Sealing Capacity Analysis of Cement Sheath Based on Combined Mechanical Model

doi:10.12068/j.issn.1005-3026.2020.09.020

Abstract

Abstract: In order to explore the mechanism of cement sheath sealing failure during hydraulic fracturing， a failure analysis method of cement sheath sealing capacity based on combined casing-cement-formation elastic-plastic mechanical model was established. The reliability of the mechanical model and analysis method was verified by numerical simulation and experimental data. With the comparison of equivalent stress and yield strength， strain and ultimate elongation of the material， the cement sheath sealing capacity chart was drawn. The research shows that there is an optimal range for the influence of the elastic modulus of the cement sheath on its sealing capacity. Under the conditions presented in this paper， the elastic modulus of the cement sheath between 6 and 9.7GPa is beneficial to maintain its sealing capacity. This study can provide a reference for the cement parameters selection in horizontal well in different shale formations.

Key words: cement sheath, casing, sealing capacity, equivalent stress, elastic modulus

CLC Number:

TE256

WANG Hai-zhu， SHI Lu-jie， ZHENG Yong， ZHANG Cheng-cheng. Sealing Capacity Analysis of Cement Sheath Based on Combined Mechanical Model[J]. Journal of Northeastern University Natural Science, 2020, 41(9): 1334-1340.

References

[1]Miles A J，Topping A D.Stresses around a deep well［J］.Transactions of the AIME，1949，179(1):186-191.
[2]Zinkham R E，Goodwin R J.Burst resistance of pipe cemented into the earth［J］.Journal of Petroleum Technology， 1962，14(9):1033-1040.
[3]Li Y，Yuan J，Qi F，et al.Analysis of cemented casing mechanical failure under arbitrary in-situ stress field coupling effects of down hole pressure and temperature［C］//IADC/SPE Asia Pacific Drilling Technology Conference and Exhibition.Tianjin:Society of Petroleum Engineers，2012:118-126.
[4]Ferda A，Al-Ghadban H H.Simulation investigation of casing eccentricity estimation for different inclination angles and tensile forces using finite element method［C］//SPE International Petroleum Conference.Mexico City:Society of Petroleum Engineers，2004:26-41.
[5]Salehabadi M，Jin M，Yang J，et al.Effect of casing eccentricity on casing stability analysis in wellbores drilled in gas hydrate bearing sediments［C］//SPE EUROPEC/EAGE Annual Conference and Exhibition.Barcelona:Society of Petroleum Engineers，2010:67-82.
[6]Gholami R，Aadnoy B，Fakhari N.A thermo-poroelastic analytical approach to evaluate cement sheath integrity in deep vertical wells［J］.Journal of Petroleum Science and Engineering， 2016，147:536-546.
[7]Boukhelifa L，Moroni N，James S，et al.Evaluation of cement systems for oil and gas well zonal isolation in a full-scale annular geometry［J］.SPE Drilling & Completion， 2005，20(1):44-53.
[8]初纬，沈吉云，杨云飞，等.连续变化内压下套管-水泥石-围岩组合体微环隙计算［J］.石油勘探与开发，2015，42(3):379-385.(Chu Wei，Shen Ji-yun，Yang Yun-fei，et al.Calculation of micro-annulus size in casing-cement sheath-formation system under continuous internal casing pressure change［J］.Petroleum Exploration and Development， 2015，42(3):379-385.)
[9]Tabatabaei M，Dahi T A，Alem N.Economic nano-additive to improve cement sealing capability［C］//SPE Western Regional Meeting.San Jose:Society of Petroleum Engineers，2019:156-163.
[10]Jackson P B，Murphey C E.Effect of casing pressure on gas flow through a sheath of set cement［C］//SPE/IADC Drilling Conference.Amsterdam:Society of Petroleum Engineers，1993:223-233.
[11]Garnier A，Fraboulet B，Saint-Marc J，et al.Characterization of cement systems to ensure cement sheath integrity［C］//Offshore Technology Conference.Houston，2007:182-193.
[12]王克诚，张立，杨秀天，等.套管-水泥石界面水力封隔能力室内实验研究［J］.西部探矿工程，2011，23(5):69-70.(Wang Ke-cheng，Zhang Li，Yang Xiu-tian，et al.Laboratory experimental study on hydraulic sealing capability of casing-cement ring interface［J］.West-China Exploration Engineering， 2011，23(5):69-70.)
[13]Vralstad T，Skorpa R，Werner B.Experimental studies on cement sheath integrity during pressure cycling［C］//SPE/IADC International Drilling Conference and Exhibition.Amsterdam:Society of Petroleum Engineers，2019:78-92.
[14]张靖华.弹塑性力学基础［M］.北京:航空工业出版社，2016:171.(Zhang Jing-hua.Elastoplastic mechanics［M］.Beijing:Aviation Industry Press，2016:171.)
[15]Witt C，Tahmourpour F.Thermal sealants improve cementing in SAGD areas［J］.Journal of Canadian Petroleum Technology， 2009，48(6):39-43.
[16]Tahmourpour F，Hashki K，Elhassan H I.Different methods to avoid annular pressure buildup by appropriate engineered sealant and applying best practices (cementing and drilling)［J］.SPE Drilling & Completion， 2010，25(2):248-252.
[17]刘继生，曾桂红，谢荣华，等.固井形成的水力封隔系统封隔能力评价方法［J］.测井技术，2006(1):94-96.(Liu Ji-sheng，Zeng Gui-hong，Xie Rong-hua，et al.Evaluation of isolation ability of the hydraulic isolating system formed by cementing［J］.Well Logging Technology， 2006(1):94-96.)
[18]景丰.陆相页岩气水平井中增韧防气窜固井水泥浆体系的研究［J］.石油化工应用，2018，37(7):5-10.(Jing Feng.Study on cementing slurry system of toughening and preventing gas channeling in continental shale gas horizontal wells［J］.Petrochemical Industry Application， 2018，37(7):5-10.)
[15]关守平，房少纯.一种新型的区间-粒子群优化算法［J］.东北大学学报(自然科学版)，2012，33(10):1381-1384.(Guan Shou-ping，Fang Shao-chun.A new interval particle swarm optimization algorithm［J］.Journal of Northeastern University(Natural Science)，2012，33(10):1381-1384.)