Technology, investment and people: a process for extending the life of the Central Fields Complex, Gippsland Basin

Abstract

The greater Central Fields complex of the Gippsland Basin, comprised of the Halibut, Fortescue and Mackerel fields, has produced 1.7 billion barrels of oil from four platforms in 37 years of production. After the initial development drilling phases from Halibut (1969–70), Mackerel (1977–80), Fortescue (1983–86) and Cobia (1983–85) platforms and five in-fill drilling campaigns (1992–2003) it is still possible to target unswept highly productive multi-darcy reservoirs along with bypassed zones in lower quality sands. During 2007, a six well program was completed from the Halibut platform using an upgraded workover rig that added significant volumes with combined initial rates of more than 16,000 barrels of oil per day. In addition, despite being conductor limited, the program tested strategic concepts and demonstrated significant remaining potential in a variety of reservoir qualities and depositional environments. The outstanding success of the 2007 program was based on an up-to-date geologic framework, key technical advances, ongoing investment commitment and multi-discipline integration across workplace functions. Advancements in 3D seismic data quality and analyses, reservoir surveillance, innovative slot recovery and data integration all played a role in the success of the program. Building on the success elements of the 2007 program, a higher capacity rig has been mobilised and upgraded to apply new drilling technologies to access the remaining potential and help mitigate basin decline.