水平井分段多簇压裂裂缝起裂和扩展影响因素分析

The Analysis of the Factors Affecting the Fracture Initiation and Propagation of Multi Cluster Fracturing in Horizontal Well

水平井分段多簇压裂工艺是目前较为先进的压裂工艺,该工艺利于增大储层改造体积、节约分段工具成本。虽然该工艺在现场已得到大规模应用,在现场施工方面取得了丰富的经验;但对于段内多簇裂缝的起裂和扩展机理仍然有待进一步认识。采用数值模拟的手段,研究段内多簇裂缝间的起裂和扩展规律;并计算分析了影响多簇裂缝起裂和扩展的5种因素。研究认为:多簇裂缝间的起裂和扩展存在竞争干扰机制,簇间距、施工排量、压裂液黏度、储层弹性模量和储层非均质性对多簇裂缝的起裂和扩展均有直接的影响,其中簇间距是最关键影响因素。

The multi-cluster fracturing technology of horizontal wells is beneficial to increase the volume of reservoir stimulation and save the cost of the segmentation tools. However,the mechanism of the fracture initiation and propagation in the segment is still need to be further recognized. By means of numerical simulation,the fracture initiation and propagation mechanism of multi-cluster fractures in a section is studied,and five factors that affect the fracture initiation and propagation of multi-cluster fractures are calculated and analyzed. The research shows that the initiation and propagation of multi-cluster fractures have a competitive mechanism,and the separation distance between the cluster,the displacement of pump,the viscosity of fracturing fluid,the elastic modulus of the reservoir and the heterogeneity of the reservoir have a direct influence on the fracture initiation and propagation.