【摘要】 题示油井增产技术适用于高含水非均质砂岩油藏,实施步骤如下:①高压注水入油井,使中低渗层压力升高;②注入高效洗油剂;③依次注入成冻时间tG递减的选择性堵水剂;④注入过顶替液;⑤关井候凝后开井生产。叙述并图示了技术原理。由目的油田条件下的等界面张力图并考虑损耗,确定0.8%的一种阴离子表面活性剂溶液为洗油剂,注入量为80 m3/m高渗层。所选3种堵水剂分别为聚合物/有机铬体系(tG=5 d,45℃7、.34 s-1初始粘度η0=10.2 mPa.s)和聚合物/无机铬体系(3 d,20.5 mPa.s和1 d,28.6 mPa.s),三者体积比50∶30∶20,总用量按处理半径18 m计算。过顶替液为η=32.9 mPa.s的聚合物溶液,将堵剂推至距井筒3 m以远。在大庆喇嘛甸油田一聚合物驱后水驱至含水98%、采出程度>50%的区块,在6口油井成功试用该技术,单井平均注入工作液1383 m3,实施较早的4口井增产油减产水,初期含水下降幅度2.6%~21.8%,有效期170~665 d,经济上可行。图2表1参8。更多还原

【Abstract】 The titled well stimulation technology is developed for high water cut heterogeneous sandstone reservoirs and conducted in following steps: ①high pressure water injection into the aimed production well to boost the pressure in middle-low permeability strata;②highly effective oil displacement agent（HEODA） injection;③injection of selective water shutoff agents of decreasing gelation time,t_G,successively;④ overdisplacing fluid injection;⑤in-situ gelation and starting production.A 0.8% solution of an anionic surfactant is chosen as HEODA according to the IFT contour diagram constructed at conditions of the aimed reservoir and with possible consumption taken into account and is injected in volume of 80 m³ per m thickness of high permeable zones.The water shutoff agents chosen are: a polymer/organic Cr system of t_G=5 d and initial viscosity at 45℃ and 7.34 s^-1 η₀=10.2 mPa·s;two polymer/inorganic Cr systems of t_G=3 d and η₀=20.5 mPa·s and of t_G=1 d and η₀=28.6 mPa·s in volume ratio 50∶30∶20 and the total volume is determined for a treatment radius of 18 m reached.An overdisplacing fluid,being a polymer solution of η=32.9 mPa·s,drives the water shutoff agents further to ≥3 m apart from the borehole.In a postpolymerflood unit of Lamadian,Daqing,where 98% water cut and >50% oil recovery extent are reached,this stimulation technology is applied in six production wells successfully with 1383 m³ of working fluids injected into one well in average;for four wells treated earlier,increase in oil output and decrease in water output are observed in 170—665 days with water cut decreased at the first time by 6.26—21.8 percents and these treatments are shown to be benificial economically.更多还原