第39参第4期 2017年7月
石油钻采工艺
OIL DRILLING & PRODUCTION TECHNOLOGY
文章编号：10007393(2017)040417-07
DOI:10.13639/j-odpt.2017.04.005
瞬态力一热耦合作用下水泥环完整性分析
席岩【李军】柳贡慧12查春青严攀
1.中国石海大学（北京)；2.北京工业大学
Vol. 39 No. 4 July 2017
引用格式：席券，李军，柳贡慧，查青，严攀.瞬态力一热帮合作用下水泥环完整性分析[J］.石油钻采工艺，2017,39(4) 417-423.
摘要：页岩气井工程实践表明，套管压裂易导致水泥环完整性发生破坏出现环空带压。基于套管压裂工程实际，建立并筒篇温度场模型和套管一水泥环一地层组合体有限元模型，采用解析法和数值法结合方式，计算页券气井压裂过程中薛态力一热帮合对水泥环应力大小、分布影响规律。结果表明：压裂过程中水泥环内外壁温差先增大后减小，压裂初近内壁处存在陡靖温度梯度，易导致内壁应力显等提高；解态力一热揭合作用导致水泥环内壁应力大幅提升，加剧了水泥环完整性失效的风险，压裂初期为水泥环易发生损环的“风险段”；水泥环内壁最大应力随着时间变化，易产生“多裂纹”形态，加剧环空带压。研完结果可为页券气井压裂过程中水泥环究整性设计控制提供参考。
关键词：页岩气；压裂；环空带压；水泥环；瞬态力-热耦合；完整性
中图分类号：TE329
文献标识码：A
Analysis on cement sheath integrity under transient thermo-mechanical coupling effect
XI Yan', LI Jun', LIU Gonghui, ZHA Chunqing', YAN Pan
1. China University of Pefroleum, Beijing 102249, China; 2. Bejing University of Technology, Bejing 100124, Chine
Citation: XI Yan, LI Jun, LIU Gonghui, ZHA Chunqing, YAN Pan. Analysis on cement sheath integrity under transient thermo-me-chanical coupling effect [J] . Oil Drilling & Production Technology, 2017, 39(4): 417-423.
eaaeeesaae eeaaee leading to sustained annular pressure (SAP). In this paper, the wellbore temperature field calculation model and the finite element model of casing-cement sheath-formation assembly were established based on the actual casing fracturing engineering. The effect laws of tran-sient thermomechanical coupling on the magnitude and distribution of cement sheath stress were calculated by using analytical method and numerical method comprehensively. It is shown that the temperature difference between inside and outside the wall of cement sheath increases firstly and then decreases in the process of fracturing. Steep temperature gradient occurs near the inside wall at the initial frac-turing and it tends to result in obvious increase of stress on the inside wall. Due to the effect of transient thermo-mechanical coupling, the stress on the inside wall of cement sheath is increased significantly, and the risk of cement sheath integrity failure is aggravated. The initial fracturing stage is the *risk period" when cement sheath failure tends to happen easily. As time goes, the maximum stress on the inside wall of cement sheath results in multiple cracks easily and makes the SAP more serious. The research results can provide thc reference for the design and control of cement sheath integrity during the fracturing of shale gas well.
Key words: shale gas; fracturing;sustained annular pressure; cement sheath; transient thermo-mechanical coupling effect; integrity 页岩气井套管压裂压力高、排量大、时间长[14]，力－热耦合作用明显【5-5],极易导致水泥环完整性
持续注人的压裂液导致井筒发生较大温度变化，失效-，造成页岩气井环空带压。统计结果显
基金项目：国家白然科学基金“长本平段非均质页岩销层非均匀分射孔优化研完"（编号：51674272)；中石西南油气分公司项
日“威远长宁页岩气水平并固并质量对并简完整性的影响"（端号：XNS21JS2014-04)。
第一作者：席案(1985-),2008年毕业于中国石油大学(北京)石油工程专业，在续博士研究生，主要从事岩石力季、井简完整性方面的研究
通讯地址：（102249)北京市高平区府学路18号。E-mail；315791585@qq.com
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