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May 12, 1999                                           Contact:  Ronald P. Nowak
                                                             or Russell L. Allen
                                                                  (281) 579-3398


                              3DX TECHNOLOGIES INC.
                   ANNOUNCES SIGNING A PLAN AND AGREEMENT OF MERGER WITH
                            ESENJAY EXPLORATION, INC.


Houston,  Texas-3DX  Technologies Inc. (3DX) (OTCBB: TDXTC) today announced that
it has signed a Plan and  Agreement  of Merger with  Esenjay  Exploration,  Inc.
(Esenjay) (NASDAQ:  ESNJ) which provides for the merger of 3DX into Esenjay. The
Boards of both  companies  have  approved  the  transaction,  and closing of the
merger is conditioned  upon approval from the shareholders of both companies and
satisfaction of certain other  conditions set forth in the Plan and Agreement of
Merger.

The terms of the  merger  provide  for 3DX  shareholders  to select  either  the
issuance of Esenjay common stock at a ratio of 1:3.25 shares of 3DX common stock
or the  issuance  of a new  Esenjay  convertible  preferred  stock at a ratio of
1:2.75 shares of 3DX common stock.  The preferred stock is limited to 50% of the
total 3DX shares  converted and may be redeemed at Esenjay's  option at any time
during the first  twelve  months  after the  merger at $1.925 per share.  If not
redeemed  during the first year, the preferred will  automatically  convert into
one share of Esenjay common stock if the average closing price of Esenjay common
is greater than $1.875 during a predefined  measurement  period.  If the Esenjay
common is less  than  $1.875  the  preferred  holder  has the right to "put" the
shares to  Esenjay.  Esenjay  will then have the right to pay for this  "put" in
cash  or  common  shares.   Esenjay   currently  has  15,784,834  common  shares
outstanding and 3DX currently has 9,685,761 shares outstanding.

Ronald  Nowak,  President  and CEO of 3DX  commented,  "We are  pleased  to have
entered into this merger  agreement with Esenjay.  We believe this gives the 3DX
shareholder an interest in a larger producing and exploration  entity that has a
similar growth vision. With both companies'  exploration philosophy focused on a
3D seismic  program,  the 3DX  shareholder  will be exposed to a larger prospect
base and  exploration  program.  This  should  provide  a higher  value  for our
shareholders than the currently depressed trading price of the 3DX stock."

3DX Technologies Inc. is a knowledge-based oil and gas exploration company whose
core  competence and strategic  focus is the  utilization of 3-D seismic imaging
and other  advanced  technologies  in the search for  commercial  quantities  of
hydrocarbons.

Certain statements in this news release regarding future  expectations and plans
for oil and gas  exploration,  development  and  production  may be  regarded as
"forward  looking  statements"  within the meaning of the Securities  Litigation
Reform  Act.  They are  subject to various  risks,  such as  operating  hazards,
drilling risks,  and other  uncertainties  inherent in the business of exploring
for,  developing and producing oil and gas which may be beyond either  Company's
control.  These risks are discussed in detail in the Companies' Annual Report on
Form 10-K for the year ended  December 31, 1998,  as well as other  filings with
the  Securities  and Exchange  Commission.  There can be no  assurance  that the
combined  Companies'  exploration  activities  will be successful in meeting the
Companies' expectations.

