Numerical Simulation On Influence Of Skin Effect On Groundwater Flow Velocity In Wellbore,
2024
State Key Laboratory of Water Resource Protection and Utilization in Coal Mining, Beijing 100011, China; School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China
Numerical Simulation On Influence Of Skin Effect On Groundwater Flow Velocity In Wellbore, Wang Qihang, Li Xu, Guo Qiang, Kuai Dawei
Coal Geology & Exploration
Groundwater flow velocity in wellbore is usually measured by single-well tracking tests or Aqua Vision flow velocity and direction meters to calculate the groundwater flow velocity in the aquifer. Due to the impact of the skin structure, the groundwater flow field near the wellbore changes, causing a difference between the flow velocity in the wellbore and that in the aquifer. In order to investigate the influence of the skin effect on the groundwater flow velocity in the wellbore, a numerical model of groundwater flow that considers the skin effect was established using the COMSOL Multiphysics software. On this basis, the …
Difficulties Of Hydrofracturing In Sandstone – Experimental Study,
2024
Research Scholar, IIT (ISM) Dhanbad, India
Difficulties Of Hydrofracturing In Sandstone – Experimental Study, S Vikram, Dheeraj Kumar, Ds Subrahmanyam
Journal of Sustainable Mining
Hydrofracturing in sandstone is not an easy task. Sandstone is porous; fluid dissipation is common hence unable to obtain breakdown pressures in certain flow rates (0.0000005–0.0001 m3/s). The higher flow rate (0.00025 m3/s) is ascertained to determine the fracturing pressures. Due to this, fracture propagation and delineation are observed [1]. To enhance, an experimental method is adopted by carrying out 6 Hydrofracturing tests in a borehole comprising sandstone. A high flow rate of 0.00025 m3/s and viscosity 0.001 Pascal second is applied. Later, the fracture simulation was run on 12 core samples collected from the same depths in a lab. …
Numerical Back Analysis Of An Underground Bulk Mining Operation Using Distributed Optical Fiber Sensors For Model Calibration,
2024
Missouri University of Science and Technology
Numerical Back Analysis Of An Underground Bulk Mining Operation Using Distributed Optical Fiber Sensors For Model Calibration, Samuel Nowak, Taghi Sherizadeh, Mina Esmaeelpour, Paul Brooks, Dogukan Guner, Kutay Karadeniz
Mining Engineering Faculty Research & Creative Works
Numerical Modeling Of Complex Underground Engineering Projects Such As Caverns, Tunnels, And Bulk Mining Zones Is An Essential Part Of The Design Phase. Large-Scale Models Require Significant Reductions In Complexity From The Real-World Scenario, Which Often Leads To Low Confidence In The Model Output. In This Work, A Mine-Scale Numerical Model Is Developed To Simulate A Room And Pillar Extraction Mining Operation. The Model Inputs Are Calibrated Through The Comparison Of The Model Response To Pillar Extraction In An Analogous Mine Geometry With Measured Strain Values Collected Using A Novel Distributed Optical Fiber Strain Sensing Technique After Pillar Extraction. Calibration …
Table Of Contents,
2024
China Coal Technology and Engineering Group (CCTEG)
Deep Coalbed Methane Production Technology For The Eastern Margin Of The Ordos Basin: Advances And Their Implications,
2024
PetroChina Coalbed Methane Company Limited, Beijing 100028, China
Deep Coalbed Methane Production Technology For The Eastern Margin Of The Ordos Basin: Advances And Their Implications, Zeng Wenting, Xu Fengyin, Zhang Lei, Sun Weiwei, Wang Qian, Liu Yinhua, Yu Lizhu, Ji Liang, Zeng Quanshu, Zhang Kang
Coal Geology & Exploration
Contrasting with shallow to moderately deep coalbed methane (CBM) reservoirs, deep CBM reservoirs exhibit favorable coal structures, high formation pressure, high free gas ratios, and high contents of total dissolved solids (TDS) and CO2. Extensive fracturing allows for CBM flowing at the initial stage, while the production parameters vary significantly throughout the CBM production. This requires wide technological boundaries of the main production technologies. Compared to shale gas and tight gas, deep CBM manifests different production mechanisms and relatively low free gas ratios, which lead to short flowing cycles of CBM. This necessitates timely water withdrawal for CBM …
Differences In Geological Conditions Of Deep And Shallow Coalbed Methane And Their Formation Mechanisms,
2024
School of Energy Resources, China University of Geosciences (Beijing), Beijing 100083, Chin; Coal Reservoir Laboratory of National Engineering Research Center of CBM Development & Utilization, China University of Geosciences, Beijing 100083, China
Differences In Geological Conditions Of Deep And Shallow Coalbed Methane And Their Formation Mechanisms, Xu Hao, Tang Dazhen, Tao Shu, Li Song, Tang Shuling, Chen Shida, Zong Peng, Dong Yu
Coal Geology & Exploration
Deep coalbed methane (CBM) boasts abundant resources and great potential for exploitation. However, there is a lack of in-depth studies on the internal connections between deep and shallow CBM. This study investigated the Upper Paleozoic coalbed in the Ordos Basin. From the perspective of coalbed formation and evolution, it obtained three burial depth evolution modes of coalbed through summaries: both the maximum and present burial depths exceeding 2000 m, the maximum burial depth over 2000 m while the present burial depth less than 2000 m, and both the maximum and present burial depths less than 2000 m. This study systematically …
Occurrence Mechanism, Environment And Dynamic Evolution Of Gas And Water In Deep Coal Seams,
2024
College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
Occurrence Mechanism, Environment And Dynamic Evolution Of Gas And Water In Deep Coal Seams, Li Yong, Xu Lifu, Liu Yu, Wang Ziwei, Gao Shuang, Ren Ci
Coal Geology & Exploration
Accurately understanding of the occurrence states, relative content, and distribution characteristics of gas - water under deep conditions has important guiding significance for efficient exploration and development of coalbed methane (CBM). Based on the theoretical model, molecular simulation and systematic analysis of gas-water, the occurrence states of gas-water in coal seam is clarified, and the boundary and dynamic evolution process of gas-water dynamic migration and accumulation are revealed. Considering the coal - water interface interaction, the mobility and occurrence states of water, the coalbed water can be divided into movable water (gravity water and capillary water), bound water (adsorbed water, …
Effects Of Depth On Gas-Bearing Properties Of Coal Reservoirs And Their Coupling Relationships With Coalbed Methane Accumulation,
2024
School of Energy Resources, China University of Geosciences (Beijing), Beijing 100083, China; Coal Reservoir Laboratory of National Engineering Research Center of Coalbed Methane Development and Utilization, Beijing 100083, China
Effects Of Depth On Gas-Bearing Properties Of Coal Reservoirs And Their Coupling Relationships With Coalbed Methane Accumulation, Chen Shida, Hou Wei, Tang Dazhen, Li Xiang, Xu Hao, Tao Shu, Li Song, Tang Shuling
Coal Geology & Exploration
Burial depth serves as a comprehensive factor influencing coalbed methane (CBM) accumulation. Understanding the effects of depth on gas-bearing properties is critical for ascertaining the occurrence states and accumulation mechanisms of deep/shallow CBM. Based on the present situation of CBM exploration and the dissection of data from CBM exploration wells on the eastern margin of the Ordos Basin, this study explored the effects of burial depth on the gas content, saturated adsorbed gas capacity, and gas saturation of coal seams, as well as their coupling relationship with accumulation processes, using conventional and unconventional petroleum accumulation. The results indicate that CBM …
Deep Coalbed Methane Resources In The Shenmu-Jiaxian Block, Ordos Basin, China: Geological Characteristics And Potential For Exploration And Exploitation,
2024
Jidong Oilfield Company, PetroChina, Tangshan 063000, China
Deep Coalbed Methane Resources In The Shenmu-Jiaxian Block, Ordos Basin, China: Geological Characteristics And Potential For Exploration And Exploitation, Li Guoyong, Yao Yanbin, Wang Hui, Meng Lingjian, Li Peijie, Zhang Yongchao, Wang Jianwei, Ma Limin
Coal Geology & Exploration
China boasts abundant coalbed methane (CBM) resources in deep layers (burial depths: greater than 2000 m), with considerable potential for CBM exploration and development. Compared to medium and shallow CBM, deep CBM differs significantly in enrichment and accumulation patterns and exploitation means. Therefore, there is an urgent need to dissect key CBM blocks. The Shenmu-Jiaxian block, situated in the northeastern Ordos Basin, is currently in the early stages of deep CBM exploration, with enrichment characteristics and exploration potential remaining undefined. Based on recently obtained seismic data, logging data from over 300 wells, and analytical results from four cored wells, this …
Potential For The Production Of Deep To Ultradeep Coalbed Methane Resources In The Upper Permian Longtan Formation, Sichuan Basin,
2024
Exploration and Development Research Institute, Southwest Oil & Gas Field Company, PetroChina, Chengdu 610041, China
Potential For The Production Of Deep To Ultradeep Coalbed Methane Resources In The Upper Permian Longtan Formation, Sichuan Basin, Ming Ying, Sun Haofei, Tang Dazhen, Xu Liang, Zhang Benjian, Chen Xiao, Xu Chang, Wang Jiaxian, Chen Shida
Coal Geology & Exploration
Breakthroughs have been achieved in the high-yield gas flow of coalbed methane (CBM) wells with burial depths ranging from 1000 to 2500 m in the Cainan area of the Junggar Basin and the Daning-Jixian and southern Yanchuan blocks on the eastern margin of the Ordos Basin, signifying the enormous potential for the production of deep CBM. In the Sichuan Basin, the thin to moderately thick coal seam groups (7‒15 layers) in the Upper Permian Longtan Formation primarily exhibit burial depths ranging between 2000 and 4500 m. In the central Sichuan Basin, characterized by north-dipping monoclines and local low-amplitude uplifts, deep …
Geological Characteristics And Favorable Area Evaluation Of Deep Coalbed Methane In Wangfu Fault Depression, Southern Songliao Basin,
2024
Research Institute of Exploration and Development, Jilin Oilfield Company, Songyuan 131200, China
Geological Characteristics And Favorable Area Evaluation Of Deep Coalbed Methane In Wangfu Fault Depression, Southern Songliao Basin, Shen Xia, Gong Haitao, Shao Mingli, Yang Minfang, Huo Wanguo
Coal Geology & Exploration
The Wangfu fault depression in the southern Songliao Basin is rich in coalbed methane (CBM) resources. However, CBM exploration in this area has been restricted by the low-level exploration of deep CBM and a lack of systematic studies on the geological characteristics of CBM, primary factors controlling CBM enrichment and accumulation, and the selection of favorable targets. Therefore, based on the systematical analysis of the geological characteristics of coal-bearing strata, this study identified the major factors controlling deep CBM accumulation, established the index system for favorable area selection, and predicted the favorable areas of CBM enrichment. The results show that: …
Moderately Deep Coalbed Methane Reservoirs In The Southern Qinshui Basin: Characteristics And Technical Strategies For Exploitation,
2024
CBM Branch Company, PetroChina Huabei Oilfield Company, Changzhi 046000, China
Moderately Deep Coalbed Methane Reservoirs In The Southern Qinshui Basin: Characteristics And Technical Strategies For Exploitation, Zhang Cong, Li Mengxi, Hu Qiujia, Jia Huimin, Li Kexin, Wang Qi, Yang Ruiqiang
Coal Geology & Exploration
This study investigated the northern Zhengzhuang-western Qinnan block for the purpose of achieving effective exploitation of moderately deep coalbed methane (CBM) reservoirs in the southern Qinshui Basin. Based on results from the analyses and tests of parametric wells, including core analysis and tests, injection/falloff tests, and in situ stress cyclic tests, as well as a large amount of dynamic and static data, this study expounded on the characteristics of moderately deep CBM reservoirs in the study area by comparison with shallow counterparts. Then, it explored the technical improvements in fracturing through vertical wells and staged fracturing through horizontal wells for …
A Calculation Model Of Free Gas Saturation In Deep Coalbed Methane Reservoirs And Its Application,
2024
National Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum (Beijing), Beijing 102249, China; Coalbed Methane Research Center, China University of Petroleum (Beijing), Beijing 102249, China
A Calculation Model Of Free Gas Saturation In Deep Coalbed Methane Reservoirs And Its Application, Shi Juntai, Cao Jingtian, Xu Fengyin, Xiong Xianyue, Huang Hongxing, Sun Zheng, Jia Yanran, Ma Shurui, Zheng Haohang, Deng Ting, Li Jing, Li Xiangfang
Coal Geology & Exploration
In recent years, breakthroughs have been achieved in the exploration of deep coalbed methane (CBM) in China based on fine-scale geological research and techniques such as multistage hydraulic fracturing using proppants in a horizontal well. As a result, some wells yielded daily gas production of up to 100000 m3, inspiring confidence again in the CBM industry. However, since deep coal reservoirs occur in a complex geological environment characterized by high in-situ stress, high geotemperature, high pore pressure, and low permeability, there is an urgent need to reveal the typical parameters of coal reservoirs at different depths and the …
Mechanisms And Technological Parameter Optimization Of Near-Wellbore Laser Thermal Fracturing For Deep Coal Seams,
2024
College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, China
Mechanisms And Technological Parameter Optimization Of Near-Wellbore Laser Thermal Fracturing For Deep Coal Seams, Zhao Haifeng, Yang Ziyi, Liang Wei, Zhong Junbing
Coal Geology & Exploration
China boasts abundant deep coalbed methane (CBM) resources, which play a significant role in further CBM production. However, deep coal seams exhibit low porosities and ultra-low permeabilities due to intricate geological conditions. In the drilling process, drilling fluids enter the reservoirs, prone to cause near-wellbore contamination. Although conventional hydraulic fracturing technology tends to create fractures in the direction of the maximum horizontal principal stress, it is challenging for this technology to achieve blockage removing throughout the whole borehole. Laser thermal fracturing technology can break rocks in a short time. Furthermore, it allows for the laser irradiation angle to change freely …
Exploring The Principle And Method For Commingled Production Of Coal-Measure Gas Through Layered Pressure Relief In Surface Wells,
2024
State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; National & Local Joint Engineering Laboratory of Gas Drainage in Complex Coal Seam, Chongqing University, Chongqing 400044, China; School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, China
Exploring The Principle And Method For Commingled Production Of Coal-Measure Gas Through Layered Pressure Relief In Surface Wells, Li Rui, Jin Lihong, Xia Binwei, Ge Zhaolong
Coal Geology & Exploration
This study aims to gain an in-depth understanding of factors restricting the commingled production of coal-measure gas and boost the contributions of various pay zones to gas production. To this end, it analyzed the essential factors of the dynamic, channel, and gas source conditions in the commingled production. The dynamic conditions for the commingled exploitation of multiple reservoirs can be met by (1) enhancing the flow conductivity of reservoirs by altering the crustal stress state and (2) changing reservoir fluid pressure by layers. Following this principle, this study proposed a method for the commingled production of coal-measure gas through layered …
Underground Coal Gasification: Overview Of Field Tests And Suggestions For Industrialization,
2024
Research Institute of Petroleum Exploration & Development, PetroChina, Beijing 100083, China
Underground Coal Gasification: Overview Of Field Tests And Suggestions For Industrialization, Dong Zhen, Chen Yanpeng, Kong Lingfeng, Wang Feng, Chen Hao, Xue Junjie, Zhang Mengyuan, Chen Shanshan, Zhao Yufeng, Yu Yueyu, Gong Wanxing, Sun Hongliang, Wang Xinggang
Coal Geology & Exploration
Driven by the dual demands for achieving the goals of peak carbon dioxide emissions and carbon neutrality and for ensuring national energy security, underground coal gasification (UCG) in China is embracing a new historical development opportunity. To scientifically formulate a route for making technological breakthroughs in UCG and accelerate its industrialization, this study analyzed the history of UCG field tests, dividing UCG into three stages: UCG based on coal mines, vertical/directional wells, and horizontal wells. By exploring the underlying logic that propelled innovations in UCG technologies in different stages, this study delved into the technical and non-technical reasons for the …
Deep Coal Reservoirs In The Ningwu Basin: Geothermal Field Characteristics And Their Effects On Gas-Bearing Properties,
2024
School of Energy Resources, China University of Geosciences (Beijing), Beijing 100083, China
Deep Coal Reservoirs In The Ningwu Basin: Geothermal Field Characteristics And Their Effects On Gas-Bearing Properties, Xi Zhaodong, Tang Shuheng, Liu Zhong, Qu Xiaorong, Zhang Pengbao, Su Yufei, Zhang Qian
Coal Geology & Exploration
Temperature acts as an important factor affecting the gas-bearing properties of deep coal reservoirs, further affecting the development performance of deep coalbed methane (CBM). Therefore, ascertaining the geothermal conditions of coal reservoirs and their effects on the gas-bearing properties of deep coal reservoirs is critical to the systemic understanding of the enrichment characteristics and production patterns of deep CBM. For coal seam No.9 in the Taiyuan Formation within the Ningwu Basin, over 90% of the area has burial depths exceeding 1000 m. In the hinterland of the basin, coal seams generally exhibit burial depths greater than 1500 m, with a …
Enrichment And Accumulation Patterns And Favorable Area Evaluation Of Deep Coalbed Methane In The Fugu Area, Ordos Basin,
2024
Unconventional Research Center, CNOOC Research Institute, Beijing 100028, China
Enrichment And Accumulation Patterns And Favorable Area Evaluation Of Deep Coalbed Methane In The Fugu Area, Ordos Basin, Guo Guangshan, Xu Fengyin, Liu Lifang, Cai Yidong, Qin Wei, Chen Zhaohui, Deng Jimei, Li Zhuolun
Coal Geology & Exploration
The Shenfu block on the eastern margin of the Ordos Basin is a typical deep coalbed methane (CBM) field with abundant resources and considerable potential for exploration and exploitation. In October 2023, the large-scale Shenfu deep CBM field successfully reported proven geological reserves exceeding 110 billion m3. The Fugu area, located in the central part of the Shenfu block, is the earliest experimental area for deep CBM production. However, there is a lack of a clear understanding of CBM enrichment and accumulation patterns, as well as the potential for exploration and development, of this area. By comprehensively utilizing …
Exploration And Exploitation Of Deep Coalbed Methane In The Baijiahai Uplift, Junggar Basin: Progress And Its Implications,
2024
Exploration and Development Research Institute of PetroChina Xinjiang Oilfield Company, Karamay 834000, China
Exploration And Exploitation Of Deep Coalbed Methane In The Baijiahai Uplift, Junggar Basin: Progress And Its Implications, Lan Hao, Yang Zhaobiao, Chou Peng, Wang Bin, Liu Changqing, Liang Yuhui, Wang Yuqiang
Coal Geology & Exploration
The Jurassic coals in the Baijiahai uplift, with breakthroughs made in the deep coalbed methane (CBM) production of vertical wells in the early stage in China, serve as an important exploration target of the Junggar Basin. Their coal reservoirs feature an ultra-low ash content, a low moisture content, medium-to-high volatility, and favorable porosity and permeability systems. With gas accumulation modes, namely, the paleo-source and young-reservoir made and the self-source and self-reservoir mode, the coal seams enjoy favorable gas-bearing properties, such as a high gas content, a high proportion of free gas, and high gas saturation, which establish them as high-quality …
Origin And Accumulation Mechanisms Of Coalbed Methane In Low-Rank Coals In Gas-Rich Sags In The Erlian Basin,
2024
Inner Mongolia Coal Prospecting Unconventional Energy Co., Ltd., Hohhot 010010, China; Inner Mongolia Coal Exploration New Energy Development Co., Ltd., Hohhot 010010, China
Origin And Accumulation Mechanisms Of Coalbed Methane In Low-Rank Coals In Gas-Rich Sags In The Erlian Basin, Lin Haitao, Li Ling, Tang Shuling, Tian Wenguang, Li Jie, Meng Qin
Coal Geology & Exploration
Inner Mongolia boasts abundant coalbed methane (CBM) resources in low-rank coals. Investigating the origin and accumulation mechanisms of CBM is crucial for the siting and assessment of these CBM resources. This study examined the CBM in low-rank coals in major gas-rich sags of the Erlian Basin through various experiments, including tests of the composition and carbon/hydrogen isotopes of CBM, as well as tests of the water quality, hydrogen/oxygen isotopes, and radioisotopes (3H and 14C) of coal seam water. By analyzing the geochemical characteristics of both CBM and coal seam water, this study revealed the origin, sources, and …
