Inversion of 4D Seismic Data
AssigneeExxonMobil Upstream Research Company
InventorsDez Chu, Grant A. Gist
Life of this patent
Estimating the term…
Abstract
The invention is a method for inferring the saturation and pressure change of a reservoir by combining the information from 4D (time-lapse) seismic and time lag data volumes (7) derived from the 4D seismic, well logs (4), and reservoir simulation results (when simulator results are available) and featuring one or more 4D well ties (1) for a quantitative 4D interpretation. The inventive method uses model-based inversion incorporating rock physics (2) at well locations (5), and is statistical-based (6) away from wells. The method thus allows integration (8) of rock physics model and reservoir simulation and honors 4D seismic change.
Claims17
A method for inversion of time-lapse (4D) seismic data (a base survey and a later monitor survey of the same subsurface formation) to estimate the change in fluid saturation and reservoir pressure from the time of the base survey to the time of the monitor survey, comprising:
- (a) inverting the 4D seismic data at least one well location to directly obtain formation pressure change and fluid saturation change for at least one formation fluid, constraining the inversion with well log data;
- and
- (b) using the saturation and pressure change from at least one well location to obtain saturation and pressure change away from well locations, thereby generating a well-tied fluid saturation and pressure change model predicting change of fluid saturation from the time of the base survey to the time of the monitor survey.
Dependencies are inferred from the claim text.