聚丙烯酰胺反相乳液深部调驱先导试验初步结果

Preliminary Results of Pilot Test on Indepth Permeability Profile Control/Emulsion Flood by Using PAM Inverse Emulsion

题示反相乳液（W／O乳液）以油田污水携带进入地层设定位置后，在环境温度、矿化度及转相剂作用下发生相反转，原分散相中所含的聚丙烯酰胺和交联剂迅速溶于水并生成可流动的水基凝胶，起深部调剖、液流转向及驱替作用。胜利孤岛油田中二南Ng^3-4先导试验区，原始地温69℃，地下原油黏度20～100mPa·s，产出水矿化度5．5g／L，注入水矿化度7．2g／L，包括5口注水井，21口采油井，试验前处于聚驱后的水驱阶段。设计注入聚丙烯酰胺反相乳液在注入水中的稀释液，其中前置段塞浓度8g／L，段塞尺寸8×10^3m，折合反相乳液64t，主体段塞6g／L，1．2×10^4m^3，72t，以及顶替液（注入水）1．2×10^4m^3，连续注入45天。预测先导试验区采收率将提高1．05％，其中高、中、低渗层分别提高0．50％，1．48％，2．47％，含水率降低2．65％，增产油效果将延续至2010年。注水井21-4的调驱作业于2004年12月底开始，共注入反相乳液25吨，转相剂1．75吨，施工注入压力由7．5MPa升至9．5MPa，作业后注水压力由6．8MPa升至7．0MPa；2005年4月统计，对应51：2油井平均日产液量上升21．3％，日产油量上升37．0％，含水率下降1．1％，有4口井产油量增加，1口井持平。图5表2参8。

The titled inverse emulsion （IE）, being carried by injection water, is placed into the aimed zones of reservoir formations, where it ehangea to a eommon O/W emulsion with the help of a phase inversion agent （PIA） at reservoir temperature and salinity and the polyaerylamide and the crossinker in the original deapersed phase fast dissolve in surronding water and form flowing hydrogel for indepth permeability profile control, fluid diverting, and oil driving. The Ng^3-4 pilot area covers 5 injection and 21 production wells in South Central District Ⅱ of Gudao, Shengli, of original reservoir temperature 69℃, underground oil viscosity 20-100 mPa·s, and TSD of produced water 5.5 g/L and of injection water 7.2 g/L and is exploided by water flood after polymer flood finished. It is designed to inject PAM IE diluted by injection water of IE concentration 8 g/L in volume 8×10^3 m^3, containing 64 t of IE, as pad slug and of 6 g/L in volume 1.2×10^4 m^3, 72 t of IE, as main slug and tail water in volume 1.2×10^4 m^3 in 45 days continuonsly. According to a prediction made, an enhancement in oil recovery of 1.05% in whole pilot area and of 0.5%, 1.48%, and 2.47% from high, medium, and low permeable layers, respectively, and a decrement in water cut of 2.65% will be obtained; the raise in oil productivily in the pilot area will extend to 2010. In profiling/flooding operation in injection well 21-4, started at the end of 2004,25 t of IE and 1.75 t of PIA were injected with injecting pressure raising from 7.5 to 9.5 MPa and after the operation finished the water injection pressure was raised from 6.8 to 7.0 MPa and for 5 production wells connected with well 21-4, the data of Apr 2005 showed that average daily output of fluid was raised by 21.3% and of oil-by 37.0%, water cut was lowered down by 1.1%, the oil productivity in 4 wells raised and in one well kept unchanged.