Novel assessment and countermeasure for micro-annulus initiation of cement sheath during injection/fracturing

Yin, Fei; Hou, Dali; Liu, Wei; Deng, Yong

doi:10.1016/j.fuel.2019.04.018

Cited by 30 publications

(23 citation statements)

References 21 publications

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“…In the linear elastic phase, the slope of the line AB represent the stiffness, the damage in this phase is 0, the constitutive relation is shown in eq 6 : 9 where t i ( n , s , t ) are the component of the stress in three directions (MPa), including one vertical direction and two tangential directions, ε ( n , s , t ) are the component of the displacement in three directions (m), and K ij ( i , j = n , s , t ) represents the stiffness matrix (GPa).…”

Section: Whole Wellbore Cement Sheath Stress Calculation Modelmentioning

confidence: 99%

“…The cohesive properties of the casing-cement-formation system assembly are listed in Table 2 , which were taken from a reference. 9 …”

Section: Whole Wellbore Cement Sheath Stress Calculation Modelmentioning

confidence: 99%

“…Yin el al. 9 used a cohesive zone method to analyze the initiation of a micro-annulus in the process of water injection/fracturing. Based on the simplified Kirsch equation and numerical simulation method, the failure possibilities for the cement sheath under different conditions were simulated based on the shrinkage.…”

Section: Introductionmentioning

confidence: 99%

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Sealing Failure Mechanism and Control Method for Cement Sheath during Hydraulic Fracturing

Lian

Qian

et al. 2020

ACS Omega

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This study focused on the sealing failure mechanism and control method for a cement sheath during hydraulic fracturing. Taking a shale gas well as an example, whole wellbore numerical models of the casing-cement sheath-formation assembly were established, failure modes of the cement sheath at different depths were clarified, and control methods were proposed based on the calculation results. The following conclusions were drawn. (1) The maximum radial/tangential stress of the cement sheath increased/decreased with an increase in the depth, and the cement sheath above the intermediate casing shoe posed the risk of tangential tensile failure, resulting in tensile cracks. The cement sheath below the intermediate casing shoe produced a micro-annulus under a cyclic casing pressure, and the tensile cracks and micro-annulus constituted passages for the sustained casing pressure. (2) The swelling stress of the expansion cement slurry could offset the circumferential tensile stress and increase the radial compressive stress. Because a cement sheath with a high Young’s modulus usually exhibits high tensile and compressive strengths, it is recommended to use a high Young’s modulus cement slurry system above the intermediate casing shoe and optimize the free expansion ratio. (3) In comparison with ordinary cement stone, low residual strain cement stone exhibited a larger elastic deformation interval. The cumulative residual strain caused by cyclic loading was smaller, and the Young’s modulus demonstrated a lesser decrease. The results of an equivalent physical experiment demonstrated that an ordinary cement sheath lost its integrity after 13 loading cycles with a maximum casing pressure of 60 MPa. A low residual strain cement sheath could guarantee integrity after 30 loading cycles when the maximum casing pressure was 90 MPa, and sealing failure occurred after 11 loading cycles when the maximum casing pressure was 130 MPa. It is recommended to use a low residual strain cement slurry below the intermediate casing shoe to prevent a micro-annulus.

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Section: Whole Wellbore Cement Sheath Stress Calculation Modelmentioning

confidence: 99%

“…The cohesive properties of the casing-cement-formation system assembly are listed in Table 2 , which were taken from a reference. 9 …”

Section: Whole Wellbore Cement Sheath Stress Calculation Modelmentioning

confidence: 99%

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Sealing Failure Mechanism and Control Method for Cement Sheath during Hydraulic Fracturing

Lian

Qian

et al. 2020

ACS Omega

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“…[1][2][3][4][5] However, this method can seriously threaten the integrity (eg, sealing failure) of the cement sheath, leading to sustained casing pressure (SCP). 6 The reason for SCP is that the down-hole fluid migrates to the wellhead through continuous leakage paths, such as a microannulus between the casing and cement sheath or between the cement sheath and formation, microcracks in cement sheath, and casing threads, and then, the gas accumulates at the wellhead. [7][8][9] That is, the formation of SCP has two necessary conditions.…”

mentioning

confidence: 99%

“…Feng et al 22 proposed the use of a cohesive zone element (CZM) to simulate the debonding of the bonding surface in carbon dioxide injection wells. Based on the CZM and the Mohr-Coulomb criterion, Yin et al 6 provided a novel assessment and countermeasure for microannulus initiation during injection/fracturing. In experimental research, Goodwin and Crook 23 built casing cement sheath equipment to analyze the effects of pressure and temperature on the integrity of the cement sheath.…”

mentioning

confidence: 99%

Formation mechanism of continuous gas leakage paths in cement sheath during hydraulic fracturing

Lian

Qian

et al. 2020

Energy Science & Engineering

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Shale gas reservoirs are characterized by low porosity and permeability. As a result, conventional development methods cannot be used for commercial production of the gas. Therefore, hydraulic fracturing technology is required to achieve higher yields. [1][2][3][4][5] However, this method can seriously threaten the integrity (eg, sealing failure) of the cement sheath, leading to sustained casing pressure (SCP). 6 The reason for SCP is that the down-hole fluid migrates to the wellhead through continuous leakage paths, such as a microannulus between the casing and cement sheath or between the cement sheath and formation, microcracks in cement sheath, and casing threads, and then, the gas accumulates at the wellhead. [7][8][9] That is, the formation of SCP has two necessary conditions. 10,11 One is the gas/fluid source, and the other is the continuous leakage paths.Because the cement sheath is an important part of the wellbore barrier, it has been the focus of extensive research. The failure modes of the cement sheath usually include debonding,

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Engineering Mechanical Characteristics and Applications of Well Cement Sheath in Salt Cavern Underground Gas Storage

Yang,

Wang

2024

Renewable Energy Sources &Amp; Energy Storage

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Novel assessment and countermeasure for micro-annulus initiation of cement sheath during injection/fracturing

Cited by 30 publications

References 21 publications

Sealing Failure Mechanism and Control Method for Cement Sheath during Hydraulic Fracturing

Sealing Failure Mechanism and Control Method for Cement Sheath during Hydraulic Fracturing

Formation mechanism of continuous gas leakage paths in cement sheath during hydraulic fracturing

Engineering Mechanical Characteristics and Applications of Well Cement Sheath in Salt Cavern Underground Gas Storage

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