Exploration and Appraisal

The first step in producing gas is actually finding gas in the earth. Then, a decision needs to be made about whether it makes economic sense to pursue it.

Geologists examine the local area and make an initial assessment about the likelihood of gas being underground.

They follow up with more in depth examinations, for example with a seismic survey that looks at the rocks underground. They figure out if the rocks are likely to contain gas and if so, how much.

If the signs all look good, the gas company will drill an exploration well. This well is used to find out if gas really is present, and if so, how far down.

If the exploration well results are promising, the gas company will drill an appraisal well. If not, the company will proceed immediately to decommissioning and rehabilitation.

An appraisal well is used to test the flow rate. It’s one thing to find gas underground, it’s another to extract it. If the gas flows too slowly the well would not be economically viable, because the cost of machinery, equipment and staff is high.

If the appraisal well results are promising, the gas company proceeds to developing the gas field.

If not, the gas company proceeds immediately to decommissioning and rehabilitation.

Most recent exploration well examples include Irwin-01 and Drover-01.

DMIRS keeps a database of all wells drilled.

Senecio-03 appraisal well

The Senecio-03 appraisal well is located on agricultural land in the Shire of Irwin. The well was originally designed to evaluate the potential for commercial gas production from the Dongara/Wagina formation. The core samples and data from Senecio-03 were used to further assess the viability of gas resources in the Mid West.

RECENT Exploration and Appraisal

Waitsia-02, Waitsia-03 and Waitsia-04 are appraisal wells

Waitsia-02, Waitsia-03 and Waitsia-04

Waitsia-02, Waitsia-03 and Waitsia-04 are appraisal wells. Find out more about Waitsia-02, Waitsia-03 and Waitsia-04.

Cessna aircraft used to conduct airborne exploration survey

Airborne Exploration Survey

Two airborne exploration surveys were undertaken in October 2020, to assess the underground geological structure.

PREVIOUS Exploration and Appraisal

Drover well head


The Drover-01 exploration well was drilled in mid-2014. Find out more about the current status of Drover-01.

Irwin well, Dongara


The Irwin-01 exploration well was completed in May 2015. Find out more about the current status of Irwin-01.

Woodada gate

Woodada Gas Field

Woodada Deep-01 was drilled in April 2012. It was a deepening of the Woodada-04 well. Find out more about the current status of Woodada Deep-01.

Denison 3D Seismic Survey

Denison 3D Seismic Survey

The Denison 3D Seismic Survey was the most complicated survey ever done in Australia at the time. Find out more about what was involved in the Denison 3D Seismic Survey.

What we do at Mitsui E&P Australia

What we do

We are actively exploring, appraising, developing and producing oil and gas in a number of locations in the northern Perth Basin. Read more about what we do


Before anything can happen we need to plan carefully. Read more about the planning process.


Once we’ve confirmed a well is commercially viable we get ready to put it into production. Read more about the development process.


During the production phase we produce gas from the well and sell it. Find out more about the production process.

Decommissioning and Rehabilitation

When the exploration or production activity has finished it’s time to clean up. Read more about how we decommission and rehabilitate a well and its surrounding area.

Sustainable energy

Sustainable Energy

MEPAU is actively transitioning to a low-carbon energy future.

The Northern Perth Basin

The northern Perth Basin is a prolific oil and gas producing area covering a large portion of the Mid West region of Western Australia. The town of Dongara, located approximately 360km north of Perth, is the regional economic hub for a number of industries, including oil and gas.