Research on Wangqing Oil Shale Physical and Mechanical Properties and Hydraulic Fracturing Pressure

Abstract:

This paper mainly studied the physical and mechanical properties and the breakdown pressure of oil shale in Wangqing of Jilin Province. Firstly, the physical and mechanical properties of oil shale were studied with DNS300 electronic universal testing machine and the range of these parameters was obtained by analysis. In the vertical bedding direction, the compressive strength of oil shale is 21～30MPa, the tensile strength is 1.1～3MPa, the elastic modulus is 7.1～9.9GPa, the Poisson’s ratio is 0.21～0.27 and the shear modulus is 3.4GPa. In the parallel bedding direction, the compressive strength is 13～17MPa, the tensile strength is 0.3～0.6MPa, the elastic modulus is 1.2～1.6GPa, the Poisson’s ratio is 0.31～0.36 and the shear modulus is 0.5GPa. According to the experiment results, the breakdown pressure of Wangqing oil shale was calculated theoretically by selecting the appropriate parameters. Then the hydraulic fracturing experiments of oil shale were carried out by using true tri-axial hydraulic fracturing device, the results show that the breakdown pressure of Wangqing oil shale is 5.34MPa. On the basis of the theoretical calculation and experiment results, it is suggested that the breakdown pressure of the hydraulic fracturing experiment in the site of Wangqing oil shale should be controlled in 4～6MPa.

Key words:Wangqing oil shale; physical and mechanical properties; hydraulic fracturing experiment; breakdown pressure of hydraulic fracturing