Experimental Study On Morphology And Permeability Of Crushed Sedimentary Rocks

Sedimentary rocks are widely distributed on the earth's surface,which contains rich deposits of mineral deposits.Under the influence of geological function and resource exploitation,the sedimentary rock is destroyed,and its permeability will change after reaccumulation.Based on the sedimentary rocks of the most widely distributed in limestone,sandstone,mudstone as the research object,through the indoor rock crushing test simulation sedimentary rocks in the destruction of nature,to study the stress after crushing morphology and particle size and rock lithology,the relationship between the load size.In addition,the seepage experiment was carried out to study the seepage characteristics of single lithologic broken particles by using the particle of rock breaking test.For shale particles in the water under the action of hydrolysis and in the actual production are often a sign of water-resisting layer characteristics of these two separate design experiment,study the permeability of shale particles over time,the change law of permeability and shale particles of broken particles.The experimental results obtained in this paper are verified through practical cases.The specific workload and the results obtained are as follows:(1)Through the indoor rock,we have a test of a single axle fracture,and we have 24 pairs of experimental data,8 groups of limestone,sandstone(including fine sandstone and siltstone)11 groups,mudstone(including sandy mudstone)5 groups.The main conclusions are:(1)With the increase of experiment pressure,the contents of coarse crumbs of limestone,sandstone and mudstone are reduced,the content of medium and fine crumbs is increased,and the crushing degree of rock samples is increased;the change of granules in each interval after breaking through different pressures and the fractal dimension D of broken particle distribution was analyzed and compared,further confirming the conclusion.(2)Limestone,sandstone and mudstone rock sample was the same pressure after crushing,crushing particle content of mudstone coarse fragment in less than the content of coarse clastic limestone,sandstone,mudstone of the broken degree is bigger than degree of crushing limestone,sandstone.(2)Through a single rock fracture of the rock,we get the data from the data of the 43 group of limestone particles,the data from the 40 group sandstone particulates,and the data from the 30 group of muck particles.The main conclusions are:(1)The porosity of test rock samples is independent of the grain size.(2)The porosity of the test samples is independent of the sample size when the test particles are less selective.(3)There is no obvious relationship between the permeability coefficient K of test rock and its porosity.(4)In the same particle size,the permeability of limestone is the best,the permeability of sandstone is second,and mudstone is the weakest.(3)Accounted for the proportion of test sample by mudstone particle on broken particles on the impact of permeability test,test the particle size of 1.125 mm,1.125 mm,1.9167 mm,mudstone percentage were 0%,20%,40%,60%,80%,100% of the permeability of mixture test sample particle data changes over time.The main conclusions are: The permeability of mudstone samples weakens as time goes on.After 2h,the spatial structure of the mudstone samples with different particle size was similar,and the permeability coefficient of the test samples with different particle sizes overlaps.After 6h,the hydrolysis of mudstone was weakened,and its internal space structure changed to stable,and the permeability coefficient of the test sample was small and close to 0.(4)Accounted for the proportion of test sample by mudstone particle on broken particles on the impact of permeability test,test the particle size of 1.125 mm,1.125 mm,1.9167 mm,mudstone percentage were 0%,20%,40%,60%,80%,100% of the permeability of mixture test sample particle data changes over time.The main conclusions are: Under the condition of the sample size is consistent,with the increase of content of mudstone,the test sample initial permeability coefficient decreased;With the passage of time,the greater the proportion of mudstone in the test sample,the larger the decrease of the permeability coefficient K.Therefore,a qualitative conclusion is drawn that the higher the shale content in the rock sample,the worse the permeability of the rock sample.