The Honors and Awards Committee recommended Paul Krail and Dwight Sukup for the Reginald Fessenden Award because of their pioneering work that showed the need for multi-azimuth acquisition in subsalt imaging. Their joint work at Texaco beginning in the 1980s included development of instrumentation to acquire multi-azimuth data and application of wave-equation imaging techniques to the resulting data for imaging beneath salt. Through modeling of synthetic data and actual fi eld results, they clearly demonstrated that superior images were obtained from using multi-azimuth data in 3D prestack depth migration.
Biography Citation for the Reginald Fessenden Award (2008)
Contributed Roberth H. Tathum
The Reginald Fessenden Award is certainly appropriate recognition of Paul Krail’s and Dwight Sukup’s contributions to the evolution of true 3D, or wide-azimuth, seismic technology. Their work has resulted in improved seismic imaging beneath salt canopies and in complex structural settings. Perhaps the most signifi cant aspect of this technological success, however, is the collaboration between Paul, Dwight, and others, with truly complementary areas of expertise: Paul Krail in acquisition, with experience as a party chief on early 3D (land) crews, designer of marine vessels and, significantly, offset VSP surveys; and Dwight Sukup, with a background as an applied mathematician developing and implementing flexible prestack depth migration schemes and algorithms compatible with varied geometrical complexities, including VSP and, ultimately, vertical cable technology.
The concept of the vertical cable evolved from a 1980s Texaco task force to address seismic imaging beneath salt, especially in deep water. Recognition of offset VSP geometries with offset sources at all azimuths led to the suggestion of a “VSP without the borehole.” Team members were familiar with marine instrument manufacturers who constructed anchored vertical hydrophone arrays for anti-submarine warfare applications. Modification of this technology to the seismic imaging application, including the cable with a hydrophone array suitable for seismic reflection imaging and a recording buoy mechanically decoupled from the cable and capable of the recording and storage requirements for seismic surveys, was a straightforward development.
The ultimate application of the vertical cable requires several cables anchored to the sea fl oor and a small source vessel shooting a dense array of source positions over a wide surface area. Migration was applied to each cable position— implementing reciprocity and mirror migration of the surface multiple—using a single shot and wide areal (and azimuthal) distribution of receiver positions. Hence, the term “true 3D” as opposed to the single azimuth of offset information in a conventional towed-streamer survey.
The applications of the vertical cable are as fascinating as the evolution of the concept. The proof of concept using a single vertical cable in 1987 was at the Ewing Bank, followed by the fi rst actual application, with three cables, over the Tick prospect. In 1992, six cables were deployed in a 3D survey of the Gemini prospect, providing subsalt images that justified drilling the discovery well in 1996. In 1995, a relatively dense survey over Strathspey Field in the North Sea addressed the objective of detailed
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