近日，中国石油大学赵海峰团队报道了考虑中间主应力和t应力影响的水力裂缝与天然裂缝相互作用判据。相关论文于2025年12月18日发表在《理论与应用力学快报》杂志上。

研究组聚焦页岩和致密砂岩等常规储层具有低孔隙度和低渗透率的特点。水平井井筒压裂技术可以在储层内形成一定复杂程度的裂缝网络，从而提高油气采收率。水力裂缝（HF）与天然裂缝（NF）之间的相互作用对裂缝网络的复杂性起着至关重要的作用。

研究组考察了HF和NF的相互作用过程，将统一强度理论作为天然裂缝对面裂缝起裂判据，并考虑了t应力对非线性区半径的影响。提出了兼顾中间主应力和t应力效应的相互作用准则，预测结果与实验结果高度一致。灵敏度分析结果表明，t应力会影响非线性区的临界半径，从而引起诱导应力大小的扰动。考虑t应力后，贯通区范围增大，开孔区范围减小。然而，当接近角较大时，t应力的影响减小。随着泊松比、黏聚力和断裂韧性的增加，抗拉强度降低，HF更容易穿透NF，形成单一断裂形态。较低的应力差和较低的拉压比促进天然裂缝的打开。随着中间主应力系数的增大，开滑区范围扩大，侵彻区范围缩小。

附：英文原文

Title: A hydraulic fracture and natural fracture interaction criterion considering the influence of intermediate principal stress and T-stress

Author: Haifeng Zhao, Wang Zhang, Hongwei Shi, Hong Guo

Issue&Volume: 2025-12-18

Abstract: Highlights of the StudyUnconventional reservoirs such as shale and tight sandstone exhibit low porosity and low permeability. By applying horizontal wellbore fracturing techniques, a fracture network with a certain degree of complexity can be created within the reservoir to enhance oil and gas recovery. The interaction between hydraulic fracture(HF) and natural fracture(NF) plays a crucial role in determining the complexity of the fracture network. This study examines the interaction process between HF and NF, using the unified strength theory as the fracture initiation criterion for the fracture on the opposite side of natural fractures, and considering the influence of T-stress on the radius of the nonlinear zone. An interaction criterion that accounts for both intermediate principal stress and T-stress effects is proposed, and the predictions are highly consistent with experimental results. The results of the sensitivity analysis indicate that T-stress influences the critical radius of the nonlinear zone, thereby causing disturbances in the magnitude of induced stress. With T-stress taken into account, the extent of the penetration zone increases, and the extent of the opening zone decreases. However, at high approach angles, the influence of T-stress diminishes. As the Poisson’s ratio, cohesion, and fracture toughness increase, the tensile strength decreases, making HF more likely to penetrate NF, resulting in a single fracture morphology. A lower stress differential and a lower tensile-to-compressive ratio promote the opening of natural fractures. Additionally, as the intermediate principal stress coefficient increases, the ranges of the opening and slip zones expand, while the penetration zone shrinks.

DOI: 10.1016/j.taml.2025.100645

Source: http://taml.cstam.org.cn/article/doi/10.1016/j.taml.2025.100645pageType=en