PARAMETER STUDY ON OIL RECOVERY PERFORMANCE PREDICTION UNDER IMMISCIBLE CO2 GAS HUFF AND PUFF INJECTION USING SIMULATION

• Main Author: Humam, Chaidar
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/38697
• Institution: Institut Teknologi Bandung

Most of the existing oil fields are mature, so they require additional energy or pressure to increase or at least maintain recovery and production. Enhanced oil recovey (EOR) is one method to maintain or increase oil recovery and production in a well or oil field. One of the EOR methods is CO2 injection. After passing a screening test, CO2 injection is an Enhanced Oil Recovery (EOR) method that is effective to reduce the amount of oil left in the reservoir. In this thesis CO2 injection is carried out using the immiscible CO2 huff and puff method. The bottom hole pressure in injection well is varied for sensitivity analyses below the Minimum Miscible Pressure (MMP), where CO2 is in immiscible state with crude oil. Other sensitivity analyses which have been done in this thesis include: Injection rate, injection time, soaking time, production time and number of cycles. All of these sensitivities are simulated to get the optimum parameter values, then these optimum parameters are put into the optimum model as the injection parameters. The optimum model is compared with the basecase model to evaluate the degree of success of the immiscible CO2 huff and puff method. Based on the sensitivity evaluation on immiscible CO2 gas huff and puff injection in this thesis, it is found that oil recovery is very sensitive to changes in injection rates in the range of intermediate variations and injection times in a small range of variations. Oil recovery is rather sensitive to changes in production time parameters in the range of short time variations and the number of cycles in a large range of variations. Oil recovery is not sensitive to changes in bottom hole pressure and soaking time parameters in the range of large variations. In the model without CO2 gas injection (base case) the average oil production rate is 3 bbl/d, the cumulative oil production is 24651 bbl and the recovery factor is 4.36 %. In the model under immiscible CO2 gas huff and puff injection (optimum model) oil recovery showed a significant increase, where the average oil production rate is 7.7 bbl / d, cumulative oil production is 64593 bbl and recovery factor is 11.42 %.