Setting New Environmental, Regulatory, and Safety Benchmarks: The 2009 Gorgon CO2 3D Baseline Seismic Project, Barrow Island, Western Australia
Authors: Scott Kevin C. , Parker Donna J. , Trupp Mark , Clulow Bruce 
Published: February 2011

Abstract The Approved Gorgon Gas Development (Gorgon Project) is developing the Gorgon and Jansz-Io Gas Fields, and includes the construction of a Liquified Natural Gas (LNG) plant on Barrow Island. The project is expected to commence extraction and processing LNG in 2014. The Gorgon Project is operated by Chevron. It is a joint venture of the Australian subsidiaries of Chevron (ap-proximately 47 percent), ExxonMobil (25 percent) and Shell (25 percent), Osaka Gas (1.25 percent), Tokyo Gas (one percent) and Chubu Electric (0.417 percent). The Gorgon Project's CO2 Injection Project will safely inject up to 3.8 MTPA of CO2 from LNG processing activities. The CO2 Seismic Baseline Survey (the Survey) was undertaken as part of Chevron Australia's commitment to develop and implement a monitoring program to track the performance of the CO2 injection system. The aim was to acquire good quality seismic data over the area where the injected CO2 is expected to migrate to enable monitoring of the injected CO2 in the subsurface over time. Barrow Island is a Class A Nature Reserve and all operational activities are subject to strict environmental and quarantine controls to protect its conservation values. Che-vron Australia and its primary seismic contractor Western-Geco, aligned environmental, health and safety management principles during the Survey's planning and execution phas-es to enable best practice project outcomes to be achieved within the operational restrictions. The final design of the Survey was a successful balance of technical objectives with land usage and envi-ronmental restrictions, and covered 135 km2 of the northern half of Barrow Island. Three source types were used to en-sure the best quality seismic data was obtained and the pro-jected CO2 plume area was completely covered. The Sur-vey's design also considered future risks associated with heliportable drilling operations and the use of explosives near future Gorgon Project infrastructure when planning for future seismic surveys to monitor the CO2 in the subsurface. Environmental, Regulatory and Safety Achievements • Achieved an environmental footprint of only 19 hec-tares over the 135 km2 project area (0.14% total land use). A similar-sized vehicle deployed survey would normally result in the disturbance of 250 to 300 hectares of land. • Design and deployment of state of the art modularized heliportable shot hole rigs equipped for both sonic and air percussion drilling to minimise the use of drilling fluids. • WesternGeco, working closely with Chevron Quaran-tine Inspectors, mobilized a significant amount of seis-mic equipment from multiple overseas locations using procedures and specifications of the Gorgon Project's Quarantine Management System that resulted in no post-border quarantine incidents on the Class A Nature Reserve. • Executed the Survey under the complex Barrow Island Act 2003 (WA) regulatory framework which required granting of land tenure for areas to be disturbed versus a typical petroleum access authority. Worked with the regulatory agencies to allow for real-time movement of vibroseis lines and seismic shot points to avoid unique flora and fauna habitats identified during the course of the Survey to achieve best environmental outcome.