沁水盆地煤层气水平井井筒煤粉迁移及控制

Coal dust migration and treatment for coalbed methane horizontal wells in Qinshui Basin

曹立虎 张遂安 石惠宁 白建梅 王欢 朱伟

CAO Lihu ZHANG Suian SHI Huining BAI Jianmei WANG Huan ZHU Wei

中国石油大学气体能源开发与利用教育部工程研究中心，北京　102249 中国石油大学北京煤层气研究中心，北京　102249 华北油田公司采油工艺研究院，河北任丘　062552

Engineering Research Center of the Ministry of Education for Gas Energy Development & Utilization in China University of Petroleum,Beijing 102249, China Coalbed Methane Research Center of China University of Petroleum Beijing, Beijing 102249, China

煤层气水平井煤粉的产出易造成储层伤害和卡泵问题，严重影响煤层气的产量。通过进行水平井井筒煤粉迁移规律物理模拟试验，研究了不同压差下，煤粉在水平井筒内的迁移特征。研究结果表明：煤粉和水两相流动为层流流动，煤粉迁移的速率与压差呈非线性增加关系，存在临界启动差压，压差增加到一定程度后，煤粉的迁移趋于稳定。根据煤粉产生机理分析、物模迁移实验和生产经验，提出了控制煤粉产出的生产措施。

Coal dust in CBM horizontal wells usually leads to reservoir damage and pump sticking, resulting in serious production decreasing of coalbed methane. The transportation characteristics of coal dust under the conditions of different pressure differentials in wellbore was studied through physical simulation experiments. The result indicates that the coal dust and water two-phase flow is a lami-nar flow, and the relationship between coal dust migration velocity and pressure drop is non-linear with transportation velocity increasing as pressure drop increasing. There is a critical startup pressure gradient for coal dust starting to flow, and the movement finally achieves a steady state once the pressure gradient reaches a certain level. The control method of coal dust treatment was discussed on the basis of analyzing coal dust forming mechanisms, physical simulation experimental results and field production experience.