摘要
为了探究多层煤层气藏合采层间储层处液面压力的关系、层间生产压差的关系以及各储层见气时间的关系,以多层叠置独立煤层气藏为研究对象,从成藏特征和煤层气产出机理出发,基于煤层气井井底压力表达式,推导了层间储层处液面压力的关系表达式,进而推导了层间生产压差的关系表达式以及层间见气时间的关系表达式。通过分析得出:①由于层间距的存在,在下储层未暴露时,上下储层间储层处液面压力存在一定的差异,当下储层暴露后,上下储层间的储层处液面压力相等;②层间生产压差和层间见气时间也不一定相等,且差异的大小均与储层压差、层间距、储层暴露情况有关,其中层间见气时间的差异还受气井排采压差的影响。研究成果为煤层气多层合采井排采制度的制定以及多储层煤层气藏合采模拟实验方法的选取提供了理论基础。
The purpose of this paper is to study that,the relationship of reservoir liquid level pressure between the combined mining layers,the relationship of production pressure difference between the combined mining lay⁃ers,and the relationship of gas-seeking time between the combined mining layers during the combined produc⁃tion of multi-layer coalbed methane reservoirs.To this end,this paper takes multi-layer independent coalbed methane reservoirs as the research object.Starting from the reservoir forming characteristics and coalbed meth⁃ane production mechanism,based on the expression of downhole pressure expression of coalbed methane wells,the relationship expression of reservoir liquid level pressure between the combined mining layers was derived.Furthermore,the relational expression of production pressure difference between the combined mining layers and the relational expression of gas-seeking time between the combined mining layers were derived.The follow⁃ing conclusions are drawn through analysis.Due to the existence of the layer spacing,there is a certain differ⁃ence in the reservoir liquid level pressure between the upper and lower reservoirs when the lower reservoir is bare.After the lower reservoir is exposed,the reservoir liquid level pressure at the reservoir between the upper and lower reservoirs is equal.The production pressure difference between layers and the gas-seeking time be⁃tween layers are not necessary to be equal.And the size of the difference is related to the reservoir layer differ⁃ence,interlayer spacing,and whether the reservoir is exposed.In addition,the difference in gas-seeking time between layers is also affected by the gas well production pressure difference.The research results provide a the⁃oretical basis for the development of the drainage system of the coalbed methane combined production well and the selection of simulation experiment methods for combined production of coalbed methane reservoirs with mul⁃tiple reservoirs.
作者
石迎爽
梁冰
薛璐
孙维吉
王青春
程志恒
SHI Ying-shuang;LIANG Bing;XUE Lu;SUN Wei-ji;WANG Qing-chun;CHENG Zhi-heng(College of Science,North China of Science&Technology,Yanjiao 065201,China;Institute of Mechanics and Engineering,Liaoning Technical University,Fuxin 123000,China;China Construction First Group Construction&Development Co..Ltd.,Beijing 100102,China;School of Safety Engineering,North China of Science&Technology,Yanjiao 065201,China;Huake Zhongan Technology(Beijing)Co..Ltd.,Beijing 102300,China)
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2020年第8期1161-1167,共7页
Natural Gas Geoscience
基金
国家重点研发项目(编号:2016YFC0801404)
国家自然科学基金面上项目(编号:51874166)
中央高校基本科研业务费资助项目(编号:3142020022)
辽宁省教育厅青年项目(编号:LJ2019QL005)联合资助.
关键词
煤层气
多层合采
井底压力
生产压差
见气时间
Coalbed methane
Multi-layer mining
Downhole pressure
Production pressure difference
Gasseeking time
