(1. College of Safety Science and Engineering，Liaoning Technical University，Fuxin，Liaoning 123000，China；2. College of Safety and Emergency Management Engineering，Taiyuan University of Technology，Taiyuan，Shanxi 030024，China；3. College of Mining
Engineering，Liaoning Technical University，Fuxin，Liaoning 123000，China)
Abstract：In order to improve coalbed methane recovery in low permeability coal seams，a concept of leaf vein bionic gas drainage of multi-branch horizontal wells was proposed. Vein structure of 4 typical leaves was extracted and analyzed by leaf specimen scanning and structural measurement. The fluorescent labeling experiment was used to study water transport in vein structureand to obtain the bionic features. The physical simulation experiment was carried out by self-developed experimental system to study the influence of leaf vein bionic characteristics on flow-temperature field. The results show that the extraction effect is better with asymmetrical branches and is most affected by the length of branch wells. When the length of branch wells increases by 50%，the gas pressure decreases by 28.37% in the reservoir. Increasing the angle of branch wells can significantly enhance the gas pressure relief. When the distance between the branch wells increases by 50%，the gas pressure decreases by 6.81%. Temperature change lags behind the pressure in the reservoir. The decreases of both the gas pressure and the temperature are positively correlated with the initial gas pressure in the early stage of gas extraction but hardly affected by the initial gas pressure in the later stage.
王兆丰，田富超，赵 彬，等. 羽状千米长钻孔抽采效果考察试验[J]. 煤炭学报，2010，35(1)：76-79.(WANG Zhaofeng，TIAN Fuchao，ZHAO Bing，et al. The testing of gas drainage efficiency about feather-veined 1 000 m length-drillhole[J]. Journal of China Coal Society，2010，35(1)：76-79.(in Chinese))
[4]
姜婷婷，杨秀娟，闫相祯，等. 分支参数对煤层气羽状水平井产能的影响规律[J]. 煤炭学报，2013，38(4)：617-623.(JIANG Tingting，YANG Xiujuan，YAN Xiangzhen，et al. Numerical simulation of fishbone horizontal well production increase in coalbed gas under multi-field coupling[J]. Journal of China Coal Society，2013，38(4)：617-623.(in Chinese))
[7]
FAN Y P，DENG C B，ZHANG X，et al. Numerical study of multi-branch horizontal well coalbed methane extraction[J]. Energy Sources，Part A：Recovery Utilization and Environmental Effects，2018，40(11)：1 342-1 350.
[9]
李晓鹏. 枣叶脉序及其功能性状研究[博士学位论文][D]. 咸阳：西北农林科技大学，2016.(LI Xiaopeng. Leaf venation characteristics and functional traits of chinese jujube[Ph. D. Thesis][D]. Xianyang：Northwest A & F University，2016.(in Chinese))
[12]
LAWREN S，CHRISTOPHER M S，N MICHELE H. Hydraulic analysis of water flow through leaves of sugar maple and red oak[J]. Plant Physiology，2004，134(4)：1 824.
[14]
王汉鹏，张庆贺，袁 亮，等. 含瓦斯煤相似材料研制及其突出试验应用[J]. 岩土力学，2015，36(6)：1 676-1 682.(WANG Hanpeng，ZHANG Qinghe，YUAN Liang，et al. Development of a similar material for methane-bearing coal and its application to outburst experiment[J]. Rock and Soil Mechanics，2015，36(6)：1 676-1 682.(in Chinese))
[17]
ZHAO P，ZHUO R，LI S，et al. Experimental research on the properties of“solid-gas”coupling physical simulation similar materials and testing by computer of gas in coal rock[J]. Wireless Personal Communications，2017，102(2)：1 539-1 556.
[11]
HUVE K，REMUS R，LUTTSCHWAGER D. Water transport in impaired leaf vein systems[J]. Plant biology，2008，4(5)：603-611.
[1]
NIE R S，MENG Y F，GUO J C，et al. Modeling transient flow behavior of a horizontal well in a coal seam[J]. International Journal of Coal Geology，2012，92(2)：54-68.
[3]
刘大伟，王益山，虞海法，等. 煤层多分支水平井安全钻井技术[J]. 煤炭学报，2011，36(12)：2 109-2 114.(LIU Dawei，WANG Yishan，YU Haifa，et al. Safety drilling technology of multi-lateral horizontal wells in coalbed[J]. Journal of China Coal Society，2011，36(12)：2 109-2 114.(in Chinese))
[5]
STEVEN A K，KRAMER D L，MICHAEL K. A numerical study on optimization of multilateral horizontal wellbore patterns for coalbed methane production in Southern Shanxi Province，China[J]. International Journal of Coal Geology，2011，86：306-317.
[6]
YANG Y，CUI S Q，NI Y Y，et al. A new attempt of a CBM tree-like horizontal well：A pilot case of Well ZS 1P-5H in the Qinshui Basin[J]. Natural Gas Industry B，2014，(1)：205-209．
[8]
陈海龙. 水平井、分支井产能分析理论研究[硕士学位论文][D]. 成都：西南石油学院，2003.(CHEN Hailong. Theoretical study on productivity analysis of horizontal wells and branch wells[M. S. Thesis][D]. Chengdu：Southwest Petroleum University，2003.(in Chinese))
[10]
KIZILOVA N N. Construction principles and control over transport systems organization in biological tissues[C]// Physics and Control International Conference. Kharkov，Ukraine：[s. n.]，2003：302-307.
[13]
彭 毅. 基于植物叶片结构的仿生均热板研究[博士学位论文][D]. 广州：华南理工大学，2015.(PENG Yi. Study of bionic vapor chamber based on the plant leaf structure[Ph. D. Thesis][D]. Guangzhou：South China University of Technology，2015.(in Chinese))
[15]
WANG J G，LIU J S，KABIR A. Combined effects of directional compaction，non-Darcy flow and anisotropic swelling on coal seam gas extraction[J]. International Journal of Coal Geology，2013，109/110：1-14.
[16]
李志强，鲜学福，隆晴明. 不同温度应力条件下煤体渗透率实验研究[J]. 中国矿业大学学报，2009，38(4)：523-527.(LI Zhiqiang，XIAN Xuefu，LONG Qingming. Experiment study of coal permeability under different temperatures and stresses[J]. Journal of China University of Mining and Technology，2009，38(4)：523-527.(in Chinese))
2019, Vol. 38 
