History of oil and gas in the Perth Basin
The surface of the Perth Basin has changed many times over hundreds of millions of years – we can see this by the many layers found underground. Some of those layers were originally plants, animals and bacteria, which died and decomposed. They were buried under mud, sand, rock and more organic matter, and all that pressure and heat turned some of the organic matter into oil and gas. That’s what we’re extracting today.
People first began looking for gas and oil in the late 1940’s but it wasn’t until 1964 that the first gas was found at Yardarino. That led to the discovery of the Dongara gas field, and in October 1971 the first gas was produced for sale. A pipeline was needed to take the gas to market, so the Parmelia Pipeline was built from Dongara to Pinjarra. It covered 416km and was the state’s first gas pipeline.
Since then, a lot of activity has been undertaken across the Perth Basin, but especially in the area around Dongara.
• Field exploration
• Seismic acquisition
• Exploration and development drilling
• Construction of plant infrastructure and pipelines
• Production and processing of oil and gas
• Decommissioning and rehabilitation
Finding oil and gas is a bit like finding a needle in a haystack. In the early days only 1 in 10 wells drilled were successful. Since 2001 that rate has improved somewhat, partly due to 3D Seismic Survey Technology.
The Perth Basin covers both land and sea, but it’s much easier to explore onshore than offshore. Only 52 wells have been drilled offshore, compared with 309 onshore. Of these, 75% are in the Northern part of the basin.
Nevertheless, after all that drilling Western Australia only ended up with around 20 commercial oil and gas fields, of which Dongara is by far the largest.
A significant amount of gas has been extracted from the Perth Basin over the last 50 years but even so, the gas fields in the Mid West have only accounted for about 5% of Western Australia’s gas usage.
Gas and oil have been extracted from:
• Dongara (in production)
• Woodada (under care and maintenance)
• Beharraa Springs (in production)
• Corybas (in production, one well field)
• Hovea (under care and maintenance)
• Jingemia (under care and maintenance)
• Xyris (under care and maintenance)
• Cliff Head (offshore, in production)
How Mitsui E&P Australia fits into the picture
Mitsui E&P Australia (MEPAU) was founded in 2004 and has grown to become Australia’s seventh largest oil producer. In 2018 MEPAU acquired AWE, an Australian energy company focused on upstream oil and gas opportunities.
AWE was established in 1997. Its first venture in Western Australia was the Cliff Head Oil Field, which is about 10km offshore. AWE was involved as a joint venture partner from 2001 to 2015.
In 2007 AWE acquired further production interests in the onshore Perth Basin.
In September 2014 AWE discovered the Waitsia gas field while drilling the Senecio-03 well. This caused great excitement because it’s very big – possibly the biggest gas field yet discovered onshore in Western Australia.
AWE sold the first gas from the Waitsia field in August 2016.