Foreign companies have invested more than 26 billion U.S. dollars in tight oil and shale gas development in the United States since 2008, according to a latest government analysis.

In one recent example, Chinese company Sinochem inked a 1.7- billion-dollar joint venture deal to acquire a stake in the Wolfcamp shale play in West Texas, reported The Houston Chronicle newspaper on Tuesday, citing the analysis conducted and published by the U.S. Energy Information Administration (EIA).

Overall, investment in shale plays in the United States totaled 133.7 billion dollars between 2008 and 2012, according to the EIA.

Most of the recent joint venture deals with foreign companies involved liquids-rich areas, it noted.

Plays with a higher liquid-to-gas ratio are more attractive because of the higher value of hydrocarbons that have crude oil and petroleum liquids in addition to natural gas, the EIA said.

Both parties in the cooperation benefit from such deals, with U. S. companies getting financial support and their foreign partners gaining experience in horizontal drilling and hydraulic fracturing, which may be applicable to other regions, the agency added.