C Oilfield Low Salinity Water Injection Enhanced Oil Recovery Mechanism And Applicability Evaluation

Water flooding is one of the most mature technologies in the oilfields. Onshore oilfields often inject produced water, offshore oilfields often inject seawater or sea water mix with fresh water injection. The salinity of injected water is widely high. With the increase of injection time, high salinity of injection water is easy to cause formation scaling or blocking, this will result in a decline in formation permeability. Low salinity water flooding (LSW) means the salinity of the injected water is controlled to be under 5000mg/L. Injecting low salinity water is an effective method to enhance oil recovery.At present, for the oilfield C, the injection wells is difficult to inject water, the injection pressure is high, the water injectivity index begins to decline, oil recovery rate is low, and recovery efficiency drops. So we put forward the low salinity water injection to solve the problems of the oilfield C. It is important for the oilfield C to improve the present situation and enhance the oil recovery. The oilfield C reservoir Ming town group is an example to research the low salinity water injection, which is combining theories with experiments to analysis the low salinity water flooding mechanisms. Those theories include the double layer diffusion, pH value analysis, wettability measurement, ion exchange experiment. Then we adopt water flooding experiment of low salinity water injection to verify low salinity water injection is able to improve oil recovery. On this basis, make full use of reservoir numerical simulation technology to compare the high salinity and low salinity water injection development effects, and the high salinity and high salinity switch to low salinity water injection development effects. It can validate the low salinity water injection development is able to improve the development effects. Finally, experiments combine with numerical simulation to evaluate the applicability of low salinity water injection development on the oilfield C.