Optimization of the reservoir pressure maintenance system by changing the injection agent from fresh water to reservoir water

UDK: 622.276.43

DOI: 10.24887/0028-2448-2020-7-97-99

Key words: the reservoir pressure maintenance system, changing the injection agent, displacement efficiency, compatibility of formation and injected waters, oil recovery factor

Authors: D.D. Vylomov (Izhevsk Petroleum Research Center CJSC, RF, Izhevsk), N.A. Shtin (Izhevsk Petroleum Research Center CJSC, RF, Izhevsk), V.P. Tsepelev (Izhevsk Petroleum Research Center CJSC, RF, Izhevsk)

This article is devoted to the optimization of the development of one of the oilfields of Udmurtneft JSC by changing the injection agent in the reservoir pressure maintenance system (RPMS) from fresh water to reservoir water. The article describes in detail the disadvantages of the current RPMS and the advantages of changing the displacement agent. The compatibility of associated produced water and formation water of the Serpukhovian as a source of injection is evaluated. Petrophysical functions of oil displacement efficiency depending on the injection agent are shown. According to the results of numerical modeling the increase in additional oil production by 17.9 thousand tons is predicted. Due to this, as well as due to savings on the purchase and transportation of fresh water, the economic effect of the introduction of the proposed technology is estimated at 56.7 million rubles. The algorithm of step-by-step transition to reservoir water injection presented in the article includes all stages of the process, starting with geological exploration and ending with the taking down of a low-pressure water pipeline and the injection of reservoir water into the formation. The described method of assessment of displacement agent change efficiency can be applied to other oilfields under the waterflooding development. The generalized algorithm describes an approach to changing the injection agent in such fields. References 1. Prokhorov A.Yu., Kurchikov A.R, Mitrofanov A.D. et al., Impact of water, pumped into layer, on oil recovery out of deposits of Jurassic period (Urnensky and Ust-Tegussky oil fields) (In Russ.), Neftepromyslovoe delo, 2010, no. 9, pp. 13–18. 2. Mashorin V.A., Fominykh O.V., Cherevko M.A., Substantiation of fresh water injection for formation pressure maintenance at Verkhne-Shapshinsky field (In Russ.), Territoriya NEFTEGAZ, 2014, no. 5, pp. 82–86. 3. Dake L.P., The practice of reservoir engineering, Elsevier Science, 2001, 570 p. 4. Nazarov V.D., Nazarov M.V., Treatment of fresh and process waters for the reservoir pressure maintenance system in the oil fields (In Russ.), Izvestiya vuzov. Neft' i gaz, 2013, no. 2, pp. 40–47. 5. Mashorin V.A., Substantiation of fresh water usage for formation pressure maintaining of oil fields (In Russ.), Neftepromyslovoe delo, 2014, no. 10, pp. 27–31.