高压水射流射孔井眼应力数值模拟研究

NUMERICAL MODELING OF STRESSES AROUND A WELLBORE WITH HYDROJETTING PERFORATIONS

刘丽 李根生 黄中伟

Liu Li Li Gensheng Huang Zhongwei

中国石油大学石油工程学院, 山东东营 257061 中国石油大学石油天然气工程学院, 北京 102249

水力射孔技术是一种新型完井方式,利用深穿透水力射孔技术辅助定向压裂,可实现油层改造和油井增产。考虑套管水泥环的影响,采用有限元理论结合ANSYS软件计算了高压水射流水力射孔井眼周围的应力,重点分析了水力射孔参数对井周应力的影响规律,初步研究了直井水力压裂时水力射孔对裂缝起裂的影响。计算结果表明,沿最大水平地应力方向布孔时,孔眼根部的周向拉应力最大,裂缝将会在孔眼根部起裂;选择合理水力射孔参数可有效降低地层破裂压力。研究结果可为高压水射流水力射孔辅助定向压裂提供参数优选的依据。

Hydraulic perforating is an emerging completion technique. Oriented fracturing aided by waterjet deep perforating will achieve improving reservoir and enhancing oil well production. consideration impact on ca sing and cement sheath of stresses, numerical analyses were calculated to obtain the understanding of hoop stress distribution around a vertical wellbore with hydrojetting perforations by means of the software package ANSYS. Meanwhile, the influence of hydrojetting perforation parameters on hoop stress was elaborated. The analysis result shows that selecting proper waterjetting perforation parameters is beneficial for hydraulic fracture initiation. So this study can provide the basis of optimizing perforation parameters for oriented fracturing assisted by hydrojetting perforating.

10.3969/j.issn.1000-7393.2005.04.020