水压裂缝缝内流场的理论研究

水力压裂过程就是地层在受到压裂液作用后裂缝向前延伸扩展的过程。水力压裂过程中,缝内流体的流动特征对裂缝的延伸和形态具有很大的影响。要确定水力压裂过程中的缝宽变化,首先应根据流体力学理论,找出缝内流体压力的分布规律,得出它与裂缝宽度的关系,再根据岩石力学和断裂力学理论,寻求二者在裂缝宽度或压力方向的流固耦合,从而最终确定出裂缝的几何形态。通过缝内流场的理论研究,推导出了一个新的描述缝内流场的理论模型,为求解全三维裂缝几何形态打下了理论基础。

THEORETICAL STUDY OF THE FLUID FIELD WITHIN THE HYDRAULIC FRACTURE

The hydraulic fracture process is the fracture prolongation period when the formation is pressured by the fracture liquid.During the process, the flow character within the fracture greatly influenced on the fracture prolongation and shapes. To determine the fracture width in the hydraulic fracture process,first, it will get the distributed law of the fluid pressure within the fracture, according to the hydraulics theory, and find the relationship between the fluid pressure and the fracture width. And then determine the fracture width or the direction of the coupled fluid-solid. Finally, calculate out the geometry parame-ters of the fracture of the principle of rock mechanics and frac- ture mechanics. The paper derived out a new theoretical model described the flow field within the fracture by the study of the flow field within the fracture, and provided a theory for the so-lution of the 3-D fracture geometry parameters.