Experimental Study on Enhancing Wellbore Stability of Coal Measures Formation with Surfactant Drilling Fluid

Zou, Yuliang; Zhu, Xuming; Wu, Xiaoming

doi:10.1007/s10553-021-01237-8

Cited by 4 publications

(4 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…m m c m 2 (10) Combined with the Langmuir adsorption equilibrium equation, the total mass of gas per unit volume of coal can be expressed as:…”

Section: Gas Diffusion Equation In the Coal Matrixmentioning

confidence: 99%

“…[7][8][9] Many scholars who are at home and abroad have carried out a great deal of research on the instability and deformation of boreholes as well as the gas flow law. Zou et al 10 have effectively improved the stability of coal rock boreholes by utilizing surfactant compounding compositions. Hao et al 11 found that the initial crustal stress, mining stress, and gas pressure of the coal seam are the key factors affecting the stability of the borehole through theoretical and numerical simulation methods, and proposed the mechanism of borehole zonal destabilization.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Damage characteristics of gas extraction boreholes under different crustal stresses and their effects on gas extraction

Guang,

Hongbao

2024

Energy Science & Engineering

View full text Add to dashboard Cite

To investigate the effects of different crustal stresses on the stability of gas extraction boreholes, several equations were deduced. Additionally, the coupled flow‐solid model of gas extraction was constructed, given the elasticity−plasticity deformation of the coal body. Using the numerical simulation and analysis software of Comsol, a study was conducted on the deformation and damage of gas extraction boreholes under different crustal stresses. The results are as follows: with vertical stress increasing, the concentration area of shear stress, deformation amount, and the area of the plastic zone around the hole increase. Varied lateral pressure coefficients led to differing distribution positions of shear stress concentration areas and plastic zones around the hole. An increase in lateral pressure coefficient shifted the distribution positions of shear stress maximum. In addition, plastic zone, and permeability ratio maximum change from the left and right sides of the borehole to the upper and lower sides, and the larger the lateral pressure coefficient is, the worse the stability of the upper and lower sides of the borehole is. Higher lateral pressure coefficients inhibited extraction, with the effect becoming more pronounced over time. Elevated vertical stress and lateral pressure coefficients hindered negative pressure propagation in the borehole.

show abstract

“…m m c m 2 (10) Combined with the Langmuir adsorption equilibrium equation, the total mass of gas per unit volume of coal can be expressed as:…”

Section: Gas Diffusion Equation In the Coal Matrixmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Damage characteristics of gas extraction boreholes under different crustal stresses and their effects on gas extraction

Guang,

Hongbao

2024

Energy Science & Engineering

View full text Add to dashboard Cite

show abstract

“…However, during the process of drilling method construction, after the drilling rig has drilled the well hole, the builders will measure the deviation of the well hole and then place the prefabricated bottom of the well wall and each section of the well wall into the well hole, then connect them with flanges in turn. The resulting well wall structure is a round tubular structure, which is referred to as the wellbore structure by many scholars [3][4][5]. The wellbore structure is prone to longitudinal instability during the construction process in drilling methods.…”

Section: Introductionmentioning

confidence: 99%

Study on the Vertical Stability of Drilling Wellbore under Optimized Constraints

Pan,

Liu,

Cheng

et al. 2024

Applied Sciences

View full text Add to dashboard Cite

With the development of coal resource extraction and wellbore construction proceeding towards deeper depths, the stability of drilling wellbore structures has become increasingly severe, even posing a barrier to the use of drilling method technology in deep wellbore construction. To address this issue, this study raised an optimized constraints method involving pre-throwing cement slurry to the bottom before wellbore decent, altering bottom constraints. Firstly, the critical depth and instability criterion of this optimized method was derived by catastrophe theory. Subsequently, the role of single-factor and multi-factor sensitivity analyses on critical depth was discussed. The engineering effects of optimized constraint methods were contrasted and examined in several drilling projects. Finally, the characteristic values of real engineering were computed using numerical techniques and ABAQUS2020 software, and the efficacy of optimization approaches was examined and validated. The results revealed that the critical depth increased by 41.39 ± 5%. The influence factors described in order of the degree were the counterweight water height, the elastic modulus, the thickness of the wellbore, and the self-weight of the wellbore, sequentially. The conclusion on structural stability between the numerical calculation solution and theoretical calculation solution was completely the same. The optimized constraints method can effectively improve the stability of the wellbore structure.

show abstract

“…Creep deformation is a typical characteristic of mud shales. When mud shale hydration expands to produce creep deformation, the open hole wall will cause shrinkage damage and a series of incidents, such as borehole instability, sticking, squeezing, and destruction of the casing after cementing, which results in significant economic losses to the drilling process 7 – 9 . A suitable evaluation method for borehole wall instability caused by illite and montmorillonite mixed layers has not yet been found.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation of the mechanical properties of mud shale under water-bearing conditions and its applications

Fang

Feng

Li³

et al. 2022

Sci Rep

View full text Add to dashboard Cite

Mud shale, used in drilling engineering, is prone to hydration and expansion, resulting in creep deformation that leads to wellbore shrinkage and pipe sticking incidents. Studying the creep characteristics of mud shale is significant for designing a reasonable well structure and determining the lower limit of drilling fluid density. The influence of moisture content on rock strength and creep mechanical properties were studied using water absorption, uniaxial compression, and creep tests. Test results show that with an increase in the moisture content, the mud shale was damaged and softened; moreover, the elastic modulus decreased with increase in moisture content. Under the same load level, the instantaneous strain increased with increasing moisture content. Under different loading stresses, the creep of the rock had nonlinear characteristics, which could be divided into three different creep stages: attenuation, second, and accelerated creep. A new improved creep model based on the Nishihara model was established to describe the accelerated creep characteristics of mud shale under different moisture contents. The ageing degradation and water-bearing weakening effects were introduced. The Levenberg–Marquardt nonlinear least-squares method was applied to invert the creep parameters. The results show that the simulated creep curves, generated using the new creep model, conform to the experimental ones. The relationship between the drilling fluid density and wellbore shrinkage ratio can be defined using this model; it provides a reference for reasonably determining the drilling fluid density.

show abstract

Experimental Study on Enhancing Wellbore Stability of Coal Measures Formation with Surfactant Drilling Fluid

Cited by 4 publications

References 25 publications

Damage characteristics of gas extraction boreholes under different crustal stresses and their effects on gas extraction

Damage characteristics of gas extraction boreholes under different crustal stresses and their effects on gas extraction

Study on the Vertical Stability of Drilling Wellbore under Optimized Constraints

Experimental investigation of the mechanical properties of mud shale under water-bearing conditions and its applications

Contact Info

Product

Resources

About