Geophysics graduate blazes new trails for UH in seismic exploration

(2005-07-20)

Innovations in seismic technology for oil and gas exploration have earned top international honors for a recent University of Houston Ph.D. graduate in geophysics.

Simon A. Shaw, a 2005 UH graduate from the department of geosciences, will receive the J. Clarence Karcher Award from the Society of Exploration Geophysicists (SEG). The award honors Karcher's contribution to exploration geophysics and is given in recognition of significant contributions by a young geophysicist of outstanding abilities under the age of 35. Shaw is the first UH graduate to receive this award, which officially will be presented during the SEG International Conference and Meeting in Houston Nov. 6-11.

"The Karcher is an extremely high honor, with a maximum of three given each year internationally by the SEG," said Cullen Distinguished Professor of Physics Arthur B. Weglein, Shaw's adviser at UH. "Shaw is an outstanding, courageous and gifted scientist."

Shaw has broken ground with a new methodology that is directly aimed at one of the most serious impediments to seismic imaging and processing – the inability to adequately define the values and boundaries when complex geologic formations are above potential petroleum targets. Shaw's insight and analysis led to an imaging series algorithm with the potential to provide accurate depth imaging beneath a complex overburden, such as salt, basalt and karsted sediments, that is not limited by the traditional requirement for adequate velocity information.

"This research project appealed to me because it represented an entirely novel approach to solving the problem of imaging beneath an unknown medium, even one as complex as can occur in sub-salt plays," Shaw said. "I feel fortunate to have been given the opportunity to contribute to such an exciting and ambitious project for my Ph.D."

According to Shaw, his embryonic algorithm is now being generalized for eventual field trials and is designed to solve the problem of developing an image to find oil and gas where current imaging methods fail.

"There is a conundrum in current imaging algorithms, which is that we assume we can provide the speed at which waves travel through the Earth, also known as the velocity model," Shaw said. "Even our best velocity estimation techniques can fail to produce an adequate velocity model, especially in complex geological environments. Using current imaging technology, and without an adequate velocity model, we can't map the subsurface geology or determine the location of reservoirs."

Unlike current imaging theory, Shaw's research began with the assumption that under some circumstances the velocity model is not able to adequately be determined. He posed the question of how to then accurately image reflectors beneath an unknown medium as complex as can occur in the Earth's subsurface. The answer that Shaw and his colleagues developed is a series of non-linear computations that converge to an accurate image of the subsurface while only using an approximate velocity model.

"His research into seismic imaging, using the inverse scattering series, avoids the need for earth property information above a subsurface target in order to determine its potential as a hydrocarbon reservoir," Weglein said. "His pioneering research contribution spearheaded our sub-salt imaging campaign, helping to develop and progress a solution to the problem of extracting information about currently inaccessible targets. His efforts derive from the inverse scattering series, a comprehensive theory that earlier contributed to similar capability for removing multiples, a form of coherent noise in seismic data."

Under Weglein's guidance, three of his former students – Paulo Carvalho of Petrobras, Fernanda Araújo of ExxonMobil, and Ken Matson of BP who is also an adjunct physics professor at UH – worked in a team that included Bob Stolt of ConocoPhillips to pioneer the research into removing multiples. Matson and Araújo, graduates of the University of British Columbia and Federal University of Bahia in Brazil, also received Karcher Awards in 1999 and 2000, respectively. According to Weglein, Shaw was the lead member of the research team on the project that addressed the processing of primaries, with other key contributors including Matson, UH Adjunct Physics Professors Doug Foster of ConocoPhillips and Bob Keys of Exxon Mobil, as well as UH graduate students Fang Liu and Haiyan Zhang and UH Research Assistant Professors Bogdan Nita and Kristopher Innanen.

"Shaw's creative and resolute doctoral research efforts to develop, analyze and test a new velocity-independent, depth-accurate imaging algorithm will be viewed in seismic exploration history as an important and critical contribution," Weglein said. "This is a milestone in providing a new vision and capability to information extraction from seismic data, aimed at locating and delineating targets beneath highly complex heterogeneous overburdens and rapidly variable boundaries that are beyond all current velocity methods' ability to adequately define. Shaw's aim is to make currently inaccessible or ill-defined targets accessible. These efforts are intended to bring the same level of effectiveness and impact to signal extraction that earlier methods, derived from the same comprehensive theory, brought to the removal of multiples."

Shaw graduated from UH in May 2005 with his doctorate in geophysics from the department of geosciences. Prior to UH, he received his master's degree in marine studies from the University of Delaware and bachelor's degree in mechanical engineering from Imperial College in London. After earning his Ph.D., Shaw joined ConocoPhillips in Houston as a research geophysicist in the subsurface technology department. He was a ConocoPhillips fellow while at UH in the Mission-Oriented Seismic Research Program (M-OSRP), a petroleum industry supported educational and research consortium that mentors students in several degree programs including physics and geophysics.

M-OSRP addresses fundamental research problems with solutions that would have a significant positive impact on the ability to locate and produce hydrocarbons, developing scientific and technical leaders capable of advancing reliable prediction and reduced risk in the petroleum industry. One such significant issue in exploration and production seismology is locating and identifying petroleum targets beneath ill-defined geologic formations.

"Simon Shaw exemplifies the highest standard of scientific and personal integrity, professional accomplishment and true leadership," Weglein said. "He makes us all proud."


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Contact: Lisa Merkl
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