the respective parties hereto in writing at the addresses designated below:

Lessor:        C-Port, L.L.C.
               106 9th Street
               Lot 1 - Port Fourchon
               Golden Meadow, Louisiana 70357
               Attention: Dionne Chouest.

                                      17

<PAGE>

Lessee:   OSCA
          156 Commission Boulevard
          P.O. Box 80627
          Lafayette, LA 70598
          Attention: Robert Hollier

unless and until either party notifies the other, in writing, of a different
address. Such notice shall be considered given under the terms of this Agreement
either: (i) when sent, addressed as provided above, postage prepaid, by
registered or certified mail, return receipt requested, by the United States
mail, or when sent, addressed as provided above, by commercial overnight
courier, or when sent, addressed as provided above, by telecopier to the
telecopier number(s) designated above at the time of actual receipt of the
notice in a legible form and received during normal business hours and if not
then on the next business day; or (ii) when delivered, addressed as provided
above, in person to the address described above.


19.00     GOVERNING LAW
          -------------

     This Agreement shall be governed by, and construed in accordance with, the
laws of the State of Louisiana.

20.00     ENTIRE AGREEMENT
          ----------------

     This Agreement and all exhibits hereto constitute the entire agreement
between the Parties.

21.00     NO CONSEQUENTIAL DAMAGES
          ------------------------

     Lessor shall not be liable to Lessee for any consequential, indirect,
special or punitive damages

                                      18

<PAGE>

     22.00     SEVERABILITY
               ------------

          If any provision of this Agreement is determined to be invalid or
     unenforceable, the remainder of this Agreement will remain in full force
     and effect.

          IN WITNESS WHEREOF, the parties hereto have caused this instrument to
be executed effective the day and year first above written.

                                   LESSOR:

                                        C-PORT, L.L.C.


                                        BY: /s/ Dionne R Chouest
                                           -------------------------

                                        TITLE: General Counsel
                                              ----------------------

                                   LESSEE:

                                        OSCA, INC.

                                        BY: /s/ [ILLEGIBLE]^^
                                           -------------------------

                                        TITLE: Sr. Vice President
                                              ----------------------

                                      19
<PAGE>

                                  Exhibit "A"

I.   Dedicated for the initial term of the agreement

     A.   A parcel of ground measuring 275' on the south side, 210' on the west
          end, 175' on the north side, 170' on the eastern end, then 100'
          towards the east, and 40' back towards the south, in close proximity
          to the Shell Offshore, Inc. office building facing Bayou Lafourche.

          Rate:                    25 cents per square foot per month
                                   (escalation at five [5%] per cent per annum
                                   during primary term)

          Total square footage:    40,750

          Monthly Rate:            $10,187.50

          Term:                    Ten (10) year primary term

          Commencement:            March 15, 1998

          Renewal Options:         A total of five (5) five-year period renewal
                                   options are available subject to a mutually
                                   agreeable renewal rate capped at a maximum of
                                   ten (10%) per cent escalation per renewal.

          Dock Space:              Vessel(s) receiving OSCA products and
                                   occupying common dock space at C-Port, L.L.C.
                                   will be charged $1.00 per linear foot per day
                                   for each vessel receiving products/services
                                   from OSCA. This charge will not apply if the
                                   vessel receiving products/services from OSCA
                                   is also receiving and being charged for
                                   unrelated and additional services from C-
                                   Port.

          Special Provisions:      All C-Port based rolling stock and craneage
                                   will be owned by C-Port and operated by C-
                                   Port personnel only, i.e. forklifts, cherry
                                   pickers, cranes and like items.

          Note:                    C-Port is finalizing leases with Halliburton
                                   to provide cement products and M-I to
                                   provide barites and liquid muds. These
                                   vendors will be granted exclusive rights to
                                   sell these products at C-Port.
<PAGE>

                                  EXHIBIT "B"

          I.   Additional space, labor, and equipment services as
               required:

               A.  Labor Rates                  Hourly Rates:
                   -----------                  ------------
                   Crane Operator               $ 32.00 per hour
                   Equipment Operator           $ 30.00 per hour
                   Skilled Laborer              $ 28.00 per hour
                   Rigger                       $ 21.50 per hour
                   Welder w/Equipment           $ 37.50 per hour

                   Labor Rates                  Daily (minimum 30 days):
                   -----------                  ------------------------
                   Crane Operator               $250.00 (per 12 hour day)
                   Equipment Operator           $230.00 (per 12 hour day)
                   Skilled Laborer              $190.00 (per 12 hour day)
                   Rigger                       $170.00 (per 12 hour day)
                   Welders/Equipment            $450.00 (per 12 hour day)

                   (Other positions available upon request.)
                   (Labor rates are subject to review on a quarterly basis.)


               B.  Storage Space
                   ------------
                   Outside leased slip area     $   .28 per sq. ft. per month
                   Inside storage               $  1.00 per sq. ft. per month

               C.  Vehicle Parking
                   ---------------
                   Parking                      $ 22.00 per vehicle/month

               D.  Equipment Rates              Operator Included:
                   ---------------              -----------------
                   175 Ton Crane                $175.00 per hour
                   33,000 lb. Forklift          $ 75.00 per hour
                   30 Ton Cherry Picker         $125.00 per hour
                   75 Ton Cherry Picker         $150.00 per hour
                   8,000 lb. 42' Ext Forklift   $ 95.00 per hour
                   15,000 lb. Forklift          $ 75.00 per hour
                   3 Ton Forklift               $ 45.00 per hour
                   10 Ton Forklift              $ 55.00 per hour
                   15 Ton Forklift              $ 75.00 per hour

                   Equipment Rates              Operator Not Included:
                   ---------------              ---------------------
                   175 Ton Crane                $150.00 per hour
                   33,000 lb. Forklift          $ 65.00 per hour
                   15,000 lb. Forklift          $ 65.00 per hour
                   3 Ton Forklift               $ 35.00 per hour
                   10 Ton Forklift              $ 45.00 per hour
                   15 Ton Forklift              $ 65.00 per hour
                   60' Manlift                  $ 75.00 per hour

                   (Other equipment available upon request.)
                   (Equipment rates are subject to review on a quarterly basis.)

                                      21

<PAGE>

                                  EXHIBIT "C"

          At all times during the term of this Agreement, Lessee shall maintain
the following insurance and all insurance that may be required under the
applicable laws, ordinances and regulations of any governmental authority:

     (i)  Worker's Compensation insurance in statutory limits as prescribed by
          applicable law, to cover all liabilities owed for compensation and
          other benefits under the relevant worker's compensation laws of any
          state or federal government, and Coverage B Employer's Liability
          Insurance in the amount of $1,000,000.00. Both the aforementioned
          statutory coverage and Coverage B shall contain endorsements naming
          the Lessor and the Port Commission as Alternate Employers, providing
          for voluntary compensation coverage and providing for occupational
          disease coverage. Should any services provided under this Agreement
          involve maritime activities, the use of maritime workers or vessels or
          work aboard vessels owned or not owned by the Lessee, then Lessee
          shall also obtain Maritime Employers Liability for all of the above
          coverages and including transportation, wages, maintenance and cure,
          covering liability under the Longshore and Harbor Workers'
          Compensation Act, the Jones Act, the Outer Continental Shelf Lands
          Act, the General Maritime Law, and specifically including coverage for
          claims by members of crews of vessels and claims under 33 U.S.C.A.
          905(b) against any vessel. All policies will provide that claims "in
          rem" shall be treated as claims against the Lessee.

     (ii) Comprehensive or Commercial General Liability (Bodily Injury and
          Property Damage) insurance including the following supplementary
          coverages: (a) Contractual Liability to cover liability assumed under
          this Agreement; (b) Products hazards coverage for any and all

                                      22

<PAGE>

           products provided or furnished by or on behalf of Lessee; (c)
           Completed operations hazard coverage, for any claims relating to
           defects or deficiencies in goods, products, materials or services
           used or rendered by Lessee in connection with its operations at the
           Premises; (d) Broad Form Property Damage Liability Insurance; and (e)
           coverage for pollution liability and environmental contamination and
           hazard liability. The limit of liability for such insurance shall be
           not less than $1,000,000.00 combined single limit per occurrence. All
           policies will provide that claims "in rem" shall be treated as claims
           against the Lessee.

     (iii) Hull and Machinery Insurance, including collision liability, on all
           vessels and barges, if any, used by Lessee at the Premises with a
                               ------
           limit equal to or greater than the fair market value of each vessel
           and barge.

     (iv)  should the work of Lessee involve maritime activities, the use of
           maritime workers or vessels or work aboard vessels owned or not owned
           by the Lessee, Protection and Indemnity Insurance containing coverage
           for contractual liability, chartered vessels, wreck removal,
           collision liability and pollution liability, (including but not
           limited to coverage for injuries to or death of master, mates and
           crews of vessels, unless provided in the insurance required by
           Section 7(i). The limits of liability of such insurance shall not be
           less than $1,000,000.00 per occurrence. All policies will provide
           that claims "in rem" shall be treated as claims against the Lessee.

     (v)   Lessee shall provide Umbrella/Excess Liability insurance policy over
           policies required herein to bring limits to a minimum of
           $10,000,000.00 per occurrence.

                                      23

<PAGE>


          The policies shall expressly include the Lessor and the Port
     Commission as additional insureds and specifically include claims which
     arise under 33 USC (S)905B, and all policies provided for shall contain
     an endorsement waiving underwriters' rights of subrogation against Lessor
     and the Port Commission. The insurers shall acknowledge that Lessor and the
     Port Commission have no liability for the payment of premiums for such
     insurance or inclusion of Lessor and the Port Commission as additional
     insureds.

          In the event Lessee fails to procure the insurance policies provided
for hereunder or the insurer fails or refuses to provide coverage as required
hereunder for any reason whatsoever including the insurer's insolvency or
Lessee's breach of any term, condition or warranty of such policies, Lessee
shall stand in the place and stead of any such insureds as if such coverages
have been obtained. Lessee covenants and agrees that its obligations, duties and
liabilities to Lessor and the Port Commission relative to the insurance
requirements set out hereinabove are independent of and shall in no way limit
the indemnification obligations owed to Lessor and the Port Commission under the
Agreement.

          The insurance policies set forth above shall be endorsed to provide
that the coverage afforded is primary irrespective of the existence of other
applicable insurance of Lessor or the Port Commission.

          The insurance coverage provided for shall be with insurance companies
and on policy forms acceptable to Lessor. Lessee's obligation to obtain such
insurance coverage is separate and distinct from the other obligations assumed
by Lessee hereunder, and the limits of insurance shall in no way be deemed to
limit any liabilities or obligations assumed by Lessee or under applicable law.

                                      24

<PAGE>


          Lessee shall furnish Lessor with documentary evidence showing that
such insurance is in effect and will not be canceled for any cause whatsoever or
materially changed without 30 days prior written notice to Lessor.

                                      25