水力压裂支撑裂缝内流体渗流特性及影响机制研究  

Fluid Seepage Characteristics and Influence Mechanism in Propped Fractures by Hydraulic Fracturing

作　　者：李辉 LI Hui(Xinyuan Company,Lu'an Chemical Group Co.,Ltd.,Jinzhong 030600,China)

机构地区：[1]潞安化工集团新元公司,山西晋中030600

出　　处：《山西煤炭》2024年第1期64-70,共7页Shanxi Coal

摘　　要：为了解支撑裂缝内流体的渗流特性及其影响机制,基于支撑剂充填裂缝导流能力物理实验,构建了单相流体在支撑裂缝孔隙结构中流动的数值模型与支撑裂缝三维裂缝模型,通过研究支撑裂缝内的流体渗流分布特性与多孔介质孔隙结构的空间分布特性,揭示了流体在支撑裂缝的渗流机制。研究结果表明:支撑裂缝空间内的流体渗流具有不均匀分布特性,从裂缝底层至顶层逐渐出现高导流能力的“明渠”,流速不均匀增大;支撑裂缝内从底层至顶层面孔隙度逐渐增大,体孔隙度先减小后增大,力链分布先增大后减小,体孔隙度是面孔隙度靠力链机制堆叠形成的;支撑裂缝空间内孔隙度分布与导流能力分布不一致,水平面孔隙度直接影响渗流速度,面孔隙度越大,流速越快。To understand the fluid seepage characteristics of propped fractures and their influence mechanisms,this paper constructs a numerical model of single-phase fluid flow in the pore structure of propped fractures and a three-dimensional model of propped fractures based on the physical experiments on the conductivity of proppant-filled fractures.The seepage mechanism of fluid in propped fractures was revealed by studying the fluid seepage distribution and the spatial distribution of the pore structure of porous media.The results showed that the fluid seepage in the propped fracture space was distributed unevenly,“open channels”with high conductivity gradually emerged from the bottom to the top of the fracture,and the flow velocity increased unevenly.The porosity gradually increased from the bottom to the top layer in the supported fracture,the volume porosity decreased first and then increased,the force chain distribution also increased first and then decreased,and volume porosity was formed by the stacking of surface porosity through the“force chain”mechanism.The porosity distribution in the propped fractures was inconsistent with the conductivity distribution.The horizontal surface porosity directly affected the seepage speed.The larger the surface porosity,the faster the flow velocity.

关 键 词：支撑剂 水力压裂 裂缝 导流能力 多孔介质 

分 类 号：TD714[矿业工程—矿井通风与安全]