DRILLING FOR OIL

How machines and people work together on an oil rig

- AILSA HARVEY

Since the 1800s, large drilling platforms called rigs have been used to create holes in the ground. The purpose of these is to access and extract oil called petroleum, also known as crude oil, which can be used as an energy source for a range of purposes. For example, petroleum is converted into gasoline and diesel to fuel vehicles, heating oil to power boilers in home heating, jet fuel and propane for heating and cooking.

Oil is found underground in small pores between the rock. These oil-rich areas are called reservoirs and are the target area for oil rig activity. An oil rig is a large structure equipped with the facilities needed to drill into the ground and access oil reservoirs. These can be based both onshore and offshore. Onshore rigs are used to drill into Earth’s surface, while offshore rigs drill into the seabed beneath the ocean.

Before an oil rig is built and begins drilling into our planet’s surface, geologists need to analyse the ground to know how large a reservoir is, how many pores there are and how fast the oil will move between pores when a hole is drilled to release it. To work out the conditions of the rock and oil, scientists direct sound waves into the rock using special equipment called geophones. These devices record how fast the sound waves travel through the rock, and scientists analyse this data to find the best reservoirs.