AN INTEGRATED,PETROPHYSICS DRIVEN CO2 EOR SCOPING STUDY

摘要

CO2 EOR scoping study typically overlooks the importance of a comprehensive geological and petrophysical description of the reservoir,focusing more on reservoir and fluid parameters,well pattern,and surface facility design.This often leads to a sub-optimal EOR project design or even project failure.This study is to propose and validate a workflow that fully incorporates a geological and petrophysical understanding into a CO2 EOR scoping framework.Key parameters investigated are the depositional setting,channel geometry,distribution of petrophysical parameters,reservoir heterogeneity and structural features.The significance of the improved workflow was demonstrated in a CO2EOR scoping study for an oilfield in Asia.The improved CO2 EOR scoping workflow integrates the disciplines of geology,petrophysics,reservoir engineering,economics and surface facility design.The work began with reservoir geological interpretation to evaluate the distribution flow-related properties of the hydrocarbon-bearing formations in between wells.This was supported by petrophysical analysis combining,openhole logs(GR-Res-Neu-Density log suites),routine core analysis data and sedimentary description of the core.Key reservoir parameters,such as poro-permeability distributions and Dykstra-Parsons coefficient are utilized to understand and quantify reservoir heterogeneity.This workflow has demonstrated the importance of petrophysical evaluation to the success of EOR scoping study.It improved the field economics by more than 15%,by reducing well count and also screening off areas with poor reservoir properties for CO2 EOR.