Oslo-listed Rocksource says May 2009 production from its US subsidiaries averaged 1,540 boepd (barrels of oil equivalent per day) - a hefty fall in output caused by technical difficulties - and the group warned of a rough patch in the immediate future concerning production levels.
The latest production figure compares to the April 2009 production of 1,675 boepd and 2,491 boepd in May 2008, Rocksource said.
"Production in the second half of May was negatively influenced by two of the most productive wells experiencing technical problems," the company said in a statement.
During an additional completion in the Lazy M2 well, the perforating tool was lost in the hole and has since been successfully retrieved.
The well is currently being swabbed for water and is expected to come back on production in the first half of June.
The Morian 6 well has also experienced problems due to corroding of the production tubing and has been producing at a curtailed rate.
New tubing
New tubing is planned to be installed in the first half of June and the well is expected to come back on full production later in June.
Rocksource had further bleak news on the production side.
It said that the higher rate early wells in the New Ace/Drews Landing field were in natural decline.
"When technical problems occur, as in the second half of May, there is therefore very limited scope to mitigate these by increasing production from other wells," the company said.
"The monthly production is therefore likely to vary more than in the past."
Production from the more recent wells had not yet established steady production levels but this would occur over the next month or two, according to the group.
"Rocksource will review the annual production forecast and total recovery from the fields when these steady production levels have been established."