SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549



                                    FORM 8-K



                             Current Report Pursuant
                          to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934



    Date of report (Date of earliest event reported)    August 17, 1998
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                               UNOCAL CORPORATION
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             (Exact name of registrant as specified in its charter)



                                    Delaware
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                 (State or Other Jurisdiction of Incorporation)



    1-8483                                   95-3825062
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(Commission File Number)                (I.R.S. Employer Identification No.)



2141 Rosecrans Avenue, Suite 4000, El Segundo, California         90245
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(Address of Principal Executive Offices)                       (Zip Code)



                                 (310) 726-7600
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              (Registrant's Telephone Number, Including Area Code)



ITEM 5.           OTHER EVENTS.


On August 17, 1998, Unocal Corporation  announced the discovery of a potentially
significant  new oil and gas field in the  deepwater  Kutei Basin area  offshore
East Kalimantan, Indonesia.

The first  exploration  well drilled on the Seno  prospect,  West Seno No. 2, is
located on the Makassar Strait production-sharing  contract (PSC) area. The West
Seno No. 2 well was drilled to a true vertical depth subsea (TVDS) of 8,770 feet
in 2,800 feet of water.

The well  encountered  172 feet of vertical oil pay in two zones  between  7,300
feet and 8,600 feet TVDS. The first of two planned  drillstem tests (DST) flowed
2,900 barrels of 37-degree API gravity oil per day and 3.1 million cubic feet of
gas per day on a 28/64-inch  choke from an interval between 8,275 feet and 8,395
feet TVDS. Flowing tubing pressure was 2,170 pounds per square inch.  Mechanical
conditions prevented a high rate test to measure the full potential of the well.

The second DST will be  performed  this week before  preparing to drill the West
Seno No. 1 sidetrack  well from the current  location  to further  appraise  the
reservoir. Following completion of that well, additional delineation drilling is
planned for the Seno area.  The extent and  commerciality  of the Seno  resource
will be determined after sufficient appraisal drilling is completed.

Unocal  Indonesia  Company  is  operator  of the  Makassar  Strait PSC and has a
50-percent  working  interest.   Mobil  Makassar,   Inc.,  holds  the  remaining
50-percent.  Under the  terms of the PSC,  Unocal and Mobil,  as  contractors to
Pertamina,  the Indonesian national oil company,  are entitled to varying shares
of the oil and gas produced from commercial discoveries.

Unocal will focus now on confirming the commerciality of the discovery and begin
planning for rapid development utilizing a tension-leg platform concept.

The Seno prospect is  approximately  13 miles northeast of the Merah Besar field
where Unocal recorded its first  deepwater  Indonesia oil and gas discovery last
year. Unocal is presently preparing a development plan for that field. The Merah
Besar  field is  located  on the  East  Kalimantan  PSC  (Unocal,  100%  working
interest) and the Makassar Strait PSC.

Forward-looking  statements  about future  exploration  activities and projected
results set forth above are based on assumptions concerning geology,  regulatory
actions,   economic,   market   conditions,   operational   concerns  and  other
considerations. Actual results could differ materially.



Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned, thereunto duly authorized.


                                         UNOCAL CORPORATION
                                            (Registrant)


Date:  August 17, 1998                    By:  /s/  JOE D. CECIL
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                                              Joe D. Cecil
                                              Vice President and Comptroller