PREMIUM FEATURES

New technique for old wells

JOHN Towner can trace his family's involvement in the Australian drilling business back to 1898, but now the 71-year-old industry veteran is about to embark on perhaps his most ambitious test yet, telling <i>Energy News</i> he has a new application of an old production technique that could revolutionise the world's most prolific basins.

New technique for old wells

Towner, who was behind Sydney Gas, Sunshine Gas, New Guinea Energy, Triangle Energy and Anzon Australia, has "always had old pumps and the like around" and got his first real taste of the oil patch after designing equipment for Woodside in the 1970s, and now believes he has developed a new system for pulling oil out of the ground.

While most oil fields around the world rely on gas drive for production, before installing artificial lift, such as nodding donkeys or electric submersible pumps, almost all of Australia's onshore oil fields, those in South Australia and Queensland, derive their energy from the Great Artesian Basin.

They have bottom-hole pressure, which means the oil comes to the surface with a large water cut.

Methods of developing oil fields were developed in the US from the late 1800s, and the US experience formed the basis of the Australian oil sector, however Towner says he started to unpick the orthodoxy last year, when he considered buying the historic Moonie oil field from Santos.

Moonie was Australia's first commercial oil field development, and while it has been in production since 1962, less than 25% of the oil-in-place at Moonie has been recovered.

The field has now declined to just 110 barrels of oil per day from 11 wells.

During his due diligence Towner looked at the numbers underpinning Moonie to assess possible ways production could be increased. He noticed the bottom-hole pressures were still 2600psi at 2000m, despite the decline in oil flow rates.

"I started using my agricultural background, and I asked what I would do if I had to change the situation in a water well," he said.

If an agricultural bore had ceased flows, the answer would be to install a pipe into the bore and pump air into the well for several weeks to dissipate the hydrostatic head after 3-4 weeks, bringing the water back to the surface.

If that worked, he reasoned, why wouldn't the principle hold true for an oil well?

Towner has applied for a patent on the application of the principle, and is a few weeks from testing it out on the Moonie-8 well.

"We would put the pipe down and pump air in the full 7-inch casing, and on the numbers we have done we could go from 110bopd to 2000-3000bopd, because the hydrostatic head is reduced, and I can flow a full 5" diameter pipe if all I am doing is pumping liquid," Towner said.

Some drilling expects have raised the issue of the air and oil reacting to spark a fire, but he believes that is unlikely.

"The oil is wet, it comes out almost like a soggy rag I suppose, and it is so small in amount, it is 10 parts water to one part oil it won't happen," he said.

And he believes the technique has an application in waterflood enhanced oil recovery fields in the US.

"I can create my own bottom-hole pressure with waterflooding, and it can bring the fluid to surface. In one field in Bakersfield, ExxonMobil and Chevron have been flooding the field for 14 years," he explained.

There are between 20-30 million wells with negligible flow around the world with no cheap means of producing them, especially at current prices.

"What we see is that, from a perspective of utilising it ourselves as we plan to do, 200 wells pumping 50bopd which would not be hard to find, gives you a few hundred million in revenue at $US50/bbl," he said.

Moonie-8 has been selected as the test well because it is well understood and it has been handed to a local farmer by Santos as a water well after it plugged the oil zone.

Santos is apparently keen to see the results, and its engineers have been briefed on the trial.

"They all asked why no one had thought of this. Well, at 71 years of age I have seen most things, but because there is no artesian structure in the US, there was no reason to go past the Archimedes principle to lift water with air more than 10m; but because I have the fluid right to the top of the well, I am able to utilise the system," Towner said.

Archimedes' principle indicates that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces.

Towner's test should cost less than $50,000, and should be simple to replicate across an entire field.

That's considerably cheaper than a workover, which can cost upwards of $400,000 purely to pull a completion and install a pump.

"It's a pipe in the well, air compression at surface which can be used at multiple wells, which makes it idea for a waterflood pilot pattern," he said.

Simple and repeatable, success could revolutionise Australia's oil production.

TOPICS:

A growing series of reports, each focused on a key discussion point for the energy sector, brought to you by the Energy News Bulletin Intelligence team.

A growing series of reports, each focused on a key discussion point for the energy sector, brought to you by the Energy News Bulletin Intelligence team.

editions

ENB Cost Report 2023

ENB’s latest Cost Report findings provide optimism as investments in oil and gas, as well as new energy rise.

editions

ENB Future of Energy Report 2023

ENB’s inaugural Future of Energy Report details the industry outlook on the medium-to-long-term future for the sector in the Asia Pacific region.

editions

ENB Cost Report 2021

This industry-wide report aims to understand current cost levels across the energy industry

editions

ENB Social Licence Report 2021

In its second year, this research now includes trends and new findings surrounding impacts and responses as the energy industry seeks to secure and maintain a social licence to operate.