The Rough Guide to Gas

Test Drilling

Selina SeagullIf the scientists think they have found the correct rock shapes, they have to start drilling into the rock to see if they are right.


Firstly, a drill is used to bring samples of rock to the surface. These are called rock cores, and allow the types of rock to be identified. The rock cores are about 10cm wide, but very, very long. They have to be broken into short sections and labelled carefully.

Test well

a test rig

If the cores show the right types of rock are present, a test well will be drilled to see if there really is gas or oil in the rocks. This is the only way to be absolutely sure!

Sometimes there is no gas present, even though the rocks are the right type. Sometimes there is gas, but not enough to be worth the cost of getting it out.

The scientists are getting very good at this: for every 4 possible places where they think gas may be found, 3 turn out to have enough gas in them.

Now let's find out what you've understood - try the quiz...