Development Planning of Tight Fractured Carbonate Oil Field

6.8% of OOIP have been produced in last 20 years by 25 wells from tight fractured carbonate oil field during the primary recovery. Wellhead pressure declined from initial 3200 psi to current 1000 psi. This led to reduction in oil production rates of each well from 4000 to 1200 stb/d. Both 3D modeling and decline curve analysis have shown that it’s necessary to create formation pressure maintenance system.

Full-field 3D simulation model was build. Different scenarios of injection were simulated. Simulation of horizontal wells with multistage fracs in comparison to directional wells have shown higher production and recovery rates for horizontal wells, but almost the same cumulative production end economic assessment. Core studies, design, pilot tests should be carried out in order to make a decision whether it makes an economic sense to drill expensive horizontal wells with multistage fracs, due to their high cost and a risk of having a high water cut. Best scenario includes drilling of new directional wells, installation of ESP pumps, different workover operations and conversion of wells to injection of water and gas and implementation of dual completion systems for simultaneous production and injection. This will increase oil recovery factor from 6.8 to 27.8%.