Coal Geology & Exploration


The reasonable control of the casing pressure and the bottom-hole pressure and the reasonable depressurization of reservoir pressure is the key technology for the CBM development. The pickup of the bottom-hole flow pressure(BHFP) will restrain CBM' desorption, lead to reservoir permeability damage and reduce the production of CBM wells. Based on production practice of Fanzhuang block in Qinshui basin, this paper puts forward the cause of a CBM abnormal well type, pickup of the BHFP, clarifies the damage mechanism of the pickup of the BHFP through theoretical research and field data analysis, and puts forward the evaluating method of the damage degree of reservoir and the countermeasures of the pickup of the bottom-hole flow pressure. The results of research show that in general if the submergence degree of coal seam increases, the casing pressure will decrease and the faster the decrease of the casing pressure becomes, the faster the decrease of the bottom-hole flow pressure is. If the submergence degree of coal seam increase faster, the bottom hole flow pressure will rise. The pickup of the BHFP results in the increase of the gas output resistance and the decrease of output power, so some gas content is blocked in the pores by capillary pressure and hard to produce, which is the damage mechanism to the reservoir caused by the pickup of the BHFP. The damage index can indirectly represent the damage degree of reservoir caused by the pickup of the BHFP. The valve leakage and air lock of the displacement pump are the main reasons for the pickup of the BHFP, which result in the drainage amount of water less than the supply amount of water from coal seams to bottom hole. The treatment of wells with abnormal BHFP pickup is hydraulic flush to remove the coal powders to deal with fixing valve leakage, mechanical vibration to remove coal powders to deal with floating valve leakage and the combination of permanent-submerged-technology and pumping-unit-intermittent-working technology to deal with gas lock.


CBM well, BHFP pickup, abnormal well, damage mechanism, damage index, countermeasures




[1] 赵贤正,朱庆忠,孙粉锦,等. 沁水盆地高阶煤层气勘探开发实践与思考[J]. 煤炭学报,2015,40(9):2131-2136. ZHAO Xianzheng,ZHU Qingzhong,SUN Fenjin,et al. Practice of coalbed methane exploration and development in Qinshui basin[J]. Journal of China Coal Society,2015,40(9):2131-2136.

[2] 胡秋嘉,贾慧敏,祁空军,等. 高煤阶煤层气井单相流段流压精细控制方法:以沁水盆地樊庄-郑庄区块为例[J]. 天然气工业,2018,38(9):76-81. HU Qiujia,JIA Huimin,QI Kongjun,et al. A fine control method of flowing pressure in single-phase flow section of high-rank CBM gas development wells:A case study from the Fanzhuang-Zhengzhuang block in the Qinshui basin[J]. Natural Gas Industry,2018,38(9):76-81.

[3] 孙仁远,宣英龙,任晓霞,等. 煤层气井井底流压计算方法[J]. 石油钻采工艺,2012,34(4):100-103. SUN Renyuan,XUAN Yinglong,REN Xiaoxia,et al. Methods of bottom-hole flow pressure calculations for coalbed methane wells[J]. Oil Drilling & Production Technology,2012,34(4):100-103.

[4] 刘新福,綦耀光,刘春花,等. 气水两相煤层气井井底流压预测方法[J]. 石油学报,2010,31(6):998-1003. LIU Xinfu,QI Yaoguang,LIU Chunhua,et al. Prediction of flowing bottom hole pressures for two-phase coalbed methane wells[J]. Acta Petrolei Sinica,2010,31(6):998-1003.

[5] 赵金,张遂安. 煤层气井底流压生产动态研究[J]. 煤田地质与勘探,2013,41(2):21-24. ZHAO Jin,ZHANG Sui'an. Production dynamics of CBM bottom hole pressure[J]. Coal Geology & Exploration,2013,41(2):21-24.

[6] 张卫东,谭雷川,任建华,等. 排采连续性对煤层气产能的影响分析[J]. 煤炭技术,2015,34(12):29-32. ZHANG Weidong,TAN Leichuan,REN Jianhuan,et al. Effects of drainage continuity on productivity of fractured CBM wells[J]. Coal Technology,2015,34(12):29-32.

[7] 刘世奇,赵贤正,桑树勋,等. 煤层气井排采液面-套压协同管控:以沁水盆地樊庄区块为例[J]. 石油学报,2015,36(增刊1):97-108. LIU Shiqi,ZHAO Xianzheng,SANG Shuxun,et al. Co-operative control of working fluid level and casing pressure for coalbed methane production:A case study of Fanzhuang block in Qinshui basin[J]. Acta Petrolei Sinica,2015,36(S1):97-108.

[8] 白建平,武杰. 压裂液对煤储层伤害实验及应用:以沁水盆地西山区块为例[J]. 煤田地质与勘探,2016,44(4):77-80. BAI Jianping,WU Jie. Experiment and application of frac-turing fluid damage to coal reservoir:A case of Xishan block in Qinshui basin[J]. Coal Geology & Exploration,2016,44(4):77-80.

[9] 王道宽,史亚运,乌效鸣,等. 渤钻低密度固井水泥浆降低煤层气储层伤害的实验[J]. 煤田地质与勘探,2015,43(3):105-109. WANG Daokuan,SHI Yayun,WU Xiaoming,et al. Ex-perimental research on decreasing coalbed methane formation damage by using low density cement slurry[J]. Coal Geology & Exploration,2015,43(3):105-109.

[10] 毛港涛,赖枫鹏,木卡旦斯·阿克木江,等.沁水盆地赵庄井田煤层气储层水锁伤害影响因素[J]. 天然气地球科学,2018,29(11):1647-1655. MAO Gangtao,LAI Fengpeng,MUKATTS Akrumyan,et al. Study on the influencing factors of water blocking damage of coalbed methane reservoir in Zhaozhuang mine,Qinshui basin[J]. Natural Gas Geoscience,2018,29(11):1647-1655.

[11] 贾慧敏,胡秋嘉,刘忠,等. 裂缝应力敏感性对煤层气井单相流段产水影响及排采对策[J]. 中国煤层气,2017,14(5):31-34. JIA Huimin,HU Qiujia,LIU Zhong,et al. Influence of fractures stress sensitivity on water production law for the single-phase flow of CBM wells and drainage countermeasures[J]. China Coalbed Methane,2017,14(5):31-34.

[12] 贾慧敏,孙世轩,毛崇昊,等. 基于煤岩应力敏感性的煤层气井单相流产水规律研究[J]. 煤炭科学技术,2017,45(12):189-193. JIA Huimin,SUN Shixuan,MAO Chonghao,et al. Study on single-phase flow water production law of coalbed methane well based on coal and rock stress sensitivity[J]. Coal Science and Technology,2017,45(12):189-193.

[13] 熊先钺. 韩城区块煤层气连续排采主控因素及控制措施研究[D]. 北京:中国矿业大学(北京),2014.

[14] 张遂安,曹立虎,杜彩霞. 煤层气井产气机理及排采控压控粉研究[J]. 煤炭学报,2014,39(9):1927-1931. ZHANG Sui'an,CAO Lihu,DU Caixia. Study on CBM production mechanism and control theory of bottom-hole pressure and coal fines during CBM well production[J]. Journal of China Coal Society,2014,39(9):1927-1931.

[15] 梁春红,王宝,赵晨光,等. 煤层气井示功图影响因素、异常类型及治理技术研究[J]. 中国煤层气,2018,15(2):33-36. LIANG Chunhong,WANG Bao,ZHAO Chenguang,et al. Study on the influencing factors,abnormal types and treatment technology of dynamometer card for coalbed methane well[J]. China Coalbed Methane,2018,15(2):33-36.

[16] 宋金星,苏现波,王乾,等. 考虑微孔超压环境的煤储层含气量计算方法[J]. 天然气工业,2017,37(2):19-25. SONG Jinxing,SU Xianbo,WANG Qian,et al. A new method for calculating gas content of coal reservoirs with consideration of a micro-pore overpressure environment[J]. Natural Gas Industry,2017,37(2):19-25.

[17] 范明,俞凌杰,徐二社,等. 页岩气保存机制探讨[J]. 石油实验地质,2018,40(1):126-132. FAN Ming,YU Lingjie,XU Ershe,et al. Preservation mechanism of Fuling shale gas[J]. Petroleum Geology & Experiment,2018,40(1):126-132.

[18] 刘峰,罗天平,杨春莉,等. 煤层气井间抽技术研究与现场应用[J]. 煤矿安全,2017,48(3):82-84. LIU Feng,LUO Tianping,YANG Chunli,et al. Research and field application of intermittent dewatering technology for coalbed methane wells[J]. Safety in Coal Mines,2017,48(3):82-84.



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