THE SECURITIES  REPRESENTED  BY THIS NOTE AND THE COMMON STOCK ISSUABLE  THEREBY
HAVE NOT BEEN  REGISTERED  UNDER THE  SECURITIES  ACT OF 1933,  AS AMENDED  (THE
"SECURITIES ACT") OR ANY OTHER APPLICABLE SECURITIES LAWS AND, ACCORDINGLY,  THE
SECURITIES REPRESENTED BY THIS NOTE MAY NOT BE TRANSFERRED EXCEPT PURSUANT TO AN
EFFECTIVE  REGISTRATION  STATEMENT  UNDER,  OR  IN  A  TRANSACTION  EXEMPT  FROM
REGISTRATION  UNDER,  THE  SECURITIES  ACT  AND IN  ACCORDANCE  WITH  ANY  OTHER
APPLICABLE SECURITIES LAWS.

THIS NOTE MAY BE SUBORDINATE TO CERTAIN  INDEBTEDNESS OF BLACK WARRIOR  WIRELINE
CORP. AS AND TO THE EXTENT SET FORTH IN THAT CERTAIN  AGREEMENT FOR PURCHASE AND
SALE DATED AS OF JANUARY 23, 1998 BETWEEN BLACK WARRIOR  WIRELINE  CORP. AND ST.
JAMES CAPITAL  PARTNERS,  L.P. (90% OF THE INTERESTS AND 100% OF THE OBLIGATIONS
UNDER WHICH WERE ASSIGNED TO SJMB,  L.P. ON MARCH 1, 1998, AND THE REMAINING 10%
OF THE INTERESTS UNDER WHICH WERE ASSIGNED TO SJMB, L.P. AS OF MARCH 16, 1998).

THIS NOTE IS SUBJECT TO THE TERMS OF A SUBORDINATION AGREEMENT DATED AS OF MARCH
13, 1998 IN FAVOR OF FLEET CAPITAL  CORPORATION,  AS LENDER,  WHICH AGREEMENT IS
INCORPORATED HEREIN BY REFERENCE.

THIS  NOTE  IS  GIVEN  IN  REPLACEMENT  OF  THAT  CERTAIN  $500,000  CONVERTIBLE
PROMISSORY  NOTE DATED JULY 27, 1998 OF BLACK  WARRIOR  WIRELINE  CORP. TO SJMB,
L.P.,  HOWEVER,  THE LIENS SECURING SUCH $500,000 NOTE AND THE INTEREST  ACCRUED
THEREON ARE NOT EXTINGUISHED HEREBY, BUT ARE CARRIED FORWARD.

                          BLACK WARRIOR WIRELINE CORP.
                     $2,000,000 CONVERTIBLE PROMISSORY NOTE

$2,000,000                  Houston, Texas                      October 30, 1998


     BLACK WARRIOR WIRELINE CORP., a Delaware  corporation  (hereinafter  called
the  "Company,"  which term  includes  any  directly  or  indirectly  controlled
subsidiaries or successor entities), for value received,  hereby promises to pay
to SJMB, L.P., a Delaware limited partnership (hereinafter called the "Holder"),
or its  registered  assigns,  the  principal  sum of up to Two  Million  Dollars
($2,000,000),  together with  interest on the amount of such  principal sum from
time to time 



outstanding,  payable in  accordance  with the terms set forth below.  It is the
intention of the parties that the principal  sums of this Note shall be advanced
in multiple  Advances (as defined  below),  subject to the  satisfaction  of the
conditions  precedent  set forth in Section 1.8 of the Agreement of Purchase and
Sale  between  the  Company  and the  Holder  dated as of the date  hereof  (the
"Agreement").  No  Advance  shall be made under this Note if an Event of Default
(as defined  below) exists or would exist but for the passage of time.  Interest
under this Note shall accrue on amounts actually advanced.

     THE  OBLIGATIONS OF THE COMPANY  CONTAINED IN THIS NOTE ARE SUBJECT TO THAT
CERTAIN BORROWER  SECURITY  AGREEMENT  BETWEEN THE COMPANY AND ST. JAMES CAPITAL
PARTNERS,  L.P., A DELAWARE LIMITED  PARTNERSHIP  ("SJCP"),  DATED AS OF JUNE 5,
1997,  AS MAY BE AMENDED OR MODIFIED AND AS AMENDED MARCH 1, 1998 TO INCLUDE THE
HOLDER  AND  AS  FURTHER   AMENDED  AS  OF  THE  DATE  HEREWITH  (THE  "SECURITY
AGREEMENT").  THE OBLIGATIONS OF THE COMPANY  CONTAINED IN THIS NOTE ARE FURTHER
SUBJECT TO THE TERMS OF A SUBSIDIARY SECURITY AGREEMENT BETWEEN THE SUBSIDIARIES
OF THE COMPANY AND SJCP DATED AS OF JUNE 5, 1997,  AS MAY BE AMENDED OR MODIFIED
AND AS AMENDED MARCH 1, 1998 TO INCLUDE THE HOLDER AND AS FURTHER  AMENDED AS OF
THE DATE  HEREWITH  (THE  "SUBSIDIARY  SECURITY  AGREEMENT"),  AND A  SUBSIDIARY
GUARANTY BY EACH OF THE SUBSIDIARIES OF THE COMPANY IN FAVOR OF SJCP DATED AS OF
JUNE 5,  1997,  AS MAY BE AMENDED OR  MODIFIED  AND AS AMENDED  MARCH 1, 1998 TO
INCLUDE HOLDER AND AS FURTHER  AMENDED AS OF THE DATE HEREWITH (THE  "SUBSIDIARY
GUARANTY").

                                    ARTICLE I

                                   DEFINITIONS

     1.1  Definitions.  For all  purposes  of this  Note,  except  as  otherwise
expressly  provided  or unless the  context  otherwise  requires:  (a) the terms
defined in this Article  have the meanings  assigned to them in this Article and
include  the  plural  as well as the  singular;  (b) all  accounting  terms  not
otherwise  defined herein have the meanings  assigned to them in accordance with
generally accepted accounting principles as promulgated from time to time by the
Association  of  Independent  Certified  Public  Accountants;  and (c) the words
"herein,"  "hereof" and  "hereunder"  and other words of similar import refer to
this  Note as a whole  and  not to any  particular  Article,  Section  or  other
subdivision.

     "Advances"  shall have the  meaning  assigned  to that term in Article  II,
Section 2.1 hereof.

     "Board of Directors" means the board of directors of the Company as elected
from time to time or any duly authorized committee of that board.

     "Business Day" means each Monday, Tuesday,  Wednesday,  Thursday and Friday
which  is  not a day  on  which  banking  institutions  in  Houston,  Texas  are
authorized or obligated by law or executive order to be closed.






     "Common  Stock" means shares of common stock,  par value $0.0005 per share,
of the Company.

     "Conversion  Price" means the price per share determined in accordance with
Articles  IV and V (as  adjusted in  accordance  with the terms of this Note) at
which shares of Common Stock shall be  delivered  to Holder upon  conversion  of
this Note.

     "Default"  means any event  which is, or after  notice or  passage  of time
would be, an Event of Default.

     "Event of Default" has the meaning specified in Section 3.1.

     "Indebtedness" of any Person means all indebtedness of such Person, whether
outstanding on the date of this Note or hereafter created,  incurred, assumed or
guaranteed,  (a) for the  principal of and premium,  if any, and interest on all
debts of the Person  whether  outstanding on the date of this Note or thereafter
created  (i) for money  borrowed  by such Person  (including  capitalized  lease
obligations),  (ii) for money borrowed by others  (including  capitalized  lease
obligations) and guaranteed,  directly or indirectly,  by such Person,  or (iii)
constituting purchase money indebtedness, or indebtedness secured by property at
the time of the acquisition of such property by such Person,  for the payment of
which  the  Person is  directly  or  contingently  liable;  (b) for all  accrued
obligations  of the Person in respect of any  contract,  agreement or instrument
imposing an obligation upon the Person to pay over funds; (c) for all trade debt
of the Person;  and (d) for all deferrals,  renewals,  extensions and refundings
of, and amendments,  modifications  and supplements to, any of the  indebtedness
referred to in (a), (b) or (c) above.

     "Maturity Date",  when used with respect to this Note, means March 16, 2001
(or such earlier date upon which this Note becomes due and payable under Section
3.2).

     "Note" means this $2,000,000 10% Convertible  Promissory Note, as hereafter
amended, modified, substituted or replaced.

     "Person" means any  individual,  corporation,  limited  liability  company,
partnership,  joint venture,  association,  joint-stock company,  trust, estate,
other  entity,  unincorporated  organization  or  government  or any  agency  or
political subdivision thereof.

     "Subsidiary"  means a  corporation  or other  entity  more  than 50% of the
outstanding  voting stock of which,  or more than 50% of the equity  interest in
which, is owned, directly or indirectly,  by the Company or by one or more other
Subsidiaries  of the Company,  or by any  combination  of the Company and one or
more other  Subsidiaries,  provided,  however,  that the following  shall not be
deemed  Subsidiaries  for purposes of this Note:  Black  Warrior  International,
Inc.; Black Warrior  International  (Bermuda),  Ltd.; Black Warrior Oil and Gas,
Inc.;   and   Black   Warrior   Syria,   Ltd.   (collectively,   the   "Inactive
Organizations").  However,  if any Inactive  Organization  begins to




conduct any business (other than  activities to "wind down" such  organization),
such Inactive Organization shall be considered a Subsidiary under this Agreement
from that point forward.  For purposes of this definition,  "voting stock" means
stock which  ordinarily has voting power for the election of directors,  whether
at all times or only so long as no senior  class of stock has such voting  power
by reason of any contingency.

     "Transaction Documents" shall have the meaning assigned to such term in the
Agreement and Purchase for Sale executed as of even date herewith.

                                   ARTICLE II

                             COMMITMENT AND ADVANCES

     2.1  Advances.  Subject  to the terms and  conditions  and  relying  on the
representations  and  warranties  set forth herein and in the other  Transaction
Documents,  Holder  agrees to advance to the Company a sum  equaling a principal
amount not to exceed $2,000,000 in one or more advances, which advances shall be
made at Holder's sole and absolute discretion.  Holder shall exercise reasonable
good  faith in the  exercise  of its  discretion,  and  shall  not  unreasonably
withhold  additional  advances.  All such  advances  shall mature and be due and
payable in full on the Maturity  Date (or such earlier date upon which this Note
becomes  due and payable  under  Section  3.2).  Each  advance  shall be made in
accordance  with the  procedures  set forth in Article  II,  Section  2.2 and as
provided in Article I, Section 1.8 of the Agreement.

     2.2 Borrowing  Procedures of Advances.  In order to effect an advance,  the
Company  shall  submit a Request  for  Advance  in writing  or by  telecopy  (or
telephone  notice  promptly  confirmed  in writing or by telecopy) to Holder not
later than 10:00 a.m., Houston, Texas time, on such dates as Company determines.
The  Requests for  Advances  shall refer to this Note and specify in  sufficient
detail the  corporate  use of the proceeds of such  Advance,  and the  principal
amount  of such  Advance.  The  obligation  of the  Holder  to make any  advance
pursuant  to such a Request for  Advance is subject to the  satisfaction  of the
Holder that (i) the proceeds  will be used for a proper  purpose and (ii) on the
date of such advance, no Default or Event of Default, as those terms are defined
herein, then exists or will exist after such advance is made.

     2.3  Interest.  From the  date of this  Note  through  the  Maturity  Date,
interest shall accrue hereunder on the unpaid outstanding  principal sum of this
Note at a rate equal to ten percent (10%) per annum calculated on the basis of a
360-day year. All past due amounts of principal and interest shall bear interest
at fifteen  percent  (15%) per annum  calculated  on the basis of a 360-day year
until paid.  The Company  acknowledges  that interest at the rate of ten percent
(10%) per annum on the  principal  amount of $500,000 has accrued since July 27,
1998 and is payable under this Note.

     2.4 Payment of Principal  and  Interest.  The principal and all accrued and
unpaid interest under this Note shall be due and payable in full on the Maturity
Date. At any time,  the Holder may, at its option and in lieu of cash,  elect to
be paid all  accrued  and unpaid  interest  owed to Holder by 


the Company in the form of Common Stock, based on a price per share equal to the
Conversion  Price (the "Price Per Share").  The amount of all accrued and unpaid
interest  on the  Maturity  Date  shall be divided by the Price Per Share into a
whole number of shares of Common Stock,  with the remainder,  if any, being paid
in cash.

     2.5 Prepayments.  Subject to Holder's right to convert,  at any time before
the  Maturity  Date,  the  Company  may prepay  this Note,  in whole or in part,
without  penalty or  discount,  upon five days' prior  written  notice  given to
Holder  pursuant  to Section  7.5.  All  payments  made under this Note shall be
applied  first to accrued  interest,  and the  balance,  if any,  to  principal;
provided, however, that interest shall accrue on any remaining principal balance
and shall be payable at the rate provided above.

     2.6 Manner of Payment. Cash payments of principal and interest on this Note
will be made by  delivery  of a check to Holder at its  address  as set forth in
this Note or a wire transfer pursuant to instructions from Holder.

     2.7 Use of Proceeds.  The proceeds of all advances shall be used to provide
working  capital  required  by the  Company and to provide  funds  necessary  to
complete various capital projects, namely the construction and completion of two
offshore  "skids".  No portion of the  proceeds of any  Advance  under this Note
shall be used by the Company in any manner that might cause the borrowing or the
application  of  such  proceeds  to  violate  Regulation  U,  Regulation  T,  or
Regulation X or any other  regulation of the Federal Reserve Board or to violate
the  Securities  Exchange Act of 1934, as amended,  in each case as in effect on
the date of such borrowing and such use of proceeds.

                                   ARTICLE III

                                    REMEDIES

     3.1 Events of Default. An "Event of Default" occurs if:

         (a) the Company defaults in the payment or mandatory  prepayment of the
     principal or interest on this Note when such principal or interest  becomes
     due and payable and such default remains uncured for a period of five days;
     or

         (b) the Company or any  Subsidiary  defaults in the  performance of any
     covenant made by the Company, and such default remains uncured for a period
     of 45 days in and of (i) that certain Agreement for Purchase and Sale dated
     as of even date herewith (the "Purchase Agreement");  (ii) the Common Stock
     Purchase  Warrants issued by the Company to Holder pursuant to the terms of
     the Purchase  Agreement  and dated as of the date hereof (the  "Warrants");
     (iii) the  Registration  Rights  Agreement;  (iv) the  Security  Agreement,
     Subsidiary  Security  Agreement or  Subsidiary  Guaranty;  or (v) this Note
     (other  than  a  default  in the  performance  of a  covenant  specifically
     addressed  elsewhere in this Section  3.1);  




     provided  that a default in the  performance  of any  covenant  in Sections
     8(a),  8(b),  8(c), 8(d), 8(e), 8(f), 8(h), 8(i), 8(j), 8(k), 8(l), 8(m) or
     8(n) of the  Security  Agreement  or  Section  6.1 of this Note shall be an
     Event of Default immediately upon occurrence; or

         (c)  any  representation  or  warranty  made  by  the  Company  or  any
     Subsidiary in the Purchase Agreement, the Warrants, the Registration Rights
     Agreement,  the  Security  Agreement  or this  Note  or in any  certificate
     furnished  by the  Company  in  connection  with  the  consummation  of the
     transaction  contemplated  thereby  or  hereby,  is untrue in any  material
     respect as of the date of making thereof and such default  remains  uncured
     for a period of 45 days; or

         (d) the Company or any  Subsidiary  defaults  in the  payment  when due
     (whether  by lapse of  time,  by  declaration,  by call for  redemption  or
     otherwise)  of the  principal  of or  interest on any  Indebtedness  of the
     Company or such Subsidiary  (other than the Indebtedness  evidenced by this
     Note) having an aggregate  principal amount in excess of $100,000 or on any
     Indebtedness  of the Company to any of its  stockholders  and such  default
     remains uncured for a period of 45 days; or

         (e) a court of  competent  jurisdiction  enters a judgment or judgments
     against the  Company or any  Subsidiary,  or any  property or assets of the
     Company or any Subsidiary, for the payment of money aggregating $100,000 or
     more in excess of applicable  insurance  coverage  (other than the judgment
     disclosed on Schedule 3.1(e) hereto) and such default remains uncured for a
     period of 45 days; or

         (f) a court of competent  jurisdiction enters (i) a decree or order for
     relief in respect of the Company or any Subsidiary in an  involuntary  case
     or proceeding under any applicable federal or state bankruptcy, insolvency,
     reorganization or other similar law or (ii) a decree or order adjudging the
     Company or any Subsidiary a bankrupt or insolvent, or approving as properly
     filed  a  petition  seeking  reorganization,   arrangement,  adjustment  or
     composition  of or in respect of the  Company or any  Subsidiary  under any
     applicable  federal or state law,  or  appointing  a  custodian,  receiver,
     liquidator,  assignee,  trustee,  sequestrator or other similar official of
     the Company or any Subsidiary or of any substantial part of the property of
     the Company or any  Subsidiary or ordering the winding up or liquidation of
     the affairs of the Company or any  Subsidiary  and any such decree or order
     of relief or any such other decree or order  remains  unstayed for a period
     of 90 days from its date of entry; or

         (g)  the  Company  or any  Subsidiary  commences  a  voluntary  case or
     proceeding under any applicable  federal or state  bankruptcy,  insolvency,
     reorganization  or other  similar law or any other case or proceeding to be
     adjudicated a bankrupt or insolvent, or the Company or any Subsidiary files
     a petition,  answer or consent seeking  reorganization  or relief under any
     applicable  federal or state law, or the Company or any Subsidiary makes an
     assignment for the benefit of creditors, or admits in writing its inability
     to pay its debts generally as they become due; or


         (h) any person or group  (within  the  meaning of Section  13(d) of the
     Securities  Exchange Act of 1934)  becomes the  beneficial  owner of 40% or
     more of the total  voting  power of the Company and was not the  beneficial
     owner of 40% or more of the total  voting  power of the  Company  as of the
     date hereof;  provided that the  foregoing  shall not include any person or
     group who or which acquires the Warrants or shares of the Company's  Common
     Stock  issuable  upon  exercise of the Warrants or upon  conversion of this
     Note;  and further  provided that such default has not been cured or waived
     within ninety (90) days following such change of beneficial ownership.

         (i) the Company or any  Subsidiary (1) merges or  consolidates  with or
     into any other Person (unless the Company or any of its Subsidiaries is the
     surviving or acquiring  party);  (2) dissolves or liquidates;  or (3) sells
     all or any  substantial  portion of its assets  (unless the  purchaser is a
     Subsidiary of the Company).

     3.2  Acceleration  of Maturity.  This Note and all accrued  interest  shall
automatically  become  immediately  due  and  payable  if an  Event  of  Default
described in Sections  3.1(f),  3.1(g) or 3.1(i) occurs and, this Note shall, at
the  option of the Holder in its sole  discretion,  become  immediately  due and
payable if any other Event of Default occurs,  and in every such case the Holder
of the Note may declare  the  principal  and  interest on the Note to be due and
payable immediately.

                                   ARTICLE IV

                               CONVERSION OF NOTE

     Subject to and upon compliance with the provisions of this Article,  at the
option of Holder,  all or any part of this Note may be converted at any time, at
the principal  amount hereof together with accrued and unpaid interest  thereon,
into fully paid and  nonassessable  shares  (calculated as to each conversion to
the  nearest  1/100 of a share) of Common  Stock.  The  Conversion  Price  shall
initially be $2.25 per share.  Notwithstanding anything else to the contrary set
forth  herein,  the Holder shall have the right to convert this Note pursuant to
the terms set forth herein at any time, including the 30 Business Days following
(i) the Maturity Date or (ii) any prepayment  pursuant to Section 2.5 hereof. If
Holder elects to convert this Note after a prepayment  has been made pursuant to
Section  2.5,  then Holder shall return all or such portion of the funds paid to
Holder as to which Holder has elected to convert.


                                    ARTICLE V

                         ADJUSTMENT OF CONVERSION PRICE


     5.1  Anti-Dilution  Provisions.  The  Conversion  Price shall be subject to
adjustment  from time to time as hereinafter  provided.  Upon each adjustment of
the Conversion  Price,  the holder of this Note shall  thereafter be entitled to
purchase, at the Conversion Price resulting from such adjustment,  the number of
shares of Common Stock  obtained by multiplying  the Conversion  Price in effect
immediately  prior  to such  adjustment  by the  number  of  shares  purchasable
pursuant  hereto  immediately  prior to such adjustment and dividing the product
thereof by the Conversion Price resulting from such adjustment.

     5.2 Adjustment of Conversion Price Upon Issuance of Common Stock.

         5.2.1 (A) If and whenever after the date hereof the Company shall issue
     or sell any Common Stock for no  consideration  or for a consideration  per
     share less than the Conversion Price,  issue  convertible  securities other
     than this Note,  issue  warrants  other than the Warrants  issued as of the
     date  hereof,  grant  stock  options,  or  issue  any  other  common  stock
     equivalent (other than shares reserved for issuance to officers, employees,
     directors,  consultants  or advisors  of the  Company  pursuant to existing
     stock option or restricted stock purchase plans) then, forthwith, upon such
     issue or sale,  the  Conversion  Price shall be reduced (but not increased,
     except as otherwise  specifically  provided in Section 5.2.2), to the lower
     price per share  (calculated to the nearest  one-ten  thousandth of a cent,
     but in any event not less than $0.001 per share).

               (B)  Notwithstanding  the  provisions  of this  Section  5.2,  no
     adjustment  shall be made in the  Conversion  Price in the  event  that the
     Company issues, in one or more transactions, (i) Common Stock upon exercise
     of any options  issued to  officers,  directors or employees of the Company
     pursuant to a stock option plan or an  employment,  severance or consulting
     agreement as now or hereafter in effect, in each case approved by the Board
     of Directors  (provided that the aggregate number of shares of Common Stock
     which may be issuable,  including  options issued prior to the date hereof,
     under all such employee  plans and  agreements  shall at no time exceed the
     number of such shares of Common Stock  outstanding  on the date hereof on a
     fully diluted basis that are issuable under  currently  effective  employee
     plans and  agreements);  (ii) Common Stock upon  conversion of this Note or
     any other warrant issued  pursuant to the terms of the Purchase  Agreement;
     (iii) Common Stock upon  exercise of any stock  purchase  warrant or option
     (other  than  the  options  referred  to in  clause  (i)  above)  or  other
     convertible  security  outstanding on the date hereof; or (iv) Common Stock
     issued as consideration in acquisitions.





         5.2.2  For  purposes  of this  Section  5.2,  the  following  shall  be
     applicable:

         (A)  Issuance of Rights or Options.  In case at any time after the date
     hereof  the  Company  shall in any manner  grant  (whether  directly  or by
     assumption  in a merger or  otherwise)  any rights to  subscribe  for or to
     purchase,  or any options for the purchase of, Common Stock or any stock or
     securities   convertible  into  or  exchangeable  for  Common  Stock  (such
     convertible  or  exchangeable  stock  or  securities  being  herein  called
     "Convertible  Securities")  (other than  warrants,  options or  convertible
     securities  issued as  consideration  for or assumed in conjunction with an
     acquisition or to officers,  directors, or employees of the acquired entity
     in  conjunction  therewith),  whether or not such  rights or options or the
     right  to  convert  or  exchange  any  such   Convertible   Securities  are
     immediately exercisable, and the price per share for which shares of Common
     Stock are  issuable  upon the  exercise  of such  rights or options or upon
     conversion  or  exchange  of such  Convertible  Securities  (determined  by
     dividing  (i) the total  amount,  if any,  received  or  receivable  by the
     Company as consideration  for the granting of such rights or options,  plus
     the minimum aggregate amount of additional  consideration,  if any, payable
     to the Company upon the exercise of such rights or options, or plus, in the
     case of such rights or options that relate to Convertible  Securities,  the
     minimum aggregate amount of additional consideration,  if any, payable upon
     the issue or sale of such Convertible Securities and upon the conversion or
     exchange  thereof,  by (ii) the  total  maximum  number of shares of Common
     Stock  issuable  upon the  exercise  of such  rights or options or upon the
     conversion or exchange of all such Convertible Securities issuable upon the
     exercise of such rights or options) shall be less than the Conversion Price
     in effect as of the date of granting such rights or options, then the total
     maximum number of shares of Common Stock issuable upon the exercise of such
     rights or options or upon  conversion  or exchange of all such  Convertible
     Securities  issuable  upon the exercise of such rights or options  shall be
     deemed to be  outstanding  as of the date of the granting of such rights or
     options and to have been  issued for such price per share,  with the effect
     on the  Conversion  Price  specified  in Section  5.2.1  hereof.  Except as
     provided in Section 5.2.2 hereof,  no further  adjustment of the Conversion
     Price shall be made upon the actual  issuance  of such  Common  Stock or of
     such Convertible Securities upon exercise of such rights or options or upon
     the actual  issuance of such Common  Stock upon  conversion  or exchange of
     such Convertible Securities.

         (B) Change in Option Price or  Conversion  Rate.  Upon the happening of
     any of the following events,  namely, if the purchase price provided for in
     any right or option  referred to in Section  5.2.2  above,  the  additional
     consideration,  if any,  payable  upon the  conversion  or  exchange of any
     Convertible  Securities referred to in Section 5.2.2(A) hereof, or the rate
     at which any Convertible Securities referred to in Section 5.2.2(A) hereof,
     are convertible  into or exchangeable  for Common Stock shall change (other
     than  under  or  by  reason  of  provisions  designed  to  protect  against
     dilution), the Conversion Price then in effect hereunder shall forthwith be
     readjusted  (increased or decreased,  as the case may be) to the Conversion
     Price that would have been in effect at such time had such rights,  options
     or  Convertible  Securities  still  outstanding  provided  for such changed
     purchase price,  additional  



     consideration or conversion rate, as the case may be, at the time initially
     granted,  issued or sold.  On the  expiration  of any such  option or right
     referred to in Section 5.2.2(A)  hereof,  or on the termination of any such
     right to convert or exchange any such Convertible Securities referred to in
     Section  5.2.2(A)  hereof,  the Conversion  Price then in effect  hereunder
     shall forthwith be readjusted (increased or decreased,  as the case may be)
     to the Conversion  Price that would have been in effect at the time of such
     expiration or termination had such right, option or Convertible Securities,
     to  the  extent  outstanding   immediately  prior  to  such  expiration  or
     termination,  never been  granted,  issued or sold,  and the  Common  Stock
     issuable  thereunder  shall no longer be deemed to be  outstanding.  If the
     purchase price provided for in Section 5.2.2(A) hereof or the rate at which
     any  Convertible  Securities  referred  to in Section  5.2.2(A)  hereof are
     convertible  into or exchangeable  for Common Stock shall be reduced at any
     time under or by reason of  provisions  with  respect  thereto  designed to
     protect against dilution, then in case of the delivery of Common Stock upon
     the exercise of any such right or option or upon  conversion or exchange of
     any such  Convertible  Securities,  the  Conversion  Price  then in  effect
     hereunder  shall,  if not already  adjusted,  forthwith be adjusted to such
     amount  as would  have  obtained  had such  right,  option  or  Convertible
     Securities  never been issued as to such Common  Stock and had  adjustments
     been made upon the issuance of the Common Stock delivered as aforesaid, but
     only if as a result of such adjustment the Conversion  Price then in effect
     hereunder is thereby reduced.

         (C)  Consideration  for  Stock.  In case at any  time  Common  Stock or
     Convertible Securities or any rights or options to purchase any such Common
     Stock or  Convertible  Securities  shall be issued  or sold for  cash,  the
     consideration  therefor  shall be deemed to be the amount  received  by the
     Company  therefor.  In case  at any  time  any  Common  Stock,  Convertible
     Securities  or any rights or options to purchase  any such Common  Stock or
     Convertible Securities shall be issued or sold for consideration other than
     cash,  the  amount of the  consideration  other than cash  received  by the
     Company  shall be deemed  to be the fair  value of such  consideration,  as
     determined  reasonably  and in good faith by the Board of  Directors of the
     Company.  In case at any time any Common Stock,  Convertible  Securities or
     any  rights  or  options  to  purchase  any  Common  Stock  or  Convertible
     Securities  shall be issued in connection with any merger or  consolidation
     in  which  the  Company  is  the  surviving  corporation,   the  amount  of
     consideration  received  therefor shall be deemed to be the fair value,  as
     determined  reasonably  and in good faith by the Board of  Directors of the
     Company,  of such  portion of the assets and  business of the  nonsurviving
     corporation as such Board of Directors may determine to be  attributable to
     such Common Stock,  Convertible  Securities,  rights or options as the case
     may be. In case at any time any rights or options to purchase any shares of
     Common Stock or Convertible  Securities  shall be issued in connection with
     the  issuance  and  sale  of  other  securities  of the  Company,  together
     consisting  of one  integral  transaction  in  which  no  consideration  is
     allocated to such rights or options by the parties,  such rights or options
     shall be deemed to have been issued without consideration.

         (D) Record  Date.  In the case the  Company  shall take a record of the
     holders  of its  Common  Stock for the  purpose  of  entitling  them (i) to
     receive  a  dividend  or other  distribution  payable  in  Common  Stock or
     Convertible Securities, or (ii) to subscribe for or



     purchase  Common  Stock or  Convertible  Securities,  then such record date
     shall be deemed to be the date of the  issuance or sale of the Common Stock
     or Convertible Securities deemed to have been issued or sold as a result of
     the  declaration of such dividend or the making of such other  distribution
     or the date of the granting of such right of subscription  or purchase,  as
     the case may be.

         (E) Treasury Shares.  The number of shares of Common Stock  outstanding
     at any given time shall not include shares owned directly by the Company in
     treasury,  and the  disposition  of any such shares shall be  considered an
     issuance or sale of Common Stock for the purpose of this Section 5.2.

     5.3 Stock  Dividends.  In case the Company shall declare a dividend or make
any other  distribution upon any shares of the Company,  payable in Common Stock
or Convertible Securities,  any Common Stock or Convertible  Securities,  as the
case may be,  issuable  in payment of such  dividend  or  distribution  shall be
deemed to have been issued or sold without consideration.

     5.4 Stock Splits and Reverse Splits. In the event that the Company shall at
any time subdivide its outstanding  shares of Common Stock into a greater number
of shares,  the Conversion Price in effect immediately prior to such subdivision
shall be  proportionately  reduced and the number of Shares into which this Note
may be converted  immediately prior to such subdivision shall be proportionately
increased,  and conversely,  in the event that the outstanding  shares of Common
Stock  shall at any time be  combined  into a  smaller  number  of  shares,  the
Conversion  Price  in  effect  immediately  prior to such  combination  shall be
proportionately  increased  and the number of Shares into which this Note may be
converted  immediately  prior  to  such  combination  shall  be  proportionately
reduced.  Except as provided in this Section 5.4 no adjustment in the Conversion
Price and no change in the number of Shares  shall be made under this  Article V
as a result of or by reason of any such subdivision or combination.

     5.5  Reorganizations  and Asset  Sales.  If any capital  reorganization  or
reclassification  of the capital  stock of the  Company,  or any  consolidation,
merger or share  exchange  of the  Company  with  another  Person,  or the sale,
transfer  or other  disposition  of all or  substantially  all of its  assets to
another  Person  shall be  effected in such a way that  holders of Common  Stock
shall be entitled to receive capital stock, securities or assets with respect to
or in exchange for their shares, then the following provisions shall apply:

         5.5.1  As  a  condition  of  such   reorganization,   reclassification,
     consolidation,  merger, share exchange, sale, transfer or other disposition
     (except as otherwise provided below in Section 5.5.3),  lawful and adequate
     provisions  shall be made whereby the holder of this Note shall  thereafter
     have the right to  purchase  and  receive  upon the  terms  and  conditions
     specified  in this Note and in lieu of the shares  immediately  theretofore
     receivable upon the exercise of the rights represented  hereby, such shares
     of capital  stock,  securities  or assets as may be issued or payable  with
     respect to or in exchange for a number of outstanding shares of such Common
     Stock equal to the number of shares  immediately  theretofore so receivable



     had such  reorganization,  reclassification,  consolidation,  merger, share
     exchange  or  sale  not  taken  place,  and in any  such  case  appropriate
     provision reasonably satisfactory to such holder shall be made with respect
     to the rights and  interests of such holder to the end that the  provisions
     hereof (including,  without  limitation,  provisions for adjustments of the
     Conversion Price and of the number of shares  receivable upon the exercise)
     shall thereafter be applicable,  as nearly as possible,  in relation to any
     shares of capital stock,  securities or assets thereafter  deliverable upon
     the exercise of this Note.

         5.5.2 In the event of a merger,  share exchange or consolidation of the
     Company with or into another Person as a result of which a number of shares
     of common stock or its equivalent of the successor Person greater or lesser
     than the number of shares of Common Stock outstanding  immediately prior to
     such merger,  share  exchange or  consolidation  are issuable to holders of
     Common Stock, then the Conversion Price in effect immediately prior to such
     merger,  share  exchange  or  consolidation  shall be  adjusted in the same
     manner as though there were a subdivision or combination of the outstanding
     shares of Common Stock.

         5.5.3 The  Company  shall not  effect any such  consolidation,  merger,
     share  exchange,  sale,  transfer or other  disposition  unless prior to or
     simultaneously with the consummation thereof the successor Person (if other
     than the Company)  resulting  from such  consolidation,  share  exchange or
     merger or the Person  purchasing or otherwise  acquiring  such assets shall
     have assumed by written instrument  executed and mailed or delivered to the
     Holder hereof at the last address of such Holder  appearing on the books of
     the Company the obligation to deliver to such Holder such shares of capital
     stock,   securities  or  assets  as,  in  accordance   with  the  foregoing
     provisions,  such  Holder  may  be  entitled  to  receive,  and  all  other
     liabilities and obligations of the Company hereunder.  Upon written request
     by the Holder hereof,  such Successor  Person will issue a new Note revised
     to reflect the modifications in this Note effected pursuant to this Section
     5.5.

         5.5.4 If a purchase,  tender or exchange  offer is made to and accepted
     by the holders of 50% or more of the  outstanding  shares of Common  Stock,
     the Company shall not effect any consolidation,  merger,  share exchange or
     sale,  transfer or other  disposition  of all or  substantially  all of the
     Company's  assets  with  the  Person  having  made  such  offer or with any
     affiliate  of  such  Person,  unless  prior  to the  consummation  of  such
     consolidation,  merger, share exchange, sale, transfer or other disposition
     the holder  hereof shall have been given a reasonable  opportunity  to then
     elect to receive upon the conversion of this Note either the capital stock,
     securities  or assets then issuable with respect to the Common Stock or the
     capital stock, securities or assets, or the equivalent,  issued to previous
     holders of the Common Stock in accordance with such offer.

     5.6 Adjustment for Asset  Distribution.  If the Company declares a dividend
or other  distribution  payable  to all  holders  of shares  of Common  Stock in
evidences  of  indebtedness  of the  Company  or  other  assets  of the  Company
(including,  cash (other than  regular cash  dividends  declared by the Board of
Directors),  capital stock (other than Common Stock,  Convertible  Securities or
options or rights thereto) or other  property),  the Conversion  Price in effect
immediately  prior to 



such declaration of such dividend or other  distribution  shall be reduced by an
amount equal to the amount of such dividend or distribution payable per share of
Common  Stock,  in the case of a cash dividend or  distribution,  or by the fair
value of such dividend or distribution  per share of Common Stock (as reasonably
determined in good faith by the Board of Directors of the Company),  in the case
of any other dividend or distribution. Such reduction shall be made whenever any
such dividend or  distribution  is made and shall be effective as of the date as
of which a record is taken for purpose of such dividend or distribution or, if a
record is not  taken,  the date as of which  holders  of record of Common  Stock
entitled to such dividend or distribution are determined.

     5.7 De Minimis Adjustments. No adjustment in the number of shares of Common
Stock  purchasable  hereunder  shall be required  unless such  adjustment  would
require  an  increase  or  decrease  of at  least  one  share  of  Common  Stock
purchasable  upon  conversion of the Note and no  adjustment  in the  Conversion
Price shall be  required  unless such  adjustment  would  require an increase or
decrease of at least $.01 in the Conversion Price;  provided,  however, that any
adjustments  which by reason of this  Section  5.7 are not  required  to be made
shall be carried  forward and taken into account in any  subsequent  adjustment.
All  calculations  shall  be made to the  nearest  full  share  or  nearest  one
hundredth of a dollar, as applicable.

     5.8 Notice of Adjustment.  Whenever the  Conversion  Price or the number of
Shares  issuable  upon the  conversion  of the Note shall be  adjusted as herein
provided,  or the rights of the holder  hereof  shall  change by reason of other
events specified herein, the Company shall compute the adjusted Conversion Price
and the adjusted number of Shares in accordance  with the provisions  hereof and
shall prepare an Officer's  Certificate  setting  forth the adjusted  Conversion
Price and the adjusted  number of Shares  issuable  upon the  conversion of this
Note or specifying the other shares of stock, securities or assets receivable as
a result of such change in rights,  and showing in  reasonable  detail the facts
and  calculations  upon which such  adjustments or other changes are based.  The
Company shall cause to be mailed to the Holder  hereof copies of such  Officer's
Certificate  together with a notice  stating that the  Conversion  Price and the
number of Shares purchasable upon conversion of this Note have been adjusted and
setting forth the adjusted  Conversion  Price and the adjusted  number of Shares
purchasable upon conversion of this Note.

     5.9 Notifications to Holder. In case at any time the Company proposes:

              (i) to  declare  any  dividend  upon its Common  Stock  payable in
         capital stock or make any special dividend or other distribution (other
         than cash dividends) to the holders of its Common Stock;

              (ii) to offer for  subscription  pro rata to all of the holders of
         its Common Stock any additional shares of capital stock of any class or
         other rights;

              (iii) to effect any capital reorganization, or reclassification of
         the capital  stock of the Company,  or  consolidation,  merger or share
         exchange of the Company 



         with another Person,  or sale,  transfer or other disposition of all or
         substantially all of its assets; or

              (iv) to effect a voluntary or involuntary dissolution, liquidation
         or winding up of the Company,

then, in any one or more of such cases, the Company shall give the holder hereof
(a) at least 10 days (but not more  than 90 days)  prior  written  notice of the
date on which the books of the Company  shall  close or a record  shall be taken
for such dividend, distribution or subscription rights or for determining rights
to vote in  respect  of any  such  issuance,  reorganization,  reclassification,
consolidation, merger, share exchange, sale, transfer, disposition, dissolution,
liquidation  or  winding  up,  and  (b)  in  the  case  of  any  such  issuance,
reorganization,  reclassification,  consolidation, merger, share exchange, sale,
transfer, disposition,  dissolution, liquidation or winding up, at least 10 days
(but not more than 90 days) prior written notice of the date when the same shall
take place.  Such notice in accordance with the foregoing  clause (a) shall also
specify, in the case of any such dividend,  distribution or subscription rights,
the date on which the holders of Common  Stock shall be  entitled  thereto,  and
such notice in accordance  with the foregoing  clause (b) shall also specify the
date on which the holders of Common  Stock  shall be entitled to exchange  their
Common Stock,  as the case may be, for securities or other property  deliverable
upon  such  reorganization,   reclassification,   consolidation,  merger,  share
exchange, sale, transfer, disposition,  dissolution,  liquidation or winding up,
as the case may be.

     5.10 Company to Prevent  Dilution.  If any event or condition  occurs as to
which  other  provisions  of this  Article  are not  strictly  applicable  or if
strictly  applicable would not fairly protect the exercise or purchase rights of
this  Note  evidenced  hereby  in  accordance  with  the  essential  intent  and
principles of such provisions, or that might materially and adversely affect the
exercise or purchase  rights of the holder  hereof under any  provisions of this
Note,  then the Company shall make such  adjustments in the  application of such
provisions,  in accordance with such essential  intent and principles,  so as to
protect such  exercise and purchase  rights as  aforesaid,  and any  adjustments
necessary  with  respect  to the  Conversion  Price  and the  number  of  shares
purchasable  hereunder so as to preserve the rights of the holder hereunder.  In
no event shall any such  adjustment have the effect of increasing the Conversion
Price as otherwise  determined pursuant to this Article except in the event of a
combination of shares of the type  contemplated in Section 5.4 hereof,  and then
in no event to an amount greater than the Conversion Price as adjusted  pursuant
to Section 5.4 hereof.






                                   ARTICLE VI

                                    COVENANTS

     The Company covenants and agrees that, so long as this Note is outstanding:

     6.1 Payment of Principal  and Accrued  Interest.  The Company will duly and
punctually pay or cause to be paid the principal sum of this Note, together with
interest  accrued  thereon  from the date  hereof  to the  date of  payment,  in
accordance with the terms hereof.

     6.2 Corporate  Existence.  The Company will, and will cause each Subsidiary
to, do or cause to be done all things  necessary  to  preserve  and keep in full
force and effect its corporate  existence,  rights  (charter and  statutory) and
franchises;  provided,  however,  that the Company or a Subsidiary  shall not be
required  to  preserve  any such  right  or  franchise  if it  shall  reasonably
determine that the preservation thereof is no longer desirable in the conduct of
its business.

     6.3 Taxes;  Claims;  etc. The Company will, and will cause each  Subsidiary
to, promptly pay and discharge all lawful taxes,  assessments,  and governmental
charges or levies imposed upon it or upon its income or profits,  or upon any of
its  properties,  real,  personal,  or mixed,  before the same  shall  become in
default,  as well as all lawful  claims for labor,  materials,  and  supplies or
otherwise  which, if unpaid,  might become a lien or charge upon such properties
or any part  thereof,  and which  lien or charge  will have a  material  adverse
effect on the  business of the  Company;  provided,  however,  that  neither the
Company nor any Subsidiary shall be required to pay or cause to be paid any such
tax,  assessment,  charge,  levy, or claim prior to  institution  of foreclosure
proceedings  if the validity  thereof  shall  concurrently  be contested in good
faith by  appropriate  proceedings  and if the  Company  shall have  established
reserves  deemed by the Company  adequate with respect to such tax,  assessment,
charge, levy, or claim.

     6.4  Maintenance  of Existence and  Properties.  The Company will, and will
cause each Subsidiary to, keep its material  properties in good repair,  working
order,  and  condition,  ordinary wear and tear  excepted,  so that the business
carried on may be properly  conducted  at all times in  accordance  with prudent
business management.

     6.5 SEC  Reports.  The Company  will  deliver to the Holder  within 20 days
after it files them with the SEC, copies of its annual and quarterly reports and
of the information,  documents, and other reports (or copies of such portions of
any of the foregoing as the SEC may by rules and  regulations  prescribe)  which
the Company is required or elects to file with the SEC pursuant to Section 13 or
15(d) of the  Securities  Exchange Act of 1934.  The Company will timely  comply
with  its  reporting  and  filing   obligations  under  the  applicable  federal
securities laws.

     6.6 Notice of  Defaults.  The Company  will  promptly  notify the Holder in
writing of the  occurrence of (i) any Event of Default under this Note, and (ii)
any event of default (or if any event 




of default would result upon any payment with respect to this Note) with respect
to any  Indebtedness  as such  event of  default  is  defined  therein or in the
instrument under which it is outstanding,  permitting  holders to accelerate the
maturity of such Indebtedness.

     6.7 Compliance  with Laws. The Company will promptly  comply with all laws,
ordinances and  governmental  rules and regulations to which it is subject,  the
violation of which would materially and adversely affect the Company.

     6.8 Amendments to Charter. The Company will not amend or modify its charter
without the prior written consent of Holder.

     6.9 Mergers  and  Acquisitions.  Without  the  consent of the  Holder,  the
Company or any Subsidiary will not dissolve,  liquidate,  consolidate,  merge or
enter  into a share  exchange  with or sell  or  transfer  all or a  substantial
portion of its assets to any Person.

                                   ARTICLE VII

                                  MISCELLANEOUS

     7.1 Consent to  Amendments.  This Note may be amended,  and the Company may
take any action herein prohibited, or omit to perform any act herein required to
be performed by it, if and only if the Company shall obtain the written  consent
to such  amendment,  action or omission to act from the holders of a majority of
the aggregate principal amount of this Note.

     7.2  Benefits  of Note;  No  Impairment  of  Rights  of  Holder  of  Senior
Indebtedness.  Nothing  in this  Note,  express  or  implied,  shall give to any
Person, other than the Company,  Holder, and their successors any benefit or any
legal or equitable right, remedy or claim under or in respect of this Note.

     7.3  Successors  and Assigns.  All  covenants  and  agreements in this Note
contained  by or on behalf of the Company and the Holder shall bind and inure to
the  benefit of the  respective  successors  and  assigns of the Company and the
Holder.

     7.4  Restrictions  on Transfer.  Holder shall not transfer this Note except
(by the grant of a  security  interest)  to its  lender or  lenders.  As between
Holder and its lender or lenders,  this Note is  transferable in the same manner
and with the same effect as in the case of a negotiable  instrument payable to a
specified person.  Any lender to which Holder grants a security interest in this
Note shall be  entitled  to  exercise  all  remedies  to which it is entitled by
contract or by law, including (without  limitation)  transferring this Note into
its own  name or into  the  name of any  purchaser  at any  sale  undertaken  in
connection with enforcement by such lender of its remedies.

     7.5  Notice;  Address  of  Parties.   Except  as  otherwise  provided,  all
communications to the Company or Holder provided for herein or with reference to
this Note  shall be deemed to have been  



sufficiently  given or served for all  purposes on the third  business day after
being sent as certified or registered mail, postage and charges prepaid,  to the
following  addresses:  if to the Company:  Black Warrior  Wireline  Corp.,  3748
Highway  #45  North,  Columbus,  Mississippi  39701,  or at  any  other  address
designated by the Company in writing to Holder;  if to Holder:  SJMB,  L.P., c/o
St. James Capital  Corp.,  777 Post Oak  Boulevard,  Suite 950,  Houston,  Texas
77056,  Attn:  Jay Brown,  or at any other  address  designated by Holder to the
Company in writing.

     7.6  Separability  Clause.  In case any  provision  in this  Note  shall be
invalid,  illegal or unenforceable in any jurisdiction,  the validity,  legality
and enforceability of the remaining provisions in such jurisdiction shall not in
any way be affected or impaired thereby;  provided,  however,  such construction
does not destroy the essence of the bargain provided for hereunder.

     7.7  Governing  Law.  This Note  shall be  governed  by, and  construed  in
accordance  with, the internal laws of the State of Delaware  (without regard to
principles of choice of law).

     7.8  Usury.  It is the intention of the parties hereto to conform  strictly
to the  applicable  laws of the  State of  Delaware  and the  United  States  of
America,  and  judicial  or  administrative  interpretations  or  determinations
thereof  regarding the contracting  for,  charging and receiving of interest for
the use,  forbearance,  and detention of money (hereinafter  referred to in this
Section 7.8 as "Applicable  Law").  The Holder shall have no right to claim,  to
charge or to receive any interest in excess of the maximum rate of interest,  if
any,  permitted  to be  charged  on  that  portion  of the  amount  representing
principal  which is outstanding  and unpaid from time to time by Applicable Law.
Determination  of the rate of interest  for the purpose of  determining  whether
this  Note is  usurious  under  Applicable  Law  shall  be  made by  amortizing,
prorating,  allocating  and  spreading  in equal parts  during the period of the
actual  time of this Note,  all  interest  or other sums  deemed to be  interest
(hereinafter  referred  to in  this  Section  7.8 as  "Interest")  at  any  time
contracted  for,  charged or received from the Company in  connection  with this
Note. Any Interest  contracted for, charged or received in excess of the maximum
rate allowed by Applicable Law shall be deemed a result of a mathematical  error
and a mistake.  If this Note is paid in part prior to the end of the full stated
term of this Note and the Interest  received for the actual  period of existence
of this Note exceeds the maximum rate allowed by  Applicable  Law,  Holder shall
credit the amount of the excess  against any amount owing under this Note or, if
this Note has been paid in full,  or in the event  that it has been  accelerated
prior to maturity, Holder shall refund to the Company the amount of such excess,
and shall not be subject to any of the penalties  provided by Applicable Law for
contracting  for,  charging or receiving  Interest in excess of the maximum rate
allowed by Applicable Law. Any such excess which is unpaid shall be canceled.





     IN WITNESS  WHEREOF,  the  Company has caused  this  instrument  to be duly
executed on the date first above written.

                                    BLACK WARRIOR WIRELINE CORP.

                                    By:

                                            William L. Jenkins, President

                      [Signature Page -- Convertible Note]