What Is Seismic Imaging Technology?
Seismic imaging is a tool that bounces sound waves off underground rock structures to reveal possible oil- and gas-bearing formations. Seismologists use ultra-sensitive microphones to record the sound waves' echoes reflecting on the structures within the earth. By studying the echoes, petroleum geologists seek to calculate the depth and outlines of underground formations. This analysis may help them identify oil- and gas-bearing reservoirs hidden beneath the earth's surface.
What Are the Benefits?
Energy companies have been using seismic imaging for about 80 years. However, ongoing technological developments have added precision and effectiveness to geologists' efforts to find oil and gas beneath the surface.
Sophisticated 3-D imaging creates high-definition pictures of subsurface geology. The result is similar to an X-ray scan that covers thousands of square miles and extends 10 miles (16 km) into the earth. Software to analyze these images continues to improve, including some programs that are able to mimic the way the human brain's neural network processes information. And more advanced computers now allow scientists to analyze the data within days rather than months, speeding the discovery and ultimate production of oil and gas.
What Chevron Is Doing
Chevron's proprietary seismic imaging technology has helped the company achieve a superior exploration discovery rate of more than 45 percent from 2001 through 2006. This technology allows Chevron scientists to see beneath the earth's surface more clearly and accurately than ever before. Using these proprietary tools, researchers have been able to find oil and gas in reservoirs underneath thick sheets of salt in the deepwater portion of the Gulf of Mexico.
Analyzing seismic data has become faster and more efficient with the development of velocity models, which contain clues about the speed with which the seismic waves travel within various rock layers. Recorded echoes produce a vast amount of data, and scientists are able to remove much of the "noise" to determine the vibrations that relate to oil and gas reservoirs.
The next step involves running the model through Chevron's powerful cluster computers, which process and analyze the data to form a 3-D image. Accuracy is essential: the better the images, the fewer wells that must be drilled to confirm a discovery and move toward production.
Leading the Way in Seismic Imaging
In 1982, Chevron became one of the first energy companies to use a supercomputer and quickly adopted more advanced parallel computers that sped seismic results and reduced costs exponentially. Fifteen years later, we introduced the industry's first 3-D visualization centers. And in 1998, Chevron developed its first VizCenter, which offered a multilayered deep-earth panorama of seismic and well data, cutting review time from days to hours and at a fraction of the cost. Since then, Chevron has continually built upon this capability with ever more powerful computers and faster analysis.
Seismic imaging also helps well-site teams optimize drilling before it actually starts. Chevron scientists estimate that 85 percent of well problems can be traced back to poor subsurface modeling and associated well planning. A precise seismic model can ensure major savings during this phase of operations.