scholarly journals Vibration Behavior during Underground Drilling Based on an Innovative Measurement Method and the Application

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Peng Cheng ◽  
Wenlong Zhang ◽  
Wenzhou Li ◽  
Jie He ◽  
Youliang Feng
Keyword(s):  
Measurement Method ◽  
Pneumatic Drill ◽  
Drilling Process ◽  
Pressure Relief ◽  
Drilling Depth ◽  
Vibration Signals ◽  
Different Depths ◽  
The Impact ◽  
Dynamic Phenomena ◽  
Relief Effect

Pressure relief drilling is one of the most common techniques to reduce the impact of rock burst, but the useful dynamic phenomena in the drilling process are ignored due to the lack of corresponding technical methods. Based on the fact, an innovative measurement method for vibration signals during the drilling construction by pneumatic drill rig is presented in this study. The acquisition and analysis of vibration signals show that the vibration information can reflect the drilling depth, the amplitude of different depth can reflect the pressure, and the vibration events of different depths can reflect the pressure relief effect. The method proposed in the study is of great significance to the supervision of the relief work quantity, the disclosure of the pressure situation, and the evaluation of the pressure relief effect.

DEVELOPMENT DEPTH AS COMPLICATION FACTOR OF WORKING OFF CONDITIONS OF COAL SEAMS

2021 ◽  
pp. 37-50
Author(s):  
Serhii Nehrii ◽  
◽  
Tetiana Nehrii ◽  
Ruslana Shepelenko ◽  
Mykyta Kachalov ◽  
...  
Keyword(s):  
Coal Mining ◽  
Practical Significance ◽  
Natural Phenomena ◽  
Coal Seams ◽  
Mining Operations ◽  
Scientific Approach ◽  
Different Depths ◽  
The Impact ◽  
Dynamic Phenomena

Purpose: development of a scientific approach to clarify the areas of technologies application for mining roadways protection on the depth of mining operations. Methodology. Analysis and generalization of the results of scientific and technical research on the impact of natural phenomena on the process of coal mining. Graphoanalytical establishment of application and areasand determination of critical depths for protection mining roadways technologies. Results. Was studied and generalized the information on the influence of natural phenomena on the process of coal mining with the transition of mining to great depths. The necessity of determining the critical depths, exceeding which complicate the conditions of coal seams development due to the negative manifestations of natural phenomena, which requires changes in the technology of mining. Critical depths for different conditions, phenomena and technologies are different. For gas-saturated seams, they are determined by the methane-bearing capacity of seams, production intensity and ventilation conditions of underground roadways, for seams prone to gas-dynamic phenomena – they are determined by the stress-strain state (SSS) and strength of surrounding rocks. The critical depth in the application of protection roadways technologies also depends on the SSS of rocks and their strength. Therefore, a scientific approach has been developed to clarify the areas of application of technologies for the protection of mining roadways on the depth of mining. The critical depths are determined by the strength conditions of the rocks according to the relevant criteria. It based on the Ncr/Rc criterion, graphoanalytical method for determining the areas of application and determining the critical depths for different technologies of protection mining roadways was proposed. Scientific novelty: was developed a scientific approach to clarify the areas of application of protection mining roadways technologies on the depth of mining. Practical significance: the proposed approach to clarify the areas of application for the protection of mining roadways technologies at different depths simplifies the search for effective engineering solutions during planning mining operations.

scholarly journals A New Width Measurement Method of the Stress Relief Zone on Roadway Surrounding Rocks

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Pengfei Cui ◽  
Banghua Yao ◽  
Yong Liu ◽  
Jianping Wei ◽  
Zhihui Wen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Field Test ◽  
Measurement Method ◽  
Extraction Efficiency ◽  
Stress Relief ◽  
Gas Pressure ◽  
Gas Extraction ◽  
Drilling Depth ◽  
Width Measurement ◽  
Different Depths

Determining the width of the stress relief zone on roadway surrounding rocks is the premise to optimize drilling borehole effect and increase gas extraction efficiency. In this study, a new width measurement method of the stress relief zone on the roadway surrounding rocks was proposed, which determined the width according to gas pressure attenuation speeds in roadway boreholes at different depths. Then, the variation curve of the gas pressure in boreholes at different depths with the time was gained through a field test. On this basis, laws of the gas pressure attenuation and the gas transmission and loss in boreholes at different depths were explored through a numerical simulation based on COMSOL Multiphysics, thus concluding the stress on roadway surrounding rocks, the distribution of plastic zones, and the stress-permeability relation. The scientificity of the proposed method was illustrated theoretically. Finally, the proposed method was verified by the field test data and numerical simulation results of the gas extraction at different sealing depths. Research results demonstrate that the pressure in boreholes attenuates in the logarithmic function pattern. The attenuation speed decreases with the increase of the drilling depth. The width of the stress relief zone on roadway surrounding rocks in the studied area was determined to be about 11 m according to the proposed method. Both the numerical simulation and the field test of the gas extraction efficiency prove the feasibility and validity of the proposed method in determining the sealing depth of the borehole for the gas extraction. Research conclusions are of important significance to enrich width measurement methods of the stress relief zone on roadway surrounding rocks and to optimize sealing parameters of underground boreholes for gas extraction.

scholarly journals Kinematics and dynamics analysis of new rotary-percussive PDM drilling tool

2021 ◽  
pp. 146134842198915
Author(s):  
Jialin Tian ◽  
Xuehua Hu ◽  
Liming Dai ◽  
Lin Yang ◽  
Yi Yang ◽  
...  
Keyword(s):  
Drill String ◽  
Structure Design ◽  
Drilling Process ◽  
Analysis Model ◽  
Drilling Tool ◽  
Stick Slip ◽  
Rate Of Penetration ◽  
Bottom Hole ◽  
Bottom Hole Assembly ◽  
The Impact

This paper presents a new drilling tool with multidirectional and controllable vibrations for enhancing the drilling rate of penetration and reducing the wellbore friction in complex well structure. Based on the structure design, the working mechanism is analyzed in downhole conditions. Then, combined with the impact theory and the drilling process, the theoretical models including the various impact forces are established. Also, to study the downhole performance, the bottom hole assembly dynamics characteristics in new condition are discussed. Moreover, to study the influence of key parameters on the impact force, the parabolic effect of the tool and the rebound of the drill string were considered, and the kinematics and mechanical properties of the new tool under working conditions were calculated. For the importance of the roller as a vibration generator, the displacement trajectory of the roller under different rotating speed and weight on bit was compared and analyzed. The reliable and accuracy of the theoretical model were verified by comparing the calculation results and experimental test results. The results show that the new design can produce a continuous and stable periodic impact. By adjusting the design parameter matching to the working condition, the bottom hole assembly with the new tool can improve the rate of penetration and reduce the wellbore friction or drilling stick-slip with benign vibration. The analysis model can also be used for a similar method or design just by changing the relative parameters. The research and results can provide references for enhancing drilling efficiency and safe production.

scholarly journals Study on the pressure relief effect in gob‐side coal body during mining an inclined longwall panel

2021 ◽  
Author(s):  
Ruoqian Zhou ◽  
Hongtu Wang ◽  
Cai Shu ◽  
Tao Chu
Keyword(s):  
Pressure Relief ◽  
Longwall Panel ◽  
Relief Effect

Analysis of Pressure Relief Effect on the Protective Layer of Hard Roof and Extra-Thickness Coal Seam Mining

2018 ◽  
Vol 37 (1) ◽  
pp. 163-172 ◽  
Author(s):  
Zhongchang Wang ◽  
Wenrui Bian
Keyword(s):  
Coal Seam ◽  
Protective Layer ◽  
Pressure Relief ◽  
Hard Roof ◽  
Seam Mining ◽  
Relief Effect

scholarly journals Stability Control of Deep Coal Roadway under the Pressure Relief Effect of Adjacent Roadway with Large Deformation: A Case Study

2021 ◽  
Vol 13 (8) ◽  
pp. 4412
Author(s):  
Houqiang Yang ◽  
Nong Zhang ◽  
Changliang Han ◽  
Changlun Sun ◽  
Guanghui Song ◽  
...  
Keyword(s):  
Large Deformation ◽  
Coal Mine ◽  
High Stress ◽  
Surrounding Rock ◽  
Western China ◽  
Engineering Practice ◽  
Pressure Relief ◽  
Coal Roadway ◽  
And Control ◽  
Relief Effect

High-efficiency maintenance and control of the deep coal roadway surrounding rock stability is a reliable guarantee for sustainable development of a coal mine. However, it is difficult to control the stability of a roadway that locates near a roadway with large deformation. With return air roadway 21201 (RAR 21201) in Hulusu coal mine as the research background, in situ investigation, theoretical analysis, numerical simulation, and engineering practice were carried out to study pressure relief effect on the surrounding rock after the severe deformation of the roadway. Besides, the feasibility of excavating a new roadway near this damaged one by means of pressure relief effect is also discussed. Results showed that after the strong mining roadway suffered huge loose deformation, the space inside shrank so violently that surrounding rock released high stress to a large extent, which formed certain pressure relief effect on the rock. Through excavating a new roadway near this deformed one, the new roadway could obtain a relative low stress environment with the help of the pressure relief effect, which is beneficial for maintenance and control of itself. Equal row spacing double-bearing ring support technology is proposed and carried out. Engineering practice indicates that the new excavated roadway escaped from possible separation fracture in the roof anchoring range, and the surrounding rock deformation of the new roadway is well controlled, which verifies the pressure relief effect mentioned. This paper provides a reference for scientific mining under the condition of deep buried and high stress mining in western China.

The Impact of the PDA Measurement Method in Forward Scatter on The Concentration of Gas-Particle Two Phase Flow

2007 ◽  
Author(s):  
Lizhe Chen ◽  
Zhichao Chen ◽  
Shaozeng Sun ◽  
Zhengqi Li
Keyword(s):  
Measurement Method ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Forward Scatter ◽  
Pda Measurement ◽  
The Impact

Dropstone deposition: Results of numerical process modeling of deformation structures, and implications for the reconstruction of the water depth in shallow lacustrine and marine successions

2021 ◽  
Vol 91 (5) ◽  
pp. 507-519
Author(s):  
Małgorzata Bronikowska ◽  
Małgorzata Pisarska-Jamroży ◽  
A.J. (Tom) van Loon
Keyword(s):  
Bottom Sediment ◽  
Water Depth ◽  
Dense Medium ◽  
Factors Affecting ◽  
Deformation Structures ◽  
Wide Range ◽  
Water Columns ◽  
Numerical Process ◽  
Different Depths ◽  
The Impact

ABSTRACT Dropstones in lacustrine and marine sediments show a wide range of sizes: from less than a millimeter to many meters. Their size and shape determine the velocity and the acceleration when they settle through the water column, and this, in turn, determines in principle the imprint that they make in the bottom sediment. Although these parameters are crucial for dropstone deposition, the unknown material (sediment) properties (like strength, porosity, pore-water content, viscosity, etc.) of the bottom sediment play a just as important role in this process as the water depth, which can physically be understood as the length of the pathway traveled vertically through a dense medium before the impact. Reconstruction of the principal environmental conditions at the time of dropstone fall and deposition consequently requires considering the variety of factors affecting the final imprint depth of a dropstone, the combination of several numerical methods. Here, we show the results of numerical modeling of dropstones with different sizes that settle through water columns with different depths. Our results show how environmental factors control the deformation structures formed at the sedimentary surface during the impact of a dropstone, and how deep the imprint caused by the settling dropstone will be.

Research on rotating speed measurement method of turbodrill based on tilt sensor

2020 ◽  
pp. 095440622094443
Author(s):  
Wu Chuan ◽  
Wen Guojun ◽  
Han Lei
Keyword(s):  
Measurement Error ◽  
Inclination Angle ◽  
Measurement Method ◽  
Periodic Signal ◽  
Drilling Process ◽  
Test Results ◽  
Rotating Speed ◽  
Speed Measurement ◽  
Geological Conditions ◽  
Tilt Sensor

The rotating speed of turbodrill is a key parameter for adjusting the drilling process, which needs to be measured in real time. Based on this, a new rotating speed measurement method used in downhole turbodrill based on the tilt sensor is proposed in this paper. The basic principle is that a periodic signal will be generated by the tilt sensor along with the turbodrill, and then the rotating speed can be obtained by using fast Fourier transform to analyze the output data. Test results show that the measurement error is related to the inclination angle of the borehole, that is, this method cannot be used when the inclination angle is less than 0.4 degrees, while the measurement error is less than 3.5% when the inclination angle is more than 0.4 degrees, which meets the practical requirements. Compared with traditional methods, this method will not be interfered by mud, geological conditions and downhole vibration, and it is also a non-contact measurement method, which is very suitable for downhole environment.

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