裂隙中煤粉运移及解堵可视化物理模拟实验  

Visual physical simulation experiment of coal fines migration and blockage removal in fractures

作　　者：魏迎春[1,2] 张琦 刘子亮 李彪 谢天成 任金伟 王安民[1] 曹代勇[1,2] WEI Yingchun;ZHANG Qi;LIU Ziliang;LI Biao;XIE Tiancheng;REN Jinwei;WANG Anmin;CAO Daiyong(College of Geoscience and Surveying Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources,China University of Mining and Technology-Beijing,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)地球科学与测绘工程学院,北京100083 [2]中国矿业大学(北京)煤炭精细勘探与智能开发全国重点实验室,北京100083

出　　处：《煤炭学报》2024年第3期1488-1500,共13页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(41972174,42042197)。

摘　　要：煤粉在煤储层裂隙中沉积会降低裂隙导流能力,制约煤层气井高效稳产开发。设计了裂隙中煤粉运移及解堵可视化物理模拟实验方案,通过裂隙中煤粉运移可视化物理模拟实验,分析了裂隙不同位置煤粉颗粒沉积面积的变化和沉积形态特征,揭示了煤粉运移、沉积的动态规律;通过裂隙中煤粉解堵可视化物理模拟实验,分析了解堵时间和流速对裂隙中沉积煤粉解堵面积的影响,揭示了煤粉启动、解堵的动态规律。实验结果表明:煤粉颗粒在裂隙不同方向和位置聚集状态不同,裂隙喉道由入口向垂直主运移方向的两端及主运移方向煤粉颗粒沉积面积逐渐减少,支路通道沿主运移方向煤粉颗粒沉积面积逐渐增加。裂隙喉道、支路通道和主路通道处煤粉沉积的形态分别呈鹰嘴状、层状和流线型,其原因是裂隙不同位置对含煤粉流体的阻力不同,导致煤粉在不同位置的沉积形态不同。在相同流速下,随解堵时间增长,煤粉解堵效果越好,但前期解堵面积大,后期解堵面积小,裂隙喉道处煤粉解堵效果明显优于支路通道,其原因是松散、易于解堵的煤粉颗粒会被首先解堵,随时间进行,剩余未被解堵的煤粉颗粒需要更大的启动流速。流速越大,裂隙喉道处和支路通道处的煤粉解堵面积越大,其原因是提升流速能增强煤粉颗粒的流动性。The deposition of coal fines in fractures can reduce the fracture conductivity and restrict the efficient and stable development of coalbed methane wells.A visual physical simulation experiment scheme for coal fines migration and blockage removal in fractures was designed.The variation of coal fines particle deposition area and sedimentary morphological characteristics at different positions of fractures were analyzed and the dynamic law of coal fines migration and deposition was revealed based on the visual physical simulation experiment of coal fines migration in fractures.Using the visual physical simulation experiment of coal fines blockage removal in fractures,the influence of plugging time and flow rate on the area of deposited coal fines blockage removal in fractures was investigated and the dynamic law of coal fines starting and blockage removal was found.The experimental results show that the coal fines particles have different aggregation states in different directions and positions of the fractures.The deposition area of coal fines particles gradually decreases from the entrance to the two ends of the vertical main migration direction and the main migration direction,and the deposition area of coal fines particles gradually increases along the main migration direction in the branch channel.The morphology of coal fines deposition at the fracture throat,branch channel and main channel is eagle’s mouth shaped,layered and streamlined,respectively.The reason is that the resistance of different positions of the fracture to the coal finescontaining fluid is different,resulting in different deposition morphology of coal fines at different positions.At the same flow rate,with the increase of blockage removal time,the blockage removal effect of coal fines is better,but the area of blockage removal in the early stage is large,and the area of blockage removal in the later stage is small.The blockage removal effect of coal fines at the fracture throat is obviously better than that in the branch channel.The reason

关 键 词：煤层气 煤粉运移 煤粉解堵 可视化 物理模拟实验 

分 类 号：P618.11[天文地球—矿床学]