The Research On The Change Law Of Flow Conductivity Under Different Proppant Filling Width

In the exploitation process of the coal seam gas,hydraulic fracturing is the main measure of coal reservoir reconstruction.The proppant agent is an important part of hydraulic fracturing to form a high conductivity channel.The formation of hydraulic fracturing is complex,and the filling width of the support agent is different in different position of the crack.Researching on flow conductivity change law of proppant filling different crack width is contribute to better understanding of the proppant performance and provide certain theoretical basis for the selection of hydraulic fracturing proppant.In this thesis,the crushing rate and flow conductivity of the type of quartz sand,ceramic I type and ceramic II type whose particle size is 20~40 are tested respectively,Considering the different of volume density and designing the proppant filling crack width is 2mm,4mm,6mm.Through the analysis of the experimental results,it is found that the change of the crack width of the proppant is influence on the crushing rate.The crushing rate of the three kinds of the proppant is increased with the increase of the closed pressure.The fracture width is smaller,the sensitivity of the proppant agent to the closed pressure is stronger and the crushing rate is higher.When the crack width increases,the sensitivity of the proppant to the closed pressure is reduced,the breaking rate is reduced,and the effect of the width on the breaking rate is reduced.Closure pressure is the main factor of the change of the crushing rate of the support.When the closed pressure exceeds the support strength of the proppant,the crushing rate of the proppant is higher.The volume density of the proppant agent has certainly influence on the crushing rate.The volume density is lower,and the crushing rate is higher under the same condition.The change of the crack width of the proppant is greatly influenced by flow conductivity.Three kinds of proppant under different crack width,conductivity capacity along with the rise of closure pressure decreased.When the closure pressure is low,conductivity capacity of the larger crack width is far greater than conductivity capacity of the smaller crack width.Under the high closure pressure,fracture conductivity of different proppant filling width is largely the same.Through the comparison of thefracture flow conductivity under the filling fracture width of the different proppant,finding that the proppant crushing rate,proppant homogeneity and sphericity have great influence in the proppant fracture conductivity capacity.