info@businessghana.com
Seismic exploration is the only method that currently makes it possible to look inside the Earth to a depth of up to 15 km without drilling, and to obtain detailed three-dimensional images of geological layers. Using special equipment, scientists generate seismic waves on the Earth’s surface that penetrate deep into the geological environment and are reflected from layers with gas accumulations, which are recorded by seismic sensors. Following the processing of the information gathered, three-dimensional images are obtained, showing potential areas of gas accumulation.
Seismic exploration plays an important role in the development of gas fields with a high degree of depletion, in which hydraulic fracturing is often used to intensify production: water mixed with various chemicals is injected into the rock through microcracks under high pressure, and this mixture squeezes out the desired resources. It is important to know the direction of these cracks during the production process, since it is much more efficient to pump out hydrocarbons along the cracks than across them.
“We proposed, and provided justification for, a special method for analysing seismic data to determine the azimuth of natural cracks. Put very simply, it works like this: the directional formation of cracks in rocks causes so-called azimuthal anisotropy: a seismic wave propagates along the cracks faster than in the transverse direction. By analysing the arrival velocities of seismic waves in different directions using special methods, we can determine the orientation of the cracks,” Vyacheslav Polovkov, Director of the Advanced Engineering School of St. Petersburg State University, is quoted as saying by St. Petersburg State University.
