US Quarterly Drilling Update

Aminex PLC 13 April 2000 US Quarterly Drilling Update Aminex PLC Aminex PLC (Aminex) the oil and gas and oilfield service group, listed on the London and Dublin Stock Exchanges, today announces the current status of its recent ongoing exploration and development drilling activity in the Company's onshore Gulf Coast prospects over the Vinton Dome Field, Calcasieu Parish, Louisiana, USA. During the first quarter Aminex USA, Inc. has made rapid progress on the Vinton Dome Field, based on results of the recently completed 30,000 acre 3D seismic programme over this salt dome play. The seismic programme around Vinton defined strong leads in the Miocene, Frio and Hackberry formations. Aminex USA, Inc., as operator, and its exploration partners have now drilled 5 wells and expect to drill an additional 16 over the dome before the end of 2000. The results of the five wells are as follows: * M.G. Stream no. 1 well was drilled and completed, brought on line on 13th December. It is currently producing 730 mcf and 83 barrels of oil per day in the secondary zone of the Frio formation. * The M.G. Stream no.2 well was brought on stream in November and is currently producing 120 Mcf of gas per day and 183 barrels of oil per day from the Frio formation. * The M.G. Stream no. R-1 was drilled on the flanks of the dome and was unsuccessful. * The J&L Jardell no.1 was drilled to 6,500 ft and has approximately 18 net feet of prospective oil bearing sand. This well will be completed for production in the next few weeks. * The J&L Jardell no.2 was drilled to 6,700 ft and has approximately 18 net feet of prospective oil bearing sand in the Het formation. This well will be completed for production in the next few weeks. The M.G. Stream no. 3, the sixth well of the current Vinton programme, was spudded on 3rd April 2000 and will drill to approximately 9,000 ft to test deeper objectives in the Vinton Dome. The three M.G. Stream wells have not been previously announced pending resolution of leasing issues on adjoining acreage. The Vinton 3-D drilling programme is expected to continue for several years as additional locations are identified form the extensive data available. Aminex's interest in the wells varies from 70% in its core acreage to 12.5% in the surrounding acreage with variable individual well interests, depending on the proximity of the reservoir to Aminex's core acreage. Aminex's cost in the programme is carried by a previously announced financing arrangement with McAlester Fuel Company. In addition to operations on the Vinton Dome, Aminex also placed its nearby Shoats Creek field on production; the first well, announced to shareholders on 21 February 2000, commenced production at a rate of 85 barrels of oil per day and recompletion works are continuing to bring additional wells on stream in the near future. Additional drilling on the company's prospects in Texas is also in progress. In Brazoria County preparations are underway for the side-tracking of the Nold no. 1 well in the Southwest Danbury prospect. Also in Brazoria County, the Sebesta Gas Unit no. 1 was put on production earlier this year, the successful drilling of which was announced to shareholders on 28 January 2000. Production on Aminex's Somerset Field has increased to approximately 280 barrels of oil per day after a partial shut down in 1998/99 as a result of low oil prices at that time. Commenting on the announcement, Brian Hall, Aminex Chief Executive said: 'This update illustrates the initial successes of our extensive drilling programme over the Vinton Dome. The advanced 3-D seismic study of the region is proving up important leads in a number of areas and we expect additional drilling to increase both production and reserves significantly over Vinton.' To visit Aminex's web site www.aminex-plc.com Contact: Brian Hall Aminex 020 7240 1600 John Evans Financial Dynamics 020 7831 3113