The Waitsia gas field is a conventional onshore gas field being developed in the Perth Basin, Western Australia. Discovered in September 2014, it is considered to be the biggest onshore gas discovery in Australia in the last 40 years.
Previously owned by a joint venture comprising operator AWE (50%) and Origin Energy’s subsidiary Lattice Energy (50%), the Stage 1A development of the field commenced production with an initial capacity of ten tera joule (TJ) of gas per day in August 2016.
Beach Energy acquired Lattice Energy from Origin Energy in January 2018, while Mitsui E&P Australia (MEPAU) became the operator of the field by acquiring AWE in May 2018.
The Waitsia Stage 1 project is being expanded to increase the production capacity to 20TJ of gas per day, while the planned Waitsia Stage 2 project involving additional wells and the construction of a new production facility is intended to increase the field’s gas output to 250TJ per day over the 20-year project life.
Construction on the Stage 1 expansion project was started in January 2020 with commissioning expected by the end of 2020, while Western Australia's Environmental Protection Authority (EPA) recommenced the Waitsia Stage 2 project for approval by the state government in September 2020.
Location and reservoir details
The Waitsia gas project is located on agricultural land in the Shire of Irwin within the northern Perth Basin, approximately 16km south-east of Dongara and 340km north of Perth.
Waitsia forms part of the production licenses L1 and L2 and contains two interconnected reservoirs of the Kingia and the High Cliff Sandstone formations.
The Waitsia field was estimated to contain 820 petajoules (PJ) of 2P reserves as of December 2017.
Waitsia gas field Stage 1 development
The Stage 1A of the Waitsia gas field development consists of two production wells, Senecio-03 and Waitsia-01, that are connected to the refurbished Xyris production facility (XPF).
The Xyris production facility was under care and maintenance since 2010. The new infrastructure built as part of the Waitsia Stage 1A development included two new flowlines, a processing hub, and a 7km pipeline connecting the XPF.
Stage 1 expansion aims to connect the appraisal well Waitsia-02 to the XPF via an infield flowline. It also involves further modernisation of the XPF and the construction of a 4km-long, large-diameter pipeline connecting the XPF to the Dampier to Bunbury natural gas pipeline (DBNGP).
The Waitsia-02 well, located 6km south-south-west of Waitsia-01, was flow-tested at a rate of 38.7 million cubic feet of gas per day (Mcfd) in November 2017.
Waitsia gas field Stage 2 development
Stage 2 development of the Waitsia field includes the drilling of up to six new production wells apart from the completion of two existing wells namely, Waitsia-03 and Waitsia-04.
The Waitsia-03 well, located 11km south of Waitsia-01, was flow-tested at a rate of 50Mcfd in October 2017, while the Waitsia-04 well, located 3km north-northeast of Waitsia-03, flowed at a rate of 90Mmcfd in November 2017.
The Stage 2 development project also includes the construction of a new gas processing facility with a production capacity of up to 250TJ per day, and the installation of flowlines and five gathering hubs for supplying the gas output from the wellheads to the processing facility.
The new gas processing plant will be built as a self-contained and standalone facility adjacent to the XPF and will be remotely operated from the site. The treated gas from the facility will be supplied to the DBNGP.
Gas supply from the Waitsia gas field
The Waitsia Stage 1A has been supplying approximately 10 tera joule (TJ) of gas per day via an existing pipeline to the Parmelia gas pipeline for domestic consumption in Western Australia.
AWE signed a gas supply agreement with Alinta Energy for the supply of 10TJ of gas in January 2016.
Alinta Energy signed another agreement with Beach and MEPAU for the purchase of up to 20TJ of gas per day from the Waitsia field for a period of four and a half years starting from July 2020.
In-situ Construction was engaged to perform earthworks, concreting, and fencing for the Waitsia Stage 1 expansion project.
GCo Australia carried out upgrades to the electrical components and instruments for the Waitsia Stage 1 expansion.
Quanta/Suez and Clough were selected as the engineering, procurement, and construction (EPC) contractors for the design competition phase of front end engineering design (FEED) for the Waitsia Stage 2 development in June 2017.
ATCO Australia was shortlisted to provide build-own-operate (BOO) solutions for Stage 2, while SNC-LAVALIN was selected for both EPC/BOO works.