REVOCABLE WARRANT AGREEMENT

                            NATURAL GAS SYSTEMS, INC.

      THIS REVOCABLE  WARRANT  AGREEMENT (this  "Agreement") is made and entered
into  as of  April  4,  2005,  between  Natural  Gas  Systems,  Inc.,  a  Nevada
corporation (the "Company"), and Robert S. Herlin ("Holder").  Terms not defined
herein  shall have the meaning  defined in the Stock Option  Agreement  (defined
below).

                                 R E C I T A L S

      WHEREAS,  the Company proposes to issue to Holder a maximum of TWO HUNDRED
EIGHTY SEVEN THOUSAND FIVE HUNDRED (287,500)  revocable warrants (the "Revocable
Warrants"),  each  such  Revocable  Warrant  entitling  the  holder  thereof  to
purchase,  under certain conditions,  one share of common stock, .001 par value,
of the Company (the "Shares" or the "Common Stock");

      WHEREAS,  the Revocable  Warrants  which are the subject of this Agreement
will be issued by the Company to Holder in connection  with Holder's  employment
with the Company pursuant to the Employment Agreement  ("Employment  Agreement")
and the  Stock  Option  Agreement  ("Stock  Option  Agreement"),  of  even  date
herewith, and attached hereto as EXHIBITS B and C, respectively; and

      WHEREAS,  the  Revocable  Warrants  shall be subject to  revocation by the
Company  without  any  further  consideration  under the  terms  and  conditions
detailed herein.

      NOW, THEREFORE, in consideration of the premises and the mutual agreements
herein set forth, the parties hereto agree as follows:

                                A G R E E M E N T

      1.  Revocable  Warrant  Certificates.   The  warrant  certificates  to  be
delivered  pursuant to this Agreement  (the  "REVOCABLE  WARRANT  CERTIFICATES")
shall be in the form set forth in  EXHIBIT  A,  attached  hereto and made a part
hereof,  with such appropriate  insertions,  omissions,  substitutions and other
variations as are required or permitted by this Revocable Warrant Agreement.

      2. Right to Exercise  Revocable  Warrants.  Each Revocable  Warrant may be
exercised,  in whole or in part, after those Revocable Warrants are fully vested
and no longer  Restricted  Warrants  (as defined in Section 3 below) until 11:59
P.M.  (Eastern  Standard Time) on the date that is ten (10) years after the date
of this Agreement (the "EXPIRATION  DATE"). Each Revocable Warrant not exercised
or revoked on or before the Expiration Date shall expire.

      Other than as specified in Section 3 herein,  each Revocable Warrant shall
entitle its holder to purchase  from the Company one share of Common Stock (each
an "EXERCISE SHARE") at an exercise price of One Dollar and Eighty Cents ($1.80)
per share, subject to adjustment as set forth below ("EXERCISE PRICE").

      The Company  shall not be required  to issue  fractional  shares of Common
Stock upon the  exercise  of this  Revocable  Warrant  or to  deliver  Revocable
Warrant  Certificates which evidence  fractional shares of capital stock. In the
event that a fraction of an Exercise  Share would,  except for the provisions of
this paragraph 2, be issuable upon the exercise of this Revocable  Warrant,  the
Company shall pay to the Holder  exercising  the Revocable  Warrant an amount in

<PAGE>

cash  equal to such  fraction  multiplied  by the  current  market  value of the
Exercise Share. For purposes of this paragraph 2, the current market value shall
be determined as follows:

            (a) if the Shares are traded in the over-the-counter  market and not
on any national  securities exchange and not in the NASDAQ Reporting System, the
average of the mean between the last bid and asked prices per share, as reported
by the National  Quotation  Bureau,  Inc., or an equivalent  generally  accepted
reporting  service,  for the last  business  day  prior to the date on which the
Revocable  Warrant is  exercised,  or, if not so  reported,  the  average of the
closing  bid and asked  prices for a Share as  furnished  to the  Company by any
member of the National Association of Securities Dealers,  Inc., selected by the
Company and Holder for that purpose.

            (b) if the  Shares  are  listed or traded on a  national  securities
exchange or in the NASDAQ Reporting  System,  the closing price on the principal
national  securities  exchange  on which  they are so listed or traded or in the
NASDAQ Reporting  System,  as the case may be, on the last business day prior to
the date of the exercise of the Revocable Warrant. The closing price referred to
in this  Clause (b) shall be the last  reported  sales price or, in case no such
reported  sale takes place on such day, the average of the reported  closing bid
and asked prices on such day, in either case on the national securities exchange
on which the Shares are then listed or in the NASDAQ Reporting System; or

            (c) if no such  closing  price or closing  bid and asked  prices are
available,  as  determined  by the  Holder  and the  Board of  Directors  of the
Company.

      3. Revocation of the Revocable Warrants.  Notwithstanding  anything to the
contrary, all Revocable Warrants granted by the Company to the Holder under this
Agreement shall be subject to forfeiture,  revocation and  cancellation  without
any  further  or  additional  consideration  due or owed to Holder as  specified
herein (the "RIGHT OF REVOCATION").

            (a) Scope of Revocation Right.  Until the Revocable Warrants vest in
accordance with Subsection (b) below, the Revocable Warrants shall be restricted
warrants and not exercisable  under Section 2 hereof and shall be subject to the
Company's  Right of  Revocation  (the  "RESTRICTED  WARRANTS").  The Company may
exercise its Right of Revocation only during the period of 180 consecutive  days
commencing on the date the Holder's Service terminates for any reason, including
(without limitation) death or disability (the "REVOCATION PERIOD"). The Right of
Revocation may be exercised automatically under Subsection (e) below.

            (b) Lapse of Revocation  Right.  Initially,  all Revocable  Warrants
granted  under  this  Agreement  shall be  Restricted  Warrants  subject  to the
Company's Right of Revocation.  The Right of Revocation shall lapse with respect
to the first 1/16th of the Revocable  Warrants when the Holder  completes  three
months of continuous  employment after the date of this Agreement.  The Right of
Revocation  shall  lapse  with  respect  to an  additional  1/16th  of the total
Revocable Warrants when the Holder completes each month of continuous employment
thereafter.

            (c)  Acceleration.  In addition to the other conditions set forth in
this  Agreement,  the  Company's  Right of  Revocation  with respect to unvested
Restricted Warrants shall lapse prior to the vesting period specified in Section
3(b) above at the time or times set forth below:

            (i) If the  Company is subject to a Change in Control (as defined in
      below) before the Holder's employment terminates,  the Right of Revocation
      shall  lapse in full if and only if (1) this  Revocable  Warrant  does not
      remain  outstanding  following the Change in Control;  (2) this  Revocable
      Warrant is not assumed by the surviving corporation or its parent; (3) the


                                       2
<PAGE>

      surviving  corporation  or its parent does not  substitute  an option with
      substantially the same terms for this Revocable Warrant;  OR (iv) the full
      value of the vested Revocable Warrants under this Agreement is not settled
      in cash or cash equivalents.

            (ii) If the Right of Revocation has not lapsed pursuant to Paragraph
      (i) above,  AND if the Holder is  subject  to an  Involuntary  Termination
      (defined  below)  within 12 months after the Change in Control,  then this
      Revocable  Warrant  shall  become  no  longer  be  subject  to a Right  of
      Revocation.

            (iii)  If the  Right  of  Revocation  has  not  lapsed  pursuant  to
      Paragraph (i) above, AND if the Company is subject to a Change of Control,
      then fifty  percent (50%) of the remaining  Restricted  Warrants  shall no
      longer be subject to a Right of Revocation,  and the remaining  Restricted
      Warrants  shall vest at the rate set forth in Section 3(b) above,  reduced
      pro rata by the amount of Restricted Warrants no longer subject to a Right
      of  Revocation  pursuant to this Section.  All other terms and  conditions
      shall remain unchanged.


            (iv) Definitions:

                  (1) "CHANGE IN CONTROL" shall mean: (A) The  consummation of a
            merger or  consolidation  of the Company with or into another entity
            or any  other  corporate  reorganization,  if  persons  who were not
            controlling  stockholders of the Company  immediately  prior to such
            merger,  consolidation or other reorganization own immediately after
            such merger,  consolidation or other  reorganization  50% or more of
            the  voting  power  of the  outstanding  securities  of  each of the
            continuing  or  surviving  entity and any direct or indirect  parent
            corporation of such continuing or surviving entity; OR (B) The sale,
            transfer or other  disposition  of all or  substantially  all of the
            Company's  assets.  A transaction  shall not  constitute a Change in
            Control if its sole purpose is to change the state of the  Company's
            incorporation  or to create a holding  company that will be owned in
            substantially  the  same  proportions  by the  persons  who held the
            Company's securities immediately before such transaction.

                  (2)  "INVOLUNTARY  TERMINATION"  shall mean the termination of
            the  Optionee's   employment  by  reason  of:  (A)  The  involuntary
            discharge of the Holder by the Company for reasons  other than Cause
            (as defined in Holder's  Employment  Agreement with the Company,  of
            even date herewith);  or (B) The voluntary resignation of the Holder
            following a reduction in the Holder's base salary or assigned duties
            or receipt of notice that the Holder's  principal  workplace will be
            relocated more than 30 miles.

                  (d) Escrow.  Upon issuance,  the certificate(s) for Restricted
Warrants  shall be deposited in escrow with the Company to be held in accordance
with the provisions of this Agreement. Any additional or exchanged securities or
other  property  described in Section 9 below shall  immediately be delivered to
the Company to be held in escrow.  All ordinary  cash  dividends  on  Restricted
Warrants (or on other  securities  held in escrow) shall be paid directly to the
Holder and shall not be held in escrow.  Restricted Warrants,  together with any
other assets held in escrow under this  Agreement,  shall be (i)  surrendered to
the Company for  repurchase  upon  exercise of the Right of  Revocation  or (ii)
released to the Holder upon his or her request to the extent that the  Revocable
Warrants  have ceased to be  Restricted  Warrants.  In any event,  all Revocable
Warrants  that have ceased to be  Restricted  Warrants,  together with any other
vested assets held in escrow under this  Agreement,  shall be released within 10
days after the termination of the Holder's employment.

                  (e) Exercise of Revocation  Right. The Company shall be deemed
to have  exercised  its Right of  Revocation  automatically  for all  Restricted


                                       3
<PAGE>

Warrants as of the  commencement  of the Revocation  Period,  unless the Company
during the  Revocation  Period  notifies the holder of the  Restricted  Warrants
pursuant to Section 12 that it will not  exercise  its Right of  Revocation  for
some or all of the Restricted  Warrants.  The  certificate(s)  representing  the
Restricted Warrants being repurchased shall be delivered to the Company properly
endorsed for transfer.

                  (e)  Termination  of  Rights as  Stockholder.  If the Right of
Revocation is exercised in accordance with this Section 3, then the Holder shall
no  longer  have  any  rights  as a  holder  of the  Restricted  Warrants.  Such
Restricted  Warrants  shall be  deemed  to have been  revoked  pursuant  to this
Section 3, whether or not the certificate(s)  for such Restricted  Warrants have
been delivered to the Company.

                  (f)  Transfer  of  Warrants.  The Holder  shall not  transfer,
assign,  encumber or otherwise  dispose of any Restricted  Warrants  without the
Company's  written consent,  except as provided in the following  sentence.  The
Revocable  Warrants  granted hereby shall not be transferable  except by will or
the laws of descent and  distribution.  During the  lifetime of the Holder,  the
Revocable  Warrant may be  exercised  only by the Holder,  the guardian or legal
representative of the Holder.


      4. Mutilated or Missing Revocable Warrant Certificates. In case any of the
Revocable  Warrant  Certificates  shall be mutilated,  lost, stolen or destroyed
prior to the Expiration  Date, the Company shall issue and deliver,  in exchange
and substitution for and upon  cancellation of the mutilated  Revocable  Warrant
Certificate,  or in  lieu  of and in  substitution  for  the  Revocable  Warrant
Certificate  lost, stolen or destroyed,  a new Revocable Warrant  Certificate of
like tenor and representing an equivalent right or interest.

      5.  Reservation of Shares.  The Company will at all times reserve and keep
available,  free from preemptive  rights, out of the aggregate of its authorized
but unissued Shares or its authorized and issued Shares held in its treasury for
the purpose of enabling it to satisfy its  obligation to issue  Exercise  Shares
upon  exercise  of  Revocable  Warrants,  the full  number  of  Exercise  Shares
deliverable upon the exercise of all outstanding Revocable Warrants.

      The Company  covenants  that all Exercise  Shares which may be issued upon
exercise  of  Revocable  Warrants  will  be  validly  issued,   fully  paid  and
non-assessable outstanding Shares of the Company.

      6. Rights of Holder. The Holder shall not, by virtue of anything contained
in this  Revocable  Warrant  Agreement or  otherwise,  prior to exercise of this
Revocable Warrant, be entitled to any right whatsoever, either in law or equity,
of a stockholder  of the Company,  including  without  limitation,  the right to
receive dividends or to vote or to consent or to receive notice as a stockholder
in respect of the meetings of  stockholders  or the election of directors of the
Company of any other matter.

      7. Investment Intent;  Accredited Investor. Holder represents and warrants
to the Company that Holder is acquiring  the Revocable  Warrants for  investment
purposes and with no present  intention of  distributing or reselling any of the
Revocable Warrants. Holder represents that it is an "accredited investor" within
the meaning of Rule 501 of  Regulation D under the  Securities  Act of 1933,  as
amended (the "Act").

      8. Certificates to Bear Legend. The Revocable Warrants and the certificate
or certificates  therefore shall bear the following  legend by which each holder
shall be bound:


                                       4
<PAGE>

      "THE  SECURITIES  REPRESENTED BY THIS  INSTRUMENT HAVE NOT BEEN REGISTERED
      UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, PLEDGED
      OR OTHERWISE  TRANSFERRED WITHOUT AN EFFECTIVE  REGISTRATION THEREOF UNDER
      SUCH ACT OR  PURSUANT  TO RULE 144 OR AN  OPINION OF  COUNSEL,  REASONABLY
      SATISFACTORY TO THE CORPORATION AND ITS COUNSEL, THAT SUCH REGISTRATION IS
      NOT REQUIRED. THE SECURITIES REPRESENTED BY THIS INSTRUMENT ARE SUBJECT TO
      TRANSFER  RESTRICTIONS,  VESTING  AND  REVOCATION  UNDER  THE TERMS OF THE
      REVOCABLE WARRANT AGREEMENT, DATED APRIL 1, 2005"

                  The  Exercise  Shares  and  the  certificate  or  certificates
evidencing any such Exercise Shares shall bear the following legend:

      "THE SECURITIES  REPRESENTED BY THIS  CERTIFICATE HAVE NOT BEEN REGISTERED
      UNDER  THE  SECURITIES  ACT  OF  1933.  THE  SHARES  MAY  NOT BE  SOLD  OR
      TRANSFERRED IN THE ABSENCE OF SUCH  REGISTRATION  OR AN OPINION OF COUNSEL
      ACCEPTABLE TO THE COMPANY THAT AN EXEMPTION FROM  REGISTRATION  UNDER SUCH
      ACT IS AVAILABLE."

      Certificates for Revocable  Warrants or Exercise  Shares,  as the case may
be, without such legend shall be issued if such  Revocable  Warrants or Exercise
Shares are sold pursuant to an effective registration statement under the Act or
if the Company has received an opinion from counsel  reasonably  satisfactory to
counsel for the Company that such legend is no longer required under the Act.

      9. Adjustment of Number of Shares and Class of Capital Stock  Purchasable.
The number of Exercise Shares and class of capital stock  purchasable under this
Revocable  Warrant are subject to  adjustment  from time to time as set forth in
this Section 9.

      (a)   Adjustment for Change in Capital Stock. If the Company:

            (i)   pays a dividend or makes a  distribution  on its Common Stock,
                  in each case, in shares of its Common Stock;

            (ii)  subdivides  its  outstanding  shares  of Common  Stock  into a
                  greater number of shares;

            (iii) combines its outstanding shares of Common Stock into a smaller
                  number of shares; or

            (iv)  makes a  distribution  on its  Common  Stock in  shares of its
                  capital stock other than Common Stock

then the number and classes of Exercise Shares purchasable upon exercise of each
Revocable Warrant in effect immediately prior to such action shall be adjusted
so that the holder of any Revocable Warrant thereafter exercised may receive the
number and classes of shares of capital stock of the Company which such holder
would have owned immediately following such action if such holder had exercised
the Revocable Warrant immediately prior to such action.

                  For a dividend or  distribution  the  adjustment  shall become
effective  immediately  after the record date for the dividend or  distribution.
For a subdivision, combination or reclassification,  the adjustment shall become
effective  immediately after the effective date of the subdivision,  combination
or reclassification.


                                       5
<PAGE>

                  If after an adjustment the holder of a Revocable  Warrant upon
exercise of it may receive shares of two or more classes of capital stock of the
Company, the Board of Directors of the Company shall in good faith determine the
allocation  of the  adjusted  Exercise  Price  between  or among the  classes of
capital  stock.  After  such  allocation,  that  portion of the  Exercise  Price
applicable to each share of each such class of capital stock shall thereafter be
subject to  adjustment on terms  comparable to those  applicable to the Exercise
Shares in this Agreement.

                  (b)  Consolidation,  Merger  or  Sale of the  Company.  If the
Company is a party to a consolidation,  merger,  transfer of assets or any other
business combination which reclassifies or changes its outstanding Common Stock,
the successor corporation (or corporation  controlling the successor corporation
or the  Company,  as the  case may be)  shall by  operation  of law  assume  the
Company's   obligations   under  this  Agreement.   Upon  consummation  of  such
transaction,  the Revocable Warrants shall automatically  become exercisable for
the kind and amount of  securities,  cash or other  assets which the holder of a
Revocable Warrant would have owned immediately after the consolidation,  merger,
transfer or business  combination  if the holder had exercised the vested amount
of  the  Revocable  Warrant  immediately  before  the  effective  date  of  such
transaction.  The Company  shall  arrange for the person or entity  obligated to
issue  securities or deliver cash or other assets upon exercise of the Revocable
Warrant to,  concurrently with the consummation of such transaction,  assume the
Company's  obligations  hereunder by executing an  instrument  so providing  and
further  providing for adjustments which shall be as nearly equivalent as may be
practical to the  adjustments  provided for in this Section 9. The provisions of
this  Section  9(b)  shall  similarly  apply  to  successive  reclassifications,
reorganizations, consolidations, mergers or other business combinations.

      10.  Successors.  All the covenants and provisions of this Agreement by or
for the benefit of the Company or Holder  shall bind and inure to the benefit of
their respective successor and assigns hereunder.

      11.  Counterparts.  This  Agreement  may  be  executed  in any  number  of
counterparts and each of such  counterparts  shall for all proposes be deemed to
be an original,  and such counterparts shall together  constitute by one and the
same instrument.

      12.  Notices.  All notices or other  communications  under this  Agreement
shall be in writing and shall be deemed to have been given if  delivered by hand
or  mailed  by  certified  mail,  postage  prepaid,  return  receipt  requested,
addressed as follows: if to the Company: Natural Gas Systems, Inc., Two Memorial
City Plaza,  820  Gessner,  Suite 1340.  Houston,  TX 77024 ,  Attention:  Legal
Counsel,  and to the Holder: at the address of the Holder appearing on the books
of the Company or the Company's transfer agent, if any.

      Either the  Company or the Holder may from time to time change the address
to which notices to it are to be mailed  hereunder by notice in accordance  with
the provisions of this Paragraph 12.

      13.  Supplements  and  Amendments.  The  Company  may  from  time  to time
supplement or amend this  Agreement  without the approval of the Holder in order
to cure any  ambiguity or to be correct or supplement  any  provision  contained
herein which may be defective or inconsistent  with any other  provision,  or to
make any other  provisions  in regard to matters  or  questions  herein  arising
hereunder  which the Company may deem necessary or desirable and which shall not
materially  adversely affect the interest of the Holder.  Except as set forth in
the immediately  preceding  sentence,  this Agreement may not be amended without
the prior written consent of the Holder.


                                       6
<PAGE>

      14.  Severability.  If for any reason any provision,  paragraph or term of
this  Agreement  is  held  to be  invalid  or  unenforceable,  all  other  valid
provisions  herein  shall  remain  in full  force  and  effect  and  all  terms,
provisions and paragraphs of this Agreement shall be deemed to be severable.

      15.  Governing Law. This  Agreement  shall be deemed to be a contract made
under the laws of the State of Nevada and for all purposes shall be governed and
construed in accordance with the laws of said State.

      16.  Headings.  Paragraphs  and  subparagraph  headings,  used  herein are
included  herein  for  convenience  of  reference  only and shall not affect the
construction  of this  Agreement nor constitute a part of this Agreement for any
other purpose.

      17. Taxes.  The  acquisition  of the Revocable  Warrants (and common stock
issuable  thereunder) may result in adverse tax consequences to the Holder.  The
Holder  understands  that he may suffer adverse tax  consequences as a result of
his  acquisition  or  disposition  of the  Revocable  Warrants (and common stock
issuable   thereunder).   Holder  represents  that  he  has  consulted  any  tax
consultants  Holder  deems  advisable  in  connection  with the  acquisition  or
disposition of the Revocable Warrants (and common stock issuable thereunder) and
that Holder is not relying on the  Company for any tax advice.  Acquisitions  or
dispositions  of cash or equity  made  under  this  Agreement  may be subject to
reduction to reflect taxes or other charges required to be withheld by law.

      18.  Registration  Rights.  Upon exercise of this Revocable  Warrant , the
Holder shall have and be entitled to exercise,  together  with all other holders
of registrable securities possessing "piggy back" registration rights under that
certain Registration Rights Agreement, of even date herewith and attached hereto
as  EXHIBIT D,  between  the  Company  and the  parties  who have  executed  the
counterpart  signature  pages  thereto  or  are  otherwise  bound  thereby  (the
"Registration  Rights Agreement"),  the rights of registration granted under the
Registration  Rights  Agreement  (with  respect  to the  Shares of Common  Stock
issuable  upon  exercise  of this  Revocable  Warrant ). By its  receipt of this
Revocable  Warrant  ,  Holder  agrees  to be  bound by the  Registration  Rights
Agreement.  Notwithstanding  the foregoing,  however,  the Company,  at its sole
discretion,  may elect to cancel the registration  rights agreement and register
the Exercise Shares, upon exercise of this Revocable Warrant, under Form S-8.

      IN WITNESS  WHEREOF,  the parties  hereto have caused this Agreement to be
duly executed, as of the date and year first above written.

 COMPANY                                       HOLDER:
 NATURAL GAS SYSTEMS, INC.                     ROBERT S. HERLIN


 By: _________________________________         By: __________________________
 Name: Robert S. Herlin, CEO


                                       7
<PAGE>

                                    EXHIBIT A


THE SECURITIES REPRESENTED BY THIS INSTRUMENT HAVE NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, PLEDGED OR OTHERWISE
TRANSFERRED WITHOUT AN EFFECTIVE REGISTRATION THEREOF UNDER SUCH ACT OR PURSUANT
TO RULE 144 OR AN OPINION OF COUNSEL, REASONABLY SATISFACTORY TO THE CORPORATION
AND ITS COUNSEL, THAT SUCH REGISTRATION IS NOT REQUIRED.

                                    REVOCABLE WARRANT TO PURCHASE SHARES
                                    OF COMMON STOCK OF NATURAL GAS SYSTEMS, INC


Initial Number of Shares:         287,500
Exercise Price:                   $1.80 per share
Date of Grant:                    April 1, 2005
Expiration Date:                  April 1, 2015

THIS CERTIFIES THAT, Robert S. Herlin ("Holder") is entitled to purchase the
above number (as adjusted pursuant to Section 4 hereof) of fully paid and
non-assessable shares of the Common Stock (the "Shares") of Natural Gas Systems,
Inc., a Nevada corporation (the "Company), having an Exercise Price as set forth
above, subject to the provisions and upon the terms and conditions set forth
herein and in the Revocable Warrant Agreement dated April 1, 2005 ("Revocable
Warrant Agreement"). The exercise price, as adjusted from time to time as
provided herein, is referred to as the "Exercise Price."

NOTWITHSTANDING ANYTING TO THE CONTRARY, THIS REVOCABLE WARRANT IS SUBJECT TO
VESTING AND REVOCATION WITHOUT CONSIDERATION BY THE COMPANY UNDER CERTAIN
CONDITIONS DEFINED IN THE REVOCABLE WARRANT AGREEMENT.

      1. Term. Subject to the revocation  provisions of of the Revocable Warrant
Agreement,   the  purchase  right  represented  by  this  Revocable  Warrant  is
exercisable,  in whole or in part,  at any time  commencing on the April 1, 2005
and ending on the Expiration Date, after which time the Revocable  Warrant shall
be void.

      2. Method of Exercise; Payment; Issuance of New Revocable Warrant. Subject
to Section 1 hereof,  the right to purchase Shares represented by this Revocable
Warrant may be exercised by Holder, in whole or in part, for the total number of
Shares  remaining  available  for exercise by the  surrender  of this  Revocable
Warrant  (with the notice of  exercise  form  attached  hereto as Exhibit A duly
executed)  at the  principal  office of the  Company  and by the  payment to the
Company,  by check made payable to the Company drawn on a United States bank and
for  United  States  funds,  or by  delivery  to  the  Company  of  evidence  of
cancellation of  indebtedness of the Company to such Holder,  of an amount equal
to the then  applicable  Exercise  Price per share  multiplied  by the number of
Shares then being purchased or by net exercise  pursuant to Section 6 hereof. In
the event of any exercise of the purchase  right  represented  by this Revocable
Warrant, certificates for the Shares so purchased shall be promptly delivered to
Holder  and,  unless this  Revocable  Warrant  has been fully  exercised  or has
expired, a new Revocable Warrant representing the portion of the Shares, if any,
with respect to which this Revocable  Warrant shall not then have been exercised
shall also be promptly delivered to Holder.

      3. Exercise Price. The Exercise Price at which this Revocable  Warrant may
be exercised shall be the Exercise Price, as adjusted from time to time pursuant
to Section 4 hereof.

<PAGE>

      4.  Adjustment  of Number of Shares.  The number of shares and/or class of
capital stock purchasable upon exercise of this Revocable Warrant are subject to
adjustment as provided in Section 9 of the Revocable Warrant Agreement.

      5. Transferability and Negotiability of Revocable Warrant.  This Revocable
Warrant  may  not be  transferred  or  assigned  in  whole  or in  part  without
compliance with applicable  federal and state  securities laws by the transferor
and the transferee  (including,  without limitation,  the delivery of investment
representation  letters  and  legal  opinions  reasonably  satisfactory  to  the
Company, if reasonably requested by the Company).  Further, the Holder shall not
transfer,  assign,  encumber or  otherwise  dispose of any  Restricted  Warrants
without the  Company's  written  consent,  except as  provided in the  following
sentence. The Revocable Warrants granted hereby shall not be transferable except
by will or the laws of descent  and  distribution.  During the  lifetime  of the
Holder,  the Revocable Warrant may be exercised only by the Holder, the guardian
or legal representative of the Holder.

      6. Net Exercise.  In lieu of exercising  this Revocable  Warrant for cash,
the Holder may elect to exchange this Revocable  Warrant for Shares equal to the
value of this Revocable Warrant by surrender of this Revocable Warrant, together
with notice of such election,  at the principal office of the Company,  in which
event the Company  shall issue to the holder a number of Shares  computed  using
the following formula:

                                                                 X = Y (A-B)
                                                                      A
         Where:

                X= the number of Shares to be issued to the holder.
                Y= the number of Shares to be purchased under this
                   Revocable Warrant.
                A= value per share of one Share determined in accordance
                   with Section 2 of the Revocable Warrant Agreement.
                B= the Exercise Price (as adjusted).

      7. Miscellaneous.  The Company covenants that it will at all times reserve
and keep available,  solely for the purpose of issue upon the exercise hereof, a
sufficient  number of Shares to permit the exercise hereof in full. Such Shares,
when issued in compliance with the provisions of this Revocable  Warrant and the
Company's Certificate of Incorporation, will be duly authorized, validly issued,
fully paid and  non-assessable.  No Holder of this Revocable  Warrant,  as such,
shall, prior to the exercise of this Revocable  Warrant,  be entitled to vote or
receive  dividends  or be  deemed to be a  stockholder  of the  Company  for any
purpose,  nor shall anything contained in this Revocable Warrant be construed to
confer upon Holder,  as such,  any rights of a stockholder of the Company or any
right to vote, give or withhold consent to any corporate action,  receive notice
of meetings,  receive  dividends or  subscription  rights,  or  otherwise.  Upon
receipt of evidence  reasonably  satisfactory to the Company of the loss, theft,
destruction or mutilation of this Revocable Warrant and, in the case of any such
loss, theft or destruction,  upon delivery of an indemnity agreement  reasonably
satisfactory  in form and  amount  to the  Company  or,  in the case of any such
mutilation,  upon  surrender and  cancellation  of such Revocable  Warrant,  the
Company  at its  expense  will  execute  and  deliver,  in lieu  thereof,  a new
Revocable  Warrant  of like date and  tenor.  The terms and  provisions  of this
Revocable  Warrant  shall  inure to the  benefit  of, and be binding  upon,  the
Company and the Holder hereof and their respective  successors and assigns. This
Revocable Warrant shall be governed by and construed under the laws of the State
of Nevada.


                                       2
<PAGE>

      IN WITNESS WHEREOF, the parties have executed and delivered this Agreement
as of the date and year first written above.

Holder:                                Company:
________________________________       Natural Gas Systems, a Nevada Corporation


By: _____________________________      By: _____________________________
Robert S. Herlin                       Laird Q. Cagan, Chairman


                                       3
<PAGE>

                               NOTICE OF EXERCISE

TO:     NATURAL GAS SYSTEMS, INC.


      1. The  undersigned  hereby  elects to  purchase  _________  shares of the
Common Stock of NATURAL GAS SYSTEMS,  INC. pursuant to the terms of the attached
Revocable  Warrant,  and tenders  herewith payment of the purchase price of such
shares in full, together with all applicable transfer taxes, if any.

      2. The  undersigned  hereby  elects to purchase  __________  shares of the
Common Stock of NATURAL GAS SYSTEMS,  INC. pursuant to the terms of the attached
Revocable Warrant on a net exercise basis in accordance with Section 6.

      3. Please issue a certificate or certificates  representing said shares of
the  Common  Stock in the name of the  undersigned  or in such  other name as is
specified below:




                                    Name:_______________________________

                                    Tax ID:___________________


                                    Address:____________________________

                                              --------------------------

                                              --------------------------

                                              --------------------------

                                              --------------------------





                                    Signed:_____________________________




                                    Date:___________________



                                       4