How do Scientists Discover Oil? Part 2

Once geologists have found an area they think may contain oil reservoirs, they turn to several different tools and techniques to ascertain if there really is oil hidden away in the ground below.

There are numerous pieces of equipment that can be used in the process of looking for oil.

One tactic is to not look but test for the smell of hydrocarbons. These specialized detectors, informally known as sniffers, use ultra-sensitive electronic noses to detect indicators of the presence of hydrocarbons.

Another technique is to deploy advance seismic equipment. These machines create special shock waves that are sent down through the Earth’s crust, passing through multiple layers of rock. The waves reflect back from the materials they pass through and are turned into information that is sent back to the seismological equipment for analysis.

These waves are generated through a handful of methods: through a blast from a compressed air gun that directs air pulses into the water for off-land exploration; a large thumper truck that pounds heavy plates into the Earth; and, the most old-fashioned way, explosives which are detonated after being drilled into the ground or thrown overboard. The trick with the reflected shock waves is that they travel along at different speeds depending on the type of rock they pass through, giving seismologists raw data to interpret as they look for indicators of oil and gas.

Another methodis the use of magnetometers. These instruments measure the magnet field of the ground beneath them. Geological formations in rocks that may contain oil deposits give off very low magnetic readings. These magnetic surveys are often done by flying over target areas to get a general indicator of possible oil deposits. Then, as a follow-up they’re deployed on the ground to get a more accurate reading of anomalies discovered by the air sweep.

Then there is to check the electrical resistance of the ground. Probes are inserted into the ground in a targeted area, and a current is then passed between them. The level of electrical resistance is used to decipher whether there may be oil deposits. This is because rocks that are porous – and thus more likely to contain oil – have a stronger resistance than non-porous rock formations.