Oil and gas group EnQuest's share price took a hit on Tuesday morning after the firm reported a drop in first-half profits and said that full-year production would be at the lower end of guidance.The company, which is largely focused on the UK Continental Shelf as well as interests in Malaysia, now expects to hit the lower half of the previous production forecast range of 22,000-27,000 barrels of oil equivalents per day (boepd) by the end of the year. This is mainly due to the new Alma/Galia field in the North Sea now not expected to produce first oil until the first quarter of 2014 instead of this year. Initial net production from Alma/Galia is predicted to be 13,000 boepd and is hoped to deliver a "substantial increase" to EnQuest's output next year.Production in the first six months of the year averaged 21,455 boepd, up 5.9% on the year before, helping revenue to 3.6% to $455.9m."EnQuest is delivering sustainable growth through increasing production and increasing reserves, and our assets are performing well," said Chief Executive Amjad Bseisu.However, profit before tax and finance costs slumped 13.2% to $167.2m owing mainly to a fall in the realised oil price during the period (by 2.6% to $108.70 a barrel) and an increase in operating costs.The stock was down 2.9% at 123.03p in early trading on Tuesday.BC