WORK is under way in the quest to find oil under a huge swathe of Dorset.

A seismic survey is currently being carried out across a 75 square kilometre area of the county to test for possible reservoirs under the surface.

Tesla Exploration International Ltd is undertaking the work on behalf of Egdon Resources UK Ltd and is using four vehicles to send shockwaves down into the ground.

The reflections from the waves are then picked up by a series of receivers placed along north to south lines in a bid to create an image of the geology underneath the surface.

Egdon’s exploration director Jerry Field said the work, which is expected to last until the middle of October, was labour intensive and involved machines capable of exerting 60,000 pounds of force.

Anyone living in areas affected by the surveys will have information sent to them and the machines are fitted with limiters that prevent any excessive disturbance to residents.

Although some residents have reported feeling the shaking, Mr Field said everything possible is done to keep the impact to a minimum.

He said: “Wherever possible we go in the places where we will have the least impact on other people and not cause any distress or damage.

“We try and get in and out without being any hassle to anybody.”

Mr Field stressed that there are no plans to hydraulically fracture rocks, known as fracking, in the area.

When all the data is collected in the coming weeks it will then be analysed at a processing centre.

The aim is then to create a three-dimensional map of the Earth’s sub-structure to identify any possible commercially-viable oil reservoirs.

If any sites are identified a series of applications would need to be made and permissions granted before a test well could be drilled.

Mr Field said even if it got to that stage there would still be only around a one in three chance of finding a commercially-viable deposit and there would again need to be further applications for a working oilfield to come into effect.

He said that, while there was always an element of chance with oil surveying, the surrounding area was known to be relatively oil rich, most notably at Wytch Farm in Purbeck.

Mr Field said: “We know this area has the correct geology for there to be petroleum deposits in the rocks.”