They drill down to the shale, then go sideways and inject high-pressure water, sand or other material into the rock.

VOA: special.2009.10.23

Wrev w reversible. in this case here let's see this is it's a pressure is going down.

曲线下的面积，可逆过程的功,这个过程中。

麻省理工公开课 - 热力学与动力学课程节选

So the force that you're pushing down on here is the external pressure times the area.

或者压缩功的概念,在活塞上施加压力。

麻省理工公开课 - 热力学与动力学课程节选

Like BP, integrated European oil supermajors Total S.A. and Royal Dutch Shell have been weighted down under the pressure, down 16.5 percent and 12 percent, respectively.

FORBES: Deepwater Euro Mess: Don't Touch BP, Call The COP

Wallace forced another save with yet another long-range strike and Parkin went down under pressure while chasing the rebound but Preston's penalty appeals were turned down.

BBC: Preston 1-5 Tottenham

However, with the pump shut down a pressure increase was seen in the standpipe (SPP).

WSJ: The Oil Disaster Is About Human, Not System, Failure