摘要
基于瞬变电磁的工作原理,利用煤层孔隙-裂隙结构电阻率的变化,分析煤层水力压裂后流场特征、煤体破裂、裂隙延伸扩展以及含水性增大的过程。通过采用瞬变电磁法对煤层水力压裂流场进行了相关探测,得出了在高压水流场的作用下,水力压裂影响半径可达30 m以上并且压裂影响区域具有不均匀性,在应力释放区容易出现水流通道,形成卸压带。如若煤层的顶、底板较为坚硬完整,则水力压裂一般只会限制在煤层进行,同样由于煤层赋存地质条件的不均匀性,因此可利用瞬变电磁探测含瓦斯煤体的水力场,为水力压裂工艺的优化提供依据,以期达到理想的压裂效果。
According to the principle of transient electromagnetic method, the resistance change of pore-fracture system was used to analyze the flow field after the hydraulic fracturing, coal fracturing,cracking extending, and aquosity increase. The flow field of the hydraulic fracturing was detected by the transient electromagnetic method. The results show that, under the high-pressure water flow filed, the radius of influence of the hydraulic fracture could be over 30 meters with uneven influential areas. Water flow path and stress release belt are prone to occur in the stress relief areas. If roof and floor of the coal seam are hard and complete, the hydraulic fracture will be limited in the seam. Similarly, due to uneven hosting geological condition, the transient electromagnetic method could be used to detect the hydraulic field of the coal body containing gas, which could provide evidence for the optimization of the hydraulic fracturing technology in order to achieve ideal fracturing effects.
出处
《山西煤炭》
2016年第4期72-75,共4页
Shanxi Coal
关键词
水力压裂
瞬变电磁
水流场
裂隙发育
hydraulic fracture
transient electromagnetic method
water flow field
fracture development
