Oil, Gas, and Energy Commons^™

The Effect Of Viscoelasticity And Velocity Anisotropy On The Reflections Of A Thin Bed, Chen Benchi, Wang Chao, Chen Changxing, Shi Lei

Coal Geology & Exploration

The coal seam is a typical thin bed characterized by much lower elastic impedance than that of the surrounding rock. Coal seam has viscoelasticity and velocity anisotropy and its reflection amplitude changes with frequency. In order to analyze the effect of viscoelasticity and velocity anisotropy on seismic responses of a thin bed, this paper aims at a thin-bed model with strong impedance contrast and simulates seismic responses under three different assumptions, elastic and velocity isotropy, viscoelastic and velocity isotropy, and viscoelastic and velocity anisotropy, through numerical simulation method based on wave equations. Comparison of these seismic reflections shows that the …

Lbfgs Csamt 1d Inversion Of Limited Memory Based On Boundary Constraint And Its Application, Tang Chuanzhang, Cheng Jianzhong, Yan Liangjun, Feng Guangye, Zhou Lei, Xu Fengjiao

Coal Geology & Exploration

CSAMT is characterized by time-consuming calculation and low accuracy. The conventional inversion method has simple boundary processing, needs big memory, it is difficult to have accurate search direction, influencing severely the effect of inversion. In order to achieve rapid and high-precision forward modeling of CSAMT, to improve the boundary processing method, to reduce memory usage, to optimize the searching direction to reduce the times of iterative inversion, LBFGS CSAMT 1D inversion method based on boundary constraint and limited memory was proposed. Firstly in CSAMT forward modeling, double-precision and parallel algorithm was adopted, realizing rapid and high-precision calculation of the horizontal …

Calibration And Experiment Of Mine Electromagnetic Lwd Gamma Logging Tool, Wang Xiaolong, Jiang Bici, Wang Kaibin

Coal Geology & Exploration

In order to effectively identify coal seam, roof and floor, mine electromagnetic LWD gamma logging tool was developed for directional drilling in coal mine. The calibration coefficient of the instrument can be obtained by natural gamma logging scale, and various measurement curves of mine electromagnetic LWD gamma logging tool can be obtained by standard well test and crossing borehole test in coal mine. Through comparing with the gamma curve of standard well and analyzing the geological data of the crossing borehole, the measurement result accuracy of mine electromagnetic LWD gamma logging tool is verified. The application test in underground coal …

The Influence Of Grounding Grid On Electromagnetic Detection Of Goaf, Xu Xing, Weng Ling, Li Shiqiang, Liu Guoqiang

Coal Geology & Exploration

The existence of underground goaf can easily cause tilting and settlement of power towers, which is a major hidden factor in the safe and stable operation of power grid. To detect the mine goaf under the power transmission corridor is of great significance. When there is a grounding grid in the detection area, the grounding grid will have certain influence on the measured value. In this paper, the detection of mine goaf in the presence of a grounding grid is presented. Based on the theoretical analysis, the mathematical model is built, and the simulation model is conducted. The influence of …

Development Of Impact Screw Motor, Wang Siyi, Li Quanxin, Liu Jianlin, Zhao Jiangpeng, Yang Dongdong

Coal Geology & Exploration

Aiming at the problems of low efficiency and high consumption of bits and drilling tools in drilling hard rock with conventional single bend screw motor, an impact screw motor is developed by adding an impact mechanism between the universal shaft of a common screw motor and the drill bit. The impact screw motor has dual functions of impact and orientation. The structure and the working principle of impact mechanism, the design of key components and the characteristics of the impact screw motor are introduced. Laboratory tests were carried out on the φ89 mm impact mechanism, and the peak impact …

Blue Biotechnology, Renewable Energy, Unconventional Resources And Products As Emerging Frontiers At Sea, Sheikh Aftab Uddin, Mohammad Mahmudul Islam

Journal of Ocean and Coastal Economics

Blue biotechnology, renewable energy and unconventional marine living resources are considered as emerging frontiers for enhancing ocean-based blue economy in Bangladesh. Blue biotechnology can help both fisheries and aquaculture industry by producing fish varieties that can become quicker, more beneficial, and greater with tastier flesh, by developing gene transfer technology to be used to develop the growth of fish or by using of monoclonal antibodies and DNA probes to new diagnostic strategies for pathogens. Transformation of marine bioresources (main, co-product and by-products) into food, medicine, animal feed and related bio-based items i.e. cosmetics, nutritional supplements, enzymes, agrichemicals etc could help …

Bakken Flares And Satellite Images, University Of North Dakota. Energy And Environmental Research Center, Xiaodong Zhang

EERC Brochures and Fact Sheets

Fact sheet refuting a magazine article about Bakken gas flares and satellite images. Includes research into gas flares and satellite images by the University of North Dakota and the Energy & Environmental Research Center. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]

Catalytic Transfer Hydrogenation Reactions Of Lipids, Alexander Asiedu

Civil & Environmental Engineering Theses & Dissertations

Catalytic transfer hydrogenation (CTH) of lipids was investigated using 2-propanol as hydrogen donor for producing liquid hydrocarbons, e.g. jet fuels. The main sources of lipids selected in this study were waste cooking oil (WCO) and oil-laden algae-derived biofuel intermediate (BI). Two different catalysts were employed in this study, namely activated carbon and trimetallic-doped zeolite.

The CTH reaction was between WCO and 2-propanol in a continuous flow reactor over a packed-bed activated carbon at near atmospheric pressure. Results revealed a high level of alkenes and aromatics compounds, which are not stable and are not environmentally unfriendly. To reduce these compounds in …

Identification Of Mined Areas That May Contribute To Water Quality Degradation At Hobet Coal Mine, West Virginia, Brian P. Murphy

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

No abstract provided.

Study On Compliance Assessment Of Ship Exhaust Emissions In China's Eca (Emission Control Area), Yahan Hu

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

Effect Of Nmr Technology-Based Ultrasonic Frequency On Stimulated Cracking Of Coal, Ma Huiteng, Zhai Cheng, Xu Jizhao, Sun Yong

Coal Geology & Exploration

In order to further study the effect of ultrasonic frequency on the stimulated cracking effect of coal, the paper conducted the crack experiment on the original coal samples by using the ultrasonic generation meter, and measured the coal by using the NMR equipment through analyzing the T₂ curve, the changes of pore structure before and after coal sample cracking were deeply studied. The results show that the pore structure of coal can be effectively improved by the ultrasonic wave. After the crack induced by the ultrasonic wave, the pore quantity inside the coal increased and the total porosity, effective …

Advances On Geological-Geochemical Research Of Coal-Type Uranium In China, Zhou Xianqing, Qin Yong, Lu Lu

Coal Geology & Exploration

There is a huge gap in uranium resources in China. Only developing traditional uranium resources is unable to meet the increasing demand in energy and national defense construction. The exploitation and utilization of coal-type uranium resources can relieve the pressure of demand for uranium resources to a certain extent. By summarizing the research results of coal-type uranium in recent years, the ore location, uranium content range, formation time and distribution range of coal-bearing strata of major coal-type uranium deposits in China, and the definition criteria of coal-type uranium are given, which provides a basis for the classification of coal-type uranium …

Structural Optimization And Simulation Analysis Of High Reliability Wire-Line Coring Drilling Tools For Submarine Drilling Rigs, Wang Jialiang, Peng Fenfei, Wan Buyan, Zhou Yun

Coal Geology & Exploration

In order to improve the working reliability of wire-line coring drilling tools used in submarine drilling rigs, based on the particularity of submarine environment, from the aspect of improvement of the single action performance of the single action mechanism and the working reliability of the suspension mechanism, the structural optimization of the single action mechanism was carried out, the numerical simulation analysis of the suspension mechanism was conducted by using ABAQUS simulation. The results show that the improved bearing assembly structure can restrain sea water corrosion, improve the centering effect of arbor and enhance the flexibility of bearing assembly. The …

Damage Mechanism And Countermeasures Of Reservoir With Abnormal Pickup Of Cbm Flow Pressure In Well, Jia Huimin, Hu Qiujia, Qi Kongjun, Qin Mengfu, Mao Chonghao, Zhang Guangbo

Coal Geology & Exploration

The reasonable control of the casing pressure and the bottom-hole pressure and the reasonable depressurization of reservoir pressure is the key technology for the CBM development. The pickup of the bottom-hole flow pressure(BHFP) will restrain CBM' desorption, lead to reservoir permeability damage and reduce the production of CBM wells. Based on production practice of Fanzhuang block in Qinshui basin, this paper puts forward the cause of a CBM abnormal well type, pickup of the BHFP, clarifies the damage mechanism of the pickup of the BHFP through theoretical research and field data analysis, and puts forward the evaluating method of the …

Analysis And Application Of Key Influencing Factors Of Cbm Well Fracturing Effects In Shizhuang Area, Qinshui Basin, Xue Haifei, Zhu Guanghui, Wang Wei, Lu Xiaoxia, Wang Minghao, Wang Yanbin

Coal Geology & Exploration

CBM fracturing effect has many influencing factors. Development effect with the same technology is different in different area. Based on a large amount of geological and engineering data in Shizhuang block, it was found that high geo-stress affects fracture extension and support in CBM fracturing, and difference between horizontal stress affects fracture direction and morphology. Coal seam with poor coal structure can produce large amount of gum during fracturing, which will block the diversion channel and result in poor fracturing effect. Engineering factors affecting fracturing effect mainly include the fracturing fluids performance, displacement, prepad fluid proportion and hole enlargement ratio. …

Study On Slope Stability And The Effect Of Highfill On The Mechanical Properties Of Red Clay Foundation, Gao Shengxiang, Xu Qiang, Ma Hongyu, Wu Shenglin, Wu Kang, Liu Peng, Wu Zehui

Coal Geology & Exploration

This paper takes a highfill slope in Anning in Yunnan Province as a case, using investigation, monitoring and other methods, on the basis of the distribution characteristics of red clay, the physical and mechanical properties of red clay before and after filling were analyzed, then the stability of slope was studied by numerical simulation software. The results show that the physical and mechanical indexes of the red clay foundation decrease first and then increase before and after the fill project, the stability of the fill slope shows the trend of decrease first and then increase. The ground fissures in the …

Influence Of Internal Friction Angle On Damage Constitutive Model Of Freeze-Thaw Rock, Yuan Chao, Zhang Huimei, Meng Xiangzhen, Yang Gengshe, Wu Luyuan

Coal Geology & Exploration

Based on Weibull random distribution and damage mechanics theory, starting from the characteristics of rock deformation process, the Drucker-Prager criterion was used to establish a damage constitutive model that can reflect the characteristics of rock various deformation stages. Through the conventional triaxial compression test of frozen-thawed sandstone, the Mohr stress circle was used to obtain the cohesion and internal friction angle of the sandstone under different freeze-thaw cycles. The model theoretical curve and the test curve of freeze-thaw sandstone were compared to verify the model rationality. By varying the internal friction angle, whether the friction angle has an effect on …

Accurate Test Technology And Device For Coal Seam Gas Content In Long Boreholes In Underground Coal Mines, Sun Siqing, Zhang Qun, Long Weicheng, Zheng Kaige, Hei Lei

Coal Geology & Exploration

In order to get actual gas content of underground coal mine during large-scale advanced detection, the sealed coring method for gas content was proposed. The sealed coring device of "three-cylinders, single motion and ball valve sealing" suitable for accurate test of gas content of long boreholes in underground coal mines was designed and trial-produced, the outer diameter of the device is 89 mm, and the diameter of the coal core can reach 38 mm, the pressure holding capacity of the sealed coring device is above 11 MPa, which satisfies the requirement of sealing sampling for the determination of coal seam …

Geological Characteristics And High Efficiency Development Technology Of Coalbed Methane In Duijiangnan Coal Mine, Guizhou Province, Gong Zewen

Coal Geology & Exploration

The development progress of coalbed methane in Duijiangnan mine field is slow. The main problems are low drilling efficiency, serious cementing leakage, long fracturing transformation period and low single well production in the block. Objectively evaluating the geological characteristics and development technology of coalbed methane is very im-portant for coalbed methane in the future. The coalbed thickness, coal body structure, reservoir pressure, gas content and permeability are systematically studied, combining with the past drilling, fracturing and drainage practices. It is proposed that directional wells are the main method of coalbed methane development in the coalfield. The coal seam M18 which …

Corrosion Behavior Analysis Of Sucker Rod For Coalbed Methane Wells In The Eastern Block Of Ordos Basin, Pang Bin, Wang Hanxiang, Lan Wenjian

Coal Geology & Exploration

In order to make clear the corrosion rule of sucker rod for coalbed methane wells in the eastern block of Ordos basin, the paper summarizes the corrosion types and corrosion intensities of the sucker rod, based on the test of produced gas, produced water, corrosion products and weight loss of sucker rod. The paper analyzes the effect of different drainage stages, coal seam and mineralization degree of water on the corrosion. The results of the research indicate that corrosion is mainly caused by CO₂ and H₂S originated from No.5 coal seam and No.11 coal seam. The corrosion …

Study On Uniaxial Compression Mechanical Properties Of Sandstone With Different Moisture Content And Wave Velocity Method, Duan Tianzhu, Ren Yaping

Coal Geology & Exploration

In order to investigate the mechanical properties and damage of sandstone under different uniaxial compression, the static uniaxial compression tests of five sandstones with different moisture content were carried out, and the physical and mechanical parameters were obtained. And the wave velocity of the sandstone samples with different moisture content were measured by ultrasonic detector. Then the sandstone was loaded to 80% peak intensity and then unloaded to 0. The acoustic wave velocity of sandstone was measured at this time. The damage was determined by acoustic wave method. The results show that the peak strength of sandstone under uniaxial compression …

A Method Of Random Noise Suppression Based On Compressed Sensing, Yang Liangang, Li Lingyun, Yang Yumei, Qu Yuanji, Yan Ke

Coal Geology & Exploration

With the development of high precision seismic exploration technology, the use of high fidelity methods to improve the SNR of seismic data becomes the key to denoising. Curvelet threshold method can effectively suppress random noise, but at the same time the method is easy to produce pseudo Gibbs shock phenomenon, resulting in local distortion of the signal, thus affecting the processing effect. To solve this problem, a method of seismic signal denoising based on compressing sensing(CS) is presented in this paper. The method uses the difference between sparse representation of random noise and effective signal in curvelet sparse domain to …

Channel Wave Advanced Detection Method Based On Kirchhoff Migration And Its Application, Zhao Yunpei, Wang Wei, Hou Xianhua

Coal Geology & Exploration

In order to detect the geological structures in the front of the working face 1199 in Gequan mine of Xingtai mining area, underground channel wave seismic exploration was used to conduct advanced detection, linear Radon transform was used to extract the reflection wave from the front of the roadway, parameter information of the surrounding rocks were obtained through velocity analysis in time domain, The abnormal geological bodies in the front of the roadway were imaged through Kirchhoff migration. The results indicated that there existed anomalies at 205 m and 237 m away from the geophone point G12 in the front …

Shale Gas Potential Of Yanguanjie Formation And Longtan Formation In Central And Southeastern Hunan Province, Cao Taotao, Deng Mo, Liu Hu, Huang Yanran, Stefan Andrew Hurssthouse

Coal Geology & Exploration

In order to reveal the shale gas potential and exploration direction of the marine-continental transitional shale in central and southeastern Hunan, samples were collected from the Lower Carboniferous Yanguanjie Formation and Upper Permian Longtan Formation, measurements were conducted on TOC, R_ran, kerogen carbon isotope, maceral composition, X-ray diffraction, scanning electron microscopy, porosity, permeability and methane sorption capacity. The results indicate that Yanguanjie Formation and Longtan Formation shale are at the mature stage, and mainly dominated by type Ⅲ kerogen. The Longtan shale generally has higher TOC content, while Yanguanjie shale has usually low TOC content. The minerals are …

Management Of National Planned Coal Mining Areas And Discrimination With Coal Mining Areas, Wang Xiangsheng, Wang Meng, Liu Jingchun

Coal Geology & Exploration

In view of the confusion between national planned coal mining areas and coal mining areas, based on the relevant standards and notices, the definitions of national planned coal mining areas and coal mining areas are interpreted in detail. This paper introduces the basic situation of the first and second batches of national planned coal mining areas and the《National Mineral Resources Planning (2016-2020)》. The differences between the two are expounded in detail from the aspects of delineation purpose, delimitation basis and formation period. It is pointed out that the competent department of national planned coal mining areas is the Ministry of …

Research And Application Of Cbm Surface Extraction Based On Coal Mine With “Gas Drainage First, Construction Later” And Resource Development, Wang Jing, Yao Tuanqi, Cheng Bin

Coal Geology & Exploration

Aiming at the safety index put forward by "gas drainage first, construction later" of coal mine at present and the resource characteristics of many coal seams in northern Guizhou Province, and at the same time making up for the lack of systematization and large blind area of surface gas drainage deployment at present, this paper took Duijiangnan coal mine as an example to carry out the research of coal bed methane surface drainage deployment. Based on the complex topographic conditions, coal seam development characteristic(multiple layers, thin thickness, group distribution), coal body structure, development and deployment requirements in this area, the …

Influencing Factors Of Surface Gas Extraction Effect In Wangpo Minefield Of Jincheng Mining Area, Du Zhiqiang

Coal Geology & Exploration

The effect of surface gas extraction in Wangpo minefield of Jincheng mining area is poor. In order to find out the causes and to guide the construction of future surface gas extraction, the occurrence conditions of CBM resources in the study area were analyzed and compared with those of adjacent Chengzhuang minefield where the extraction effect is good, the quality of the produced water was tested, at the same time the fracture forms were observed underground. The comprehensive analysis indicated that the abundance of coal gas resources and the reservoir conditions were the major intrinsic basic factors influencing the gas …

Coal Control Factors Of Middle Jurassic Shimengou Formation In Beidatan Area, East Part Of The Northern Qaidam Basin, Peng Minghong, Tian Jingchun, Zhang Xiang, Chen Lei, Zeng Jianqiang, Wang Suying

Coal Geology & Exploration

The key of the coal exploration in Beidatan area of Qinghai Province is the coal accumulation environment in the sedimentary period and the control of coal seam occurrence by tectonic action before and after sedimentation. To identify Shimengou Formation coal controlling factors in Beidatan area, east part of the northern Qaidam basin, effectively guide the coal exploration of the coal bearing area, through field outcrops, drilling, geophysical prospecting and other geological information system, based on the analysis of coal accumulating environment and structural function of Shimengou Formation in Beidatan area, the control factors of coal were deeply discussed from coal …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Technology And Application Of Indirect Fracturing In Cbm Vertical Well Of Broken And Soft Coal Seam With Low Permeability, Zhou Jiajia

Coal Geology & Exploration

In order to solve the problems of pulverized coal output and fracturing fracture not easy to extend during fracturing operation in the broken and soft coal seam with low permeability, the adaptability and fracturing fracture distribution of CBM during indirect fracturing are studied by means of in-situ stress and numerical simulation, and the engineering practice of indirect fracturing has been tested in Hongshandian mining area of Hunan Province. The results show that indirect fracturing can effectively improve the fracturing effect of the broken and soft coal seam with low permeability, and increase the fracture length. When the roof and floor …