3-D Seismic Technology Locates Natural Gas In Fractured Reservoirs

In this cost-shared project, GeoSpectrum, Inc., of Midland, Texas, uses 3-D seismic to locate fractures in the earth that provide access to millions of cubic feet of untapped natural gas in four new wells—including one well that is now producing up to 2 million cubic feet per day.

"The key innovation in this project is the integration of technologies that map previously unseen fracture lineaments and perturbations in seismic data, and then target fracture "sweet spots" where multiple fractures intersect," said geophysicist Francis Toro, who manages the project for DOE’s National Energy Technology Laboratory.

The Energy Department awarded the contract in 1999 to spearhead the development of technologies and methods to locate known resources of natural gas contained within naturally fractured, tight reservoirs. Locating those fractures is important because they provide pathways for gas flow in rocks that have very low permeability. By drilling in those locations, greater supplies of natural gas can be accessed and recovered.

About 460 trillion cubic feet of natural gas—almost three times the amount of existing gas reserves nationwide—is estimated to exist nationwide in these low-permeability reservoirs. The key to producing this vast resource is to locate and drill areas where natural fractures improve the quality of these tight reservoirs.

To find natural fractures, GeoSpectrum, along with Burlington Resources and Huntington Energy, applied an innovative technology that combines seismic analysis, petrophysical analysis, and analysis of existing wells to identify potential fracture sweet spots, where gas is concentrated and able to flow to a well bore.

The successful demonstration shows that the technology can locate natural fractures in gas-bearing formations while reducing the risks associated with drilling in tight reservoirs. The ultimate benefit will be the location and recovery of vast new energy sources to meet increasing needs nationwide for clean-burning natural gas.