EXHIBIT (a)(4)

                              [Esenjay Letterhead]



To Esenjay Exploration, Inc.

         We are pleased to inform you that on March 17, 2002, Esenjay
Exploration, Inc. ("ESENJAY") entered into an agreement with Santos Americas and
Europe Corporation ("SANTOS") and ECM Acquisition Company, a wholly-owned
subsidiary of Santos ("PURCHASER"), pursuant to which Purchaser has today
commended a cash tender offer to purchase all of the outstanding shares of
Esenjay common stock (the "SHARES") for $2.84 per share in cash.

         The tender offer is conditioned on the minimum tender of a majority of
the Shares as well as other conditions described in the offering materials
enclosed with this letter. Those materials also describe Santos' commitment to
complete its acquisition of Esenjay, once the tender offer is successfully
consummated, through a merger in which all Shares not purchased in the tender
offer will be converted into the same net price as is paid in the tender offer.

         Current directors, executive officers and certain other stockholders of
Esenjay have individually agreed to tender their Shares pursuant to a
Stockholders Agreement dated March 17, 2002. These Shares, in total, represent
approximately 52% of the outstanding Shares.

         YOUR BOARD OF DIRECTORS HAS APPROVED THE MERGER AGREEMENT AND
UNANIMOUSLY DETERMINED THAT THE TERMS OF SANTOS' TENDER OFFER ARE FAIR TO, AND
IN THE BEST INTERESTS OF, ESENJAY'S STOCKHOLDERS AND RECOMMEND THAT YOU ACCEPT
THE SANTOS OFFER BY TENDERING ALL OF YOUR SHARES PURSUANT TO THE OFFER.

         Enclosed with this letter is a Solicitation/Recommendation Statement on
Schedule 14D-9 containing the Esenjay recommendation and explaining the reasons
behind it, as well as the background to the transaction and other important
information. Included as Exhibit (a)(5) to our Schedule 14D-9 is the written
opinion, dated March 16, 2002, of Hibernia Southcoast Capital, Inc., Esenjay's
financial advisor, to the effect that, as of that date and based on and subject
to the matters stated in the opinion, the $2.84 per share cash consideration to
be received by the Esenjay's stockholders in the tender offer and the merger is
fair, from a financial point of view, to Esenjay's stockholders.

         Please give all of the enclosed tender offer materials, which are being
filed today with the Securities and Exchange Commission, your careful
consideration.

                                      Sincerely,

                                      /s/ MICHAEL E. JOHNSON

                                      Michael E. Johnson
                                      President and Chief Executive Officer