煤层水力喷射成孔实验研究
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摘要
煤层气藏在我国储量巨大且具有低压、低饱和、低渗透、非均质性强、储层构造复杂、煤岩易破碎的特点。水力喷射成孔工艺能够避免煤层坍塌,消除常规射孔所导致的压实效应,破碎煤岩改善储层的渗透性。通过大尺寸物理模型实验研究得出喷嘴直径变大且孔径增加、磨料浓度升高孔径增加但孔深先增加后减小、泵压升高孔深增加。筛选出一组泵压25MPa,喷嘴直径4mm,磨料浓度6.6%的作业参数,对现场施工的参数设计有指导作用。
There are huge coalbed methane reserves existing in our country. These CBM reservoirs have the characteristics of low pressure, low saturation, low permeability, high heterogeneity and complex reservoir structure, with the easily broken coal rocks.The technology of the pore-creating by the hydraulic jet can avoid the collapse of the coal bed, eliminate the compaction effect caused by the conventional perforation and break the coal petrography to promote the permeability of the reservoir. By the study of the large physical models, the conclusion was that the bore diameter increases by the increasing of the nozzle diameter. The abrasive concentration and the pore diameter increases but the bore depth decreases after the increasing and the pumping pressure and the bole depth increase. Finally, the operation parameters were optimized, that is, the pumping pressure is 25 MPa, the nozzle diameter is 4 mm and the abrasive concentration is 6.6 %. These parameters are helpful for the parameter design of the site construction.
There are huge coalbed methane reserves existing in our country. These CBM reservoirs have the characteristics of low pressure, low saturation, low permeability, high heterogeneity and complex reservoir structure, with the easily broken coal rocks.The technology of the pore-creating by the hydraulic jet can avoid the collapse of the coal bed, eliminate the compaction effect caused by the conventional perforation and break the coal petrography to promote the permeability of the reservoir. By the study of the large physical models, the conclusion was that the bore diameter increases by the increasing of the nozzle diameter. The abrasive concentration and the pore diameter increases but the bore depth decreases after the increasing and the pumping pressure and the bole depth increase. Finally, the operation parameters were optimized, that is, the pumping pressure is 25 MPa, the nozzle diameter is 4 mm and the abrasive concentration is 6.6 %. These parameters are helpful for the parameter design of the site construction.
引文
[1]饶孟余,杨陆武,张遂安,等.煤层气多分支水平井钻井关键技术研究[J].天然气工业,2007,27(7):52-55.
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[3]林晓东,卢义玉,汤积仁,等.基于SPH-FEM耦合算法的磨料水射流破岩数值模拟[J].振动与冲击,2014,33(18):170-176.
[4]廖华林,李根生,易灿,等.围压对射流破岩特性影响的试验研究[J].石油钻探技术,2007,35(5):46-48.
[5]王建明,宫文军,高娜.基于ALE法的磨料水射流加工数值模拟[J].山东大学学报(工学版),2010,40(1):49-52.
[2]李根生,牛继磊,刘泽凯,等.水力喷砂射孔机理实验研究[J].石油大学学报(自然科学版),2002,26(2):31-34.
[3]林晓东,卢义玉,汤积仁,等.基于SPH-FEM耦合算法的磨料水射流破岩数值模拟[J].振动与冲击,2014,33(18):170-176.
[4]廖华林,李根生,易灿,等.围压对射流破岩特性影响的试验研究[J].石油钻探技术,2007,35(5):46-48.
[5]王建明,宫文军,高娜.基于ALE法的磨料水射流加工数值模拟[J].山东大学学报(工学版),2010,40(1):49-52.