Reasonable limits of main controlling parameters for balanced displacement by gas-water injection in low permeability limestone reservoirs and their performance evaluation
In order to formulate reasonable technical guidelines for balanced displacement by gas-water injection in low permea-bility bioclastic limestone reservoirs in the Middle East region,an orthogonal simulation testing program of the operation param-eters was designed,and a numerical modeling technique was applied to create a technical chart of the main controlling parame-ters to specify their reasonable limits.A dynamic fuzzy comprehensive evaluation system based on the simulation model was constructed to quantitatively characterize the difference of oil well production,evaluate production performance,and provide guidelines for field pilot testing.The results show that the descending sequence of the main control parameters influencing on a ratio of total oil produced to OOIP is as follows:gas injection rate,injection timing,oil production rate,well spacing and water injection rate.The recommended reasonable oil production rate is about 2.0%,with gas injection rate of(34-45)×104 m3/d,water injection rate of 240-320 m3/d,well spacing of 700 m and the injection timing is to maintain current reservoir pres-sure above 85% .of the original formation pressure.The pilot testing of gas-water synergy injection should be carried out as the priority for the development area.A good field performance of the pilot test based on the new guidelines has been obtained.
万方数据
维普
