What's hiding in the basement?

Geologist doing fieldwork in Azerbaijan

Fieldwork in Azerbaijan in association with BP. The geologist is using a laser scanner to build a detailed topographic model of a fold structure developed in Pliocene-aged sedimentary rocks.

12 February 2010 by Tom Marshall

A Royal Society Industry Fellowship has taken Ken McCaffrey from a quiet academic existence in Durham to working in some of the world's most rugged locales. Tom Marshall talked to him to find out more.

A few years ago, Dr Ken McCaffrey wanted a change of pace from the life of an academic geologist. He certainly got one.

A reader in Durham University's Department of Earth Sciences, he's now nearing the end of a four-year research project in collaboration with international energy company BP.

He's spent much of this time looking at how the formation of geological structures that can later fill with oil or gas is conditioned by the older structures they've formed on top of - what geologists call their 'basement'. Traces of basement structures are hard to find, but they can offer crucial insights into how later formations arose and what rock types they might contain.

In Azerbaijan, for example, analysis of basement structures is helping geologists understand relatively young underground structures in which oil is forming. McCaffrey sees his project as combining the strengths of academic and private-sector researchers. Academic geologists have time to develop and refine sophisticated theoretical models of how tectonic plates move and interact. Conversely, exploration all over the world for new oil and gas re-serves gives the private sector a wealth of data that most scientists never get to see.

"BP's project in Libya recently produced one of the biggest datasets ever from a marine seismic survey," McCaffrey says. "By working with them I get instant access to that data, whereas many geologists won't get to see it for years, if at all."

Map of Caspian Sea

View of the Caspian Sea towards the Absheron peninsula in the background. BP Caspian Sea oilfield is in foreground and is located on an elongate ridge that has formed along a basement fault zone between the Eurasian and Arabian tectonic plates.

Shipborne seismic surveys, which map the structure of the ground under our feet by directing powerful sound waves into it and monitoring how they are reflected back, cost hundreds of millions of pounds. So they're a rare undertaking in academia, although there are international initiatives supplying data in areas of particular interest. For energy companies, by contrast, such surveys are a routine necessity when looking for new oil- and gas-fields.

McCaffrey is working on bringing the two sets of expertise together, combining the latest academic theoretical insights with the three-dimensional maps that BP's seismic data can create. In effect, he's applying the latest theoretical insights to new data from comparatively little-explored regions.

The results won't just help future efforts to find fossil fuel reserves - they'll also shed light on much wider questions about how the Earth's crust developed. The research is still primarily academic in focus - it won't directly influence BP's day-to-day commercial decision-making. But in the long term, McCaffrey hopes it'll improve our understanding of where to look for oil and gas.

BP recently negotiated agreements to drill in Azerbaijan, based partly on analysis and mapping involving McCaffrey. And it's now planning where to drill its first exploratory boreholes in Libya - a decision that McCaffrey's work will influence. Increasingly oil and gas reserves held within the basement rocks themselves are being targeted for exploration. An example is the Clair field, west of Shetland, which is the biggest on the UK continental shelf. Here, knowledge of basement structures is directly relevant to how much oil or gas a field can produce.

Our work will be useful for making better hazard maps, an important consideration for any future carbon or radioactive waste storage facilities.

Knowledge of basement structures could also help us forecast and manage the effects of geohazards like earthquakes, volcanic eruptions or landslides. "Even in the UK, for example, there are places where old faults have been put under stress by present-day tectonic forces," McCaffrey explains.

"Where there is a basement component it can mean these faults behave in a different way from what you'd normally expect; you get unusual earthquakes that happen on different cycles from what you'd otherwise expect. So our work will be useful for making better hazard maps, an important consideration for any future carbon or radioactive waste storage facilities in the UK and else-where."

The idea for the project arose after a chance meeting at a conference in 2005. McCaffrey had worked with BP before, and on running into one of their employees who'd been a PhD student alongside him, he happened to mention he was looking for a break from the academic routine. They suggested he should come to work at BP for a while.

Serendipitously, a few days later McCaffrey spotted an advertisement in his department for the Royal Society Industry Fellowship scheme, which supports collaboration between academics and the private sector. A grant application later, he found himself working in BP's headquarters along-side their petroleum geologists.

Clair oil field

BP's Clair oil field off Shetland

This has certainly provided the change of pace he was hoping for; working with BP has taken him over the world, to places including Libya, Azerbaijan, Canada and Brazil. And he's developed a new respect for the speed at which private companies must make decisions - waiting a few years to gather all possible evidence before making a decision simply isn't an option.

He says he'd recommend the scheme to any scientist looking to expand their horizons. There have been difficulties, of course. He undertook his fellowship part-time, so he's had to juggle two jobs at different ends of the country - Durham and Sunbury-on-Thames. On top of family commitments, this has proved tiring and occasionally difficult. "I have sometimes found myself asking why BP couldn't be based somewhere in Yorkshire," he admits.

These are minor objections, though. "There are immense benefits - I've gained huge insight into parts of the world I've never been able to study before. And it's been incredibly invigorating to take a break from the cycle of lectures, exam marking and teaching," says McCaffrey.

"Most people go off on sabbatical and write a book or something," he continues. "I've acquired a huge new pile of knowledge, and it should improve my teaching and research for years to come."

Dr Ken McCaffrey is a reader in the Department of Earth Sciences at Durham University.