Sensitivity analysis of drilling parameters in rock rotary drilling process based on orthogonal test method

Li, Yanlong; She, Lei; Wen, Lifeng; Zhang, Qiang

doi:10.1016/j.enggeo.2020.105576

Cited by 68 publications

(25 citation statements)

References 22 publications

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“…However, the average thickness of Carboniferous ultra-thick coal seam in Datong mining area is 15 m, and the damage area of the rock strata is usually enlarged with the highly developed mining fractures [34,35]. The downward leakage of harmful gas in the Jurassic gob is mainly caused by the mining-induced fracture in the interval strata of the dual-system coal seam [36][37][38]. Therefore, the research on the development law of overburden breakage characteristics and mining-induced fracture in Datong mining area should be carried out systematically.…”

Section: Introductionmentioning

confidence: 99%

Influence of Key Strata on the Gas Downward Leakage Law in Dual-System of Coal Seam

Jiang

Ma³

2020

Geofluids

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In Datong mining area, CO and other harmful gases were discharged from the gob in the Jurassic overburden strata to the panel of Carboniferous coal seam. To this end, panel 8309 of Tongxin coal mine in Datong mining area was taken as the engineering background; the change law of CO concentration in the upper corner of the panel and the law of mining pressure were studied through field measurement, and the influence of periodic movement of key strata on the downward leakage law of harmful gases was analyzed. In this paper, the fracture law of the key strata and fracture development characteristics of overburden strata were further studied by the similar simulation test, and the influence of the periodic movement of the key strata on the pathway formation of gas downward leakage was analyzed. The results show that the main cause of harmful gas downward leakage in the Jurassic gob is through the fracture produced by the fracture of the higher key strata. If the higher key strata fractures in the coal mining in the Carboniferous system, through fracture connecting the Jurassic gob above the open-off cut and the upper part of the panel are formed, and effective pathways for gas downward leakage are generated. The fracture and rotation of the higher key strata are accompanied by the formation and disappearance of the effective pathway for gas downward leakage above the panel. Then the periodic change of harmful gas discharging to the panel is caused and consistent with the law of mining pressure.

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Section: Introductionmentioning

confidence: 99%

Influence of Key Strata on the Gas Downward Leakage Law in Dual-System of Coal Seam

Jiang

Ma³

2020

Geofluids

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“…Under the influence of a single factor, the drill cutting weight (S) and coal stress are correlated positively (Chen 2012). Additionally, the stress distribution around the roadway can be reflected by measuring the operating parameters of the drilling rig (Li et al 2020b;Zhang et al 2016a), the main ones being the hydraulic-motor inlet oil pressure (P 1 ), which makes the drill bit rotate to break the rock, and the oil-cylinder inlet oil pressure (P 2 ), which pushes the drill rod toward the bottom of the borehole. For the same coal and rock materials under the same stress, a higher drilling velocity (v) corresponds to larger drilling thrust and torque (Li et al 2020a).…”

Section: Field Investigations Of Stress Distributions Around Roadwaysmentioning

confidence: 99%

Method for designing the optimal sealing depth in methane drainage boreholes to realize efficient drainage

Wang

Chen

et al. 2021

Int J Coal Sci Technol

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The purpose of underground methane drainage technology is to prevent methane disasters and enable the efficient use of coal mine methane (CMM), and the sealing depth is a key factor that affects the performance of underground methane drainage. In this work, the layouts of in-seam and crossing boreholes are considered to analyze the stress distribution and failure characteristics of roadway surrounding rock through a numerical simulation and field stress investigation to determine a reasonable sealing depth. The results show that the depths of the plastic and elastic zones in two experimental coal mines are 16 and 20 m respectively. Borehole sealing minimizes the air leakage through the fractures around the roadway when the sealing material covers the failure and plastic zones, and the field test results for CMM drainage at different sealing depths indicate that the CMM drainage efficiency increases with increasing sealing depth but does not change once the sealing depth exceeds the plastic zone. Moreover, sealing in the high-permeability roadway surrounding rock does not have a strong influence on the borehole sealing performance. Considering these findings, a new CMM drainage system for key sealing in the low-permeability zone was developed that is effective for improving the CMM drainage efficiency and prolonging the high-concentration CMM drainage period. The proposed approach offers a valuable quantitative analysis method for selecting the optimum sealing parameters for underground methane drainage, thereby improving considerably the drainage and utilization rates of CMM.

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“…Additionally, a variance analysis could balance the difference between the results caused by the changes of the factor and the level as well as the error fluctuation, so a variance analysis was also conducted. e larger the ratio of the sum of the squares of the deviations between and within groups to the degree of freedom F j to F(f j , f e ), the greater the influence of the factor on the rock fragmentation is [34]: 10 Shock and Vibration…”

Section: Influence Analyses Of Nozzle Parametersmentioning

confidence: 99%

Failure Mechanism and Effect of Nozzle Parameters on Abrasive Water Jet Rock Breaking

Zhu

2021

Shock and Vibration

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Abrasive Water Jet (AWJ) technology has vast application prospects in the assisted drill-blasting of tunnel excavation, with the advantages of fast-breaking speed, low tool wear, less dust, and good mobility. Nevertheless, AWJ technology has some limitations and shortcomings, such as the small effective fracturing range and parameter mismatch, which influence the fracturing effect of AWJ. To solve the abovementioned issues, it is necessary to study the failure mechanism of rock impacted by AWJ and nozzle parameter effects on rock fragmentation. Based on the coupling algorithm of Smooth Particle Hydrodynamics and Finite Element Method (SPH-FEM), in this research, the numerical model of AWJ impacting rock was established, and the result was verified with Computed Tomography (CT) scanning after the AWJ impacting rock experiment and image processing technology. Through the analysis of the stress characteristics of typical particles in the rock model at different stages and positions, the formation and expansion mechanisms of the crater and the cracks were revealed. Additionally, in this research, the comprehensive damage factor of rock (X) representing the fragmentation degree was defined. By comparatively analyzing X-values with certain technical parameters of AWJ, the importance ranking of the nozzle parameters, the effect of each nozzle parameter on the rock fragmentation, and the optimal parameter combination were also investigated.

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Sensitivity analysis of drilling parameters in rock rotary drilling process based on orthogonal test method

Cited by 68 publications

References 22 publications

Influence of Key Strata on the Gas Downward Leakage Law in Dual-System of Coal Seam

Influence of Key Strata on the Gas Downward Leakage Law in Dual-System of Coal Seam

Method for designing the optimal sealing depth in methane drainage boreholes to realize efficient drainage

Failure Mechanism and Effect of Nozzle Parameters on Abrasive Water Jet Rock Breaking

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