Dukhan Field CO2 Injection EOR Pilot: Reservoir Modeling & Planning

A reservoir study was conducted to plan a near-miscible CO2 gas injection pilot in the Dukhan Field with the following study guidelines: • Determine overall objectives and timeframe for the pilot • Design the pilot to meet the objectives and timeframe • Plan the pilot in a portion of the field with representative reservoir description • Propose a surveillance and monitoring plan to ensure high quality information is obtained for interpreting the pilot performance • Design the pilot so the recovery processes are scalable to larger well spacing for reservoir-wide application Using these guidelines, the following pilot objectives were developed: • Provide data on well injectivity and productivity • Reduce uncertainty in the estimation of incremental oil recovery from CO2 gas injection relative to waterflood • Provide data to allow commercial scale well and facility CO2 gas injection design • Minimize the impact on current operations outside the pilot area. The results of the reservoir modeling study provided the detail for well orientation and placement to satisfy the pilot objectives at a reasonable cost and within appropriate timeframe for information gathering, analysis, and commercialization decisions. The reservoir model pilot area selected is one kilometer square segment in a crestal structural location that does not contain active wells and is near existing surface facilities. The reservoir description data used for the segment models were extracted from history matched full-field reservoir models. The proposed pilot wells are located within close proximity of each other to achieve gas breakthrough and oil bank arrival within the proposed pilot evaluation period of two years. The pilot design ensures that the pilot would allow for data gathering of key project design information; such as injectivity, gas breakthrough timing, oil displacement, and reservoir sweep.