The Schooner Field, Blocks 44/26a, 43/30a, UK North Sea
The Schooner Field is Shell U.K.’s first Carboniferous gas development in the North Sea. The field was discovered in 1987 by well 44/26-2 and gas production began in October 1996 from four wells. In contrast to the majority of the fields in the Southern North Sea producing from the aeolian Leman Sandstones Formation (Rotliegend), Schooner targets the low net-to- gross, fluvial Upper Carboniferous Barren Red Measures and Coal Measures formations. The reservoir consists of discrete, low sinuosity fluvio-deltaic channels draining a swampy coastal floodplain evolving upwards into a highly aggrading, low gradient, distal fluvial fan, dominated by braided and anastomosing channels. In Schooner, like other Carboniferous fields, reservoir connectivity is one of the key subsurface uncertainties due both to channel lateral discontinuity and fault compartmentalization. Production data and reservoir properties distribution, together with a new stratigraphical subdivision driven mostly by chemostratigraphic techniques, have been used to reassess the volume of gas-in-place which currently is estimated at 29.98 Gm3 (1059 BCF).