Barossa Offshore Development Project, Australia
Barossa is a gas and condensate field located in the Bonaparte Basin of the Timor Sea offshore Australia, in a water depth between 130m and 350m.
The field is planned to be developed along with the nearby Caldita field under the Barossa offshore development project.
The project is owned by the Barossa-Caldita joint venture, which comprises ConocoPhillips Australia Exploration (37.5%), SK E&S Australia (37.5%) and Santos Offshore (25%).
ConocoPhillips is serving as the operator and has submitted a development proposal to the National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA).
The proposal is currently under review by the NOPSEMA.
First gas from the offshore project is expected to be achieved in 2023 with an estimated annual production rate of 3.7 million tonnes (Mt) of liquefied natural gas and 1.5 million barrels of gas.
The project is expected to have a life of approximately 20 years from first gas.
Pre-front end engineering and design (Pre-FEED) work is currently underway, which will be followed by FEED studies in 2018.
The final investment decision on the project is expected in 2019.
Barossa and Caldita discovery
Barossa was discovered in 2006 with the drilling of the Barossa-1 exploration well to a depth of 4,310m.
Two drill stem tests were conducted on the well, which confirmed the presence of gas. One test flowed at the rate of 30.1 cubic feet a day, while the second flowed at a rate of 0.8 million cubic feet a day.
The Caldita field was discovered in 2005 by the Caldita-1 well and subsequently appraised by the Caldita-2 well in 2007.
Appraisal on Caldita-Barossa
The Barossa field has been appraised by a total of five wells. The first three wells, Barossa-2, Barossa-3 and Barossa-4, were part of a three-well appraisal programme that was completed in 2015.
Barossa-2 struck 88m of net pay in the Upper Elang, Lower Elang and Plover reservoirs, while Barossa-3 encountered 104m of net pay and Barossa-4 further confirmed the potential of the field.
A second appraisal programme consisting of two wells, Barossa-5 and Barossa-6, was completed in June 2017. The two wells confirmed reservoir productivity and provided critical data for field development planning.
Barossa-6 struck gas and condensate in the Elang reservoir located between depths of 4,103m and 4,144m. Tests conducted on the well resulted in a flow rate of 65 million standard cubic feet (Mmscf) a day.
Barossa offshore development project details
The Barossa-Caldita project is planned for development via a permanently moored floating, production, storage and offloading (FPSO) facility.
A total of 10-25 subsea production wells are planned to be drilled across the two fields and a production gathering system will transfer the produced hydrocarbons to the FPSO through in-field flowlines.
The Barossa field will be developed first, while the Caldita Field will be developed as a subsea tie-back to the FPSO at a later date.
A fibre optic cable is scheduled to be laid between the FPSO and Darwin to allow the remote operation of the facility.
Hydrocarbons export and processing
Natural gas and condensate produced from the field will be separated by the FPSO, and the condensate will then be offloaded directly into tankers.
The dry gas will be transported onshore to the Darwin Liquefied Natural Gas (LNG) facility via a 260km-to-290km-long subsea gas export pipeline, featuring a diameter ranging between 24in and 28in, for further processing.
The exact route of the pipeline is yet to be identified, though it is proposed to tie-in with the Bayu-Undan to Darwin gas export pipeline.
Barossa project is intended to replace production from the Bayu-Undan field following its expected depletion in 2022.