缓交联高强度凝胶的制备和性能研究

Preparation and properties of slow crosslinking high strength gels

为平衡注入性与封堵性间的矛盾,需选择初始黏度低、成胶时间长、成胶后强度高的凝胶堵剂,鉴于铬冻胶成胶时间调控难度大、酚醛交联剂毒性大等问题,采用聚乙烯亚胺为交联剂、聚酰胺-胺为主剂、硫脲为除氧剂、硅溶胶为增强剂制备凝胶。实验结果表明,该凝胶可在70℃、总矿化度为26205 mg/L的储层条件下使用,成胶时间为4 d,凝胶强度可达到H级,封堵率可达90%以上,对实现深度堵水有一定的指导意义。

To balance the contradiction between injection and plugging,it is necessary to select a gel plugging agent with low initial viscosity,long gelation time and high gel strength.In view of the difficulties in regulating the gelation time of chromium gel and the high toxicity of phenolic crosslinker,the gel was prepared with polyethylenimide as crosslinker,polyamide-amine as the main agent,thiourea as the deoxidizer and silica sol as the strengthening agent.The results show that the gel can be used under the conditions of reservoir temperature of 70℃,total salinity of 26205 mg/L with gelation time of 4 d,gel strength of H level,and plugging rate of more than 90%,which provides certain guiding significance for the solution to deep water plugging.