From Wiki:
In 2014, US government sanctions resulted in Exxon having until September 26 to discontinue its operations in the Kara Sea.[2]
http://en.wikipedia.org/wiki/Kara_Sea
Washington extended sanctions on Russia last week over its aggression in Ukraine. The new measures seek to stop billions of dollars worth of cooperation between Western and Russian energy companies on oil drilling in Russia’s Arctic, in Siberia and offshore. Companies have until Sept. 26 to stop the work.
The U.S. Treasury Department gave Exxon a short extension to wind down a rig, beyond the 14 days outlined in the sanctions, the Texas-based oil major said on Friday without elaborating.
“Following the short time extension, the license is non-renewable and no further work is permitted,” Exxon spokesman Richard Keil told Reuters.
UPDATE 4-Exxon winds down drilling as U.S. sanctions hit Russia
http://www.reuters.com/article/2014/09/19/usa-exxon-russia-idUSL1N0RK1HA20140919
Exxon is already out, but it doesn’t change much. If they start pumping from there, the price of oil will drop to unsustainable for Russian economy level - suicide by overproduction of sorts. They entered a vicious circle: in order to support their ambitions, they must sell more hydrocarbons, yet by selling more they are dropping prices.