85 ℃下高矿化度地层化学堵水剂研究

Research on chemical water plugging agent in high salinity reservoir at 85 ℃

周洪涛 黄安华 张贵才 吴文明 付立欣

ZHOU Hongtao HUANG Anhua ZHANG Guicai WU Wengming FU Lixin

中国石油大学华东石油工程系，山东青岛　266555 新疆油田公司开发事业部，新疆库尔勒　841000 中石化西北分公司工程技术研究院，新疆乌鲁木齐　830011 中国石油集团工程设计有限公司华北油田分公司，河北任丘　062552

Petroleum Engineering Department, China University of Petroleum, Qingdao 266555, China Exploitation Enterprise Part, CNPC Xinjiang Oilfield Co., Korla 841000,China Engineering Technology Institute of Sinopec Northeast Oilfield Company, Urumqi 830011, China Huabei Co. of CPE. Co. Ltd., Renqiu 062552, China

针对高矿化度地层堵水需求，结合油田实际出水情况分析了聚丙烯酰胺结构与耐盐性能的关系，并研制了一种耐高矿化度的阳离子聚丙烯酰胺为主剂的凝胶型堵剂，交联剂采用含苯环结构的树脂，并加入保护剂减缓高温下主剂水解。实验评价结果表明：堵剂体系能封堵85 ℃下、NaCl 矿化度220 000 mg/L、CaCl2矿化度10 000 mg/L的地层水，堵剂体系最佳pH值为7~11；有效期长；岩心封堵水突破压力大于45 MPa/m，突破后20 PV体积驱替后封堵强度大于30 MPa/m，封堵率98%以上；并且堵剂对含油饱和度高的地层封堵强度低，具有一定选择性。

The relationship between polyacrylamide structure and salt resistant capacity was analyzed, and a new gel type plugging agent with cationic polyacrylamide (CPAM) as main agent and with high salinity resistant capacity was developed. Resin with benzene ring structure is taken as crosslinker, and protectant is added to decrease the hydrolysis of main agent. Experimental results show that this agent can plug the formation water with NaCl salinity of 220 000 mg/L and CaCl2 of 10 000 mg/L below 85 ℃. Optimal pH of the plugging agent is 7~11.The breakthrough pressure measured by cores is more than 45 MPa/m. For continuous injection of 20 PV water after breakthrough, plugging strength is still more than 30 MPa/m, with plugging rate of 98%. The plugging agent has long period of validity under high salinity. It also has selectivity, since plugging strength is low for the layer of high oil saturation.