Looking below the surface
20 Nov 2001
Conoco has been awarded the first in a series of pending US patents for a technique that is expected to improve exploration results in challenging areas like the sub-salt province of the Gulf of Mexico.
Geophysical experts in Conoco's Seismic Imaging Technology Center (SITC) in Ponca City, OK developed the patent, 'Method for Gravity and Magnetic Data Inversion Using Vector and Tensor Data,' over several years. Conoco says the technique has been applied with impressive results to challenging areas in the Gulf of Mexico and the UK's Atlantic Margin.
'We first developed the technique for the purpose of seeing below the large salt bodies that exist in the Gulf of Mexico,' said Dr. Alan R. Huffman, Conoco's Seismic Imaging Technology Center manager. 'These salt bodies can often make it difficult to see below the salt, even with high-quality 3D seismic data.'
The method was later applied to similar challenges caused by lava flows in the Atlantic deepwater provinces in the UK, and to several other international exploration plays where seismic data alone was not sufficient to explore for oil and natural gas.
'This method allowed our explorers to accurately delineate the base of a salt body in the Gulf Coast region that seismic data alone could not resolve. This resulted in better placement of a sub-salt exploratory well, and led to a discovery in the Green Canyon area of the Gulf of Mexico,' Huffman added.
Conoco's first application of the new method involved use of conventional gravitational and magnetic data, before using more advanced, full tensor gravity gradiometry (FTG) methods.
FTG methods were developed by the US Navy and later licensed to Bell Geospace Corporation for use in the petroleum industry.
The Conoco patent provides broad protection for the company's proprietary technology, including the use of all types of gravity and magnetic data and application to a broad range of exploration problems.
The method permits gravity, magnetic and FTG data to be integrated with Conoco's other technologies in depth imaging, pore pressure prediction, and seismic analysis to solve complex problems in the most difficult exploration areas where seismic data alone cannot determine what is in the subsurface.
