London-listed Enquest posted a rise in profits for 2012 as lower expenses helped offset a fall in revenue.

The company posted an after tax profit of $259.7 million, up 90.8% compared to the $136.1 million profit booked in 2011.

EnQuest mainly attributed the rise in profits to a reduction in income tax expense, with the company booking a tax charge for the year of $126.4 million.

This represented an effective tax rate of 33%, compared to 64% the previous year, with the company saying the decrease was mainly due to the benefit provided by leasing arrangements, the increase in the ring fence expenditure supplement and prior year deferred tax adjustments.

The company also booked a $44 million decrease in cost of sales in 2012, to $448.2 million, which is said partly reflected a $39 million change in the lifting position and also a reduction in the absolute level of operating costs.

These factors helped offset a 5% dip revenue to $889.5 million on the back of an expected slump in production.

Output during the year averaged 22,802 barrels of oil equivalent per day, down from an average of 23,698 boepd in 2011.

The fall in output was partly due to the decline in production from the S5 well on the Dons and Conrie fields, as well as natural decline from the Broom field in the North Sea.

This was partially offset by an increase in production at the Thistle and Deveron fields, partly due to more reliable power and enhanced water injection rates as well as a number of new wells coming online during the year.

EnQuest’s average production guidance for 2013 is a range of between 22,000 and 27,000 boepd, with first oil from the Alma and Galia development expected in the fourth quarter of the year, while new wells at the Don Southwest and Thistle fields, as well as one well coming back on stream as a result of a workover on the Heather field, will also add to production.

In total the company is planning to complete 12 wells in 2013, including three new exploration and appraisal wells.

Capital expenditure this year is expected to amount to roughly $750 million, with about $350 million to be invested in the Alma and Galia development and another $75 million earmarked for pre-development expenditure for the Kraken development prior to submission of the field development plan.