The Gryphon, Maclure, Tullich and Ballindalloch fields, Blocks 9/18b, 9/18c, 9/19a, 9/23d and 9/24e, UK North Sea

Abstract

AbstractThe Gryphon Field was discovered in 1987 in Quadrant 9 in the Beryl Embayment. Oil was encountered in a thick Balder Formation sandstone, and the reservoir was interpreted as lobes of a submarine fan system, such as many of the prolific early Tertiary fields in the North Sea. After an extensive appraisal phase, oil production started in 1993 through the Gryphon floating production, storage and offloading vessel.After a successful initial development phase, the integration of production data, improved and regularly acquired seismic data, and a better geological understanding resulted in the identification of sandstone intrusions. These have since been interpreted to form a volumetrically significant part of the Gryphon reservoir. The drilling of further infill wells, and the development of satellite fields Maclure, Tullich and the future Ballindalloch, ensued from this change to the geological model. To date, the Gryphon, Maclure and Tullich fields have produced more than 200 MMbbl of oil compared to an initial reserve estimate of 151 MMbbl.Although the current and mid-term focus remains on maximizing oil production, the final phase of the wider Gryphon area fields’ development should see the production of the regional gas cap.