Bao Dan, Liu Siyuan, Zhang Xianli, Li Feng, Wang Jiaqin, Jia Huan, Liu Shanghao, Zhang Peng
School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, Chongqing 401331, China.
Chongqing Oil and Gas Chemical Engineering Technology Research Center, Chongqing 401331, China.
Gels. 2023 Sep 9;9(9):735. doi: 10.3390/gels9090735.
Lost circulation is a world-class problem, and the contradiction between plugging and unplugging in reservoirs is a problem that needs to be solved urgently. The traditional LCM is not suitable for reservoirs and the complex subsequent operations. Currently, a self-degrading plugging material is proposed. In this paper, a new self-degradation plugging material, CKS-DPPG, was prepared by AM, GG, nano silica, and PEGDA. The effects of reactant concentration, pH, mineralization, etc., on the swelling and degradation performance of CKS-DPPG were investigated. The plugging capacity was tested by fracture plugging equipment, and the mechanism of self-degradation was revealed. The results show that the CKS-DPPG reached a 50% degradation rate in 54 h and complete degradation in 106 h at 80 °C and pH = 8. Low temperatures, high mineralization, and weak alkaline conditions prolong the complete degradation time of CKS-DPPG, which facilitates subsequent operations. The simulation of the 3 mm opening fracture plugging experiment showed that the pressure-bearing capacity reached 6.85 MPa and that a 0.16 MPa pressure difference could unplug after degradation. The ester bond of PEGDA is hydrolyzed under high-temperature conditions, and the spatial three-dimensional structure of CKS-DPPG becomes linear. The CKS-DPPG can effectively reduce subsequent unplugging operations and lower production costs.
漏失是一个世界级难题，储层封堵与解堵之间的矛盾是亟待解决的问题。传统的堵漏材料不适用于储层及后续复杂作业。目前，提出了一种自降解堵漏材料。本文采用丙烯酰胺（AM）、瓜尔胶（GG）、纳米二氧化硅和聚乙二醇二丙烯酸酯（PEGDA）制备了一种新型自降解堵漏材料CKS-DPPG。研究了反应物浓度、pH值、矿化度等对CKS-DPPG溶胀和降解性能的影响。通过裂缝堵漏设备测试了其堵漏能力，并揭示了自降解机理。结果表明，在80℃、pH = 8条件下，CKS-DPPG在54 h内降解率达到50%，106 h完全降解。低温、高矿化度和弱碱性条件会延长CKS-DPPG的完全降解时间，有利于后续作业。3 mm开口裂缝堵漏实验模拟表明，承压能力达到6.85 MPa，降解后压差0.16 MPa时可解堵。PEGDA的酯键在高温条件下水解，CKS-DPPG的空间三维结构变为线性。CKS-DPPG能有效减少后续解堵作业，降低生产成本。
