The state-owned behemoth has bought Trican Well Service LLC for an undisclosed sum, it said on Friday.
Trican later disclosed the purchase price was US$140 million.
Trican in Russia specialises in pressure pumping and services geared towards the enhancement of production in conventional oil and gas plays.
The deal is set to close on or before 20 August.
“The implementation of the signed agreements will allow Rosneft to increase economical and production efficiency in the area oil recovery increase, downhole operations and wells' cementing,” Moscow-based Rosneft said.
“Increasing
