In a lava over oil prediction system

Researchers at

are developing a software modelling system that could unearth major potential new oil fields hidden under ancient lava on the sea bed off the Shetland Isles, opening up an entire new area of production for petroleum engineers to exploit.

The Faroe-Shetland basin is one of the world's largest lava fields, situated under the sea surface in what was once a narrow continental seaway. However, such lava fields have historically proven to be a serious obstacle to oil exploration below and within the lavas. In this area, a 3km thick layer of lava covering over a 300km² area acts as a seal, trapping sand and mud – the sediment where oil can be found – between and beneath its flows.

Researchers from Aberdeen's College of Physical Sciences are taking part in a two year £600,000 project aimed at developing a system that can predict the conditions and location of oil below this layer of lava in a way which has never before been trialled.

The first wells in the region were drilled in 2001 and showed experts that the geographical area contained significant resources.

However, when applied there, traditional seismic techniques employed for oil exploration in areas such as the Gulf of Mexico or the North Sea give readings that are hard to interpret, meaning it is difficult to predict where oil lies. Owing to the cost of drilling, the best areas to do this must be pinpointed. The new technology will allow mapping of sediments between the lava flows and so the identification of oil reservoirs.

The initial research being undertaken by the university could have huge implications for the future of the British oil industry by introducing a significant new field and revitalising production in northern Scotland. Although drilling through basalt presents some significant engineering challenges and so may be more expensive than tapping reserves elsewhere, with the present increase in the price of oil, exploiting such resources is becoming increasingly more economically viable.

‘The area is as big as the north and central North Sea but there are only six wells there at the moment. The system will allow the integration of geological data,’ said Dr David Jolley, senior lecturer at Aberdeen’s School of Geosciences. ‘The actual acquisition of geophysical data from basalt is getting better and better, but the problem is that people don’t know how to interpret it and what the environment is like there as people don’t usually go looking for oil under lava piles. Using seismic equipment it is currently possible to see about 3km down. We will be using 3G physics and combining it with environmental data about microfossils and sediments, as well as looking at the geochemical data. By combining this with geophysical data and information from available wells in the area we will be able to model potential reservoirs. We think that with this, we will be able to be quite specific about drilling targets.’

Once the technology has been developed it will be used for exploration of the western part of the Faroe – Shetland basin for the first time, a stretch of water that has lain undisturbed for 40 million years.

‘We currently know as much about this particular area of the subsea as we did about the North Sea in the mid 1970's,’ said Dr Jolley. ‘There is minimal knowledge of the fluids there and how they will behave, though there looks to be a fair degree of reservoir compartmentalisation. The revolutionary technology which we will utilise may enable this promising region to become an extremely prosperous part of the oil and gas industry in the future. Although the exploration will be taking place on the Faroese side of the basin, Aberdeen is ideally placed to provide the infrastructure and support for getting any resources to market. There are definite spin off benefits for the UK.’

Aberdeen University is currently working with Chevron as well as Statoil and ENI. This research is being funded by the Sindri Group as part of the 2008 Sindri Round funding programme. The Sindri group aims to carry out joint projects of relevance to the future investigation of the Faroese continental shelf.

As well as helping to locate reserves, the team has also been working with Smiths to develop new drill bits that will be able to bore most efficiently through the lava cap and the geological conditions that they are likely to meet once below it.