延长油田CO_(2)大气扩散数值模拟研究及监测点位优化  

Numerical simulation of atmospheric diffusion of CO_(2) and optimization of monitoring points in Yanchang Oil Field

作　　者：杨康 杨红 沈振振 刘瑛 梁全胜 杨强强 王宏 姚振杰 王苛宇 马振鹏 YANG Kang;YANG Hong;SHEN Zhenzhen;LIU Ying;LIANG Quansheng;YANG Qiangqiang;WANG Hong;YAO Zhenjie;WANG Keyu;MA Zhenpeng(Shaanxi Key Laboratory of CO_(2) Sequestration and Enhanced Oil Recovery,Xi’an 710065,China;Research Institute of Shaanxi Yanchang Petroleum(Group)Co.,Ltd.,Xi’an 710065,China;Department of Geology,Northwestern University,Xi’an 710000,China;Yanchang Gas Field Production Plant of Shaanxi Yanchang Petroleum(Group)Co.,Ltd.,Yan’an 716000,China)

机构地区：[1]陕西省CO_(2)封存与提高采收率重点实验室,陕西西安710065 [2]陕西延长石油(集团)有限责任公司研究院,陕西西安710065 [3]西北大学地质学系,陕西西安710000 [4]陕西延长石油(集团)有限责任公司延长气田采气一厂,陕西延安716000

出　　处：《中国矿业》2024年第2期201-207,共7页China Mining Magazine

基　　金：国家重点研发计划项目“二氧化碳提高油藏采收率与地质封存一体化关键技术及应用示范”资助(编号:2022YFE0206700);陕西省青年科技新星项目“促进CO_(2)与原油混相的伴生气体系构筑及其改善CO_(2)驱油效果评价”资助(编号:2021KJXX-86)。

摘　　要：由于陕北地区局部气象环境复杂,造成CO_(2)浓度扩散方向的不确定性,同时,延长油田地处黄土塬,地貌沟壑纵横高低起伏,导致布置CO_(2)大气监测点位困难。本文基于Fluent软件模拟了不同泄漏情景下CO_(2)驱油与封存泄漏后在大气中的扩散规律,优化监测点位布局,并开展了监测实践。研究结果表明:随着风速的不断增加,CO_(2)云的浓度在纵向上呈现出一直缩小的趋势,但是CO_(2)云的浓度在横向上的扩散距离呈现出先增大后缩小的趋势;当风速为2.0 m/s时,CO_(2)云的扩散距离最远为47 m,浓度最大的CO_(2)云扩散距离为15 m;随着泄漏速度的增大,近地表处CO_(2)云的浓度无论是在纵向上还是在横向上都在不断增大;当泄漏速度小于0.4 m/s时,随着泄漏速度的增加,CO_(2)云的扩散距离增加得较快;当泄漏速度大于0.4 m/s时,随着泄漏速度的增加,CO_(2)云的扩散距离增加速率变缓。结合模拟结果、陕北地区气象环境、裂缝发育方向、“注气”优势方向和近地表植被高度,确定监测点位布局:方向上为北东—南西向;平面上为距离井口下风向15 m;纵向上为采样高度50 cm。CO_(2)浓度大气监测点的监测结果表明并未发生泄漏。Due to the complex local meteorological conditions in Northern Shaanxi,the diffusion direction of CO_(2) concentration is uncertain.Additionally,the rugged and undulating topography of the oil field in the loess plateau makes it difficult to arrange CO_(2) atmospheric monitoring points.In this paper,Fluent software is used to simulate the diffusion patterns of CO_(2) during flooding and storage leakage in different leakage scenarios.The monitoring point layout is optimized,and monitoring practices are conducted.The research results indicate that as wind speed increases,the concentration of the CO_(2) cloud decreases longitudinally,but the lateral diffusion distance of the CO_(2) cloud shows an initial increase followed by a decrease.When the wind speed is 2.0 m/s,the maximum diffusion distance of the CO_(2) cloud is 47 m,the cloud diffusion distance of the largest concentration of the CO_(2) cloud is 15 m.With an increasing leakage rate,the concentration of the CO_(2) cloud near the ground surface increases both longitudinally and laterally.When the leakage rate is less than 0.4 m/s,the diffusion distance of the CO_(2) cloud increases rapidly with increasing leakage rate.When the leakage rate exceeds 0.4 m/s,the rate of increase in the diffusion distance of the CO_(2) cloud slows down.Taking into account the simulation results,the meteorological conditions in Northern Shaanxi,the direction of fissure development,the preferred direction of gas injection,and the height of near-surface vegetation,the layout of the monitoring points is determined as follows:a northeast-southwest direction;a downwind distance of 15 m from the wellhead in the horizontal plane;a sampling height of 50 cm in the vertical direction.The monitoring results of CO_(2) concentration in the atmosphere indicate that no leakage has occurred.

关 键 词：CO_(2)驱油与封存泄漏 CO_(2)泄漏 CO_(2)浓度大气扩散 监测点位 黄土塬地区 

分 类 号：TD76[矿业工程—矿井通风与安全] X83[环境科学与工程—环境工程]