Abstract

The Terang-Sirasun development is reservoired in the Paciran limestones of the Plio-Pleistocene. Development of the 1 TCF GIIP is complicated by a range of seismically driven overburden and surface processes that constitute a substantial geohazard risk to planned well bore and gas gathering installations. Terang is characterised by significant shallow gas in the overburden and faults, some of which have seabed expression. Sirasun is characterised by fewer faults and little shallow gas but by the location of the present day shelf-slope break. This exhibits extreme erosion and potential mass flow features. The challenge for the business unit is to create a development scenario that, where possible, avoids all geohazards for the lowest CAPEX. This involves identification of the risks from conventional geohazard survey datasets totalling some 2 terabytes of data. Manipulation and integration of the data and the associated interpretation has involved a multidiscipline team ranging across 3 different companies, using a number of software packages for seabed site investigation, subsurface evaluation and well planning, etc. to define the optimum development scenario. This paper attempts to detail the methods used to deliver the data sets into visualisation packages, identify and analyse the geohazards, the geohazards themselves and the development scenario through visualisation based on a novel risk assessment approach of these geohazards.