The Walyering gasfield is an onshore project located in the Perth Basin near the town of Cataby in the mid-west region of Western Australia.
The project is being developed by a joint venture between Strike Energy and Talon Energy. Strike Energy is the operator of the project and holds a 55% interest while the remaining 45% is held by Talon Energy.
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The final investment decision on the project was made in August 2022, with an estimated development cost of $30m. Production from the field commenced in September 2023.
Project location
The field is situated in Production License L23, approximately 150km north of the Perth Basin near the town of Cataby in the mid-west region of Western Australia.
Walyering gasfield discovery and appraisal
The Walyering gasfield was discovered in 1971 with the drilling of the Walyering-1 well. The well encountered 40m of low-quality net pay over the Jurassic-aged Cadda and Cattamarra Coal Measures.
The Walyering-2 well followed shortly after while the Walyering-3 appraisal well was drilled in 1973.
The Walyering-2 and Walyering-3 wells were subsequently abandoned due to tight gas with marginal flow rates.
Walyering-4 was drilled on the western block in 2001 while Walyering-5 was drilled in 2021 and currently flows at 75 million metric standard cubic feet per day.
Walyering-6 was drilled in 2022. The Walyering-5 and Walyering-6 wells contained sufficient conventional natural gas volumes to support the commercial development of the Walyering gasfield.
Strike Energy and Talon Energy will drill the Walyering-7 appraisal well in the first quarter of 2024 in the western compartment with the aim of converting the block’s resources to reserves. The block is estimated to contain 34 petajoules equivalent (PJe) of gross 2C contingent resources.
Reserves
The 2P reserves at Walyering are estimated at 56PJe as of October 2023.
Field development details
The project encompasses the development of the Walyering Processing Facility (WPF), Walyering Gathering Network (WGN), Walyering Gas Pipeline (WGP), and the connection point to the Parmelia Gas Pipeline (PGP), located within Lease 23 and Production License 130.
The WGN comprises two DN150 carbon-steel fabricated flowlines to convey gas from the wells to the WPF via a manifold.
The WGP also features a DN150 carbon-steel pipeline to transport processed dry natural gas from the processing facility to the Parmelia Gas Pipeline CS3 compound.
The infrastructure is designed to manage a capacity of 33 million metric standard cubic feet per day of gas, and storage and offloading facilities for 1,400 barrels of condensate. The project was also designed with sustainability in mind and is powered fully by solar and battery.
Processing facility
The Walyering processing facility purifies raw natural gas by removing impurities and non-methane hydrocarbons to produce high-quality dry natural gas.
The facility processes gas from the Walyering-5 and Walyering-6 wells prior to export via the PGP.
Key components of the project include a slug catcher, a three-phase separator for water, gas, and condensate, a gas exchanger, and filter.
Also included are systems for controlling water content and a hydrocarbon dew point, condensate storage tanks, high-pressure venting, air systems, and solar batteries.
Metering equipment, storage sheds, truck offloading facilities, and support utilities are also part of the facility.
Supply agreements
A long-term gas supply agreement was signed with Santos, Australia’s biggest gas supplier, for the supply of 36.5PJ over a period of five years.
Under the terms, gas will be supplied on a take-or-pay basis at 20TJ a day, with arrangements for the supply of additional gas based on availability.
Contractors involved
West Australian Petroleum conducted the drilling of the Walyering-1, 2, and 3 appraisal wells.
AUSAM, a gas and oil exploration company, drilled the Walyering-4 well in the western block.
Momentum Engineering was awarded the front-end engineering and design contract for the Walyering upstream processing facilities and related infrastructure in April 2022.
