... geologist wellbore design reservoir characterization characteristic united states government reservoir geomechanics rock mech uniaxial loading static compressive load jointed rock coalescence compressive load fracture behavior failure mode fissured rock wing crack uniaxial compression...

... fracturing wing crack coalescence eng compression int ARMA 21 1131 Fracture Coalescence in Brittle Materials under Uniaxial and Biaxial Compression: Numerical Investigation via FDEM Di Wu, Haibo Li, Liwang Liu and Shuaiyang Fu State Key Laboratory of Geomechanics and Geotechnical Engineering...

... significant flow rate increase can be achieved through the fracture network generation in the process of fracture propagation and coalescence. In addition, both tensile wing cracks, shear and/or mixed-mode propagated secondary cracks can form during shear stimulation. These observations show that the so...

... Abstract: Shear slip on the natural fractures is proposed as a viable stimulation mechanism in unconventional geothermal and petroleum reservoirs. Fracture mechanics studies show that the propagation of mechanically closed fractures often involves both mode I and II propagation. Wing cracks...

... to describe the path of wing crack propagation which is more closed to reality. third, representative elemental volumes are adopted to tackle the damage localization. The new model is applied to investigate the influence of microcrack parameters on the depth and area of splitting failure zone. This study can...

... at the tip of the flaw and may propagate in two directions: (1) coplanar or nearly coplanar to the flaw; (2) parallel to the wing cracks but in the opposite direction. Among the two directions observed for secondary cracks, the coplanar direction has been reported in a large number of studies while...

... initiation specimen hydraulic fracturing wing crack einstein hh Reservoir Characterization element method DEM Coalescence loading fracture flaw compression open flaw tensile crack rock mass crack initiation application uniaxial compression propagation 1. INTRODUCTION It is well known...

... reasonably well tensile and shear coalescence in gypsum and marble, respectively. For the coplanar flaws, it was found that the stress field analysis is capable of explaining wing crack initiation and propagation observed in tests on gypsum and marble. It is also capable of explaining shear coalescence...

... with single closed type pre-existing surface crack in glass, marble, etc (Figs. 1a and 1b). Besides the initiation of wing cracks, petal cracks which grew along the internal curve fronts of the pre-existing surface cracks were reported. In marble specimens, the propagation of the wing cracks and petal cracks...

... in the vicinity of the crack tip is altered significantly. Reservoir Characterization inclination angle wing crack hydraulic fracturing CCNBD specimen crack inclination angle chevron notch crack reservoir geomechanics Upstream Oil & Gas crack plane failure load notch crack cyclic loading...

... to some representative cases. In general, with the load increasing, the preformed crack closed first. Then, slide deformation occurred along the crack. Wing crack appeared on the tip of original crack and propagated along the maximum stress direction. Afterwards, secondary cracks grew in echelon shape...

... has been done on fracturing processes on rocks and rock-model materials in compression. Although there are some differences in the crack patterns observed in compression depending on the materials used, two types of cracks are commonly found from a pre-existing fracture: wing cracks and secondary...

... ABSTRACT: A total of 170 tests (68 tests for monotonic loading, 102 tests for cyclic loading) have been performed to investigate crack initiation, propagation and coalescence. The specimens have two pre-existing flaws which are arranged at different distances and angles. Wing cracks...

... ABSTRACT: Two types of cracks are observed in brittle materials in compression: wing cracks and secondary cracks. Wing cracks are tensile cracks that initiate at the tips of pre-existing cracks (flaws) and propagate in a stable manner towards the direction of maximum compression. Secondary...

... strength grain marble wave speed measurement Reservoir Characterization microcrack crack length prediction peak strength Upstream Oil & Gas crack density reservoir geomechanics wing crack grain size initial crack density specimen fine grain marble marble crack growth...

... tensile failure crack length deflection loading reservoir geomechanics Thickness pressure solution long-term loading Reservoir Characterization Upstream Oil & Gas wing crack initial crack length compressive strength tensile strength compressive failure deformation stress...

... cracks sufficiently grown due to the stress concentration at the fault front. This mechanism makes the fault "thick" and, hence, restricts the stress concentration. It is shown that while this stress concentration is sufficient for connecting wing cracks, it is not enough to produce tensile out-of-plane...