caa a22 4500 605454159 CHVBK 20210128100205.0 cr unu---uuuuu 210128e20150801xx s 000 0 eng 10.1007/s10064-014-0665-x doi (NATIONALLICENCE)springer-10.1007/s10064-014-0665-x Experimental investigation of hydraulic fracture propagation in fractured blocks [Elektronische Daten] [Ali Dehghan, Kamran Goshtasbi, Kaveh Ahangari, Yan Jin] Natural fractures in reservoirs can be the cause of many adverse effects during hydraulic fracturing treatment. In the present paper, hydraulic fracturing tests are used to investigate the interaction of a propagating hydraulic fracture with a natural fracture in the fractured blocks. Systematic experiments were designed and performed on the cement blocks with different pre-existing fracture strikes and dips (30°, 60° and 90°). The effect of horizontal stress difference on the propagation of hydraulic fractures was also determined through a series of experiments with different values for Δσ, which were 5 and 10MPa, respectively. Propagation arrest of the hydraulic fracture and crossing the pre-existing fracture were two dominating fracture behaviors at horizontal stress differences of 5 and 10MPa, respectively. It was observed that both the magnitude of differential stress and the pre-existing fracture geometry can magnify the effect of a pre-existing fracture on hydraulic fracture propagation. When the horizontal differential stress is low (5MPa), the hydraulic fracture crosses the pre-existing fracture at a high pre-existing fracture dip (90°) and at an intermediate to high pre-existing fracture strike (60°-90°), while hydraulic fracture is arrested by the opening of the pre-existing fracture at a pre-existing fracture strike (30°). Meanwhile, when the pre-existing fracture dip is low to intermediate (30°-60°) and its strike is low to high (30°-90°), hydraulic fracture is arrested by the opening and shear slippage of the pre-existing fracture in this situation. However, at a high horizontal differential stress (10MPa), when the pre-existing fracture dip is low to high (30°-90°), the hydraulic fracture crosses the pre-existing fracture at the strike of the pre-existing fracture of 60°-90°, and when it is decreased to 30°, the hydraulic fracture is arrested by th eopening and shear slippage of the pre-existing fracture. Therefore, the pre-existing fracture's strike and dip play a significant role in the propagation of hydraulic fracture at a low horizontal stress difference, while the role of the pre-existing fracture dip at a high horizontal stress difference is less than the pre-existing fracture strike on the propagation of hydraulic fracture. Springer-Verlag Berlin Heidelberg, 2014 Hydraulic fracture propagation nationallicence Laboratory experiments nationallicence The pre-existing fracture strike and dip nationallicence Horizontal stress difference nationallicence μ : Fluid viscosity, m/Lt (Pas) nationallicence σ h : Minimum principal stress in horizontal direction, m/Lt2 (Pa) nationallicence σ H : Maximum principal stress in horizontal direction, m/Lt2 (Pa) nationallicence σ v : Principal stress in vertical direction, m/Lt2 (Pa) nationallicence ∆σ : Horizontal stress difference, m/Lt2 (Pa) nationallicence p : Fluid pressure, m/Lt2 (psi) nationallicence q : Flow rate of fluid, L3/t (m3/s) nationallicence E : Young's modulus of elasticity, m/Lt2 (Pa) nationallicence $$ \nu $$ ν : Poisson's ratio nationallicence σ c : Unconfined compressive strength, m/Lt2 (Pa) nationallicence T 0 : Tensile strength, m/Lt2 (Pa) nationallicence k : Permeability, L2 (m2) nationallicence ϕ : Porosity (%) nationallicence α : Angle of the dip, angle (°) nationallicence β : Angle of the strike, angle (°) nationallicence $$ U_{\text{m}}^{i} $$ U m i : Maximum allowable closure for load cycle i, L (mm) nationallicence U n : Current normal displacement, L (mm) nationallicence K n0 : Initial normal stiffness, m/L2 t2 (Pa/mm) nationallicence σ n : Confining stress, m/Lt2 (Pa) nationallicence Dehghan Ali Department of Mining Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran aut Goshtasbi Kamran Department of Mining Engineering, Tarbiat Modares University, Tehran, Iran aut Ahangari Kaveh Department of Mining Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran aut Jin Yan Faculty of Petroleum Engineering, China University of Petroleum, Beijing, China aut Bulletin of Engineering Geology and the Environment Springer Berlin Heidelberg 74/3(2015-08-01), 887-895 1435-9529 74:3<887 2015 74 10064 https://doi.org/10.1007/s10064-014-0665-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10064-014-0665-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Dehghan Ali Department of Mining Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran aut NATIONALLICENCE 700 1- Goshtasbi Kamran Department of Mining Engineering, Tarbiat Modares University, Tehran, Iran aut NATIONALLICENCE 700 1- Ahangari Kaveh Department of Mining Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran aut NATIONALLICENCE 700 1- Jin Yan Faculty of Petroleum Engineering, China University of Petroleum, Beijing, China aut NATIONALLICENCE 773 0- Bulletin of Engineering Geology and the Environment Springer Berlin Heidelberg 74/3(2015-08-01), 887-895 1435-9529 74:3<887 2015 74 10064