Earth Sciences Commons^™

Research Progress Of Drilling And Borehole Completion Technologies In Broken Soft Coal Seam In Underground Coal Mine, Wang Li, Yao Ningping, Yao Yafeng, Wang Yi, Zhang Jie, Fang Jun, Wei Hongchao

Coal Geology & Exploration

In China, broken soft coal seams are in many strata and widely distributed. It is generally characterized by complex tectonic stress, high gas pressure, low mechanical strength and poor permeability, therefor, the hole is easy to collapse, outburst, which will probably cause many problems such as drilling difficulties, frequent accidents in the hole, inadequate hole depth, borehole blockage, drainage blind area and so on. With the continuous increase of coal mining depth, it is more difficult for drilling and completion in broken soft coal seam. Therefore, the high efficiency, deep hole and precise drilling technology, as well as the completion …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Review On Carbon Neutralization Associated With Coal Geology, Sang Shuxun, Wang Ran, Zhou Xiaozhi, Huang Huazhou, Liu Shiqi, Han Sijie

Coal Geology & Exploration

Coal-based carbon emissions constitute the largest part of China's total carbon emissions. Reducing coal-based carbon emissions and realizing the efficient, clean and low-carbon utilization of coal are the important ways to achieve the goal of "carbon neutralization". This paper systematically reviews the research fields of coal geology related to carbon neutralization, analyzes the role and application prospects of coal geology in carbon neutrality research and engineering practice, and discusses the development direction of coal geology in the context of carbon neutralization. The following understandings are obtained. Promoting clean coal geology research to advance the efficient and clean combustion of coal. …

Technologies And Prospect Of Geological Guarantee For Intelligent Coal Mining, Dong Shuning, Liu Zaibin, Cheng Jianyuan, Chen Baohui, Dai Zhenhua, Li Dan

Coal Geology & Exploration

Intelligent coal mining is the strategic selection of the coal industry under the new round of technological change. It is the way that must get through to achieve efficient production of coal mine safety. Geological guarantee technologies can provide accurate and reliable geological data for intelligent coal mining. Moreover, it could reduce the occurrence of coal mine production disasters and accidents by effectively detecting hidden geological factors. The development process of coal geological guarantee technologies in China is systematically expatiated, from serving for resource exploration, high-yield and efficient mine construction to serving for safe and efficient production of coal mines, …

The Main Progress In The 13Th Five-Year Plan And The Prospect Of Coal Geology, Jia Jiancheng, Gong Zewen, Jin Dewu, Li Quanxin, Wu Yan

Coal Geology & Exploration

Based on the brief analysis the evolution of "coal geology", the main progress of discipline in basic theoretical research, geological guarantee technology, coal and rock detection during the 13th five-year Plan period is reviewed emphatically, meanwhile the main problems faced and the development direction in the 14th five-year plan period and even a longer period of time are pointed out. It is considered that coal geology should around the development goals of coal industry of "providing sufficient green coal" and "reducing geological disasters in coal mine", taking the key geological theories and technical bottlenecks in green coal exploration, precise intelligent …

Sequence-Paleogeography And Coal Accumulation Of Lopingian In Guizhou Province, Shao Longyi, Hua Fanghui, Yi Tongsheng, Guo Lijun, Wang Xuetian

Coal Geology & Exploration

Based on outcrop sections and borehole data, the sequence stratigraphy, paleogeography, and coal accumulation of Lopingian(Upper Permian) in Guizhou Province have been studied. According to distribution of marine limestone beds which reflects variation of the transgressions, we have subdivided the Lopingian into 3 third-order composite sequences(CSⅠ, CSⅡ, CSⅢ) and related lowstand, transgressive, highstand sequence sets. CSⅠcorresponds to the lower and middle parts of the Lower Member of Longtan Formation. CSⅡcorresponds to the upper part of the Lower Member of Longtan Formation. CSⅢcorresponds to upper part of the Upper Member of Longtan Formation and Changxing Formation. The paleogeography map of these …

Numerical Simulation Of Pore Structure Stress Characteristics Of Coal And Rock Mass, Wang Gang, Jiang Chenghao, Chen Xuechang

Coal Geology & Exploration

In order to explore the stress distribution around the pores of coal and rock mass under different loading modes, the skeleton model of coal and rock mass with different pore shapes was constructed through CT three-dimensional reconstruction technology, and uniaxial and triaxial compression experiment simulations were conducted using ABAQUS software. The results showed that under uniaxial compression, the upper and lower regions of spherical pores showed tensile stress concentration, while the left and right regions showed compressive stress concentration. The stress concentration types in the long and short axis of elliptic pores were distinct with different dip angles. Under uniaxial …

Experimental Study On The Influence Of Co2 Injection Pressure On Gas Diffusion Coefficient, Zhou Xihua, Han Mingxu, Bai Gang, Lan Anchang, Fu Zhihao

Coal Geology & Exploration

Most of the coal seams in China are characterized by low pressure, low permeability and low saturation. The methane gas in the coal seam is slowly desorbed and diffused slowly, which affects the production rate of coalbed methane. The coal samples from Zhaozhuang Coal Mine of Jinmei Group were selected to study the influence of different gas injection pressure on CH₄ displacement process and the variation law of CH₄ diffusion coefficient in the process of displacement. Independently developed CO₂ displacement CH₄ test platform was used to carry out the experiments under different gas injection pressures such …

Chemical Compositions And Technological Properties Of Low-Rank Coals In The South Shenfu Mining Area: Characteristics, Relationship And Practice, Guo Chen, Wang Shengquan, Shi Qingmin, Qiao Junwei, Li Huantong, Zhang Weiguo, Li Jun, Zhang Chi, Wang Xiaokang, Du Fangpeng

Coal Geology & Exploration

Coal grading utilization is an essential way to fit its high-efficiency, clean and green development trends. Understanding the basic chemical composition and key technological properties of coal is the basis for achieving grading and qualitative utilization of coal resources. The South Shenfu mining area in Shaanxi Province is rich in coal reserves and it is an important low-rank coal production base in West China. However, it has not been able to achieve the qualitative utilization of coal practically completely for a long time, which restricts the full play of the value of coal resources and the further improvement of coal …

Evaluation Of The Hydro-Fracturing Potential For Coalbed Methane Reservoir: A Case Study Of Zhengzhuang Cbm Field, Yao Yanbin, Wang Hui, Yang Yanhui, Liu Dameng, Lu Xiuqin, Cao Lutong

Coal Geology & Exploration

The "double low" rate of exploration and utilization of CBM resources in China leads to a significant slowdown in CBM production, which has become a bottleneck restricting the development of CBM industry in China. The common CBM reservoir evaluation method did not pay enough attention to the hydro-fracturing potential, resulting in low discovery rate of high-quality gas reserves and low mobilization-rate of the present reserves. Thus, it is extremely necessary to do some research regarding to hydro-fracturing potential evaluation. Targeting on the Zhengzhuang CBM field of the southern Qinshui Basin, this study did comprehensive investigations including coal core analysis, physical …

Study On The Optimization Of Well Location And Extraction Life In Mining Disturbed Zone Of Yuecheng Mine In Jincheng, Wu Xi, Li Guofu, Wang Zheng, Fu Junhui, Zheng Fei, Zhou Xianjun

Coal Geology & Exploration

The aim of the study is to reduce the coalbed gas accumulation in the upper corner caused by U-type ventilation in the working face of Yuecheng Coal Mine, Jincheng City, and improve the production and extraction life of coalbed methane surface wells in the mining disturbed area and goaf. Based on the research of surface mining test wells in Chengzhuang Mine and Sihe Mine, and taking the geological conditions of coalbed methane in Yuecheng Coal Mine as the engineering design basis, this paper puts forward that the well location in the surface mining disturbed area should be close to the …

Study On Density Of The Supercritical Methane, Zhang Xinbin, Song Dangyu, Li Yunbo, Qi Yong'an, Fan Shunli

Coal Geology & Exploration

The density of supercritical methane is not only an important parameter for calculation of unconventional natural gas resources and adsorption capacity of methane in coal, but also a main indicator for measurement of the diffusion efficiency of supercritical methane and the ability to dissolve organic matter. Through analysis and comparison of the applicability of various gas state equations, it is realized that the Helmholtz energy state equation can accurately calculate the density of methane under the conditions of 0-30 MPa and 270-360 K. A calculation program for methane density was written using Microsoft Office Excel, and the error was less …

Framework On Intelligent Decision Support System For Coal Seam Floor Water Hazard Prevention And Control, Jin Dewu, Li Peng

Coal Geology & Exploration

Coal floor water inrush is a common type of water disaster in the production process of coal mines in North China coalfield. In order to solve the scientific decision making problem of water hazard prevention and control engineering and further improve the reliability of the relevant projects, this paper puts forward a technical idea of establishing an intelligent decision support system(IDSS). The IDSS is a combination of the traditional decision support system(DSS) and artificial intelligence. On the basis of analyzing the functional requirements of DSS for water hazard prevention and control, an integrated design process of "data-model-solution" is proposed, and …

Deep Mining Under Safe Water Pressure Of Aquifer: Inheritance And Innovation, Yin Shangxian, Lian Huiqing, Xu Bin, Tian Wuzi, Cao Min, Yao Hui, Meng Haopeng

Coal Geology & Exploration

The paper reviews the development course of inheritance and innovation of mining under pressure, expounds the concept and the necessary and sufficient conditions of mining under pressure, and on the basis of the connotation of mining under pressure, the base level of erosion is defined as the boundary(interface) of shallow and deep mining under pressure. The paper clarified that mining above confined water is mining under pressure, while mining under aquifer does not belong to the category, and corrects the improper expression of roof and floor pressure in "Coal Mine Safety Regulations". This paper summarizes the theory and technology directly …

Thoughts On Mine Water Control And Treatment In Yushen Mining Area, Fan Limin, Sun Kui, Li Cheng, Ning Kuibin, Ji Ruijun

Coal Geology & Exploration

In order to scientifically explain the water gusting(bursting) events with large water inflow in Yushen mining area and provide basic information for mine water control and treatment, this paper analyzes the water bursting events and large mine water gusting situations in recent years, and questions such as formation mechanism of large water inflow in mine, hydrogeological property of red soil layer and accuracy of mine inflow prediction are put forward. It expounds how to break through the "mine field" scope and study groundwater system and water bursting source in terms of regions and focus on weakly water-rich aquifers such as …

Variation Law And Estimation Model Of Permeability Coefficient In Unconsolidated Confined Aquifer, Chen Luwang, Peng Zhihong, Wang Yingxin, Ge Rutao, Li Ruirui

Coal Geology & Exploration

The coal measure strata in the concealed coalfields in North China are generally covered by the Quaternary loose soils. Many hydrogeological hazards, such as mine water inrush, surface subsidence and wellbore deformation failure, have occurred in mining under unconsolidated confined aquifer, which has caused huge economic losses and casualties. The permeability coefficient is an important parameter that reflects the permeability of soil medium in the unconsolidated confined aquifer. A reasonable estimation of its values has important guiding significance for the prevention and control of such hydrogeological hazards. At present, the permeability coefficient of the unconsolidated confined aquifer in the concealed …

Design And Implementation Of Mine Water Hazard Monitoring And Early Warning Platform, Lian Huiqing, Xu Bin, Tian Zhentao, Liu Demin, Yang Yi, Pan Guangyi, Wang Rui

Coal Geology & Exploration

Any mine water hazard will show different omens. In order to consolidate the foundation of intelligent early warning of water disaster, the connotation of system construction of perception, identification, evaluation, prediction and the interlogical relation are clarified. The mechanism of water inrush is varred for different types of water hazards, we designed three types of multi-mode water inrush typical scenarios and established the corresponding water inrush criteria. In addition, so we proposed two kinds of forecasting methods, namely the precise prediction of deterministic theory and the non-deterministic trend projections including big data and deep learning, which laid a solid theoretical …

Investigation And Simutation On The Model And Prevention Technology Of Water Inrush From Roof Bed Separation, Zhang Wenquan, Wang Zaiyong, Wu Xintao, Shao Jianli, Lei Yu, Wu Xunan

Coal Geology & Exploration

In order to prevent water inrush from roof separation, a partial backfill scheme is proposed for simulation study. First of all, based on the existing data, many kinds of separation water inrush accidents occurred in China were summarized and analyzed, and the disaster model of separation water accumulation was studied deeply. Then, taking the separation water accident of 1307 working face in the first mining area of a mine in Shaanxi Province as an example, the hydrogeological conditions and the relationship between upper aquifer and separation water inrush were analyzed, and the development characteristics of roof separation space of working …

Experiment Investigation On The Influence Of Mixing Effect On Dispersion Scale Dependence, Ma Ziqi, Dai Zhenxue, Dong Shuning, Wang Hao, Liu Xiaoqian

Coal Geology & Exploration

Dispersivity, a property parameter defined to characterize the degree of dispersion and mixing, is crucial for the prediction and remediation of groundwater contamination. However, in field tracer tests, the real mixing effect has often been ignored. In this paper, an aquifer with horizontal layered structure was simulated by laboratory experiments. Three kinds of media were chosen to reconstructed experimental aquifer. Two monitoring methods, buried sensor and sensor in the well, were adopted to compare the difference of breakthrough curves, so as to investigate the influence of mixing effect in the well on the dispersion scale dependence. The results showed that …

Design And Analysis Of Hole-Forming Technology For Surface Large Diameter Emergency Rescue Borehole, Hao Shijun, Mo Haitao

Coal Geology & Exploration

Surface large diameter borehole can be used as the escape channel for trapped people underground, and it is one of the important emergency rescue plans when mine accidents cause people trapped underground. However, the conventional large-diameter engineering hole is mainly formed by mud positive circulation and multi-stage reaming, which can not meet the rescue requirements. Focusing on the purpose of rescue and escape of large-diameter hole, this paper expounds the hole forming technology design principles including accurate connecting roadway, optimization of borehole structure, high-efficiency hole forming and safety connecting roadway. According to the specific construction conditions of overburden drilling, second …

Experimental Study Of Co2 Injection Into Carbonate Depleted Field: A Case Study From Central Luconia Field, Sarawak, East Malaysia, Nur Zafirah Mat Razali

Student Works (2020-2029)

This study aimed to address the challenges and strategies to determine the critical rate of CO2 injection into carbonate depleted gas fields. In this research, the critical rate is the maximum allowable injection rate before formation damage initiation. The cause of formation damage could be due to in-situ mobilization or trapping of migratory fines resulting in plugging of the flow path. This study performed a thorough investigation of a different rock-fluid system to evaluate the safe injection limit, as the critical rate is different for each rock-fluid system. The geochemical effect of CO2 injection toward carbonate formation was also investigated …

Policy Analysis Of Emissions Cap And Trade: The United State And The European Union, Drew Bealby

Master's Theses or Doctor of Nursing Practice

Effects of climate change are appearing each day therefore proactive steps need to be made to reduce these effects. The National Aeronautics and Space Administration (NASA) notes that humans producing greenhouse gases (GHGs) such as carbon dioxide (CO₂), methane, and nitrous oxide are the main reason the Earth’s overall temperature is rising (NASA 2019). A policy analysis was done on the European Union Emissions Trading Scheme (EU ETS) along with comparisons to the United States’ emissions policies that are in place currently. The European Union (E.U.) itself is both an economic and political union of 27 countries in …

Petrographic And Core Analysis Of The Jurassic Norphlet Formation: A Case Study In The Lithofacies Control Of Diagenesis And Porosity In The Flomaton Field, Al, Jarrett Thomas Smith

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study includes a sedimentologic and petrographic study of cores and thin-sections from the Jurassic Norphlet Formation in the Flomaton Field in southern Alabama to define a specific paragenetic history of each facies encountered and to identify key controls on reservoir quality. Eolian dune, nearshore, sand flat, and wadi facies were likely encountered in Norphlet core and thin-section samples that displayed a high degree of heterogeneity between them in terms of porosity, grain contacts, cement abundance/type, intergranular volume, and overall diagenetic processes. These distinct petrographic differences suggest that the paragenesis in the Flomaton Field is primarily facies controlled. The eolian …

Variations In Produced Water Chemistry And Relation To Regional Geology And Production In The Marcellus Shale, Northcentral West Virginia, Jonathan M. Brady

Graduate Theses, Dissertations, and Problem Reports (ETD)

An investigation of 74 Marcellus Shale wells across northcentral West Virginia indicates changes in produced water chemistry and quantity can be related to geologic conditions based on well logs and core data. These changes are determined by reviewing multiple produced water analyses for individual wells for periods up to ten years. Results show variations among the areas in this study. From west to east across central Harrison County to central Taylor County, then north into Monongalia County, gamma-ray logs show increasing intensity, especially in the middle and lower Marcellus. XRD mineralogy from core data shows increasing clay content from west …

Fracking Florida, Emily Faulconer

Publications

• Traditional Hydraulic Fracturing
• Why Frack?
• Why it’s Controversial
• Acid Fracking
• What’s in the Wastewater?
• Ethylene Glycol
• 2-Butoxyethanol
• Benzene
• So Where Does the Wastewater Go?
• “Halliburton Loophole”
• Drilling in Florida
• Timeline of Events at Collier-Hogan Well
• Lease Termination & Permit Revocation
• Frack Fluid used at Collier-Hogan Well
• Groundwater Monitoring Wells
• FDEP Tested 142 Analytes
• House Bills 71 & 157: Fracturing Chemical Usage Disclosure Act
• Proposed Sabal Trail Pipeline
• Hands Across the Sand” Rally
• My $0.02

The Application Of Ovt Domain Processing Technology In Deep Cbm Exploration In Qinshui Basin, Tian Zhongbin, Li Juan, Shen Youyi, Feng Ajian, Yang Xiaodong

Coal Geology & Exploration

The high concentration slurry is poured into the goaf to form filled piers. The bearing capacity of the piers to the superstructure are affected by the overlap size. In order to grasp the influence of the overlap size on the bearing capacity of the overlying rock layer, high concentration slurry was prepared which selected cement as the cementing material, standard sand as the aggregate. 3D printing technology was used to make the mold to produce the overlapped round table samples. The uniaxial compression test was carried out. Test results show that, when the top area and height of each single …

Pulverized Coal-Controlling Method Based On Supermolecular Film In Cbm Well, Wu Ying, Li Xiaonan, Liu Zixiong, Liu Rumin

Coal Geology & Exploration

Correctly understanding the micro-scale fracture characteristics of the Lower Cambrian shale and the evolution law of acoustic emission signals are of great reference value in the study of shale mechanical characteristics, fracture mechanism and shale gas development and utilization. In this paper, based on digital image processing technology, the non-uniform characterization of quartz-filled shale is carried out, and a numerical model is established using the real rock fracture analysis system RFPA^2D-DIP to simulate the failure process of shale under different confining pressures. The test results show that under the micro-scale structure, the shale failure mode can be roughly …

Analysis On The Cbm Extraction Effect Of The Horizontal Wells In The Coal Seam Roof In Luling Coal Mine In Huaibei, Fang Liangcai, Li Guihong, Li Dandan, Li Haozhe, Liu Jia

Coal Geology & Exploration

Aiming at the scientific evaluation of coaxial casing heat transfer of geothermal resources with medium burial depth(1 500-4 000 m), a rock-water coupled heat transfer model of a vertical single well was built based on the simulation platform of COMSOL Multiphysics software. Taking the stratigraphic and geothermal characteristics of Xi'an area as the simulation background, the heat transfer capacity of single well(3 500 m)casing under two different geothermal gradients(0.027℃/m and 0.030℃/m) and four flow velocities(0.25, 0.50, 0.75, 1.00 m/s) was calculated and analyzed. Meanwhile, the numerical models of group wells with five kinds of well spacing were established, and the …

Construction And Transformation Technology Of Three-Dimensional Fine Model Of Mine Water Diversion Structure, Fan Juan, Hou Enke, Jin Dewu, Qiao Wei, Nan Shenghui

Coal Geology & Exploration

The development degree of natural fractures is the main factor affecting coalbed methane productivity. In order to accurately obtain the distribution position of the natural fractures in the a coalbed methane field in the southern Qinshui basin, 7 refracturing wells in the area were adopted by surface microseismic vector scanning to monitor the natural fractures. A certain amount of three-component geophones were deployed around the fracturing well to collect microseismic events in the surrounding reservoir during fracturing, and after Semblance superposition, the fracture energy slices at different times in the monitoring area were obtained to explain the natural fractures in …

Research On The Fracture Mechanics Model Of Deep Hole Pre-Splitting For Forced Caving, Li Jinhua, Chen Wenxiao, Su Peili, Duan Dong, Song Yongjun

Coal Geology & Exploration

Tight radius drilling technology based on high pressure water jet is an important technical means to realize low-cost and efficient development of oil and gas resources. According to the research and application of tight radius drilling technology based on high pressure water jet, the equipment buildup, drilling theory, technical process and application effect of three tight radius drilling technologies and equipments(i.e., forging milling and reaming hydraulic type, forging milling and reaming jet thrust type and casing window type) are summarized systematically, and the advantages, disadvantages and adaptability of different technologies are included. From the point of view of increasing production …