Definition of seismics – how does a seismic measurement work?

In order to secure a future supply of energy from crude oil, natural gas or geothermal energy, the targeted search for oil, gas and geothermal deposits by means of seismic measurements is becoming more and more important.

The basic principle of seismic measurements

In seismic measurements, the ground is examined using sound waves to obtain a seismic echo. The reflection or refraction of sound waves at the boundary surfaces of different layers of rock allows geological formations to be identified.

Interpreting the sound waves recorded by geophones makes it possible to determine the size and depth of crude oil and natural gas deposits. Seismics has established itself as a key process for the exploration of crude oil, natural gas and geothermal deposits.

Seismic procedures and investigations for the exploration of oil and gas fields as well as geothermal energy

The onshore exploration for deposits with seismics is generally conducted using shot seismics or vibro-trucks. In offshore seismics, special ships equipped with air guns are used to explore oil and gas fields under the ocean with air pressure waves. Seismic procedures are differentiated into 2D seismics and 3D seismics.

Shot seismics

For shot seismics, small charges are detonated in bore holes with a depth of 20 to 30 metres. By evaluating the sound waves using geophones, conclusions can then be drawn regarding oil, gas or geothermal deposits.

Seismic truck measurements

In seismic measurements using seismic trucks or vibro-trucks, the sound waves in an area are triggered by vibrators mounted on trucks. Measurements using vibro-seismics are very well suited for developed areas since the vibrations are less severe compared to shot seismics.

2D seismics

Measurements using 2D seismics are frequently used in the early exploration phase in order to draw conclusions about crude oil, natural gas or geothermal deposits based on a 2-dimensional image of geological formations.

3D seismics

In 3D seismics, several geophones and beacons arranged in a grid formation are distributed across an area. Compared to 2D seismics, 3D seismics makes it possible to determine the location of oil and gas deposits with far greater accuracy. 3D seismic measurements have been used for exploration in Germany for years in order to develop geothermal, oil and gas deposits.

Specialised service providers for seismic measurements

Specialised companies are often commissioned to take seismic measurements. For project implementation and monitoring, experienced experts are often engaged as project managers and outsourcing partners.