Whicher test revives SW gas prospect

Gas extraction at the Whicher Range continues to divide the community after a new attempt to make the project viable started this week.

Joint-venture partners Whicher Range Energy and CalEnergy started test drilling operations on an existing well on Wednesday after gaining State Government approvals.

The rig operations will run for up to 20 days, followed by a 40-day testing period to determine if gas extraction is commercially viable.

CalEnergy managing director Peter Youngs said they were using a new “underbalancing” technique to avoid problems encountered in previous attempts.

Mr Youngs said the reservoir contained a clay mineral that expanded on contact with water, meaning conventional drilling techniques caused formation damage.

“The underbalanced (or managed pressure drilling) operations is a technique that will prevent drilling fluids from coming into contact with the highly water-sensitive clay mineral in the reservoir,” he said.

He said the project only had a 40 per cent chance of success but that was normal in the industry.

WRE chairman Cameron Manifold said successfully tapping into the estimated 5 trillion cubic feet of gas could have enormous ramifications for the South West.

Viable gas extraction could reinforce the South West’s supply and even provide more economical prices for domestic and commercial users, he said.

Busselton Chamber of Commerce chief executive Ray McMillan said this would be a bonus for the region as they currently relied on piping gas from the Pilbara and offshore.

However, No Oil for SW Beaches convenor Rob Alder said it could come at the cost of long-term damage.

Mr Alder said if gas extraction was found to be commercially viable the drilling of new wells could lead to gas infiltrating the precious underground water supply.

“We’re really creating a huge amount of risk,” he said.

“Well casing technology is decades old but geology is hundreds of millions of years old. I don’t think we can expect our best endeavours to defy the products of earth movement.”

Mr Manifold was confident this would not occur.

The integrity of the well was secured and the gas was located at a depth of 4000m, well below the aquifers.

Geologist Peter Lane has also said he has no problem with the WRE project due to the depths involved.

Though that didn’t mean engineering errors weren’t possible, he believed those risks could be managed.

If the test drilling project is successful, the companies will run a small pilot project for two to three years to determine the gas field’s greater potential.