Geophysical Methods for Reservoir Characterization

Abstract

ABSTRACT Petroleum resources are finite and becoming ever more elusive. As known reserves are depleted, efficient management of existing reservoirs is crucial. One valuable tool for reservoir development is computer simulation. Unfortunately, although the technology is available to construct geologically complex computer models of reservoirs, the level of detail which can be included in such models is far beyond the ability of traditional methods for measuring reservoir properties to accurately constrain those models. For example, geostatistical techniques permit a modeler to describe a geologic representation of a generic reservoir which is realistic and empirically matches historical measurements related to reservoir performance. However, the resulting model will not be a true representation of the specific reservoir and consequently predictions based on the model may be suspect. Seismic imaging methods are emerging as promising new measurement tools which can be used to bridge the information gap between wells and help constrain stochastic models. 1 Recent breakthroughs in hardware and software have improved the resolution of seismic methods to the point where they can now address production-scale problems. Parameters and attributes extracted from seismic data can be empirically and analytically related to rock properties of interest for reservoir development. This offers the tremendous potential for improving profitability through efficient development of reservoirs. This paper will illustrate the application of seismic imaging to, characterize reservoir properties. Examples from two geologic settings will be used to compare the resolution of four seismic imaging methods; Surface Seismic Surveying, Reversed Vertical Seismic Profiling (RVSP), Cross well Reflection Imaging, and Crosswell Tomography.