The UK’s Heritage Oil has started a four-month drilling programme on its Miran West 2 well in Kurdistan, marking the first stage in its attempt to unlock up to 4 billion barrels of oil reserves in the overall Miran structure.

Heritage says the Miran West 2 well will appraise oil encountered in the Miran West 1 discovery well, while minimising the risk of formation damage.

The Miran structure contains a western and eastern section. Testing of the Miran West 1 well finished in August 2009, with oil flowing at a rate of 3,640 barrels a day.

Heritage is the operator and 75 per cent stakeholder in the Miran licence. Turkey’s Genel Energy International owns 25 per cent.

On 23 November, Heritage cancelled its proposed merger with Genel which would have created the largest oil exploration firm working in the Kurdistan region of Iraq.

Heritage says the deal was cancelled because of concerns over payment mechanisms in Kurdistan and the sale of its two oil blocks in Uganda to Italian oil major Eni.