Abstract:In order to study the influences of shale natural bedding inclination angle and strength on hydraulic fracturing crack growth, indoor hydraulic fracturing experiment was performed. Real-time monitoring of crack growth and water injection pressure information and sample cutting after fracturing were conducted through monitoring holes to analyze the influence of bedding inclination angle and strength on fracturing crack growth. The results indicate that in the hydraulic fracturing process, when the main crack with stable expansion of minimum vertical ground stress is encountered with the bedding plane, the smaller the angle between the bedding plane and the initial fracture expansion direction is, the more easily the main crack will be expanded along the direction of the bedding plane. The greater the angle between the bedding plane and the initial fracture expansion direction is, the more easily the main crack will be expended through the bedding plane in the original direction. When the bedding azimuth, the ground stress and the tensile strength do not change, and the tensile strength of bedding plane is far weaker than the tensile strength of the matrix, the main crack encountering the bedding plane is much easier to extend in the direction of the bedding plane. The closer the tensile strength of bedding plane approaches to that of the matrix, the more easily the main crack will be extended through the bedding plane along the original direction. When the bedding azimuth and strength do not change, the main crack is much easier to expend through the bedding plane along the original direction for the greater ground stress and stress difference.