Christine Warren Brandes, 1991. "3D Seismic Surveys: Scrimp Now, Pay Later", The Integration of Geology, Geophysics, Petrophysics and Petroleum Engineering in Reservoir Delineation, Description and Management, Robert Sneider, Wulf Massell, Rob Mathis, Dennis Loren, Paul Wichmann
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The declining cost and widespread coverage of “recon” Exploration 3D surveys have made 3D almost as available and priced competitively with 2D seismic data. Many operators are using 3D seismic to conduct initial exploration evaluations. There is a growing belief within the Industry that the earlier a 3D survey is gotten, the better. BPX is a technology leader in deep water field development, using 3D seismic data to evaluate 92% of their producing and pre-development fields in the Gulf of Mexico. The savings in time and capital through utilizing an Exploration/Appraisal 3D survey are illustrated with the evaluation history of upper Pleistocene gas zones at BP's Snapper field (East Breaks 165/209).
Post-discovery appraisal may use the same 3D data set as the initial exploration effort. Such data is often cited to support lower development risk estimates in pre-development planning. It may be inappropriate to apply an Exploration-purpose 3D survey to Production development needs. Seismic dataacquired “too early” to be appropriate for development use is defined as data that is shot and/or processed without quantifying the critical factors controlling a discovery’s commerciality. Beyond structural imaging, these factors usually include continuity of reservoir area, identification of production barriers, and accurate net reservoir thickness. Their resolvability from 3D data are controlled by line orientation, line spacing, shot-receiver offset, wavelet phase and dominant frequency. A number of BPX offshore development examples will show how 3D seismic surveys, designed for exploration/appraisal use, lacked the detailed structural definition and stratigraphic resolution required for optimal placement ofproduction wells.