Shale gas extraction: how the process works

Vast reserves of natural gas can be found trapped in densely packed rock such as shale. Here is how it is reached

1,500m-6,000m

Steel casing surrounded

with special cement

Shale rock

Bore

2. Bore is lined with steel and cement and small holes made in the casing and into the shale

1. A vertical hole is drilled into the shale rock. The drill can run horizontally once it enters the shale layer

Sand is used to

keep fissures open

3. High-pressure water, sand and various chemicals are pumped into

the bore. The holes

in the horizontal section allow water to enter and fracture the shale

4. Gas in the rock

is forced into the

bore and flows

to the surface

1,500m-6,000m

Sand is used to

keep fissures open

Steel casing surrounded

with special cement

Shale rock

Bore

2. Bore is lined with steel and cement and small holes made in the casing and into the shale

3. High-pressure water, sand and various chemicals are pumped into

the bore. The holes

in the horizontal section allow water to enter and fracture the shale

1. A vertical hole is drilled into the shale rock. The drill can run horizontally once it enters the shale layer

4. Gas in the rock

is forced into the

bore and flows

to the surface