The Lennox oil and gas Field

Abstract

Abstract The Lennox oil and gas Field is located in Block 110/15 of the East Irish Sea, approximately 10 km west of Southport, Lancashire. The field was discovered in 1992 with well 110/15-6 drilled by the P791 BHP group. The Lennox structure is a rollover anticline in Permo-Triassic sediments formed in the hanging wall of the Formby Point Fault. The reservoir comprises the Triassic Sherwood Sandstone Group, and is characterized by excellent permeability aeolian and fluvial sandstones. The structure is sealed by the overlying shales and evaporites of the Mercia Mudstone Group. To date four wells have been drilled on the Lennox Field and have delineated a free gas cap in communication with a constant thickness oil rim. The hydrocarbons have been sourced from Namurian Holywell shales and reflect complex migration into the Lennox structure. Reservoir studies indicate likely hydrocarbons-in-place of 463 BCF of gas and 218 MMBO of oil. Development approval for the Lennox Field was granted in 1993 with production due to commence in late 1995 from a series of horizontal oil producers. Gas produced during the early years will be recycled and re-injected into Lennox via a crestal gas well to help maximize the oil production. During the later years, production will switch to sales gas. Lennox will be developed as an integral part of BHP’s Liverpool Bay Development.