Yang Shichu, Yu Weichu, Zhao Mingwei, Ding Fei, Zhang Ying
College of Chemistry & Environmental Engineering, Yangtze University, Jingzhou 434023, China.
Hubei Engineering Research Centers for Clean Production and Pollution Control of Oil and Gas Fields, Jingzhou 434023, China.
Gels. 2024 May 18;10(5):345. doi: 10.3390/gels10050345.
Low-viscosity slickwater fracturing fluids are a crucial technology for the commercial development of shallow shale gas. However, in deep shale gas formations with high pressure, a higher sand concentration is required to support fractures. Linear gel fracturing fluids and crosslinked gel fracturing fluids have a strong sand-carrying capacity, but the drag reduction effect is poor, and it needs to be pre-prepared to decrease the fracturing cost. Slick water fracturing fluids have a strong drag reduction effect and low cost, but their sand-carrying capacity is poor and the fracturing fluid sand ratio is low. The research and development of viscous slick water fracturing fluids solves this problem. It can be switched on-line between a low-viscosity slick water fracturing fluid and high-viscosity weak gel fracturing fluid, which significantly reduces the cost of single-well fracturing. A polyacrylamide drag reducer is the core additive of slick water fracturing fluids. By adjusting its concentration, the control of the on-line viscosity of fracturing fluid can be realized, that is, 'low viscosity for drag reduction, high viscosity for sand-carrying'. Therefore, this article introduces the research and application status of a linear gel fracturing fluid, crosslinked gel fracturing fluid, and slick water fracturing fluid for deep shale gas reservoirs, and focuses on the research status of a viscous slick water fracturing fluid and viscosity-controllable polyacrylamide drag reducer, with the aim of providing valuable insights for the research on water-based fracturing fluids in the stimulation of deep shale gas reservoirs.
低粘度滑溜水压裂液是浅层页岩气商业开发的关键技术。然而，在高压深层页岩气地层中，需要更高的砂浓度来支撑裂缝。线性凝胶压裂液和交联凝胶压裂液携砂能力强，但减阻效果差，且需提前配制以降低压裂成本。滑溜水压裂液减阻效果强且成本低，但其携砂能力差且压裂液砂比低。粘性滑溜水压裂液的研发解决了这一问题。它可在低粘度滑溜水压裂液和高粘度弱凝胶压裂液之间在线切换，显著降低单井压裂成本。聚丙烯酰胺减阻剂是滑溜水压裂液的核心添加剂。通过调节其浓度，可实现对压裂液在线粘度的控制，即“低粘度减阻，高粘度携砂”。因此，本文介绍了深层页岩气藏线性凝胶压裂液、交联凝胶压裂液和滑溜水压裂液的研究与应用现状，并重点阐述了粘性滑溜水压裂液及粘度可控聚丙烯酰胺减阻剂的研究现状，旨在为深层页岩气藏增产改造中水性压裂液的研究提供有价值的见解。
