“There has been no impact on any of our business activities in Russia to this point, nor has there been any discernible impact on the relationship” with Rosneft, he added.

The energy giants, in part, are wary of offending their partners in Russia. Several big Western companies have large existing investments and important joint ventures in Russia that they want to protect from a government that is sometimes seen as fickle on property rights.

Image Vladimir Putin shaking hands with Ben van Beurden, right, Shell’s chief executive, in Moscow. Credit... Maxim Shipenkov/European Pressphoto Agency

Exxon has a wide-ranging relationship with Rosneft, including existing oil production off Sakhalin Island in eastern Russia. BP has a nearly 20 percent stake in the Russian company. In all, Western energy companies have invested an estimated $35 billion in Russia.

The future opportunities could prove even more valuable.

The recent agreements signed by BP, Exxon and Total will help Russia push its petroleum industry into the high-tech field of extracting oil from shale. The big Western companies mostly arrived late to the shale boom in the United States as smaller companies took the lead, and Russia, which geologists estimate has the greatest potential for shale outside of the United States, represents a chance to gain an early edge. In the last few years, shale formations like the Bakken in North Dakota and the Eagle Ford in Texas have added three million barrels a day to the oil output of the United States.

Exxon is also gaining access to offshore drilling sites in the Russian Arctic Ocean, while the waters off Alaska remain tied up in lawsuits and regulation. Exxon and Rosneft plan to drill the first exploratory well this summer in the Kara Sea, one of the shallow extensions of the Arctic Ocean north of Russia, where there could be enormous oil and gas resources.

And Exxon is joining with Rosneft to explore the Bazhenov shale formation in western Siberia, an area that has already produced tens of billions of barrels of oil through conventional drilling methods — a good sign for shale drillers, according to geologists. “Compared to other opportunities worldwide, Russia is certainly one of the most promising,” said John Webb, an analyst at the market research firm IHS who specializes in Russian energy.