具有近疏远调作用的双液法深部调剖剂LF-1

Two-Component Indepth Profile Modifying Agent LF-1 with Blockage Relieving Function in Near Bore Zones

为了封堵中原胡庆油田高压注水井远井地带的高渗层 ,研制了双液法堵剂LF 1。LF 1的A剂为可在水中解离出H+ 的无机盐溶液 ,B剂为硅酸钠溶液。 10 %A剂溶液对注水井结垢物的溶解率为 9.1%～ 10 .2 % ,加入 0 .2 %缓蚀剂后 85℃下的腐蚀速率降至 0 .10 8mm/a ,缓蚀率 95 %。根据等体积A、B剂溶液生成的沉淀物质量和堆积体积 ,求得A、B剂实用浓度为 10 %、15 %。在此实用浓度下 ,LF 1生成的沉淀物质量和堆积体积远大于对比双液法堵剂 (碳酸钠 /氯化钙、碳酸钠 /硫酸亚铁、硅酸钠 /氯化钙体系 )。注入 10 %A剂溶液 1PV使水泥 /粘土 /氧化钙堵剂封堵的石英砂压实岩心渗透率 (5 .6 7× 10 -3 μm2 )升高 18.2 %。在 85℃下 5支长 6 0mm的岩心注入 1.5PVA剂溶液 /0 .2 5PVB剂溶液 /0 .2 5PVA剂溶液后 ,突破压力为 1.6～ 3.6MPa ,平均 2 .4MPa ,堵水率为 6 6 .8%～76 .2 % ,平均 72 .0 % ,注水 10 0PV后渗透率上升 1.0 7%～ 5 .6 3% ,再在 85℃和注水压力下保持 12 0d后 ,渗透率上升 4 .30 %～ 7.31%。 2 0 0 1年 1～ 9月进行的 18次注水井深部调剖 ,平均处理半径 11.5m ,单井注入剂量 94 8.5m3 ,工艺上完全成功 ,绝大部分对应油井增油减水。给出了 4口注水井封堵前后注水参数的变化。表 8参 1。

A two-component indepth profile modifying agent, LF-1, is prepared for plugging high permeable channellings in further bore zones of high pressure water injection wells in Huqing, Zhongyuan. The reaction solution A of LF-1 is composed of an inorganic salt capable of ionization in water to give H^+ and B-silicates(water glass). 9.1-10.2% scaled substances in the water injection pipeline can be dissolved out by 10% solution A; the corrosivity of 10% solution A can be lowered by 95% with a chosen inhibitor added at a use level 2 g/L and the corrosion rate of N80 steel specimen at 85℃ is of 0.108 mm/a. According to dry mass and wet volume of the precipitates formed from reaction solutions A and B in equal volume ratio, the proper solution concentration for practical uses is of 10% A and 15% B. At these component concentrations, LF-1 gives much higher dry mass and wet volume of precipitates than the control two-component (Na_2CO_3/CaCl_2,Na_2CO_3/FeSO_4, and silicates/CaCl_2)agents. Injecting 10% solution A in 1 PV increases the water phase permeability of a compressed quartz model having been plugged by a cement/clay/CaO composition (5.76×10^(-3)*'μm^2) by 18.2%. In core flow experiments on six quartz models (60 mm long) at 85℃ following results are obtained after injecting 1.5 PV of solution A/0.25 PV of solution B/0.25 PV solution B: breakthrough pressure in range 1.6-3.6 MPa and of (2.4) MPa in average; plugging rate to formation water in range 66.8-76.2% and of 70.0% in average; percentage of increase in permeability 1.07-5.63% after 100 PV of water flooded and 4.30-7.31% after standing at 85℃ and the injction pressure in (120) hrs. Totally 18 indepth profile modification jobs have been performed successfully in Jan-Sept, 2001 with solutions A and B injected in volume of 948.5 m^3 per well-job and average treating radius of 11.5 m. Increased oil productivity and decreased water output are observed in the majority of the oil wells connected with the treated injection ones. The changes in injection parameters after the jobs performed in 4 water injectoon wells are presented..