裂缝三维非对称延伸模型的建立及加砂程序的确定

油气层水力压裂时,所产生的裂缝将在长、宽、高三方向同时延伸。为了提高压裂设计的准确性和施工的成功率,本文建立了水力压裂裂缝三维非对称延伸的数学模型。该模型考虑了注液过程中的井筒温度变化和裂缝中的热交换对裂缝几何形态的影响。在此基础上,根据各段裂缝所需的导流能力,确定了各段裂缝填砂所应具有的面积浓度,以及相应的地面各注入段的砂比。

Establishment of Mathematical Model for Hydraulic Fracture 3D Propagation and Determination of Proppant Injection Schedule

The fracture created in reservoirs by hydraulic fracturing will propagate in three directions of length, width and height. Consequently , in order to improve the design of hydraulic fracturing and assure successful operation, a mathematical model for hydraulic fracture three dimensional propagation is presented in the paper. The model takes into account the effect of the heat transfer in the wellbore and fractures during fracturing fluid injection on fracture geometry. On the basis of this, and according to the fracture conductivity needed by each segment of fracture, this paper determines the in-situ area sand concentrations for each segment and the sand ratio of the corresponding surface injection segments.