Study on Failure Mechanism of Cement Sheath Sealing of Shale Gas Well Under Alternating Loading and the Controlling Method

Shale gas well casing deformation failure is extremely serious in complex fracturing process. Based on the elastic mechanics theory, the distribution law of casing’s maximum equivalent stress field with the non uniform external extrusion is calculated by the complex variable function method. Meanwhile, casing deformation failure mechanism with non uniform external extrusion is revealed. For another, the maximum equivalent stress of the casing is analyzed with the case of a/b=2 and a/b=5. The result shows that the unevenness of the extrusion load has a great influence on the casing maximum equivalent stress distribution. The findings provide technical support for casing design and selection in complex fracturing process of shale gas well. Keywords: shale gas well; complex fracturing; casing formation; failure mechanism

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Casing failure mechanism during volume fracturing: A case study of shale gas well

Advances in Mechanical Engineering ◽

10.1177/1687814017717182 ◽

2017 ◽

Vol 9 (8) ◽

pp. 168781401771718 ◽

Cited By ~ 5

Author(s):

Tiejun Lin ◽

Hao Yu ◽

Zhanghua Lian ◽

Biao Sun

Keyword(s):

Failure Mechanism ◽

Shale Gas ◽

Gas Well ◽

Volume Fracturing ◽

Casing Failure

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Status and Influence of Shale Gas Well Integrity Failure

Materials Science Forum ◽

10.4028/www.scientific.net/msf.944.892 ◽

2019 ◽

Vol 944 ◽

pp. 892-897

Author(s):

Wen Bao Zhai ◽

Jun Li ◽

Yan Xi ◽

Gong Hui Liu ◽

Ying Сao Zhou

Keyword(s):

Failure Mechanism ◽

Shale Gas ◽

Structural Integrity ◽

Oil And Gas ◽

Gas Production ◽

Control Methods ◽

Gas Well ◽

Seal Integrity ◽

Well Integrity ◽

At Home

The well integrity issues in oil and gas wells have a long history, especially in the shale gas development, which has a direct impact on improving single well production of shale gas horizontal wells. Reviewing the domestic and foreign literature researches, the development status of major shale gas blocks at home and abroad were introduced. Well integrity failure characteristics of major shale gas blocks at home and abroad were counted and analyzed in detail. Finally, considering the shale gas development blocks in China as an example, the structural integrity (casing deformation) and seal integrity (Sustained Casing/Annulus pressure, SCP/SAP) were analyzed by clarifying the failure mechanism that well integrity issues affected shale gas production and that shale gas well integrity issues in China are a new problem was thought. The failure mechanism of shale gas well integrity needs to be further clarified, and a complete set of failure prediction and control methods has not yet been formed. Therefore, based on the concept of shale gas geology-engineering integration, taking into account the actual conditions of shale gas development blocks, it is proposed to scientifically and reasonably study shale gas well integrity failure mechanisms and their control methods, which has a reference and guidance to improve shale gas development.

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Economic benefit of shale gas exploitation based on back propagation neural network

Journal of Intelligent & Fuzzy Systems ◽

10.3233/jifs-189279 ◽

2020 ◽

Vol 39 (6) ◽

pp. 8823-8830

Author(s):

Jiafeng Li ◽

Hui Hu ◽

Xiang Li ◽

Qian Jin ◽

Tianhao Huang

Keyword(s):

Neural Network ◽

Shale Gas ◽

Bp Neural Network ◽

Large Scale ◽

Linear Prediction ◽

Back Propagation ◽

Back Propagation Neural Network ◽

Economic Benefits ◽

Gas Well ◽

Well Production

Under the influence of COVID-19, the economic benefits of shale gas development are greatly affected. With the large-scale development and utilization of shale gas in China, it is increasingly important to assess the economic impact of shale gas development. Therefore, this paper proposes a method for predicting the production of shale gas reservoirs, and uses back propagation (BP) neural network to nonlinearly fit reservoir reconstruction data to obtain shale gas well production forecasting models. Experiments show that compared with the traditional BP neural network, the proposed method can effectively improve the accuracy and stability of the prediction. There is a nonlinear correlation between reservoir reconstruction data and gas well production, which does not apply to traditional linear prediction methods

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Application of Assisted History Matching Workflow to Shale Gas Well Using EDFM and Neural Network-Markov Chain Monte Carlo Algorithm

Proceedings of the 7th Unconventional Resources Technology Conference ◽

10.15530/urtec-2019-659 ◽

2019 ◽

Cited By ~ 5

Author(s):

Sutthaporn Tripoppoom ◽

Wei Yu ◽

Kamy Sepehrnoori ◽

Jijun Miao

Keyword(s):

Neural Network ◽

Monte Carlo ◽

Markov Chain ◽

Markov Chain Monte Carlo ◽

Shale Gas ◽

History Matching ◽

Monte Carlo Algorithm ◽

Gas Well ◽

Assisted History Matching

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Quantifying Fracture and Reservoir Properties in Unconventional Reservoir from Production Data: A Case Study of Shale Gas Well

Proceedings of the 8th Unconventional Resources Technology Conference ◽

10.15530/urtec-2020-2594 ◽

2020 ◽

Author(s):

Sutthaporn Tripoppoom ◽

Wei Yu ◽

Jijun Miao

Keyword(s):

Shale Gas ◽

Production Data ◽

Unconventional Reservoir ◽

Reservoir Properties ◽

Gas Well

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Solidifying Mud Cake to Improve Cementing Quality of Shale Gas Well: A Case Study

The Open Fuels & Energy Science Journal ◽

10.2174/1876973x01508010149 ◽

2015 ◽

Vol 8 (1) ◽

pp. 149-154 ◽

Cited By ~ 5

Author(s):

Jun Gu ◽

Ju Huang ◽

Su Zhang ◽

Xinzhong Hu ◽

Hangxiang Gao ◽

...

Keyword(s):

Shale Gas ◽

Calcium Silicate Hydrate ◽

Drilling Fluid ◽

Cement Slurry ◽

Gas Well ◽

Safety Requirements ◽

Mud Cake ◽

Gas Bearing

The purpose of this study is to improve the cementing quality of shale gas well by mud cake solidification, as well as to provide the better annular isolation for its hydraulic fracturing development. Based on the self-established experimental method and API RP 10, the effects of mud cake solidifiers on the shear strength at cement-interlayer interface (SSCFI) were evaluated. After curing for 3, 7, 15 and 30 days, SSCFI was remarkably improved by 629.03%, 222.37%, 241.43% and 273.33%, respectively, compared with the original technology. Moreover, the compatibility among the mud cake solidifier, cement slurry, drilling fluid and prepad fluid meets the safety requirements for cementing operation. An application example in a shale gas well (Yuanye HF-1) was also presented. The high quality ratio of cementing quality is 93.49% of the whole well section, while the unqualified ratio of adjacent well (Yuanba 9) is 84.46%. Moreover, the cementing quality of six gas-bearing reservoirs is high. This paper also discussed the mechanism of mud cake solidification. The reactions among H3AlO42- and H3SiO4- from alkali-dissolved reaction, Na+ and H3SiO4- in the mud cake solidifiers, and Ca2+ and OH- from cement slurry form the natrolite and calcium silicate hydrate (C-S-H) with different silicate-calcium ratio. Based on these, SSCFI and cementing quality were improved.

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