The Application of Seismic Techniques to Drilling Techniques
Authors: Reynolds Edward B. 
Published: December 2007

This paper was prepared for the 48th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in Las Vegas, Nev., Sept. 30-Oct. 3, 1973. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
For the last five years or so, the petroleum industry has used geophysical data petroleum industry has used geophysical data to predict the depths and magnitudes of abnormally pressured formations in sedimentary basins throughout the world. The strong emphasis on obtaining accurate seismic velocity information for reliable pressure and lithologic prognosing has not pressure and lithologic prognosing has not only helped the drilling engineer to design wildcat wells more realistically but has been applied to other engineering fields such as soil mechanics and structure design.
This paper reviews the results of one company's international application of these seismic predictions and engineering applications in nine different countries at offshore and onshore locations. Post mortems of several wells show the reliability of predicting (1) interval velocities, (2) the location and magnitude of overpressured intervals, and (3) other lithologic or drilling phenomena. In all, thirty-five wells are presented statistically to show the seismic techniques overall predictive reliability as compared to actual results from well log analyses and test data in wildcat areas.
Other marine engineering applications of geophysical data are also reviewed. These include (1) using shallow seismic data for sea bed and sub-bottom investigation, (2) detecting shallow gas accumulations by the "bright spot" technique, and (3) using seismic data for special wildcat well design problems, such as estimating geothermal problems, such as estimating geothermal gradients.

Introduction
The petroleum industry of today faces more adverse economic, ecologic, technical, and political obstacles than ever before. With dwindling oil and gas reserves, oil and gas companies are forced to explore and drill in such hostile environments as deep water or in remote jungles or deserts which may have as many or more geologic and engineering barriers in the subsurface as geographic or logistical obstacles on the surface. It is, therefore, imperative that each drilling venture be thoroughly investigated so that many of the unknowns of a prospect be reduced to a level which will allow a safe and economical prospect evaluation.