Degradable preformed particle gel as temporary plugging agent for low-temperature unconventional petroleum reservoirs: Effect of molecular weight of the cross-linking agent

作者：Hongjun Zhang, Dao-Yi Zhu, Yonglong Gong, Junhui Qin, Xiaoning Liu, Yuan-Hang Pi, Qi Zhao, Run-Tian Luo, Wansheng Wang, Keke Zhi, Zongjie Mu · 发表于：Petroleum Science · 年份：2022 · DOI：10.1016/j.petsci.2022.07.013 · 被引用次数：39 · 研究领域：Enhanced Oil Recovery Techniques、Hydraulic Fracturing and Reservoir Analysis、Petroleum Processing and Analysis

The development of unconventional petroleum resources has gradually become an important succession for increasing oil production. However, the related engineers and researchers are paying more and more attention to the application of temporary plugging agents (TPAs) for their efficient development. TPAs can expand the stimulated reservoir volume (SRV) and facilitate the flow of oil and gas to the bottom of the well. Particle-gels used as temporary plugging agents have the characteristics of the simple injection process, good deformation, high plugging strength, and complete self-degradation performance, which have been widely applied in recent years. In this paper, five samples of DPPG polymerized by different molecular weights of cross-linking agents were prepared. In addition, infrared spectroscopy analysis, differential calorimetry scanning (DSC) analysis, static particle gel swelling and degradation performance evaluation experiments, and dynamic temporary plugging performance experiments in cores were conducted at 34 °C. Results show that as the molecular weight of the cross-linking agent (at 0.01 g) in the DPPG molecule decreased from 1,000 to 200 Da, the fewer cross-linking sites of DPPG, the looser the microscopic three-dimensional mesh structure formed. The swelling ratio increased from 7 to 33 times. However, the complete degradation time increased from 40 to 210 min. Moreover, the DSC results confirmed that the higher the molecular weight of the cross-linking agent...