The Argyll Field After A Decade Of Production

Abstract

Abstract The Argyll Field was discovered in 1971, brought on stream in 1975, and has the distinction of being the first oil producing field in the U.K. North Sea. Development wells have been completed with sub-sea wellheads and connected by flow lines to a floating production platform. After ten years of production the field has produced over fifty million barrels of oil. Development drilling has proved commercial oil from five reservoir zones in rocks ranging in age from Devonian to late Jurassic. The geology of each zone is discussed in relation to environments of deposition, structure and reservoir parameters. Field development and performance are reviewed and the timing and contribution of each reservoir to the production history are described. The benefits which have been achieved from continuing geological, petrophysical and engineering studies for identifying and establishing petrophysical and engineering studies for identifying and establishing further development possibilities are emphasised. The complex nature of the reservoir and its effect on fluid movement and productivity are explained. The field has been produced by natural depletion which has been achieved by virtue of an effident water drive. This paper highlights the importance of geology and engineering in reservoir development planning. Introduction The Argyll Field was discovered in 1971, brought on stream in 1975, and has the distinction of being the first oil production field in the U.K. North Sea. It is located in the central North Sea, some 200 miles east of Montrose, Scotland (Figure 1). The field structure is a tilted fault block measuring some 7 km by 2.5 km and enclosing a productive area of approximately 2800 acres (figure 2). The structure lies mainly in U.K. Block 30/24 and partly in Block 30/25a. Water depths in this area vary from 246 to 265 feet. By the end of 1984, the field had produced 53.1 MMSTBO. Block 30/24 constitutes part of U.K. Licence P073 awarded as part of the U.K. first licensing round in September, 1964. The field is operated by Hamilton Brothers Oil and Gas Limited. The Partner participants' interests are: Hamilton Oil GB Plc (28.8%), Hamilton Brothers Petroleum (U.K.) Ltd (7.2%), RTZ Oil and Gas Ltd (25.0%), Texaco North Sea U.K. Co Ltd (24.0%), Blackfriars Oil Company Ltd (12.5%) and The Trans-European Company Ltd (2.5%).