The London-listed explorer now expects annual average production from Shaikan to fall between 30,000 and 34,000 barrels per day of crude.
In early April it said it was aiming for a stable average of 36,000 bpd.
The lower estimate is due to a previously announced five-week suspension at the end of the first quarter.
The company said on Thursday that it expects output from the field to be between 36,000 and 40,000 bpd from now until the rest of the year.
Despite