Anthony Doesburg: Deep knowledge brings in the work

Where does the world's leading space agency turn when it is planning a drilling programme on Mars?

Not Halliburton, the huge American supplier of oil drilling equipment and services, nor Schlumberger, its even bigger rival. Combined, the two firms rake in revenue of US$55 billion ($83.7 billion) and have 137,000 employees.

Instead, the company giving Nasa the benefit of its wide experience is based in Porirua, has about 60 staff and annual sales of $10-$15 million.

Webster Drilling & Exploration, which in 25 years has undertaken work in Antarctica, the Arctic, Asia, the Middle East and the Pacific, is yet to set up a rig on Mars.

But Bain Webster, the company's managing director, jokes that if the consulting work he did for Nasa's Mars mission planners comes to anything, he has staff whom he'd readily send to the cold planet.

"We did have some volunteers around here to go and do it, and there were one or two we were dead keen to send on a one-way trip," says Webster.

In reality, any Mars drilling would be done robotically. The particular expertise that brought Nasa into contact with Webster was the company's experience drilling in ice. A demonstration was arranged in the Arctic, studied by "an army" of officials from Johnson Space Centre and Nasa's Langley Research Centre, and a California Institute of Technology consultant.

"They figure that as Mars cooled, liquid water sank into the sand and gravels and froze and so it is locked and trapped in the sub-surface."

If there had been life on Mars, the theory is that there would be traces trapped in the frozen water.

"If they can take core samples and recover them back into the spacecraft ... they would be able to thaw out the permafrost cores and analyse them and detect whether there were any life forms."

A key element of the drilling process, Webster says, is that it must be aseptic.

"Everything has to be filtered so there are no bacteria transferred from the air to contaminate the core samples."

Since the Arctic demonstration, Webster has had nothing further to do with the project, although Nasa is pressing ahead with experiments.

"It is happening," Webster says. "We all know they've been up there with their little digger and taken some shallow samples but they want to take deeper core samples."

Webster Drilling is involved with a number of ongoing scientific projects, primarily in the Antarctic. Invariably the technical difficulties are enormous.

One job took the company to Hawaii's Big Island, where the aim was to drill down to 3350m through the Mauna Kea volcano. While such projects are seldom big money-spinners, they provide Webster's drill crews with rare experiences. "They're a challenge to be involved with and it's good for the company to be able to offer our guys something different from the normal day-to-day stuff that we have to do to make a living - going around drilling holes for oil companies and construction companies and the like."

Webster Drilling's usual headcount is between 30 and 40. But that has expanded to 60 since it began a major contract - or as Webster puts it, "a fascinating little one" - on Barrow Island off Western Australia.

"It's for a huge gas find. We don't hear about it here but they do in WA - it looks like it's going to be WA's biggest energy project ever."

The so-called Gorgon find is a group of gasfields off Barrow Island. The intention is to pipe the gas to three liquefaction and purification plants on the island, from where it will be exported. Just to complicate matters, Barrow Island is a nature reserve, never having been invaded by exotic animals, which means anyone setting foot on it requires three weeks of training in conservation techniques.

That's not to say the island is pristine - since the discovery of oil there in 1964, the southern half has been dotted with hundreds of wells. The Gorgon strike means it is now destined to be the site of Australia's largest resource project.

Webster's role is to help limit the project's carbon footprint. Carbon dioxide makes up about 14 per cent of the Gorgon gas and, while that once would have been vented into the atmosphere, the plan at Barrow Island is to store it 2500m underground.

A seismic survey is being done of the structure where the CO2 will be pumped, so its capacity is known.

"Our job is to drill down below sea level and put in explosive charges."

As blasts are set off, pressure waves are recorded by numerous hydrophones, from which the shape and size of the reservoir is calculated. "That will give them a baseline picture of the structure before any gas is put in it."

After 12 months of pumping in a known quantity of CO2, Webster Drilling will repeat the seismic survey.

"Twelve to 18 months later they'll do it again, and it's got to be repeated in the identical format each time so you can monitor the growth of the CO2 plume in the structure," Webster says.

Because of the island's reserve status, a truck-mounted drilling rig that could be driven off-road was out of the question. That meant designing a rig that could be helicoptered in - "albeit by a monstrous helicopter", Webster says.

Gorgon is "quite a sexy project" to be involved with, Webster says.

"But then we do lots of boring stuff as well, that pays the bills."

The business is nothing if not unpredictable. While Webster has had no recent contact with Nasa, there's no telling what might be around the corner.

"It's a strange world, this one, you just do not know - in comes an email and, holy hell, you're involved in something you never dreamt you were going to get involved in."