Integrated History Matching Simulation Study of the First Miscible CO2-EOR Pilot in Abu Dhabi Heterogeneous Carbonate Oil Reservoir

Abstract

Abstract Carbon Dioxide (CO2) Enhanced Oil Recovery (EOR) process is most likely to be the future hydrocarbon recovery process in Abu Dhabi[1]. In November 2009, Abu Dhabi Company for Onshore Oil Operations (ADCO) has commissioned the first CO2-EOR pilot in the Middle East. The pilot project was implemented successfully on a fast track basis with a broad objective to test the concept of CO2 flooding in Abu Dhabi complex carbonate oil reservoirs. The project comprises three wells, a single CO2 injection well, an observation well and a single oil producing well An intensive reservoir monitoring plan was implemented pre-and post- CO2 injection to evaluate the uncertainties related to the reservoir fluid and rock properties, CO2 injectivity, miscibility, and sweep efficiency. Available reservoir static and dynamic data was employed to construct a fully compositional simulation model to history match the pilot performance based on remarkable field observations. Effort was made to ensure that all reservoir data were quality checked, re-interpreted and validated before being utilized in the simulation model. Conventional history matching was conducted to match the model response to the pilot performance. This is complemented with Software Assisted History Matching to further quantify and assess the range of uncertainties for different reservoir parameters that would impact the quality of the history match. Sensitivity analysis was carried out to identify those parameters that have the most effect on the pilot performance. This paper outlines the main findings for the first miscible CO2-EOR pilot in Abu Dhabi based on well calibrated compositional model considering the most critical reservoir uncertainties affecting the process.