description of the activity

The exploration activity will take place entirely within Petroleum Exploration Permits EPP44 and EPP45. Located in Commonwealth marine waters adjacent to South Australia (approximately 200 km south-west of Ceduna and 300 km west of Port Lincoln), the exploration permits span more than 32,000 km2. The Great Australian Bight Exploration Drilling Environment Plan (EP) covers drilling anywhere within these permit areas. During exploration, a 500 m radius petroleum safety zone will be established around the drill rig once in position at the well locations.
Chevron Australia (Chevron) will use a semi-submersible drill rig for its exploratory drilling program. These are very stable floating rigs able to withstand harsh wave and wind conditions. Once at the well location, the drill rig will be held in position via a dynamic positioning (powered propeller) system. A dynamically positioned rig does not require seabed anchoring, but instead relies on a global positioning system (GPS) and seabed reference points. The rig maintains location by constantly adjusting its dynamic thrusters.

The wells will be designed in accordance with Chevron standards and accepted industry practice. They will be drilled according to standards defined in the Well Operations Management Plan (WOMP) approved by the National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) in accordance with the Offshore Petroleum and Greenhouse Gas Storage (Resource Management and Administration) Regulations 2011 and the Offshore Petroleum and Greenhouse Gas Storage (Safety) Regulations 2009. The wells will be designed to suit all conditions anticipated during the drilling program.

Drilling at each well location will consist of a series of activities.  Firstly, the rig will be moved to the well location and position.  Next the well will be spudded and drilled, including the installation of the wellhead and blowout preventer (BOP) prior to drilling to the well to total depth.  Finally, at the conclusion of drilling, the BOP and wellhead infrastructure will be removed and the well plugged and abandoned.

The rig will be serviced and supplied by helicopters and support vessels that will be operated from locations in South Australia. As transit activities are managed and regulated under Australian aviation law, the Great Australian Bight Exploration Drilling Environment Plan (EP) only covers these operations when conducted within the 500 m radius safety zone around the rig. Other support operations include power generation, bulk chemical transfers, discharge of treated waste water, solid waste management, the storage of hazardous materials and the management of hazardous waste.
The drilling program includes allowance for contingency activities. While these are not planned activities, Chevron has procedures and protocols in place for operational or technical issues that prevent a well being drilled to total depth as well as severe weather events.