The Low Salinity Waterfooding Enhanced Oil Recovery Feasibility Evaluation In Jiangsu Oilfield

Major oil fields are looking for low-cost oil recovery methods in the low oil prices, It can greatly improve the recovery and economic benefits by Low salinity water flooding, and the technology can use existing injection patterns, reducing investment and it does not require a large number of chemicals and complex ground action, it have a high economic efficiency, more environmentally friendly and it is easy to implement the enormous potential of oilfield.The subject of the Jiangsu oilfield, Liangduo Anfeng block in low salinity water flooding experiments, mainly to complete the determination of Anfeng and Liang Duo two blocks of the original oleic acid; chromatography of crude oil component analysis experiment; research of literature analysis of the two block of Jiangsu oilfield is suitable to carry out the low degree of mineralization water flooding; Jiangsu oil field for the determination of low salinity water by core flooding formula; the low salinity water were screened and the scaling tendency prediction and simulation research; low salinity water flooding increased four flooding oil recovery mechanism; contact angle test; Study on oil displacement efficiency of low salinity water; research swelling prevention process of low salinity water; low salinity water injection mode selection; active water imbibition experiment; research on the efficiency of oil water activity mechanism and active water flooding.Through the research of this project, we achieved the following seven conclusion:1, Based on the research literature and the analysis of the geological features of Jiangsu oilfield, the Jiangsu oilfield is suitable for low salinity water flooding.2, Produced water and injection water 1:10 mixing, and 500mg/L NaCl, total salinity of 3713mg/l Liangduo blocks of low salinity water flooding formulations.The formula of low salinity water flooding in the Anfeng block is:the output water is mixed with the injected water 1:13, coupled with NaCl 500mg/L, the total mineralization degree is 4381mg/l.3, The experimental results show that the mechanism of low salinity water flooding is a kind of mechanism, such as alkaline flooding, multi component ion exchange, particle migration and wettability change.4, For reservoirs with different permeability types, low salinity water flooding is more suitable for low permeability reservoirs.5, Low salinity water flooding is suitable for the use of advanced anti inflation program, which can protect the reservoir well.6, Through the injection of anti swelling agent under the condition of low mineralization degree of water construction experimental parameters:anti swelling agent injection slug 0.2pv, low salinity water injection slug lpv, injection speed 0.05mL/min, the recovery rate was 5.44%; and the low salinity water as secondary oil displacement liquid ratio as EOR flooding for liquid has a higher recovery rate.7. According to the experimental results, the final selection of the surfactant is the low molecular weight 950-70, the concentration of the active water is 0.2%, the injection phase plug 1PV, and the injection rate of 0.05mL/min. Liang duo recovery rate of increase 8.73%, Anfeng harvest is 9.15%, and low salinity water in the preparation of the active water recovery yield increase (9.15%) than the injected water preparation of activated water recovery yield increase (8.64%) to high growth rates.