单元生死功能数值法在井壁稳定中的应用APPLICATION OF THE NUMERICAL METHOD BY ELEMENT BIRTH AND DEATH FUNCTION IN THE WELLBORE STABILITY
孙清华,邓金根,李玉梅,谭春飞,李军,杨恒林
SUN Qinghua,DENG Jingen,LI Yumei,TAN Chunfei,LI Jun,YANG Henglin
摘要(Abstract):
为了减少煤储层伤害以及最大程度地提高煤层气水平井单井产量,开展了煤层气欠平衡钻井技术的现场应用研究。以沁水盆地3#煤层水平井为例,建立了煤层水平井井壁稳定分析的三维弹塑性有限元模型,运用ANSYS有限元程序中单元生死功能,诊断井周破坏单元并通过对破坏单元的杀死和激活功能,有效地实现了井筒开挖的非连续动态过程,得到了不同钻井液密度下井壁破坏半径长轴、破坏区角度和井径扩大率。单元生死功能数值法对煤层井壁稳定分析准确有效,可进一步推广应用。
In order to reduce the coal reservoir damage and improve the production of individual horizontal CBM well to the greatest extent,the field application researches on CBM underbalanced drilling technology are carried out.Taking No.3 coal seam horizontal well in Qinshui Basin as an example,3D elastoplastic FEM(finite element method) model is established for the analysis of the wellbore stability of the coal-bed well,the element birth and death function in the program of ANSYS finite element is first used to diagnose the damaged elements near the wellbore,and furthermore by means of the functions of killing and activating these failed elements,the discontinuous dynamic process of the wellbore excavation is effectively realized,and morover,the major axis of the damaged wellbore radius,angle of failure zones and wellbore enlarged rate under the conditions of different drilling fluid densities are obtained.The numerical method is accurate and effective for the analysis of the wellbore stability of coal beds,so it can be further generalized and applied.
关键词(KeyWords):
煤层气;井壁稳定;弹塑性;ANSYS;单元生死
CBM;wellbore stability;elastoplastic/elastic-plastic/elastoplasticity;ANSYS;element birth and death
基金项目(Foundation): 国家科技重大专项“煤层气钻井工程技术及装备研制——煤层气储层保护与井壁稳定技术研究”(2011ZX05036);国家科技重大专项课题“复杂结构井优化设计与控制关键技术”(2011ZX05009-005);; 国家“973”重大专项“深井复杂地层安全高效钻井基础研究——深井复杂地层钻井压力系统模型与规律”(2010CB226704)
作者(Author):
孙清华,邓金根,李玉梅,谭春飞,李军,杨恒林
SUN Qinghua,DENG Jingen,LI Yumei,TAN Chunfei,LI Jun,YANG Henglin
参考文献(References):
- [1]郭布民,张士诚,李艳丽,等.支撑剂嵌入对煤岩水力裂缝导流能力的影响[J].大庆石油地质与开发,2010,29(5):121-124.
- [2]鲜保安,高德利,陈彩红,等.煤层气高效开发技术[J].特种油气藏,2004,11(4):63-66.
- [3]Mutalik P N,Magness W D.Production data analysis of horizontal CBM wells in Arkoma Basin[R].SPE 103206,2006.
- [4]Clarkson C R,Jordan C L,Production data analysis of fractured and horizontal CBM wells[R].SPE 15929,2009.
- [5]李涛,董平川,曹丽丽.双区复合煤层气压力动态特征分析[J].大庆石油地质与开发,2012,31(5):79-82.
- [6]陈科贵,夏亚良.斜井井壁稳定的测井预测方法[J].大庆石油地质与开发,2011,30(6):172-174.
- [7]李孟杰,刁素,张国东,等.定向井压裂特征及原因[J].大庆石油地质与开发,2009,28(6):196-199.
- [8]Gennanovich L N,Dyskin A V.Fracture mechanisms and instability of opening in compression[J].International Journal of Rock Mechanics and Mining Sciences,2000,37(1):263-284.
- [9]Mclean M R,Addis M A.Wellbore stability:the effect of strength criteria on mud weight recommendations[R].SPE 20405,1990.
- [10]韩有旺,李九红.ANSYS在纤维布加固钢筋混凝土梁的非线性分析的应用[J].西北水力发电,2006,22(4):53-55.
- [11]司政,李守义.基于ANSYS的大体积混凝土温度场计算程序开发[J].长江科学院院报,2011,28(9):53-56.
- [12]李嗣贵,邓金根,李明志.节理破碎地层井壁稳定的离散元分析[J].岩石力学与工程学报,2002,21(增1):2139-2143
- 煤层气
- 井壁稳定
- 弹塑性
- ANSYS
- 单元生死
CBM - wellbore stability
- elastoplastic/elastic-plastic/elastoplasticity
- ANSYS
- element birth and death