| High-temperature and high-salinity oil reservoirs are widely distributed in Dagang Oilfield,Huabei Oilfield,and Qinghai Oilfield.In order to ensure the continuous growth of crude oil production in China,the research and application of tertiary oil recovery technology for high-temperature and high-salinity oil reservoirs is essential.Chemical flooding technology has achieved good application results in medium and low temperature oil reservoirs.Due to the influence of temperature and salinity,current conventional oil-displacing agents could no longer meet the requirements of chemical combination flooding infield application.This paper takes the Dagang Guan 109-1 fault block reservoir as the research object,carries out targeted research on the temperature-tolerant and salt-tolerant composite flooding system,and finally develops a highly efficient and cheap composite flooding product suitable for the reservoir,and further improves the reservoir The recovery factor provides scientific basis and technical guidance for the overall investment and development of Dagang Guan 109-1 fault block reservoir.The main results and understandings of the thesis are as follows:Using experimental methods such as the determination of oil-water interfacial tension and the determination of system viscosity,the surfactants and polymers are optimized,and the compatibility of the main surfactant petroleum sulfonate and other different types of chemical agent compound systems is studied,and the compound flooding is clarified.The composition of the oil system.Using evaluation methods such as emulsifying power and aging stability,the formulation of this binary composite flooding system was optimized,and the interfacial activity,temperature and salt resistance,emulsification and viscosity stability of the system were studied.Using the experimental method of physically simulating core flooding,compare the effects of different slug combinations,injection speeds and injection volumes on the flooding effect,optimize the slug design parameters,and carry out research on the flooding effect of the combined flooding system.The results showed that Fushun petroleum sulfonate V3005-17 and heavy alkylbenzene sulfonate HABS-1#have a good synergistic effect,which could make the interfacial tension of oil and water reach 10-3 orders of magnitude.Comb-type polymer KY-6 has good temperature resistance,viscosifying action,injection and aging stability,and meets the requirements of chemical combination flooding oil reservoir conditions,and has good compatibility with reservoirs.When the ratio of V3005-17 and HABS-1#two surfactants is 50:50,the total surfactant concentration was 0.2wt%,and the polymer KY-6 concentration was 2000mg/L,a good synergistic effect was produced between the chemical agents.The oil-water interfacial tension of this combined flooding system was 4.5×10-3m N/m,reaching ultra-low interfacial tension.Under the conditions of Na+concentration of 10000?50000mg/L,Ca2+concentration of100?1000mg/L and 78?,the oil-water interfacial tension of this combined flooding system could reach the order of 10-3,and the salt tolerance is good.After 30 days of aging at 78?,the interfacial tension could still reach 9.69×10-3m N/m,the viscosity retention rate was 77%,and it has good long-term thermal stability.This composite flooding system has moderate emulsification ability,and the system's good interfacial activity makes the crude oil easy to flow,so that the displacement fluid emulsifies and carries the crude oil to achieve the purpose of improving the oil displacement efficiency.0.2wt%V3005-17+HABS-1#(50:50)+2000mg/L KY-6 formula has the best oil displacement effect.The optimal injection rate was 0.1 m L/min,and the optimal injection volume was 0.5 PV.The oil recovery increased by 33.25%. |
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