| The design of a seismic survey for reservoir geophysics purposes can often be optimized for specific interpretation goals. Once a field has been discovered, developed, and under production for some time, information is available to the geophysicist, allowing a geophysical survey design that maximizes the likelihood that the data collected will significantly aid reservoir management. That is, if the goal of the survey is to define the structural limits of the field, a 3D seismic survey can be designed with that in mind. If, however, the goal of the survey is to define the extent of a gas zone, the geophysicist may be able to use log data, seismic petrophysical modeling, and pre-existing ("legacy") seismic data to determine which offset ranges are required, for example, to differentiate between the water and gas zones. If highly accurate well ties or wavelet phase control are needed, an appropriately placed vertical seismic profile (VSP) may be designed. Or, if an acquisition "footprint" (features that appear in seismic data but are acquisition-related artifacts) was observed in a previously acquired seismic data set and that footprint obscured the attributes needed to define the reservoir target, the geophysicist can design the new survey in a way that eliminates the troublesome artifacts.<ref name="r3">Cordsen, A., Galbraith, M., and Peirce, J. 2000. Planning Land 3D Seismic Surveys, 204. Tulsa: Geophysical Developments, Society of Exploration Geophysicists.</ref> In short, the fact that the target is well known permits the reservoir geophysics survey to be designed in a more enlightened manner than a typical exploration survey. The expense of a properly conducted seismic survey for reservoir characterization purposes can often be justified (or at least properly evaluated) because the financial impact of the survey can be calculated with greater confidence than for typical exploration seismic surveys.<ref name="r4">Aylor, W.K. 1995. Business Performance and Value of Exploitation 3-D Seismic. The Leading Edge 14 (7): 797. http://dx.doi.org/10.1190/1.1437165 | | The design of a seismic survey for reservoir geophysics purposes can often be optimized for specific interpretation goals. Once a field has been discovered, developed, and under production for some time, information is available to the geophysicist, allowing a geophysical survey design that maximizes the likelihood that the data collected will significantly aid reservoir management. That is, if the goal of the survey is to define the structural limits of the field, a 3D seismic survey can be designed with that in mind. If, however, the goal of the survey is to define the extent of a gas zone, the geophysicist may be able to use log data, seismic petrophysical modeling, and pre-existing ("legacy") seismic data to determine which offset ranges are required, for example, to differentiate between the water and gas zones. If highly accurate well ties or wavelet phase control are needed, an appropriately placed vertical seismic profile (VSP) may be designed. Or, if an acquisition "footprint" (features that appear in seismic data but are acquisition-related artifacts) was observed in a previously acquired seismic data set and that footprint obscured the attributes needed to define the reservoir target, the geophysicist can design the new survey in a way that eliminates the troublesome artifacts.<ref name="r3">Cordsen, A., Galbraith, M., and Peirce, J. 2000. Planning Land 3D Seismic Surveys, 204. Tulsa: Geophysical Developments, Society of Exploration Geophysicists.</ref> In short, the fact that the target is well known permits the reservoir geophysics survey to be designed in a more enlightened manner than a typical exploration survey. The expense of a properly conducted seismic survey for reservoir characterization purposes can often be justified (or at least properly evaluated) because the financial impact of the survey can be calculated with greater confidence than for typical exploration seismic surveys.<ref name="r4">Aylor, W.K. 1995. Business Performance and Value of Exploitation 3-D Seismic. The Leading Edge 14 (7): 797. http://dx.doi.org/10.1190/1.1437165fckLR↑ Sheriff, R.E. ed. 1992. Reservoir Geophysics, Investigations in Geophysics, 7. Tulsa: Society of Exploration Geophysicists.</ref> |