__________ is natural gas that is found trapped within shale formations. It has become an increasingly important source of natural gas in the United States since the start of this century. A: Methane B: Shale gas C: Coal gas

The BEST holding ground for conventional anchors is ___ . A: sand B: very soft mud C: shale D: ock

中国大学MOOC: Much of the new gas is coming from what were once called “unconventional” sources, such as the shale gas.

The role and position of unconventional oil and gas resources in global oil and gas production are becoming more and more important. Which of the following are unconventional oil and gas resources? A: Tight rock oil and gas B: Mud shale oil and gas C: Coalbed methane D: Oil shale E: Oil sands F: Natural gas hydrate

Much of the new gas is coming from what were once called “unconventional” sources, such as the shale gas. A: irregular B: unusual C: indifferent D: non-traditional