Seismic waves, the same tool that is used to study earthquakes, tend to be frequently used for searching for oil and natural gas deep down the surface of the earth. These waves of energy move through the earth, much like how sound waves move through the air.
Paul Favret mentions that in oil and gas exploration, seismic waves tend to be sent deep into the earth and are subsequently allowed to bounce back. Geophysicists record these waves to learn about the oil and gas reservoirs that are located beneath the surface of the earth.
Paul Favret mentions how seismic technologies are used oil and gas industry
3-D seismic surveys have significantly lowered the cost associated with oil and gas exploration. It allows the exploration of reserves not locatable by other means, thereby revolutionizing the industry. A seismic survey is conducted by creating a shock wave or a seismic wave on the surface of the ground along a predetermined line. This wave travels into the earth, is reflected by subsurface formations, and returns to the surface where it is recorded by receivers called geophones. By analyzing the time it takes for the seismic waves to reflect off of subsurface formations and return to the surface, geophysicists can map subsurface anomalies and formations, in order to predict where oil or gas might be trapped in sufficient quantities for exploration activities. Prior to the development of 3-D seismic surveys, these surveys were conducted along a single line on the ground, and their analysis created a 2D picture akin to a slice through the earth beneath that line.
In the opinion of Paul Favret, when it comes to oil and gas exploration, seismic surveys are widely used to map geological structures beneath the earth’s surface or beneath the seabed. Reflection seismology is used during the onshore exploration and involves sending seismic waves underground. As these waves bounce back, they get picked up by surface sensors, providing crucial information about the geophysical properties of potential oil reserves. When a person uses seismic waves in the study of earthquakes, the earthquakes themselves are the source of energy or waves. But while using reflection seismology for oil and gas exploration, one needs to deploy some type of energy source on the surface of the earth and then distribute an appropriate number of seismic sensors that would record the waves that are reflected back.
When it comes to offshore exploration, seismic airguns are widely used to release a chamber of compressed air into the water. This creates a pressure wave that penetrates the seabed, illuminates the geological structures, and ultimately reflects this information back through the water, where it is detected by hydrophone cables. Determining the geological structure of a potential oil reserve is vital for locating promising oil deposits and planning the drilling operations in an effective manner.
Seismic data holds a lot of valuable information. Not only does it help in identifying reserves, but it also offers vital information on fracture density and orientation that is important for accurate drilling and well placement. Seismic surveys also tend to limit the environmental impact of oil and gas exploration by determining the need for further drilling.