Geomechanics for Energy and the Environment最新文献_第3页

Sealing simulation experiment of old well collapse debris in carbon capture and storage (CCS) 碳捕集与封存中老井坍塌碎屑密封模拟实验

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-12-01 DOI: 10.1016/j.gete.2025.100776

Yuda Zhang , Jingnan Dong , Guangjie Yuan , Yan Xia , Hong Zhang , Pan Fu

Carbon storage in depleted reservoirs has emerged as a critical technology for mitigating atmospheric CO₂ concentrations, where the sealing integrity of old wells constitutes a pivotal factor in site selection. This study investigates the sealing performance of old wells containing fish and buried by wellbore collapse debris through comprehensive experimental approaches, including full-scale wellbore debris sealing simulations and small-scale core permeability tests. The experimental design systematically examined key variables including debris composition, compaction degree, and permeability characteristics under varying hydraulic pressures. Results demonstrate two distinct failure mechanisms: (1) gas breakthrough occurring at pressure differentials of 1.3–2.7 MPa with approximately 30-second response time, where gas migration predominantly follows interfacial pathways between compacted debris (permeability <0.031 D) and casing/fish structures; and (2) persistent gas leakage through debris pore networks, exhibiting permeability ranges of 0.0024–0.031 D. These findings provide fundamental insights into failure dynamics of debris-sealed abandoned wells, offering critical empirical data for safety assessment of CCS/CCUS reservoir candidates. The experimental methodology establishes a replicable framework for evaluating wellbore sealing integrity under simulated reservoir conditions.

枯竭储层中的碳储存已成为降低大气CO₂浓度的关键技术，其中老井的密封完整性是选址的关键因素。本研究通过全面的实验方法，包括全尺寸井筒碎屑密封模拟和小规模岩心渗透率测试，研究了含鱼井和井筒坍塌碎屑埋藏的老井的密封性能。试验设计系统地检查了不同水压下的关键变量，包括碎屑成分、压实程度和渗透性特征。结果显示了两种不同的破坏机制：(1)气侵发生在压力差为1.3-2.7 MPa时，响应时间约为30秒，气体运移主要沿着压实碎屑（渗透率<；0.031 D）与套管/鱼体结构之间的界面通道进行；(2)碎屑孔隙网络中持续的气体泄漏，渗透率范围为0.0024 ~ 0.031 d。这些发现为碎屑密封废弃井的破坏动力学提供了基本见解，为CCS/CCUS候选储层的安全性评估提供了关键的经验数据。该实验方法建立了一个可复制的框架，用于在模拟油藏条件下评估井筒密封完整性。

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引用次数: 0

Mechanism of anomalous “internal subsidence and peripheral uplift” in a salt mine goaf: A multi-source validated superposition of poroelastic uplift and mining-induced subsidence 盐矿采空区异常“内沉降外隆升”机理：多源验证的孔弹性隆升与采动沉陷叠加

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-11-19 DOI: 10.1016/j.gete.2025.100769

Ahu Zhao , Yinping Li , Xilin Shi , Shefeng Hao , Zengguang Che , Kun Yang , Mingnan Xu , Hongling Ma

Solution mining in salt mine typically induces regional ground subsidence and even localized collapse. However, monitoring data from a large-scale salt mine in eastern China reveal significant ground uplift in peripheral areas, while persistent subsidence occurs in the Internal mining area. This study systematically investigates the mechanisms underlying this anomalous phenomenon through integrated InSAR and first-order leveling surveys, detailed geological exploration, and theoretical modeling approaches. A six-year deformation monitoring campaign identified anomalous surface deformation characterized by internal subsidence and peripheral uplift, exhibiting pronounced spatial heterogeneity and temporal non-stationarity. Field core drilling, hydraulic connectivity testing, borehole inflow monitoring, and dynamic injection-extraction analyses confirmed that the high-pressure aquifer within the Dainan Formation(Ed) is an anthropogenic geological formation resulting from injection-extraction imbalance. The core hypothesis posited in this study is that leakage from injection wells elevates pore pressure in deep sandstone aquifers, triggering poroelastic expansion effects that fundamentally drive the sustained ground uplift around mined-out regions. To quantitatively evaluate this large-scale uplift deformation, the issue was conceptualized as a semi-infinite spatial boundary condition, and a corresponding computational model for surface uplift was developed. Following numerical validation of the model and integration with established subsidence theories associated with solution mining, the spatiotemporal deformation patterns from 2018 to 2023 were successfully inverted. The results indicate that the observed deformation pattern of internal subsidence and peripheral uplift arises from the spatial superposition of ground subsidence induced by salt mining and poroelastic uplift driven by injection-induced leakage. The established model quantitatively assesses the contributions of critical injection-extraction parameters to ground deformation, providing a universally applicable theoretical framework for predicting future surface deformation and facilitating geological hazard mitigation.

盐矿溶液开采通常会引起区域地面沉陷甚至局部塌陷。然而，中国东部某大型盐矿的监测数据显示，周边地区地面明显隆起，而内部矿区则持续下沉。本研究通过综合InSAR和一级水准测量，详细的地质勘探和理论建模方法，系统地探讨了这种异常现象的机制。一项为期6年的变形监测活动确定了以内部沉降和外围隆起为特征的异常地表变形，表现出明显的空间异质性和时间非平稳性。现场岩心钻探、水力连通性测试、井眼流入监测和动态注采分析证实，戴南组高压含水层是由注采不平衡引起的人为地质层。本研究提出的核心假设是，注水井的泄漏提高了深部砂岩含水层的孔隙压力，引发了孔隙弹性膨胀效应，从根本上推动了采空区周围地面的持续隆升。为了定量评价这种大规模的隆升变形，将该问题概念化为半无限空间边界条件，并建立了相应的地表隆升计算模型。在对模型进行数值验证的基础上，结合已有的沉降理论，成功反演了2018 - 2023年的时空变形格局。结果表明，观测到的内部沉降和周边隆升的变形模式是由采盐引起的地面沉降和注泄引起的孔弹性隆升在空间上叠加而成的。建立的模型定量评价了注采关键参数对地面变形的贡献，为预测未来地表变形和促进地质灾害减灾提供了普遍适用的理论框架。

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引用次数: 0

Observation of water transport in compacted bentonite at elevated temperatures using X-ray tomography and image analysis 用x射线断层扫描和图像分析观察高温下压实膨润土中的水输送

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-11-17 DOI: 10.1016/j.gete.2025.100767

Janne Yliharju , Tero Harjupatana , Jukka Kuva , Heini Reijonen , Markku Kataja , Arttu Miettinen

X-ray tomography and image analysis were applied to monitor the 4D (3D spatial with time) evolution of partial densities of bentonite and water in compacted Wyoming sodium bentonite under constant volume conditions at elevated temperatures. The experiments were conducted at four temperatures: 21 °C, 50 °C, 90 °C, and 130 °C, in a uniform temperature distribution. The study encompassed the validation of the method, and the applicability and limitations of the methodology for experiments at elevated temperatures were discussed. The results showed that the water uptake in bentonite is sensitive to temperature, and significant changes were observed between all the studied temperatures. Although the impact of temperature on water uptake has been observed before, this study obtained detailed 4D data, which is difficult to acquire using other methods. This methodology provides data for modelling the thermo-hydro-mechanical behaviour of compacted bentonite, which is required in the safety assessment of the geological final disposal of radioactive waste.

采用x射线断层扫描和图像分析技术，在高温等体积条件下监测压实怀俄明州钠基膨润土中膨润土和水部分密度的4D（三维空间随时间）演化。实验在21°C、50°C、90°C、130°C四个温度下进行，温度分布均匀。研究包括方法的验证，并讨论了该方法在高温下实验的适用性和局限性。结果表明，膨润土吸水率对温度敏感，在不同温度下均有显著变化。虽然之前已经观察到温度对水分吸收的影响，但本研究获得了详细的四维数据，这是其他方法难以获得的。这种方法为模拟压实膨润土的热-水-力学行为提供了数据，这在放射性废物的地质最终处置的安全评估中是必需的。

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引用次数: 0

Fracture evolution and energy dissipation characteristics of limestone under triaxial loading and unloading experiments 三轴加卸载试验下灰岩断裂演化及能量耗散特征

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-11-17 DOI: 10.1016/j.gete.2025.100771

Ding Liu , Bowen Cheng , Xinping Li , Mingyang Wang , Yu Wang , Yuliang Zhang

To elucidate the failure mechanism of limestone during excavation-induced unloading in underground engineering, a series of triaxial loading–unloading tests were conducted under various confining pressures(σ₃) and initial unloading levels (n). The results show that increasing σ₃ enhances both the peak strength and plastic deformation capacity of limestone. Although a higher n leads to a strength increase, it remains lower than that under conventional triaxial loading and intensifies the brittleness of failure. In terms of energy evolution, both the maximum elastic strain energy (U_e-max) and the maximum dissipated energy (U_d_-max) increase linearly with σ₃. During the unloading path, the dissipated energy exhibits a pronounced hysteresis effect, which becomes more evident at higher n values, revealing the sudden energy release characteristic of highly pre-damaged rock masses. Macro- and micro-scale analyses indicate that the failure mode evolves from tensile–shear mixed failure to shear-dominated failure as σ₃ and n increase. Furthermore, the unloading damage constitutive model, established based on strain equivalence and Weibull distribution, shows good agreement with experimental results, effectively characterizes the damage evolution process of limestone.

为了阐明地下工程开挖卸荷过程中石灰岩的破坏机理，在不同围压（σ₃）和初始卸荷水平(n)下进行了一系列三轴加卸载试验。结果表明，σ 3的增加可以提高石灰石的峰值强度和塑性变形能力。较高的n值虽然提高了强度，但仍低于常规三轴载荷下的强度，并加剧了破坏的脆性。在能量演化方面，最大弹性应变能（Ue-max）和最大耗散能（Ud-max）都随着σ₃的增加而线性增加。在卸荷过程中，耗散能量表现出明显的滞后效应，且在n值越高时更为明显，揭示了高度预损伤岩体能量释放的突变性。宏观和微观尺度分析表明，随着σ₃和n的增大，破坏模式由拉剪混合破坏向剪切为主破坏演化。基于应变等效和威布尔分布建立的卸荷损伤本构模型与试验结果吻合较好，有效表征了灰岩的损伤演化过程。

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引用次数: 0

Energy evolution law and multi-scale failure strength criterion of granite under multiaxial compression 花岗岩多轴压缩下能量演化规律及多尺度破坏强度准则

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-11-16 DOI: 10.1016/j.gete.2025.100770

Yingqing Lyu, Haijun Wu, Heng Dong, Tianlong Zhang, Meng Li, Fenglei Huang

High-strength hard rock and its complex stress environment are one of the challenges faced by deep underground engineering. Mastering the strength characteristics, such as deformation and failure of rock under a multiaxial compression environment, is the basis for solving such problems. This paper proposed a strength criterion based on energy evolution and multi-scale failure characteristics to describe the failure behavior of granite under multiaxial compression. Firstly, the multiaxial compression test of granite was carried out to analyze its stress-strain curve, macro-meso failure characteristics, and energy evolution law, and its meso-failure characteristics were quantitatively characterized based on fractal theory. Secondly, the relationship between shape change energy density, confining pressure, and mesoscopic failure fractal dimension is established, and the rock's multi-scale failure strength criterion is proposed. Finally, the calculation results of the multi-scale failure strength criterion are compared with the test results, Mohr-Coulomb criterion, and Hoek-Brown criterion, and the sensitivity analysis of the parameters in the multi-scale failure strength criterion is carried out. The results show that the multi-scale failure strength criterion can accurately reflect the deformation and failure behavior of rock, and it is proven that the failure characteristics of rock significantly influence the accuracy of its strength criterion. The multi-scale failure strength criterion considers the influence of meso-damage on rock failure behavior, which makes up for the deficiency of the traditional strength criterion in considering damage characteristics and meso-mechanical parameters. It provides a new idea for analyzing rock failure mechanisms and a more accurate prediction model for engineering practice.

高强度硬岩及其复杂应力环境是深埋地下工程面临的挑战之一。掌握岩石在多轴压缩环境下的变形破坏等强度特性，是解决这类问题的基础。提出了一种基于能量演化和多尺度破坏特征的强度准则来描述花岗岩在多轴压缩下的破坏行为。首先，对花岗岩进行多轴压缩试验，分析其应力-应变曲线、宏细观破坏特征和能量演化规律，并基于分形理论对其细观破坏特征进行定量表征。其次，建立了岩石形态变化、能量密度、围压与细观破坏分形维数之间的关系，提出了岩石的多尺度破坏强度准则；最后，将多尺度破坏强度准则的计算结果与试验结果、Mohr-Coulomb准则和Hoek-Brown准则进行比较，并对多尺度破坏强度准则中各参数进行敏感性分析。结果表明，多尺度破坏强度准则能准确反映岩石的变形破坏行为，并证明岩石的破坏特征对其强度准则的准确性有显著影响。多尺度破坏强度准则考虑了细观损伤对岩石破坏行为的影响，弥补了传统强度准则在考虑损伤特征和细观力学参数方面的不足。为分析岩石破坏机理提供了新的思路，为工程实践提供了更准确的预测模型。

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引用次数: 0

Incipient motion of sands in the pipe and numerical modelling of the pipe depth 砂在管道中的初始运动及管道深度的数值模拟

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-11-13 DOI: 10.1016/j.gete.2025.100768

Yingping Xiao , Hong Cao , Hong Pan , Guanyong Luo , Bo Li , Dongfeng Zhu

Backward erosion piping is an internal erosion process that creates shallow pipes at the interface between an impermeable cover layer and a sandy foundation. Shallow pipes develop intermittently towards the riverside. Seepage and pipe flow are the main drivers of pipe erosion. Accurately simulating this coupled system is crucial for revealing the underlying erosion mechanisms, and the pipe depth is a significant parameter in these simulations. The pipe depth is determined by applying the incipient motion condition of bed particles, a method which relies on the pipe being in a limit-state equilibrium. This condition, along with the depth-averaged critical velocity, is derived from a force balance analysis of a single particle at the pipe's bottom under upward seepage. Accordingly, a coupled approach simulating erosion in the pipe, groundwater flow, and pipe flow is proposed. Pipe deepening coupled with groundwater flow and pipe flow are simulated for some available experiments to illustrate this simulation approach.

反向侵蚀管道是一种内部侵蚀过程，在不透水覆盖层和砂质基础之间的界面上形成浅管道。浅管道断断续续地向河边延伸。渗流和管道流动是管道侵蚀的主要驱动因素。准确模拟这种耦合系统对于揭示潜在的侵蚀机制至关重要，而管道深度是这些模拟中的一个重要参数。利用床层颗粒的初始运动条件来确定管道深度，这种方法依赖于管道处于极限状态平衡。这一条件以及深度平均临界速度是通过对管道底部单个颗粒在向上渗流条件下的力平衡分析得出的。据此，提出了一种模拟管道侵蚀、地下水流动和管道流动的耦合方法。通过一些现有的实验，模拟了地下水流和管道流耦合下的管道深化。

引用次数: 0

Experimental study of sugar-induced sand cementation in dry conditions 干燥条件下糖诱导砂胶结试验研究

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-11-07 DOI: 10.1016/j.gete.2025.100765

Gianmario Sorrentino , Andrea Franza

This paper presents an experimental study of sugar as a low-viscosity cementing agent for sand in dry laboratory conditions. Sand was mixed with aqueous sugar solutions of varying concentrations (15%–40% by mass) and oven-cured at different temperatures. Unconfined compressive strength (UCS) tests showed that strength increased with sugar concentration, with UCS values reaching up to 6 MPa —comparable to or exceeding those achieved with conventional bio-cementation methods. Optimal curing occurred at 105 °C, balancing rapid hardening and peak strength, while excessive heating at 170 °C reduced strength due to sugar caramelisation. Nevertheless, all conditions yielded mean UCS values above 1 MPa, demonstrating the method’s reliability. Scanning electron microscopy (SEM) was used to observe the interaction between sugar and sand particles, revealing a substantial sugar coating bonding the grains. These findings reveal some of the fundamental mechanisms of sugar-induced cementation. Finally, research pathways and current shortcomings for field applications are discussed.

本文介绍了在干燥实验室条件下，糖作为低粘度砂胶凝剂的实验研究。将沙子与不同浓度的糖水溶液混合（质量比例为15%-40%），并在不同温度下进行烤炉固化。无侧限抗压强度（UCS）测试表明，强度随糖浓度的增加而增加，UCS值可达6 MPa，与常规生物胶结方法的结果相当或超过。最佳固化温度为105°C，可以平衡快速硬化和峰值强度，而在170°C下过度加热会因糖焦糖化而降低强度。尽管如此，所有条件下的平均UCS值都在1 MPa以上，证明了该方法的可靠性。利用扫描电子显微镜（SEM）观察了砂粒与砂粒之间的相互作用，发现砂粒之间有一层糖包覆层。这些发现揭示了糖诱导的胶结的一些基本机制。最后，讨论了现场应用的研究途径和目前存在的不足。

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引用次数: 0

Molecular insights into the shear behavior of interstratified illite-smectite clays: Effects of hydration and illitization 层间伊利石-蒙脱石粘土剪切行为的分子洞察：水化和伊利化的影响

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-11-06 DOI: 10.1016/j.gete.2025.100759

Wenbo Niu , Chaofa Zhao , Hamza Mhamdi Alaoui , Zhongxuan Yang , Pierre-Yves Hicher

Clayey geomaterials rarely occur in a pure mineralogical state in nature and are more commonly found as mixed-layer clays, such as interstratified illite-smectite. These clays consist of varying proportions of illite and smectite layers, which significantly affect their mechanical properties. Under variable mechanical conditions, the shear behavior of mixed-layer clays exhibits considerable complexity, underscoring the need for in-depth investigations. This paper presents a molecular-scale study on the behavior of interstratified illite-smectite minerals, simulating a geotechnical shear setup at the molecular level. Multiple molecular models were constructed to explore the effects of water content and illite layer proportions, effectively replicating stages of the illitization process. The results reveal that the mixed-layer clays exhibit clear stick–slip behavior during shear simulation. Models with low illite content demonstrated relatively similar shear characteristics, while higher illite content led to a significant reduction in nanoscale cohesion and a slight increase in friction coefficient. Pure illite exhibited the highest shear strength among the studied materials, with a friction coefficient and cohesion of 0.111 and 0.172 GPa, respectively. Furthermore, the illitization process was observed to progressively enhance the shear modulus, ranging from 0.63 GPa to 26.81 GPa under various hydrostatic pressures. A statistical analysis was also performed to further examine the stick–slip behavior of mixed-layer clays. These findings provide essential insights into the nanoscale mechanical properties of mixed-layer clay minerals, contributing to a deeper understanding of geomaterial stability in critical applications.

粘土土工材料在自然界中很少以纯矿物学状态出现，更常见的是混合层状粘土，如层间伊利石-蒙脱石。这些粘土由不同比例的伊利石和蒙脱石层组成，这显著影响了它们的力学性能。在不同的力学条件下，混合层粘土的剪切行为表现出相当的复杂性，强调了深入研究的必要性。本文在分子水平上模拟岩土剪切装置，对层间伊利石-蒙脱石矿物的行为进行了分子尺度的研究。构建了多个分子模型来探索含水量和伊利石层比例的影响，有效地复制了伊利石化过程的各个阶段。结果表明，混合层粘土在剪切模拟过程中表现出明显的粘滑特性。低伊利石含量的模型剪切特性相对相似，而高伊利石含量导致纳米尺度黏聚力显著降低，摩擦系数略有增加。纯伊利石的抗剪强度最高，摩擦系数和黏聚力分别为0.111和0.172 GPa。此外，在不同的静水压力下，钝化过程逐渐提高了剪切模量，从0.63 GPa到26.81 GPa不等。为了进一步研究混合层粘土的粘滑特性，还进行了统计分析。这些发现为混合层粘土矿物的纳米级力学特性提供了重要的见解，有助于更深入地了解关键应用中的地质材料稳定性。

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引用次数: 0

Experimental investigation of damage behavior of coal pillars during injection-production in abandoned coal mine gas storage 废弃煤矿储气库注采过程中煤柱破坏行为试验研究

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-11-06 DOI: 10.1016/j.gete.2025.100766

Xiaoming Shi , Lei Geng , Xuejie Deng , Gustavo Paneiro , Zhide Wu , Yang Li , Hao Liu , Jianye Feng

The mechanical behavior and damage evolution of coal pillars under cyclic loading govern the long-term stability of underground gas storage in abandoned coal mines. Using coal from Ningxia, we conducted uniaxial constant-amplitude cyclic tests and incremental loading-unloading tests, combined with acoustic-emission monitoring, damage-mechanics modeling, and PFC particle-flow simulations, to elucidate a stress-threshold-controlled evolution law. The results show that the first loading cycle dominates damage progression, contributing 36.75 %-75.19 % of the cumulative AE ringing counts and markedly degrading mechanical integrity. Also, macroscopic failure is mainly shear (73.9 %-80.1 %), while the proportion of tensile events rises with stress amplitude. This study also shows that a stress-threshold range of about 89.2 %-95.4 % UCS is identified for the coal specimens, within which sub-threshold damage is self-limiting and the damage variable grows by only 9.3 % after 50 cycles, whereas super-threshold loading induces a three-stage process of compaction, stable accumulation, and accelerated instability. Finally, a damage-evolution model that couples Ashby’s microcrack mechanics with geometric damage predicts a nonlinear link between crack growth and loss of load-bearing capacity and reproduces the measured stress-damage trajectory more accurately than classical formulas. PFC simulations further show that a stress difference of 0.05 MPa can trigger an abrupt transition to instability, confirming the decisive control of the threshold. These findings provide a basis for safety-threshold design and long-term stability assessment of rock masses under cyclic loading.

循环荷载作用下煤柱的力学行为和损伤演化决定着废弃煤矿地下储气库的长期稳定性。利用宁夏产煤进行单轴等幅循环试验和增量加卸载试验，结合声发射监测、损伤力学建模和PFC颗粒流模拟，阐明了应力阈值控制的演化规律。结果表明，第一次加载周期对损伤进程起主导作用，对累积声发射振铃数的贡献为36.75 % ~ 75.19 %，并显著降低了机械完整性。宏观破坏以剪切破坏为主（73.9 % ~ 80.1 %），拉伸破坏的比例随应力幅值的增大而增大。研究还表明，煤样的应力阈值范围约为89.2 % ~ 95.4 % UCS，在此范围内，亚阈值损伤是自限的，50次循环后损伤变量仅增长9.3 %，而超阈值加载则导致压实、稳定堆积和加速失稳三个阶段的过程。最后，将Ashby微裂纹力学与几何损伤相结合的损伤演化模型预测了裂纹扩展与承载能力损失之间的非线性联系，并比经典公式更准确地再现了测量的应力-损伤轨迹。PFC模拟进一步表明，0.05 MPa的应力差可以触发突变到不稳定，证实了阈值的决定性控制。研究结果为循环荷载作用下岩体的安全阈值设计和长期稳定性评价提供了依据。

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引用次数: 0

Pressure relief and zonal extraction and utilization of medium-thick coal seams with high gas content 高含气量中厚煤层卸压与分区开采利用

IF 3.7 2区工程技术 Q3 ENERGY & FUELS

Geomechanics for Energy and the Environment

Pub Date : 2025-11-04 DOI: 10.1016/j.gete.2025.100764

Zechen Chang , Pengxiang Zhao , Shugang Li , Diego Maria Barbieri , Xu Guo , Weidong Lu , Quan Jin , Linyue Jie

In this study, the precise layout of the pressure-relief gas drainage boreholes significantly impacted the efficiency of gas drainage and the efficient utilization of gas. This research considered a certain main mining face of the Lutang Coal Mine in Guizhou Province as its research background. The evolution law of the overburden fracture evolution during the mining of high-gas coal seams was analyzed, and a regional division was conducted. A characterization model of the gas migration zone in a high-gas coal seam was constructed. This model was applied to the test working face to perform directional borehole gas drainage and gas utilization. The results showed that the goaf area can be divided into subsidence, rupture, and curved subsidence zones based on the evolutionary trend of the fractures. The goaf area was laterally divided into gas migration and compaction areas based on the density of the fractures. A characterization model of the gas migration zones in high-gas coal seams was established, the stability of rock masses in different regions was analyzed, and the optimal area for directional drilling in the gas migration zone of the fracture was determined. The drilling layout parameters were optimized, and the wellbore gas production, average volume fraction of wellbore gas production, and pure gas production under pressure relief increased by 267 %, 240 %, and 241 %, respectively. The gas-fired power generation increased from 519.3 kWh to 1311.1 kWh. The gas volume fraction in the return air duct and upper corner decreased to between 0.27–0.53 and 0.22–0.43. These results provide theoretical guidance for parameter optimization of extraction boreholes in high-gas coal seams and the utilization of depressurized gas.

在本研究中，泄压瓦斯抽放钻孔的精确布置对瓦斯抽放效率和瓦斯的高效利用有重要影响。本研究以贵州鲁塘煤矿某主采工作面为研究背景。分析了高瓦斯煤层开采过程中覆岩裂隙演化规律，并进行了区域划分。建立了高瓦斯煤层天然气运移带的表征模型。将该模型应用于试验工作面进行定向井瓦斯抽采和瓦斯利用。结果表明：根据裂缝演化趋势，采空区可划分为沉陷带、破裂带和弯曲沉陷带；根据裂缝密度将采空区横向划分为气体运移区和压实区。建立了高瓦斯煤层气体运移带的表征模型，分析了不同区域岩体的稳定性，确定了裂缝气体运移带的最佳定向钻井区域。通过优化钻井布局参数，井筒产气量、井筒产气量平均体积分数和卸压下的纯气量分别提高了267 %、240 %和241 %。燃气发电量从519.3千瓦时增加到1311.1千瓦时。回风管道和上角的气体体积分数下降到0.27-0.53 ~ 0.22-0.43之间。研究结果为高瓦斯煤层抽采钻孔参数优化及降压瓦斯利用提供了理论指导。

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引用次数: 0