Scholarlink

<p>The interaction between fracturing fluid and rock through hydration significantly alters the mineral composition and pore structure of the rock. Despite its potential, the beneficial effects of hydration on hydraulic fracturing in deep reservoirs are still largely unexplored. Therefore, we conducted large-scale multi-stage pre-soaking hydraulic fracturing tests on sandstone, considering the stress state of deep reservoirs. The investigation focused on the impact of soaking pretreatment at different sustained pressures and soaking durations on multi-fracture propagation and peak pump pressure. Subsequently, we analyzed the microstructural evolution characteristics of sandstone under continuous hydration using scanning electron microscopy (SEM), energy-dispersive spectrometer (EDS) and X-ray diffraction (XRD). The results indicate that conventional multi-stage fracturing induces relatively simple fracture propagation patterns, with peak pump pressure exhibiting a progressive increase across phases (phase I → phase II → phase III). Soaking pretreatment reduces the fluctuation range of peak pump pressure between fracturing phases and increases the complexity of hydraulic fractures. Increasing sustained pressure levels further stabilizes inter-stage pressure fluctuations and promotes multiple hydraulic fracture initiation within a single stage. Additionally, we observed that extended soaking durations at constant pressure levels facilitate peak pump pressure reduction, while shorter durations favor the development of complex fracture networks. Quartz is the predominant mineral component in sandstone, and its brittle failure under hydration is a significant reason for the premature initiation of hydraulic fractures. The longer soaking duration promotes the disintegration of quartz minerals, whereas high sustained water pressure suppresses their failure. Conversely, mineral expansion reduces pore volume and closes local microfractures, increasing the pump pressure required to initiate hydraulic fractures. These findings provide valuable data and theoretical guidance for multi-stage fracturing optimization in deep reservoirs.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Experimental Investigation of Hydration Effects on the Initiation and Propagation of Multiple Hydraulic Fractures

  • 期刊论文

  • 发表日期：

    2025年10月10日

查看全文
  • Mingyu Yao,
  • Hai Yang,
  • Yingjie Xia,
  • Jian Chen,
  • Chun’an Tang

摘要

The interaction between fracturing fluid and rock through hydration significantly alters the mineral composition and pore structure of the rock. Despite its potential, the beneficial effects of hydration on hydraulic fracturing in deep reservoirs are still largely unexplored. Therefore, we conducted large-scale multi-stage pre-soaking hydraulic fracturing tests on sandstone, considering the stress state of deep reservoirs. The investigation focused on the impact of soaking pretreatment at different sustained pressures and soaking durations on multi-fracture propagation and peak pump pressure. Subsequently, we analyzed the microstructural evolution characteristics of sandstone under continuous hydration using scanning electron microscopy (SEM), energy-dispersive spectrometer (EDS) and X-ray diffraction (XRD). The results indicate that conventional multi-stage fracturing induces relatively simple fracture propagation patterns, with peak pump pressure exhibiting a progressive increase across phases (phase I → phase II → phase III). Soaking pretreatment reduces the fluctuation range of peak pump pressure between fracturing phases and increases the complexity of hydraulic fractures. Increasing sustained pressure levels further stabilizes inter-stage pressure fluctuations and promotes multiple hydraulic fracture initiation within a single stage. Additionally, we observed that extended soaking durations at constant pressure levels facilitate peak pump pressure reduction, while shorter durations favor the development of complex fracture networks. Quartz is the predominant mineral component in sandstone, and its brittle failure under hydration is a significant reason for the premature initiation of hydraulic fractures. The longer soaking duration promotes the disintegration of quartz minerals, whereas high sustained water pressure suppresses their failure. Conversely, mineral expansion reduces pore volume and closes local microfractures, increasing the pump pressure required to initiate hydraulic fractures. These findings provide valuable data and theoretical guidance for multi-stage fracturing optimization in deep reservoirs.