Knowledge Management System of Institute of Rock and Soil Mechanics,CAS
| Mechanical analysis on cement sheath integrity under asymmetric load | |
| Zhang, Xiaoyu1,2; Wang, Lei1; Bi, Zhenhui1; Guo, Yintong1; Yang, Chunhe1; Yang, Hanzhi3; Chang, Xin1 | |
| 2021-10-29 | |
| Source Publication | JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY
 |
| ISSN | 2190-0558 |
| Pages | 12 |
| Abstract | In large-scale multi-section hydraulic fracturing, the stress environment of wellbore is extreme complex, often causing the unbalanced stress distribution around the wellbore. That poses great challenges to the integrity of the sheath. In this paper, firstly, triaxial compression test and triaxial cyclic test are carried out at 130 degrees C to study the deformation characteristics of the cement under high temperature. Then based on that, an appropriate plastic mechanics model is established. Finally, the shakedown theory is applied to analyze the model and acquires a maximum cyclic loading under asymmetric stress. The result shows that (1) the well cement, with the increase of load, shows the plastic flow characteristics and can be regarded as an ideal elastic-plastic material under high temperature. (2) During the cyclic loading and unloading process, the "hysteresis loop" becomes denser, which indicates that the accumulation rate of plastic deformation is continuously declining. The main plastic strain appears in the phase of the first loading. (3) The external pressure P-z plays a positive role in the deformation control of the sheath. With the growth of P-z, the maximum cyclic loading P-max will also increase. (4) Asymmetric stress distribution can significantly affect the bearing capacity of the sheath. If stress difference coefficient lambda = 0.3, the P-max tends to decrease nearly by 50%. With the growth of lambda, the negative influence of stress asymmetry reduces gradually. High external pressure is beneficial to reduce the negative impact of the asymmetry. With the growth of lambda, the benefit tends to enhance. (5) In engineering practice, if the geology around wellhole showcases the strong asymmetry (the value of lambda is large), some steps need to be adopted to reduce the stress concentration. |
| Keyword | Deep shale gas Cement sheath Shakedown theory Asymmetry |
| DOI | 10.1007/s13202-021-01346-4 |
| Indexed By | SCI |
| Language | 英语 |
| Funding Project | National Natural Science Foundation of China[52104010] ; Sinopec Science and Technology Department Project[P21056] |
| WOS Research Area | Energy & Fuels ; Engineering ; Geology |
| WOS Subject | Energy & Fuels ; Engineering, Petroleum ; Geosciences, Multidisciplinary |
| WOS ID | WOS:000712736400001 |
| Publisher | SPRINGER HEIDELBERG |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://119.78.100.198/handle/2S6PX9GI/28367 |
| Collection | 中科院武汉岩土力学所 |
| Corresponding Author | Guo, Yintong |
| Affiliation | 1.Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Hubei, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Chongqing Univ, Chongqing 400030, Peoples R China |
| First Author Affilication | Institute of Rock and Soil Mechanics, chinese Academy of sciences |
| Corresponding Author Affilication | Institute of Rock and Soil Mechanics, chinese Academy of sciences |
| Recommended Citation GB/T 7714 | Zhang, Xiaoyu,Wang, Lei,Bi, Zhenhui,et al. Mechanical analysis on cement sheath integrity under asymmetric load[J]. JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY,2021:12. |
| APA | Zhang, Xiaoyu.,Wang, Lei.,Bi, Zhenhui.,Guo, Yintong.,Yang, Chunhe.,...&Chang, Xin.(2021).Mechanical analysis on cement sheath integrity under asymmetric load.JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY,12. |
| MLA | Zhang, Xiaoyu,et al."Mechanical analysis on cement sheath integrity under asymmetric load".JOURNAL OF PETROLEUM EXPLORATION AND PRODUCTION TECHNOLOGY (2021):12. |
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