低密度有机-无机互穿网络堵漏体系研究

Study on low-density organic-inorganic interpenetrating network plugging system

采用常规可固化堵漏剂解决低压地层裂缝性漏失时会产生密度过大或承压不足的技术难题,因此研究低密度高抗压的堵漏体系具有重要意义。通过合成聚丙烯酰胺(polyacrylamide,HPAM)交联形成有机网络,并优选水泥材料形成无机网络,构建低密度有机-无机互穿网络堵漏体系;采用模拟水驱实验、X射线衍射、扫描电子显微镜(scanning electron microscope,SEM)、高温高压(high temprature and high pressure,HTHP)堵漏模拟实验、抗压实验等分析了堵漏体系的性能和堵漏机理。结果表明,聚丙烯酰胺交联反应形成的有机网络与水泥水化形成的无机网络通过静电力和范德华力等作用可形成互穿网络体系,体系抗压达6.3 MPa,密度为1.28 g/cm^(3),固化时间实现2~5 h可控,固化前后的酸溶率分别为87.8%和63.4%,堵漏及解堵性良好。

In view of the problem of leakage in low-pressure formation fractures,the use of conventional curable plugging agents will cause technical difficulties such as excessive density or insufficient pressure bearing.Therefore,it is of great significance to study a low-density and high-pressure plugging system.By synthesizing polyacrylamide(HPAM)cross-linked to form an organic network,and optimizing cement materials to form an inorganic network,a low-density organic-inorganic interpenetrating network plugging system was constructed.The performance and plugging mechanism of the plugging system were analyzed by simulated water flooding experiments,X-ray diffraction,scanning electron microscopy(SEM),high temperature and high pressure(HTHP)plugging simulation experiments,and pressure resistance experiments.The results show that the organic network formed by the cross-linking reaction of polyacrylamide and the inorganic network formed by cement hydration can form an interpenetrating network system through electrostatic force and van der Waals force.The system has a pressure resistance of 6.3 MPa,a density of 1.28 g/cm^(3),and a controllable curing time of 2-5 h.The acid solubility before and after curing is 87.8%and 63.4%,respectively,and the plugging and unblocking properties are good.