Vibroseis: A Very Special Source
Published:January 01, 2011
The vibroseis method was introduced in the mid-1950s by Conoco. The name Vibroseis was a trademark of Continental Oil Company, granted in 1962. William Doty and John Crawford applied for the original patent on 27 February 1953, and it was granted on 31 August 1954. The first claim of this patent is as follows (Doty and Crawford, 1954, p. 7):
Transmitting such a signal from said first point,
Providing a counterpart of said transmitted signal,
at least a substantial portion of the total transmitted vibration energy of said signal which is received at said second point, by
said counterpart signal,
Integrating for a substantial period the product of said multiplication, and altering the phase relation between said counterpart signal and said transmitted signal during successive integrating periods, and
Recording the values derived from such integration; whereby the out-of-time-phase relation of said counterpart signal with respect to the transmitted signal at said first point, which yields the greatest value from such integration, may be used as a parameter of the travel time of said unique signal between said points.
In 1953, the seismic business focused mainly on measuring traveltimes, which still are the center of our attention. Perhaps we can obtain slightly better precision now, and after almost 60 years, we can measure more than just traveltimes.
Doty and Crawford (1954) include a description of correlation, but surprisingly, they never use the word correlation itself. Could we describe vibroseis operations
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Seismic Acquisition from Yesterday to Tomorrow
During the last few years, seismic acquisition has gone through a phase of fast acceleration, attested to by the development of wide-azimuth surveys, the continuous increase in channel count, and the progress in simultaneous shooting. These developments, made possible by technological advancements today, will enable the production of clearer seismic images tomorrow. Seismic Acquisition from Yesterday to Tomorrow (SEG Distinguished Instructor Series No. 14), the companion book for the 2011 SEG/EAGE Distinguished Instructor Short Course, offers a reflection on this evolution. It starts with a short historical overview, followed by discussions of signal and noise. The core of the book is the relationship between acquisition parameters and seismicimage quality. It will provide geoscientists and all those interested in seismic images with the still unconventional view of seismic data acquisition as the first component of seismic imaging.