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

2017 ◽  
Vol 9 (8) ◽  
pp. 168781401771718 ◽  
Author(s):  
Tiejun Lin ◽  
Hao Yu ◽  
Zhanghua Lian ◽  
Biao Sun
Keyword(s):  
Failure Mechanism ◽  
Shale Gas ◽  
Gas Well ◽  
Volume Fracturing ◽  
Casing Failure

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

2015 ◽  
Vol 8 (1) ◽  
pp. 149-154 ◽  
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.

A Case Study of Hydraulic Fracturing Monitoring in Shale Gas Well Based on DAS

2021 ◽  
Author(s):  
S. An ◽  
X. Liang ◽  
G. Yu ◽  
D. Li ◽  
J. Wu ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Shale Gas ◽  
Gas Well

Horizontal well of Shale Gas Complex Fracturing Casing Failure Mechanism

2019 ◽  
Vol 944 ◽  
pp. 898-902
Author(s):  
Shang Yu Yang ◽  
Jian Jun Wang ◽  
Guang Xi Liu ◽  
Li Hong Han
Keyword(s):  
Failure Mechanism ◽  
Shale Gas ◽  
Equivalent Stress ◽  
Great Influence ◽  
Distribution Law ◽  
Gas Well ◽  
Fracturing Process ◽  
Variable Function ◽  
Maximum Equivalent Stress ◽  
Casing Deformation

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

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

2019 ◽  
Author(s):  
Shiming Zhou ◽  
Rengguang Liu ◽  
Qiani Tao ◽  
Peiqing Lu ◽  
Xiaojiang Li
Keyword(s):  
Failure Mechanism ◽  
Shale Gas ◽  
Gas Well ◽  
Cement Sheath

Semianalytical Model for Fault Slippage Resulting from Partial Pressurization

SPE Journal ◽  
2019 ◽  
Vol 25 (03) ◽  
pp. 1489-1502 ◽  
Author(s):  
Kui Liu ◽  
Arash Dahi Taleghani ◽  
Deli Gao
Keyword(s):  
Shale Gas ◽  
Hydraulic Fracture ◽  
Fault Reactivation ◽  
Hydraulic Fractures ◽  
Gas Wells ◽  
Principal Stresses ◽  
Casing Deformation ◽  
Spacing Selection ◽  
Casing Failure

Summary Casing failure in shale gas wells has seriously impacted production from Weiyuan and Changning fields in Sichuan Province, China. Linearly distributed microseismic data and the corresponding casing shear deformation close to these microseismic signals indicate fault reactivation in these areas during hydraulic-fracturing treatments. Apparently, interaction of hydraulic fractures with nearby faults causes fault slippage, which in some situations has led to well shearing. Hence, we propose a semianalytical model in this paper to estimate the length of slippage along the fault that is caused by pressurization of a fault intercepted by the hydraulic fracture. These calculations have been performed for different configurations of the fault with respect to the hydraulic fracture and principal stresses. Using the semianalytical model provided in this paper, two fault slippage cases are calculated to assess the casing failure in nearby wells. In one case study, the calculated results of the fault slippage are consistent with the scale of casing deformation in that well and a microseismic magnitude caused by fault slippage is calculated that is larger than the detected events. The presented model will provide a tool for a quick estimation of the magnitude of fault slippage upon intersection with a hydraulic fracture, to avoid potential casing failures and obtain a more reliable spacing selection in the wells intersecting faults.

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

2019 ◽  
Author(s):  
Shiming Zhou ◽  
Rengguang Liu ◽  
Qiani Tao ◽  
Peiqing Lu ◽  
Xiaojiang Li
Keyword(s):  
Failure Mechanism ◽  
Shale Gas ◽  
Gas Well ◽  
Cement Sheath

Status and Influence of Shale Gas Well Integrity Failure

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.

Sign in / Sign up

Export Citation Format

Share Document