RNS Number:4882E Sound Oil PLC 26 September 2007 Sound Oil plc 26 September 2007 Pasundan-1 Operations Update - Drill Stem Test Results The first phase of testing operations on the Pasundan-1 well were completed on 23 September 2007. Two tests of the lower part of the Baturaja Formation carbonates were undertaken through the previously set 7-inch liner. DST 1 (8302-8374 ft) recovered 73 barrels of fluid after acidization by reverse circulation, mostly formation water and a trace of hydrocarbon gas. DST 2 (8024-8069 ft) flowed at a stabilized rate after acidization of 3000 BWPD* with a trace of hydrocarbon gas. These results indicate that the Baturaja Formation is an effective reservoir with good porosity and permeability characteristics. Although both tests produced formation water, the significance of the traces of hydrocarbon gases will need to be assessed. In any event the results provide encouragement for testing the higher levels of the formation. The well is currently being suspended pending testing of the higher cavernous zone of the Baturaja (DST 3, 6770-6900 ft). This test will be carried out at a later date with another rig as previously announced (see Sound Oil announcement 18 September 2007). It is expected that rigging down and demobilization of the GW93 rig will commence in the next few days. Sound Oil plc is a 20% shareholder (through its wholly owned subsidiary Mitra Energia Citarum Limited) in the BPREC operating company that has been drilling the Pasundan - 1 exploration well, located approximately 50 km southeast of Jakarta, Indonesia. * Barrels of water per day. Dr Michael Cope BSc PhD CGeol, Head of Exploration at Sound Oil, a qualified petroleum geologist, has reviewed the technical information contained in this news release. Contacts. Gerry Orbell, Chairman, Sound Oil plc Tel: 44 (0)7903 861145 Dr A Basirov/David Jones, Smith & Williamson Corporate Finance Limited Tel: 44 (0)207 131 4000 Tim Thompson/Nick Melson - Buchanan Communications Tel: 44 (0)207 466 5000 This information is provided by RNS The company news service from the London Stock Exchange END