Vietnam Well Test Results

Soco International PLC
23 May 2005


                             SOCO International plc
                           ('SOCO' or 'the Company')

                          Successful Vietnam Well Test


SOCO is an international oil and gas exploration and production company,
headquartered in London traded on the London Stock Exchange and a constituent of
the FTSE 250 Index. The Company has continuing interests in Vietnam, Yemen,
Mongolia, Libya and Thailand with ongoing production operations in Yemen and
Mongolia. SOCO's transaction to dispose of its Mongolian operations is pending
completion after gaining approval from its shareholders at an EGM  on 10 May
2005.


The appraisal well on the Ca Ngu Vang ('CNV') structure on Block 9-2 offshore
Vietnam, the CNV-3X, has tested water-free at a maximum combined rate of
approximately 13,040 barrels of crude oil equivalent per day comprised of
approximately 9,010 barrels of crude per day and approximately 22.6 million
cubic feet of gas per day.


The final un-stimulated open hole test was conducted over a 12 hour period from
a Basement interval of approximately 2,000 metres.  Spudded on 30 January 2005,
the well was drilled to a total vertical depth of 4,426 metres at an average
angle of 82 degrees from vertical through the Granitic Basement. The CNV-3X was
drilled to a measured depth ('MD') of 6,123 metres making it the longest MD well
to be drilled in Vietnam.


The well will be suspended as a potential producer and the rig will be moved
immediately after the conclusion of testing and suspension to drill the 'Te Giac
Trang' prospect on Block 16-1. This initial exploration well, the TGT-1X, will
test the Oligocene interval in a previously un-drilled part of Block 16-1.  It
is the second well in the four to six well drilling programme scheduled for
Vietnam this year.


Ed Story, President and Chief Executive of SOCO, commented:


'The results of the CNV-3X well were outstanding. This demonstrates the
technical competence of our team and proves that the complexities of Basement
exploration and development can be solved by rigorous adherence to enhanced
seismic reprocessing and through careful planning and execution in drilling.  We
expect that these successful results will lead to an early declaration of
commerciality.


The drilling rig will now move  to the TGT-1X exploration well on Block 16-1
where we are equally excited about the potential.  Vietnam is clearly  a core
area for SOCO and we expect to join the ranks of significant producers there.'


                                                                     23 May 2005


ENQUIRIES:


SOCO International plc

Roger Cagle                       Deputy Chief Executive and Chief Financial      Tel: [phone]
                                  Officer


Pelham Public Relations

James Henderson                                                                   Tel: [phone]
Charles Vivian                                                                    Tel: [phone]



Notes to editors:


SOCO holds its interests in Vietnam, all in the Cuu Long Basin offshore, through
its 80% owned subsidiary SOCO Vietnam Limited ('SOCO Vietnam').  SOCO Vietnam
holds a 25% working interest in Block 9-2, which is operated by the Hoan Vu
Joint Operating Company and a 28.5% working interest in Block 16-1, which is
operated by the Hoang Long Joint Operating Company.


                      This information is provided by RNS
            The company news service from the London Stock Exchange