To Suck The Cow Hooves Pond Group Of Shale Fracture Permeability Experiment Research

With the shortage of the global energy,it's becoming more and more important for the development of new energy,Shale gas has become a new source of clean energy for energy developers.The shale gas reserves of the Niuotutang Formation in Guizhou Qianbei area are large and widely distributed and has great development and application value,however,with the complicated reservoir geological structure and the lower permeability of shale gas and the unsatisfactory mining technology,therefore,research on Shale lithology of Niuotutang Formation in northern Guizhou and Permeability under different fracturing has practical engineering significance.This paper is sampled in a region of Guizhou in northern Guizhou experiment research from the following several aspects:(1)Accessing to historical data,the geological structure of the shale of Niuotong Formation in Qianbei is analyzed.The experimental study on the mineral composition,organic matter characteristics and pore characteristics of shale is carried out.The results showed that: the shale of geological structure is complicated,mineral composition is rich,rich in organic matter,but its permeability is poor and the gas is not easy to flow.Combining with the data,analyzing the part of shale permeability influence factors.(2)Using MTS815 to tested the permeability of the shale under different confining pressure and osmotic pressure,the correlation between permeability and confining pressure and osmotic pressure was studied.The results showed that: in the case of low confining pressure,osmotic pressure difference plays a major role in permeability,shale permeability is exponentially related to osmotic pressure,shale permeability and osmotic pressure difference showed an exponential relationship,shale permeability and rise with the rise of osmotic pressure difference,osmotic pressure of different loading methods on shale permeability of shale has certain influence.With the increase of confining pressure,the main influence factors of shalepermeability is confining pressure,shale permeability and confining pressure present exponential relationship,shale permeability is reduced with the increase of confining pressure.(3)Using MTS815 in combination with different fracturing and acoustic emission method,testing respectively to this kind of shale with hydraulic fracturing?net seam fracturing?repeated fracturing.The results showed that: within the local area,vertical single slit hydraulic fracturing of shale rock permeability is relatively high.Net seam fracturing of shale permeability significantly higher than single seam hydraulic fracturing,after the second fracturing,the cracks of the rock samples are developed again,permeability is also relatively increased again and the permeability of the shale is exponentially related to the permeation time.The steady-state permeability eventually approaches stability,therefore,the main influencing factors of permeability are shale internal mineral content?Organic matter type?Microporosity and crack and other factors,induced fractures are also have a significant effect on shale permeability.