Petroneft, the oil and gas exploration firm , gave an update on Monday on drillling at its two wells in western Siberia, in which the Dublin-headquartered firm has a 50 per cent interest.

Both horizontal wells were completed in the Tungolskoye fields (T-501 and T-505), and the log data “suggests that the oil pay is of better quality than that encountered in earlier wells”. However, both wells experienced flow problems when brought online, and Petroneft says this is likely due to some formation damage in the horizontal section caused during the drilling process

Dennis Francis, chief executive of PetroNeft Resources said: "We are generally pleased with our ability to drill horizontal wells at Tungolskoye which will be a key element of optimising recovery of existing reserves and successful execution of new developments in Licence 61. While the initial results of the last two horizontal wells have been disappointing, we believe the results can be improved at minimal costs with the planned workovers and acid treatment of the reservoir".

Petroneft said that production has increased by over 40 per cent in 2015 but that this is below expectations because of the delays in bringing the Tungolskoye T-501 and T-505 wells into production and the greater than expected declines from the Arbuzovskoye wells drilled earlier this year.

“We are implementing workover programmes designed to address these issues and expect to see production begin to improve shortly,” Petroneft said.

Petroneft also gave an update on the new wells drilled at Arbuzovskoye earlier this year, noting that production has declined more than expected. As such, it is planning a batch workover of these wells in January 2016.