Case History of the Matzen Field/Matzen Sand (16th TH): A Story of Success-Where is the End?

摘要

The Matzen Sand (16th TH) was discovered in 1949. Todate, some 42.3 million m3 (266 million STB) oil and 3.75billion m3(Vn) (140 billion scft) gas were produced whichleads to a recovery factor of 48.5 %. Average water cut is 93.5%. Mean porosity is 27 %. The oil has 25°API gravity. Thesand is relatively homogeneous and exhibits a pay thicknessbetween 1 m up to 70 m (3.3 ft to 230 ft). ‘Hard layers’ (tightstreaks) reduce vertical permeability in certain areas.1968 a peripheral water injection project was commenced.Discontinuous hard layers distributed throughout the reservoiraffect water flooding. Sweep efficiency is related to these hardlayers. Areas of unswept oil between these tight layers havebeen proved by reperforation of certain producing wells.In 1996 natural gas injection started into the gas cap whichcaused a reduction of the oil production decline by 50 %.Successful production history of the 16th TH results fromproper reservoir management through 55 years of field life.