Dysfunctional oil wells at Sakhalin-2 are threatening to decrease production at the field in Russia's Far East and could be indicative of more serious problems.

The problems on Sakhalin-2 in the Piltun-Astokhskoye oil field were documented in a government report to the State Duma on the implementation of the production sharing agreement, a copy of which was obtained by Vedomosti.

According to the report, the wells are not functioning "due to the need to remove a significant amount of sand after a water breakthrough." This mishap prompted a shutdown of six of the 13 oil wells on the Astokhskoye section, where the Molikpaq Platform extracts oil.

The unexpected impediment diminished planned production by more than 20 percent over the first two quarters of this year. The report did not elucidate the amount expected.

It is possible they are referring to a loss of pressure, said an official at the Natural Resources Ministry. The situation is not common, he said. Until now, there have only been problems in one or two wells.

The depressurization may be caused by a breakthrough of ground water, said a member of a major oil holding company. This is something that happens during oil spills, he warned. The most recent case similar to this incident is the BP oil spill in the Gulf of Mexico.

There has not been an oil spill at the platform, said Ivan Chernyakhovsky, a spokesman for Sakhalin Energy, operator of Sakhalin-2. Despite the failure of the well's seal, he continued, "the release from a few of the wells was part of a planned process."

Sakhalin Energy exploits the Lunskoye gas field and Piltun-Astokhskoye oil field in the Sea of Okhotsk. Three platforms extract natural resources — Lunskloye-A with seven gas wells, Piltun-Astokhskoye operating eight oil wells and Molikpaq.

Last year Sakhalin Energy extracted 6.1 million tons of oil, while Molikpaq yielded 2.2 million tons. If all factors remain the same, Molikpaq will be short 440,000 tons of oil this year, and the production for the entire project will fall short 7 percent.