基于黏聚力单元法的单双射孔水力裂缝扩展数值模拟研究

为研究单双射孔下的水力劈裂规律,基于Abaqus的黏聚力单元损伤本构,建立了含单双射孔裂隙的有限元模型,对不同水力压裂因子D下的裂纹扩展过程,位移矢量进行了数值模拟研究.结果表明:单裂隙情况下,裂纹扩展产生于裂缝尖端,随着水压的不断增大,D值较小的工况裂缝沿着最大主应力的方向发展,对于D值较大的情况而言,裂缝将呈现45...

Numerical simulation of hydraulic fracture propagation with single-double perforation based on cohesive force element method

In order to study the hydraulic splitting law under single and double perforations, based on the Abaqus cohesive force element damage constitutive law, a finite element model containing single and double perforating fractures is established. the crack propagation process and displacement vector under different hydraulic fracturing factor D are numerically simulated. the results show that the crack propagation occurs at the crack tip in the single fracture condition. with the increasing of water pressure, the fracture with smaller D value develops along the direction of maximum principal stress. for the case with larger D value, the fracture will present a 45 degree failure characteristic. Under the condition of double crack, there is the problem of mutual interference of crack inside, D=1, D. =5 and D=20, the inner end of the two perforating fractures is first separated from each other, then overlapped with each other, and finally a interacting region is formed. when D=2, the inner end will be directly overlapped; the displacement vector of the crack reveals the crack propagation mechanism. Based on the characteristics of tensile failure and shear failure, the mechanism of tensile failure and shear failure is discussed, and the I failure is obtained.