The Process of Making Gas
Natural gas from Mitsui E&P Australia’s Mid West gas fields is processed in production facilities and then transported by independently-owned pipelines to customers for electricity generation, household gas and industrial uses.
Mitsui E&P Australia (MEPAU) has one active gas production facility in the Mid West region: Xyris Production Facility, which is producing gas from Waitsia Stage 1. MEPAU engages operators through a lead contractor, Upstream Production Solutions, to help operate these facilities under MEPAU management. Almost all operational personnel live locally in the Mid West region.
Dongara Production Facility
The Dongara Production Facility (DPF) began operating in 1971 when the Parmelia Gas Pipeline was commissioned. During almost five decades of production, 96 wells have been drilled in the Waitsia, Dongara and adjacent gas fields which coexist amongst the primary regional land use, broad acre farming. DPF has mainly produced gas, as well as some hydrocarbon liquids, which are normally called condensates.
Gas is transported and sold through the Dampier to Bunbury Natural Gas Pipeline, owned by Australian Gas Infrastructure Group (AGIG), as well as the Parmelia Gas Pipeline operated by APA Group and any oil and condensate is trucked to the BP Kwinana refinery.
The Dongara gas fields have been depleted and are no longer producing. They have been placed in shut-down. MEPAU is preparing care and maintenance plans for the Dongara Production Facility and decommissioning plans for the associated wells, infrastructure and the gas processing equipment. In January 2021 the gas processing equipment was removed. The administration building, workshop and two condensate storage tanks remain and are still being used.
Xyris Production Facility
The Waitsia gas field began producing natural gas in August 2016 when the Waitsia Gas Project Stage 1A was commissioned, providing an ongoing source of gas to consumers and jobs for local employees. Gas flowed from two wells (i.e. Senecio-03 and Waitsia-01) to the Xyris Production Facility, which was refurbished in 2016 following a period of care and maintenance.
In August 2020, the Waitsia Stage 1 Expansion was commissioned. Gas is now flowing from three wells (i.e. Senecio-03, Waitsia-01 and Waitsia-02) and is exported via a new pipeline, the Waitsia Export Pipeline, to the Dampier to Bunbury Natural Gas Pipeline.
MEPAU has several other production facilities in the Mid West region that are in care and maintenance and are no longer producing.
- The Hovea Production Facility (HPF), an oil and gas production facility constructed in 2003, is located within Production Licences L1/L2. The Hovea field has been in care and maintenance since 2012. Since then, the HPF area has been used to support general regional operations (eg equipment laydown storage, evaporation ponds). Removal of more facility equipment is planned in early 2021.
- The Woodada Gas Field (WGF), located in Production Licences L4/L5, was discovered in June 1980, with production commencing in May 1982. In December 1987, the area surrounding the field was declared a nature reserve known as Lake Logue Nature Reserve. The WGF was placed under care and maintenance in 2011 and the gas processing facility was decommissioned in late 2020. Additional removal work is planned for early 2021.
- Other facilities in the northern Perth Basin, including the Mt Horner Oil Field, Mondarra Gas Storage Facility and Beharra Springs Gas Processing Plant, are run by other Operators.
Gas production involves the controlled transport of natural gas flowing from the underground rock formations through the well heads and on to the processing facility via flowlines and pipelines.
In an actively operating gas well, a wellhead located on the surface maintains control of the well and the well is pressure-tested to ensure that it is safe. The wellhead contains barriers, valves and seals that allow the pressure of the well and the flow of fluids to be controlled at the surface. The control mechanism on top of the well is often called a ‘Christmas tree’.
The well is then connected to infrastructure, either a flowline or pipeline, so that the gas can be transported to the production facility and then on to markets via a pipeline. A flowline carries unprocessed hydrocarbons from the well to a processing facility, whereas a pipeline carries processed fluids.
Once the gas reaches the production facility, it goes through a series of treatment processes to ensure it has the correct characteristics the gas purchaser requires.
After treatment the gas is transported to markets via a pipeline. This requires either building a new pipeline or connecting to an existing pipeline. Most MEPAU pipeline routes are buried underground allowing farming and other land uses to continue. Burying the pipe also minimises the visual impact.
(now decommissioned and rehabilitated for agricultural use)
Waitsia Gas Project Stage 1A coexisting amongst agricultural activities
Safety and environment controls
Production facilities operate under the rigorous safety and environmental approval framework defined by various petroleum acts and regulations. The lead regulatory agency in Western Australia is the Department of Mines, Industry Regulation and Safety. Facilities are also covered by a site licence issued by the Department of Environmental Regulation under Part V of the Environmental Protection Act, 1986.
During the gas production process, some controlled emissions may occur and these are closely monitored and reported.
Primarily for safety reasons, some gas may need to be vented (the controlled release of gas into the atmosphere) at the production facility. For example, sometimes there will be a disruption to production that’s triggered by inbuilt safety systems designed to protect people and equipment. When that happens, we follow a plan to manage the gas, which may include relieving pressure in the system by controlled venting.
Natural gas is predominantly composed of methane, which is non-toxic and non-poisonous, and is categorised as a Greenhouse Gas. Methane is produced both naturally and from human activities. It is a major by-product of agricultural activity, burning off and rotting waste in landfills. MEPAU reports emissions from gas production promptly to the Department of Mines, Industry Regulation and Safety and annually in our National Greenhouse and Energy Report. MEPAU transparently reports and publicly discloses environmental incidents, spill volumes and any fines incurred in our Annual Report. MEPAU also engages with local stakeholders to ensure they are regularly updated on the company’s activities and that any concerns can be promptly addressed.