Mello, Ulisses T.(1); Guerin, G. (2); He, Wei (2) and Anderson, Roger N. (2)
(1) IBM Thomas J. Watson Research Center, Yorktown Heights, NY 10598
(2) Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York, 10964, U.S.A.
In this study we show how reservoir simulation can be used to generate independent 4-D impedance maps that can be used to validate and/or constrain 4-D impedance maps obtained from seismic datasets. By using physical properties from water and hydrocarbon fluids and reservoir characterization before production, we build a pre-production impedance map that serves as a reference for independent 4-D impedance analyses based on seismic and reservoir fluid flow. Fluid flow-based impedance maps are calculated using fluid saturations derived from reservoir simulation that are compared to impedance maps obtained by inverting seismic amplitudes. We have applied this approach to the LF Reservoir in Eugene Island area (block 330) using 3-D seismic datasets from 1985 (pre-production) and from 1992 (in-production) provided by Pennzoil and Shell, respectively. The reservoir simulation was performed using a parallel version of ECLIPSE on SP2. Inverted impedance and 4-D seismic were calculated using Lamont's 4-D software. Preliminary results show that this technique is valuable to constrain fluid flow inferences obtained from 4D seismic. This is especially true in cases of studies that use legacy seismic datasets, where different orientation, processing and quality can potentially introduce significant noise in the 4-D seismic processing.