Abstract: Using Geophysical Data to Improve Reservoir Description

John R. Waggoner

Geophysical data has long been used in exploration for new oil and gas. More and more, it is also being used to better manage existing oil and gas fields. Since the management of oil and gas fields is routinely performed with the aid of a numerical reservoir simulator, geophysical data must be integrated with reservoir simulation in order to have any appreciable effect on reservoir management.

The two geophysical techniques included in this presentation will be electromagnetics (EM) and seismics. The EM technique responds primarily to the amount and type of fluid in the pore space, while the seismic techniques respond primarily to the rock matrix, but can contain significant fluid response in the less consolidated formations. In both cases, there has been considerable petrophysical work over the years on the relationship between the characteristics of the rock and the response of the rock to geophysical methods.

The technical approach presented forges the interaction of geophysical data and reservoir simulation by building petrophysical knowledge into a reservoir simulator, thus giving the simulator the ability to generate a synthetic geophysical attribute map. This map can then be compared to the attribute map generated by the geophysical data collected from the field. The comparison will then lead a geologist and engineer to modify the reservoir characterization and fluid distributions which, through an iterative process, will result in a more accurate model of the reservoir to be used in reservoir management. This procedure was developed for the DOE Electromagnetic Imaging program from 1990 - 1993.

AAPG Search and Discovery Article #90959©1995 AAPG Rocky Mountain Section Meeting, Reno, Nevada