The Malory Field straddles blocks 48/12d and 48/12c of the UK Sector of the Southern North Sea on the western margin of the Sole Pit Trough. The field is located within an upthrown part of the Dowsing Fault Zone and was discovered by the Mobil operated well 48/12d-9 in early 1997. The Malory Field is a small fault-bounded horst structure with expected recoverable reserves of 75 BSCF. The reservoir consists of a 249 ft-section of Lower Permian, Rotliegendes Leman Sandstone Formation sandstones, is sourced from the Carboniferous Westphalian Coal Measures below, and is sealed by overlying Upper Permian Zechstein evaporites. Reservoir quality is generally good with an average porosity of 14.7% and core permeabilities (Kh) between 0.2 and 1651 mD. This preservation of reservoir quality is attributed to a combination of the structure being located on a broad palaeostructural high, with a lower maximum burial depth than adjacent structures and associated lower compactional porosity loss, the presence of an early hydrocarbon charge and the preferential precipitation of chlorite over illite cements.