煤层气井循环补水排采工艺  

Cycle replenishment drainage and gas production in CBM

作　　者：莫日和[1] 刘冰[2] 刁秀芳 綦耀光[2] 

机构地区：[1]中联煤层气有限责任公司,北京100011 [2]中国石油大学(华东)机电工程学院,山东青岛266580

出　　处：《煤炭学报》2014年第A01期141-145,共5页Journal of China Coal Society

基　　金：国家科技重大专项资助项目(2011ZX05062-004);国家自然科学基金资助项目(51174224);国家科技支撑计划资助项目(2012BAH26F04)

摘　　要：针对在煤层气的排采过程中大部分井的采出液量较少,不能满足进入井筒的煤粉排出条件,导致煤粉在井筒内堆积,造成卡泵、埋泵频繁发生的问题,提出在不停产情况下,通过循环补水,增加井液流量,将进入井筒的煤粉排出地面的工艺条件和要求,延长煤层气井无故障排采周期。根据煤粉颗粒的沉降末速度,综合考虑浓度及速度分布的影响,将杆管环空煤粉颗粒排出的最小水流提升速度定为自由沉降末速的2倍,计算了不同杆管组合满足煤粉排出条件的最小排量,根据煤粉最大粒径为0.3 mm的假设,给出了沉降罐体积。通过现场连续循环补水试验,实现连续运转6个月以上不修井的良好效果。In the process of drainage and gas production, due to the small amount of produced liquid, it can＇ t meet the discharge of pulverized coal into the wellbore. This cause the coal powder into the wellbore to accumulate in the well- bore, the pump to be stuck or be buried frequently and average work over cycle to be short, what affecting CBM well＇ s stable yield. In this paper, a method and the equipment to discharged the coal powder into the wellbore through in- creasing the well＇ s flow in the case of non-stop production was proposed, which extending the trouble-free period of CBM well＇ s. On the basis of the terminal settling velocity of the coal powder, the concentration and velocity distribu- tion of the coal powder were considered, the authors designed the minimum carrying flow speed twice as much the ter- minal settling velocity of the coal powder. The minimum carrying flow rate was calculated according to various combi- nation of rods and tubes. Finally, the settling tank＇ s volume was obtained under the supposition of the maximum coal particle size is 0.3 mm. The field tests have verified the feasibility of this process because the CBM wells can be con- tinuous operated for more than 6 months.

关 键 词：煤层气 补水 排采 煤粉 

分 类 号：P618.11[天文地球—矿床学]