摘要
为探究地层倾角对咸水层CO_(2)地质封存中羽流迁移、压力响应及封存分布的影响。基于准噶尔盆地东沟组砂岩储层相关资料,构建三维地质模型,对超临界CO_(2)在倾斜地层中运移规律进行模拟研究。结果表明:地层倾角增大显著增大了CO_(2)羽流的侧向迁移距离,促使其沿盖层下缘汇聚,增加了突破盖层的潜在风险。封存过程中随着部分CO_(2)相态改变,扩散范围持续扩大但迁移速率减缓。压力场演化中,注入期近井区域压力显著抬升并向两侧传播;相较于水平地层,倾斜地层压力影响半径更大,压力等值线呈不对称分布。封存量分配受倾角影响,储层上半区域有利于构造封存;停注后残余与溶解封存持续增强,形成封存机制的动态转换,储层上半区域累计封存量占比较高。研究结果为倾斜地层CO_(2)地质封存的封存效率与安全性评价提供相关的理论依据,为碳捕集、利用与封存(Carbon Capture,Utilization and Storage,CCUS)工程选址及注入策略提供优化。
This study aims to systematically elucidate the coupling mechanisms of formation dip angles on plume migration behavior,pressure field evolution,and storage mechanism partitioning in geological CO_(2)sequestration within deep saline aquifers.Deep saline aquifers in sedimentary basins,characterized by high porosity and permeability,moderate burial depth,and continuity,serve as ideal repositories for CO_(2)storage.Focusing on the Donggou Formation sandstone reservoir in the Junggar Basin,this research employs Petrel and CMG-GEM to construct a three-dimensional numerical model integrating heterogeneity and multi-field coupling effects,based on actual geological and well-log data.By establishing formation dip angle gradients from 0°to 12°and implementing a constant-rate injection scheme,the evolution of supercritical CO_(2)during the 30 years injection period and 70 years post-injection phase was simulated,with emphasis on CO_(2)saturation distribution,pressure field response,and the evolving contributions of four storage mechanisms:structural,solubility,residual,and mineral trapping.The simulation results indicate that formation dip angles significantly govern the spatial distribution and migration velocity of CO_(2)plumes.At a 12°dip angle,lateral migration distance increases by 76.9%compared to horizontal formations.Plume migration velocity is constrained by both injection pressure and formation structure,declining markedly and stabilizing post-injection.Formation dip angles enhance the updip migration tendency of CO_(2);larger angles facilitate plume diffusion toward shallower aquifers and even the surface.Post-injection,plume extent continues to expand updip.The pressure field transitions from symmetric distribution in horizontal formations to pronounced asymmetry in inclined strata.After 100 years of simulation,maximum pressure increase in inclined formations reaches 59.4%,while minimum pressure decrease attains 59.5%relative to horizontal formations.Formation dip angles exacerbate near-well pressure buildup and far-field diffusion,resulting in significantly asymmetric pressure distribution with a notably larger radius of influence compared to horizontal strata.Storage mechanism allocation exhibits distinct directional dependency.Increasing dip angles amplify spatial heterogeneity in storage capacity,with enhanced storage updip and reduced storage downdip.Updip regions are more prone to prematurely reaching storage capacity limits.Structural trapping dominates updip areas,accounting for a substantially higher proportion than in downdip regions.Solubility and residual trapping continue to strengthen post-injection,whereas mineral trapping progresses slowly,with a conversion rate of merely approximately 10%over a century.The findings provide a theoretical foundation for assessing storage efficiency and security in inclined formations for geological CO_(2)sequestration,offering insights for CCUS project site selection and injection strategy optimization.
作者
韩顺琦
杨国栋
张银银
陈浪
韩积斌
张喜龙
闵康婷
HAN Shunqi;YANG Guodong;ZHANG Yinyin;CHEN Lang;HAN Jibin;ZHANG Xilong;MIN Kangting(College of Resources and Environmental Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xi'ning 810008,China)
出处
《有色金属(冶炼部分)》
北大核心
2026年第1期128-140,共13页
Nonferrous Metals(Extractive Metallurgy)
基金
自然资源部地质环境监测工程技术创新中心开放基金(2022KFK1212006)
企业委托项目(2024H30109)
青海省科技厅项目(2025-ZJ-754)。
