The Rough Gas Storage Field, Blocks 47/3d, 47/8b, UK North Sea

Abstract

Abstract The Rough Gas Field is operated by British Gas as the world's first offshore gas storage reservoir. This relatively small field (original reserves 366 BCF) is located on the western margin of the Southern North Sea Basin. The reservoir, the Rotliegendes Gp (Leman Sandstone Fm.) average thickness 95 ft, is developed in a basin-margin facies association in which aeolian and wadi-related fluvial processes have interacted. Small-scale dune and interdune sandstones, with generally excellent permeability, alternate with wadi facies sandstones with variable but mainly poorer permeability. The vertical distribution of these facies permits a three-fold zonation of the reservoir. Flow profiles obtained from Production Logging Tools show a very strong correspondence between sedimentary facies and productivity/injectivity. The Carboniferous subcrop includes several very low-permeability sandstone intervals which contact the Rotliegendes at the angular Base Rotliegendes unconformity. A small amount of gas from these sandstones seeps across the unconformity surface into the Rotliegendes. The Rough Field was discovered by Gulf in 1968, and was operated by Amoco on a conventional depletion basis with 6 development wells from 1975 until the early 1980s. In 1980 British Gas secured 100% ownership of the Field and its facilities, and converted it to storage mode. Excess summer supplies are injected into the reservoir, to be produced during the winter to meet the peak demand. Conversion to storage mode has necessitated the installation of substantial new facilities, and the drilling of 23 further wells. First injection of gas was achieved in 1985.