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

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, Libya, Thailand and the Republic of Congo with ongoing production operations in Yemen.

The appraisal well on the Ca Ngu Vang ("CNV") structure on Block 9-2 offshore Vietnam, the CNV-4X, has encountered an oil and gas interval with unexpected high pressure in the Oligocene E Sequence, the sandstone sequence overlying the Basement objective, and has been temporarily suspended. The joint venture partners decided to suspend the well, which spudded on 31 August, following the loss of the 12 ΒΌ" hole section above the granitic Basement reservoir. The pressures encountered were significantly higher than those seen previously on the other CNV wells.

The well encountered a gross 370 metre vertical section of oil shows with attendant gas through the Oligocene "E" sandstone section, based on mud logs, drilling cuttings analysis and LWD logs. The use of higher than anticipated mud weights to control the encountered pressures led to problems higher in the open hole section where the drill string became differentially stuck while pulling out of the hole to run casing into the top of Basement. Numerous attempts to fish the stuck drill string have been unsuccessful. Plans are underway to incorporate a different drilling fluid and casing design into the programme to enable the overpressured section to be redrilled safely.

The rig will be moved immediately to drill a follow-up appraisal well to the 9,432 barrels of oil equivalent per day TGT-1X well drilled earlier this year on the Te Giac Trang ("TGT") structure. It will be the fourth well in the multi-well drilling programme which began this year in Vietnam. The rig will return to Block 9-2 following completion of the appraisal programme in Block 16-1.

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

"This bodes well for the high prospectivity of Block 9-2 as the CNV-4X well is only the second location in the Cuu Long Basin that has encountered such good oil and gas shows in the E Sequence sandstones. This adds significant remaining exploration potential to Block 9-2 as the Oligocene section has been identified and mapped over other prospects on the Block. Time spent drilling in Block 16-1 will afford us the opportunity to obtain the necessary materials to return to Block 9-2.

The recent TGT-1X discovery and our experience in the Oligocene section of the CNV-4X well underscores the significant potential of these two acreage positions on either side of the giant Bach Ho field."

1 December 2005


ENQUIRIES:

SOCO International plc
Roger Cagle Tel: 020 7747 2000
Deputy Chief Executive and Chief Financial Officer

Pelham Public Relations
James Henderson Tel: 020 7743 6673
Charles Vivian Tel: 020 7743 6672


NOTES TO EDITORS:

SOCO holds its interests in Vietnam, all in the Cuu Long Basin offshore, through its 80% owned subsidiary SOCO Vietnam Ltd ("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.
 
 
 
 
 
 
 
 

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