有机铬/活性酚醛树脂交联聚合物弱凝胶及其在濮城油田调驱中的应用

Cr^(3+)/Phenolic Resin Crosslinked Weak Gel and Its Use as Permeability Adjusting/oil Displacing Agent in Pucheng Oil Field

实验研究了用污水配制、可在58～120℃使用、室温粘度2.5～5.0Pa·s的聚合物弱凝胶调驱剂的配方;所用聚合物HPAM的分子量1.8×107,水解度25%;交联剂为有机铬与活性酚醛树脂复合物,与HPAM在水溶液中形成的弱凝胶具有互穿聚合物网络结构;配液用水为中原濮二联污水,矿化度153g/L,含Ca2+3.2g/L,含Mg2+0.25g/L。弱凝胶中HPAM浓度用作主段塞时为1.2g/L,用作保护段塞时为1.0g/L。1.2g/LHPAM+0.5g/L有机铬+0.8g/L酚醛树脂+稳定剂溶液90℃成胶时间134h,90℃老化时间(凝胶保持完整,不脱水)>90d,90℃老化90d后粘度保持率>90%,在岩心上测得阻力系数和残余阻力系数分别为15.4和56.9,剪切后粘度下降到45.3mPa·s,放置1d后恢复到186.7mPa·s。考察了HPAM、Cr3+、酚醛树脂浓度的影响,简述了pH值、HPAM分子量和水解度、成胶温度的影响。介绍了用该弱凝胶在濮城油田2口注水井调驱,对应6口油井的增产情况。图3表4参7。

The formulation and performance properties of a weak gel prepared in brine, having viscosity at ambient temperatures 2.5—5.0 Pa·s and for use at 58—120℃ are studied experimentally.The polymer used is an HPAM of M=1.8×10~7 and HD=25%.The crosslinker chosen is an organic Cr compound and a reactive phenolic resin in combination,with which the polymer solution forms gel of structure IPN (interpenetrating polymer network).The gelling solution is prepared with the recycled produced water of TSD=153 g/L,Ca^(2+) content 3.2 g/L,and Mg^(2+) content 0.25 g/L taken from the 2nd Pucheng oil galhering/water treating plant in Zhongyuan. The polymer concentration in the gelling solution as main slug is of 1.2 g/L and that as protection slag — 1.0 g/L.1.2 g/L HPAM+0.05 g/L Cr compound +0.8 g/L phenolic resin+stabilizer solution gelates at 90℃ in 134 hrs and maintains intact without syneresis and more than 90% of the highest viscosity reached in ageing treatment at 90℃ in more than 90 days;the resistance and residual resistance factors of the gel determined on cores are of 15.4 and 56.9,respectively, the gel viscosity decreases to 45.3 mPa·s after shearing and recoveries to 186.7 mPa·s after one day standing. The effects of concentrations of HPAM,Cr compound, and phenolic resin are investigated and the effects of pH value, polymer molar mass and hydrolysis degree, and gelation temperature are presented concisely.The trial on permeability control/oil displacement by using the weak gel described in 2 water injection wells and the enhancement in oil productivity in 6 connected oil wells are presented.