Oil, Gas, and Energy Commons^™

Coupling Mechanisms Of Fracture Propagation And Proppant Transport Indeep Coalbed Methane Reservoirs, Guo Xiaodong, Zhang Shicheng, Zhang Jingchen, Zhou Changjing, Zhang Chengsheng, Qiu Shixin, Xi Xiangrui

Coal Geology & Exploration

Objectives and Methods Deep coalbed methane (CBM) reservoirs commonly exhibit well-developed beddings, strong mechanical heterogeneity, and high in-situ stress gradients. These characteristics result in pronounced nonlinear fracture propagation and strong multi-field coupling effects during hydraulic fracturing. Consequently, it is challenging to accurately describe the mechanisms governing fracture complexity in deep coal reservoirs using conventional mechanical models for fractures. Using a super-large true triaxial system with dimensions of 2.0 m × 2.0 m × 1.0 m, this study conducted physical simulation experiments on hydraulic fracturing under varying injection rates and viscosities of fracturing fluids. In combination with fracture mechanics and energy …

Advances In Research On Mechanisms And Prevention And Control Technologies For Solid-Phase Production In Hydraulically Fractured Coalbed Methane Wells, Zhang Fengsan, Wu Jinqiao, Lin Jin, Li Yu, Zhang Ying, Li Bing, Zhang Guobiao, Sun Ying, Gan Yuke

Coal Geology & Exploration

Background The effective coalbed methane (CBM) exploitation using hydraulic fracturing wells is severely constrained by two major solid-phase production issues: coal fines blockage and proppant flowback. The mechanisms behind both issues are associated with complex interplays between geological conditions and engineering disturbances. This study presents a systematic review of the current status of domestic and international research on the mechanisms of the solid-phase production, as well as relevant prevention and control methods. Furthermore, future research directions are proposed.Advances The solid-phase production in hydraulically fractured CBM wells essentially arises from flow-solid-chemical multi-field coupling processes under interplays between geological conditions and …

Characteristics And Mechanisms Of The Adsorption Of Shales For Ba2+ In Fracturing Fluids, Xie Chenyang, Liu Bo, Zhang Yuting, Zhu Fang

Coal Geology & Exploration

Objectives and Methods Large-scale hydraulic fracturing represents a key technology for shale gas exploitation. However, engineering practices indicate that the flowback rates of fracturing fluids are low and vary significantly across different blocks. Furthermore, some components in fracturing fluids may cause groundwater contamination. To explore the adsorption characteristics and mechanisms of Ba²⁺ within fracturing fluids in shale reservoirs, this study investigated four typical types of samples, including shale and three shale samples with different compositions, from the Longmaxi Formation in the Changning Block, southern Sichuan Basin. Systematic experiments were conducted on the adsorption of shales with different mineral …

Influence Mechanisms Of Cleats On Hydraulic Fracture Propagation In Deep Coalbed Methane Reservoirs, Wang Haiyang, Lu Chen, Su Xu, Wang Yufei, Zhou Desheng

Coal Geology & Exploration

Objective Creating large-scale fracture networks through hydraulic fracturing serves as an important approach to the commercial development of deep coalbed methane (CBM) reservoirs. However, these reservoirs contain extensively developed cleats. The significantly different cementation strengths of cleat fillings lead to complex interactions between cemented cleats and major hydraulic fractures during fracture propagation. Therefore, clarifying the mechanisms underlying the influence of cemented cleats on hydraulic fracture propagation is critical to improving the simulation effects of deep CBM reservoirs. Methods Using particle flow code (PFC) discrete element method, combined with quasi-triaxial mechanical test results of the No.8 coal seam within the Yichuan …

Agricultural Productivity Under Energy Development: Insights From California, Wai Yan Siu, Sherzod B. Akhundjanov

ODU Articles

This paper examines how agricultural productivity patterns in Kern County, California, a leading region for both agricultural production and oil and gas development, co-vary with the spatial and temporal expansion of hydraulic fracturing and associated energy infrastructure. Using parcel- and county-level analyses, we characterize how agricultural productivity differs across proximity to energy development and across spatial scales. The results reveal spatially heterogeneous and scale-dependent patterns: parcel-level evidence indicates lower Enhanced Vegetation Index-based vegetation productivity within the 20-mile proximity zone around fracking wells, while county-level results show heterogeneous crop-specific yield changes during the post-expansion period. Together, these findings highlight the importance …

Microseismic Monitoring And Assessment Of Segmented Hydraulic Fracturing Of Horizontal Wells In Coal Seam Roofs, Li Quangui, Peng Shuyue, Liang Yunpei, Li Wenxi, Qian Yanan, Cheng Chunhui, Yu Changjun, Zhan Jinfei

Coal Geology & Exploration

Background Microseismic monitoring, a non-destructive monitoring technique, has been extensively applied in the hydraulic fracturing performance assessment of coal seams. However, little attention is paid to the vertical wave velocity gradients in media in the same layer during the construction of layered wave velocity models. This leads to limited precision of travel time calculation and microseismic source localization, thus affecting the assessment accuracy of the hydraulic fracturing of coal seams. Objective and Methods Based on the coal seam segmented hydraulic fracturing project in a mine in Anhui, this study proposes an improved velocity model based on the Universal Kriging interpolation …

Parameter Optimization For Multistage Horizontal Well Fracturing Based On Multi-Cluster Perforation For Deep Coal Measure Gas: A Case Study Of The Jurassic Baijiahai Area In The Junggar Basin, Wang Bo, Jin Chenghong, Liu Jiang, Wang Zhiwei, Li Shenjian, Sheng Mao

Coal Geology & Exploration

Objective The multistage horizontal well fracturing based on multi-cluster perforation has emerged as an effective approach for the efficient production of deep coal-measure gas (CMG). However, deep coals feature unique rock mechanical properties, fluid loss characteristics of reservoirs, and microfracture developmental characteristics, which differ significantly from those of unconventional shales, tight sandstones, and shallow coals. As a result, existing fracturing experience cannot be directly applied, highlighting the investigation of fracturing parameter optimization tailored for deep CMG production.Methods Focusing on deep CMG reservoirs in the Baijiahai area within the Junggar Basin, this study constructed a model of multistage horizontal well …

Distributed Optical Fiber Acoustic Sensing-Based Optimization Of Microseismic Source Localization In The Hydraulic Fracturing For Coalbed Methane Production, Hua Hao, Cheng Bingjie, Xu Tianji, Yan Zhenqian, Gao Bo, He Cheng

Coal Geology & Exploration

Objective To achieve safe and efficient hydraulic fracturing, it is necessary to conduct timely and accurate microseismic monitoring in the reservoir stimulation process. The purpose is to analyze and assess the fracturing effects. Methods Using a permanently deployed fiber-optic cable outside the casing of a coalbed methane (CBM) well, this study employed distributed optical fiber acoustic sensing (DAS)for full-borehole, wide-azimuth, and high-density real-time monitoring of microseismic events induced by the hydraulic fracturing of coal seams. Furthermore, this study proposed a novel method for localizing microseismic sources based on information about wave travel time and a source-constrained mapping algorithm. First, effective …

Influencing Analysis Of Bedding Plane Location On The Dynamic Failure Characteristics Of Coal-Rock Combinations, Zheng Jianwei, Zhang Xiufeng, Ju Wenjun, Wang Cunwen, Han Yueyong, Li Guoying, Chen Yang, Li Haitao, Hao Jinwei, Liu Biao

Coal Geology & Exploration

Objective The bedding plane location significantly impacts the dynamic failure processes and mechanical properties of coal-rock composites, but the specific influence patterns remain unclear. Methods Dynamic mechanical tests were conducted on coal-rock composite specimens with bedding planes located at the top, middle, and bottom using the split Hopkinson pressure bar (SHPB). The investigation focused on the dynamic stress-strain behavior, failure process, energy distribution, and fragmentation characteristics under impact loading conditions. Results and Conclusions The findings indicate that: (1) The dynamic stress-strain behavior of coal-rock composites can be segmented into five distinct stages: near-linear stage, nonlinear dynamic stress-strain stage, elastic modulus …

Technology For Efficient Production Of Deep Coalbed Methane In The Shenfu Block, Li Bin, Yang Fan, Zhang Hongjie, Feng Lei, An Qi, Hao Zhaobing

Coal Geology & Exploration

Objective Deep coalbed methane (CBM), representing one crucial resource successor for ensuring the oil and gas security of China and achieving peak carbon dioxide emissions and carbon neutrality of the country, exhibits broad prospects for production. However, due to the small low universality of CBM production technologies under varying geological conditions, a technology that has been successfully applied in some blocks cannot be directly extended to other blocks. This leads to blind deployment of well types and well patterns in the early-stage exploration and development of new blocks to a certain extent. Given this, it is necessary to develop a …

Fracture Propagation Mechanism In Directional Perforation And Hydraulic Fracturing Of Coal Seam Horizontal Wells, Pang Tao, Jiang Zaibing, Hui Jiangtao, Jia Bingyi

Coal Geology & Exploration

Horizontal well perforation and fracturing in complex coal-bearing strata are key to increasing coal seam permeability and enhancing gas extraction efficiency, with the formation structure and perforation location determining fracture propagation. Considering the characteristics of formation structure and perforation locations, a fracturing geological model is established. Based on the finite element method, a numerical model is constructed to study the effects of perforation location, formation conditions, and the difference between vertical stress and horizontal stress on fracture perforation. Engineering verification is conducted, and construction suggestions are proposed. Key findings are as follows: There are three scenarios for the perforation locations: …

Numerical Simulations Of The Effects Of Bedding Planes On Hydraulic Fracture Propagation Law In Oil Shale, Li Yanwei, Zhu Chaofan, Zeng Yijian, Shui Haoche, Fan Cunhan, Guo Wei

Coal Geology & Exploration

Hydraulic fracturing serves as a major technical means for the exploitation of oil shale reservoirs presently, and the hydraulic fracture morphology in oil shales is primarily affected by differences in the characteristics of bedding planes. However, current studies mostly focus on the influence of the developmental degree of bedding planes on fracture propagation, overlooking the effects of the bedding plane thickness itself on hydraulic fracture propagation. This study delves into the oil shale in the Xunyi area, Ordos Basin. Based on the theory of linear elastic fracture mechanics, this study developed a stress-damage-seepage model of hydraulic fracture propagation. Using the …

Investigating The Impact On Private Water Supply Of Hydraulic Fracturing Communication With An Abandoned Conventional Gas Well In New Freeport, Pa, Kiley Miller

Electronic Theses and Dissertations

In June of 2022 a “frac out” occurred in New Freeport, PA when an unconventional gas well under development by hydraulic fracturing, communicated with an abandoned gas well to the surface. An initial “zone of impact” encompassed much of the town’s main thoroughfare. Water samples were obtained from 17 private water wells, 5 springs and 1 pond (31 total samples) and analyzed for cations, anions, and light hydrocarbons. Methane was found in 18 of the samples, both located within and outside of the “zone of impact”. Mass ratio analyses indicated contamination from both unconventional and conventional wells. Interferometric Synthetic Aperture …

Propagation Of Hydraulic Fractures In Thin Interbedded Tight Sandstones, Yang Fan, Mei Wenbo, Li Liang, Sun Zening, An Qi, Yang Qi, Lu Meiquan, Yang Ruiyue

Coal Geology & Exploration

Thin interbedded tight sandstone reservoirs are characterized by strong vertical heterogeneity due to the superimposed pattern of the deposited sandstones and mudstones. As a result, hydraulic fractures are difficult to propagate vertically to effectively connect the reservoirs. Given this, ascertaining the vertical propagation patterns of hydraulic fractures in thin interbeds is of great significance for the development of thin interbedded tight sandstones. With the thin interbedded tight sandstone reservoirs of the lower Shihezi Formation in the Linxing block, Ordos Basin as a case study, this study built the fracture propagation model of these sandstones. Accordingly, it analyzed the effects of …

An Experimental Study On Factors Controlling The Proppant Transport In Hydraulic Fractures Of Coal Reservoirs, Su Xianbo, Fan Jian, Wang Ran, Wang Lufei, Zhao Fengzhen, Wang Qian

Coal Geology & Exploration

Effectively propping open hydraulic fractures in coal reservoirs plays an important role in ensuring the efficient production of coalbed methane (CBM). This study investigated the effects of fracture morphology and the volume, injection rate, and properties of fracturing fluids on proppant transport in fractures through visualized experiments. The results are as follows: (1) Proppants showed a relatively homogeneous distribution in simple fractures with a constant aperture. In contrast, they form room-and-pillar props composed of proppant pillars and proppant-free rooms in local simple fractures with varying apertures and reticular fractures due to the effects of the varying flow rates of fracturing …

A New Model Of Surface And Underground Integrated Three-Dimensional Prevention And Control Of Rock Burst In Binchang Mining Area, Wu Xueming, Ma Xiaohui, Lyu Dazhao, Zheng Kaige, Wang Dongjie

Coal Geology & Exploration

With the continuous increase of coal mining intensity, the mine gradually moves to the deep, bringing about increasingly serious rock burst hazard. The deep rock burst mines often have one or more layers of hard and thick rock strata. These hard roofs are thick and strong integrity. When they suddenly rupture, they can release a large amount of elastic energies, which can easily to cause rock burst accidents and seriously restrict the safety of mine production. Herein, appropriate treatment measures were put forward for the special situation of deep burial depth of coal seam and general presence of many kinds …

Experimental Study Of Hydraulic Fracture Evolution With Materials Similar To The Structural Plane, Li Quangui, Wu Xiaobin, Hu Qianting, Liu Le, Shi Jialin, Song Mingyang

Coal Geology & Exploration

The structural plane extensively occurs in coal measures, and is one of the key factors affecting the hydraulic fracturing effect of coal/rock. The fabrication time and filling material types of the structural plane were adjusted to obtain the coal/rock specimens without the filling structural plane, or the coal/rock specimens with the filling structural plane. The physical experiment for hydraulic fracturing was carried out to find out the effect and action mechanism of the structural plane type and injected flow rate on hydraulic fracture extension. As indicated by the result, in the condition of the injected flow rate of 50 mL/min, …

High-Efficiency Regional Gas Drainage Model After Hydraulic Fracturing Of Comb-Shaped Long Boreholes In The Roof Of Broken Soft And Low Permeability Coal Seam, Chen Dongdong, Wang Jianli, Jia Bingyi, Xi Jie

Coal Geology & Exploration

Advanced management of gas enrichment area is an important guarantee to realize safe, efficient and intelligent mining in coal mine. Aiming at the problem of high-efficiency gas drainage in broken and soft coal seam region, taking No.3 coal seam in Hancheng mining area as the research object, a gas drainage mode of comb-shaped long borehole hydraulic fracturing in the roof of coal seam is proposed. The applicability of the model is verified by means of theoretical analysis, numerical simulation and field test, and the fracture propagation law, gas drainage mechanism, and fracturing curve features of comb-shaped borehole in adjacent roof …

Experimental Study On The Mechanical Properties Of Coal-Like Materials For Hydraulic Fracturing Simulation, Zhai Cheng, Zheng Yangfeng, Yu Xu, Xu Jizhao, Sun Yong, Cong Yuzhou, Tang Wei, Li Yujie, Zhu Xinyu, Chen Aikun

Coal Geology & Exploration

Simulation experiments on hydraulic fracturing of the coal seam in the laboratory are an effective method to study the mechanism of fracturing and enhancing permeability of coal-rock mass by hydraulic fracturing in coal mines. However, the technology in-situ sampling for large-size coal mass is immature, and the existing large-size coal samples are mostly taken from the stress-relaxation area, which can be further damaged in the transportation and preparation processes, causing large dispersion in test results. Therefore, The use of coal-like materials is a viable option to replace large-size raw coal for hydraulic fracturing simulation experiments. The mechanical properties of coal-like …

Mesoscopic Law Of Stress And Fracture Evolution Of Coal Seams Hydraulic Fracturing, Li Quangui, Deng Yize, Hu Qianting, Zhang Yuebing, Song Mingyang, Liu Jichuan, Shi Jialin

Coal Geology & Exploration

Hydraulic fracturing is a technology to increase coal seam permeability, and its stress evolution characteristics and the judgment of fracture morphology and propagation range are particularly important. In this paper, based on directional fracturing, a fluid-structure coupling model of hydraulic fracturing is established by using the discrete element numerical method. The effects of fracturing flow, Poisson’s ratio, natural fracture density on stress evolution and fracture evolution, and their mesoscopic laws are investigated by means of the stress path and crack hot spot diagram. The results show that the stress evolution direction and the final stress path curve shape are obviously …

Evaluation Method And Application Of Fracturing Effect Based On Dynamic Permeability Change Of Coal Reservoir Hydraulic Fracturing, Shan Tuo, Sun Changyan, Wang Qian, Xie Xiangjun, Fan Yigang

Coal Geology & Exploration

The fracturing construction curve is considered to be an important basis for reflecting the fracturing effect, while the dynamic change of reservoir permeability in the fracturing stage can more intuitively reflect the effect of fracture formation. In this paper, a quantitative evaluation method for reservoir dynamic permeability in fracturing stage was established based on the principle of well testing. Then, the method was applied to evaluate the fracturing effect of two coalbed methane (CBM) wells in a block in southern Junggar Basin, and the dynamic permeability curve of reservoir during fracturing stage is obtained. Meanwhile, the G-function method was …

Application Of Advanced Regional Treatment Technology Of Hard Roof In Buertai Coal Mine Of Shendong Coal Group, Yang Junzhe, Wang Zhenrong, Lyu Qingxu, Yang Sen, Li Guo, Zheng Kaige

Coal Geology & Exploration

The hard roof is a difficult problem in rock stratum control. The breaking and instability of high hard rock strata often induces strong coal pressure disasters, seriously threatening the safety production in coal mines. Hard roof control is one of the major problems in coal mine safety production. In response to the problems of large thickness, high hardness of the coal seam roof and its difficulty in collapse in Buertai Coal Mine in Shendong Mining Area, the hydraulic fracturing mechanism and technical advantages of directional long borehole segmented hydraulic fracturing are analyzed. The location of boreholes is determined based on …

Medium Characteristics And Hydrodynamic Evolution Law Of High Salinity Mine Water Recharge In Deep Well, Liu Qi, Wang Weijun, Luo Bin, Wang Houzhu, Zhang Zhijun

Coal Geology & Exploration

The treatment and discharge of high salt mine water is one of the important factors affecting efficient coal mining in recent years. It is a worth exploring method to reduce the discharge of mine water by selecting the appropriate aquifer under the floor of the coal seam and transferring the high salt mine water to other places. Taking the X mine in the Ordos Basin as an example, the Baotashan sandstone and the deep Liujiagou Formation sandstone formation below the coal seam have transfer storage space. By mercury intrusion experiment and rock mechanics analysis, the two groups of formations were …

Impacts Of Oil And Gas Wastes On Landfill Leachate, Sewage Treatment Plants, And The Environment, Lauren Badertscher

Electronic Theses and Dissertations

Between January 2011 and March 2021 oil and gas wells in Pennsylvania produced

305,637,795 barrels of liquid waste and 6,992,957 tons of solid waste with the majority from

Marcellus Shale unconventional wells. This waste is not considered hazardous and over 89% of

the solid waste generated by unconventional and conventional oil and gas extraction has been

disposed of in landfills over the past decade. This study examined trends in the quantity of waste

produced and methods of disposal. Landfills accepting this waste were identified and their

general method of leachate treatment, using onsite facilities or offsite at wastewater treatment

plants, …

Modeling Hydraulic Fracturing Initiation And Propagation In Porous Rock Formationsl, Chang Huang

LSU Doctoral Dissertations

Hydraulic fracturing has long been introduced to the oil and gas industry since the early nineteenth century for both reservoir characterization and reservoir stimulation. Despite the progress made in the last two decades, many challenges still have not been tackled regarding not only the propagation problem but also the initiation problem due to its complexity. The dissertation is divided into two stages, i.e., before and after fracture initiation. The first stage of the research aimed at improving the accuracy in solving the poro-mechanical response of wellbore during fluid injection before a tensile fracture occurs, which is crucial to determine the …

Application Of Borehole Transient Electromagnetic Detection In The Test Of Hydraulic Fracturing Effect, Zhao Rui, Fan Tao, Li Yuteng, Wang Jikuang, Ma Yuan, Wang Bingchun, Liu Lei, Fang Zhe

Coal Geology & Exploration

Hydraulic fracturing technology is widely used in various aspects such as mine rock burst prevention and surrounding rock depressurization, but there has been a lack of efficient and intuitive technology for evaluating the fracturing effectiveness. To solve this problem, a three-component borehole TEM detection method using dynamic source and reception unit was proposed, and detection equipment and supporting construction techniques suitable for construction in hydraulic fracturing holes were developed. Two engineering tests have been carried out in a coal mine. By comparing the processing results of the vertical components of the two detection data before and after fracturing, a pure …

Productivity Prediction Of Hypotonic Cbm Test Well In Jiaozuo Mining Area Under Hydraulic Fracturing, Wang Zhirong, Yang Jie, Chen Lingxia, Guo Zhiwei

Coal Geology & Exploration

In order to explore the permeable mechanism and the output law after fracturing of CBM in the "three soft" coal seam(soft coal, soft roof and soft bottom) of Jiaozuo under hydraulic fracturing, Based on the permeable model of reservoir fracture, considering the influence of fracture porosity on permeability after fracturing, a reservoir fracture penetration model was established, the application and analysis of the test well was carried out to obtain the characteristics of pressure cracks such as length, width, permeability and reservoir parameters after fracturing. Through the comprehensive analysis of isothermal adsorption curves and historical fitting, the recovery rate of …

Shale Play: Poems And Photographs From The Fracking Fields By Julia Spicher Kasdorf And Steven Rubin, Kelly Shepherd

The Goose

Review of Julia Spicher Kasdorf and Steven Rubin's Shale Play: Poems and Photographs from the Fracking Fields

Water Quality Assessment Of Deer Lakes County Park Before, During And After Unconventional Shale Gas Drilling, Daniel Robinson

Electronic Theses and Dissertations

Allegheny County, Pennsylvania, signed a lease to allow unconventional natural gas extraction from Marcellus Shale beneath Deer Lakes County Park in 2014. The park has three man-made lakes and four waterways that eventually flow into the Allegheny River. Drilling commenced in early 2016, and there are now five producing wells. The park has an extensive abandoned coal mine network and several abandoned oil and gas wells. Thus, an independent water quality study was undertaken beginning in July 2015. Samples from seven different sites in the park were used to establish a water quality baseline prior to the drilling. Monthly sampling …

Estimating The Creation And Removal Date Of Fracking Ponds Using Trend Analysis Of Landsat Imagery, Rutherford V. Platt, David Manthos, John Amos

Environmental Studies Faculty Publications

Hydraulic fracturing, or fracking, is a process of introducing liquid at high pressure to create fractures in shale rock formations, thus releasing natural gas. Flowback and produced water from fracking operations is typically stored in temporary open-air earthen impoundments, or frack ponds. Unfortunately, in the United States there is no public record of the location of impoundments, or the dates that impoundments are created or removed. In this study we use a dataset of drilling-related impoundments in Pennsylvania identified through the FrackFinder project led by SkyTruth, an environmental non-profit. For each impoundment location, we compiled all low cloud Landsat imagery …