Impact of Rock Compaction on NSO Gas Field Performance

The North Sumatra Offshore (NSO) field is a large gas field that supplies gas to the P. T. Arun Liquified Natural Gas (LNG) plant in Aceh, Indonesia. The field came onstream in 1999 and produces about 450 MMscf/d currently. The field has produced about 34% of the Original Gas In Place (OGIP) as of 1/1/2007, and the ultimate recovery is expected to be around 75%. The producing carbonates have an average porosity of 23% with zones of higher porosity at the top of the reservoir. Geomechanical testing of Malacca limestone cores indicated that the rock has high compressibility and suffers elastic and significant plastic deformation when mechanical stresses are increased.