螺旋射孔对水平缝水力压裂过程影响的数值模拟  

A numerical study on effects of helical perforation on hydraulic fracturing of horizontal fractures

作　　者：杨野[1,2] 彪仿俊[1,3] 王瀚[3] 

机构地区：[1]中国石油大学石油天然气工程学院,北京102249 [2]中国石油大庆油田有限责任公司采油工程研究院,黑龙江大庆163453 [3]中国科学技术大学近代力学系,安徽合肥230026

出　　处：《石油学报》2012年第6期1076-1079,共4页Acta Petrolei Sinica

基　　金：中国石油科技创新基金项目(2010D-5006-0209)资助

摘　　要：以非线性流固耦合方程为基础建立了射孔油井和地层的水力压裂三维计算模型,并模拟、讨论了常用螺旋射孔相位角对水平裂缝压裂的影响。数值模拟结果表明,在地应力方向不确切的情况下,采用螺旋射孔是一种有效降低裂缝起裂压力的技术措施。在裂缝扩展过程中,每个射孔都可能形成一条裂缝,但由于相邻射孔之间的距离很近,在井筒附近各条裂缝相互干扰严重,各条裂缝的形态差异很大;伴随着岩石破碎,各个射孔形成的裂缝相互贯通,逐渐融合成一条主裂缝。螺旋射孔对压裂的延伸压力和裂缝形态有相当程度的影响。A 3D fluid-solid coupling finite element model for hydraulic fracturing of＇ oil wells with perforation anti tormauons was established. Effects of different helical perforation phase angles on fracture evolution were simulated and studied. The result of numerical simulation demonstrates that helical perforation is an effective technique of reducing fracture initiation pressures when the direction of horizontal maximum stress is not confirmed. During fracture propagation each perforation may generate a fracture, however, different fractures can disturb each other seriously near wellbore because they are close to each other and their configurations are very different. Fractures connect together accompanied with rock fragmentation gradually to engender a main fracture. Helical perforation has a considerable effect both on fracture propagation and on final configuration. The present result is valuable for the design of horizontal fracture treatments.

关 键 词：三维有限元模型 螺旋射孔 定向射孔 水平缝 缝间干扰 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]