I WOULD like to correct the errors in your fracking story of Friday, September 11.

First, the the area to the north of Andover has previously been licensed for hydrocarbon exploration and drilled in 1986 (Enham Alamein) and Hurstbourne Tarrant in 1998.

The licenses were returned and have been recycled for future exploration by the government.

Both wells were abandoned dry, with no sign of hydrocarbons.

In our area the discovered oil fields are confined to the geological Wessex basin to the southwest (containing the Wytch Farm oilfield) and the Weald basin to the east containing the Goodworth, Stockbridge and Humbly Grove oil fields and the minor gas field at Godley Briggs.

The two wells drilled north of Andover found the oilprone Kimmeridge shale, but it had not been buried deep enough to release its oil and the target underlying Middle Jurassic oolite limestone reservoir contained only water.

Indeed, the source rock for the Wessex and Weald geological basins is the marine Lower Jurassic Lias shales, which due to being laid down in a marine environment means that it produces largely oil and very little gas.

Fracking it would be useless!

If new exploration is undertaken then new geophysical surveys would still have to obtained and evaluated before any assessment of further drilling is considered.

The two dry wells in the area of your map would not bode well for future success.

Then, if oil was found in the Jurassic limestones it would still not be recovered by hydraulic fracturing, but probably by having acid put down the well to dissolve some of the limestone to increase the connectivity of the holes in it so the oil could flow into the well more efficiently.

As the acid dissolves the limestone it is neutralised and is therefore not harming the underground environment.

Talking up a fracking scare story is not only disingenuous but inconsistent with the underlying geology.

The risk of economic success will also be important to any potential bids on the acreage.

To get gas from hydraulic fracking you must find a source shale that contains large amounts of plant (not marine) matter and that is why the main fracking areas will be associated in areas where coals have been discovered.

Dr David Ellis, Recently retired oil geologist, Hurstbourne Tarrant