In recent years the successful drilling, completion and tie-back of three Griffin area infill wells and a re-entry campaign has resulted in improved production rates and increased reserves.
The Griffin Area Development in the southern Carnarvon Basin, offshore Western Australia, consists of three oil fields; Griffin, Chinook and Scindian, tied to the "Griffin Venture" Floating Production Storage and Offloading (FPSO) facility. First production commenced in January 1994, with a maximum rate of 85,000 stb/d reached shortly after start-up.
The Zeepaard Formation is the primary reservoir in the development. It has excellent productivity and strong aquifer support. In eight years of production, over 100 MMstb of oil has been recovered through nine vertical wells. Production began to decline from 1996, with escalating water cuts from the majority of the wells.
Reprocessing of the 1991 3D seismic data, combined with reservoir modelling studies, led to the approval and subsequent drilling of two Zeepaard infill wells in mid 2000, one in the Scindian Field and the other in Griffin. The results of the Griffin infill well changed the understanding of reservoir sweep in that field and led to a re-entry campaign in late 2000. This was followed by a second infill well in early 2002.
Each infill well has flowed in excess of 20,000 stb/d, lifting the production potential of the Griffin Venture, improving the reservoir sweep and accelerating reserves into field life. In February 2002, the facility was producing at 60,000 stb/d, with 40,000 stb/d of this attributable to the three infill wells drilled in the area since July 2000.