Time Lapse Reservoir Monitoring and Characterization - An Update

SPARKMAN, GENE, and JOHN CASTAGNA

How much better could reservoirs be managed if periodic snapshots of reservoir fluid distributions could be made during the life of a field? How much greater would ultimate recoveries be it unrecovered pockets could be identified? These are only a few of the possible applications of an exciting new technology which promises to revolutionize reservoir management: time lapse reservoir monitoring. Frequently referred to as 4D seismic (the fourth dimension being calendar time), this technology involves the acquisition of repeated 3D seismic surveys during production, calculating detailed differences between the surveys, rendering these in volumes, maps and/or cross-sectional views, and reconciling these observations with geological interpretations and reservoir simulations.

Although, time lapse surveys have been experimentally conducted for over a decade, recent developments in 3D seismic acquisition, processing, and visualization, along with improved understanding of rock and fluid physics, have advanced time-lapse technology to the point where widespread commercial application is imminent.

Six top priority research topics are: (1) Understanding Petrophysics, (2) Reservoir Characterization, (3) Estimating Value, (4) Reservoir Simulation, (5) Seismic Operations, and (6) Measurable Attributes.

AAPG Search and Discovery Article #91021©1997 AAPG Annual Convention, Dallas, Texas.