Study On Proppant Migration In Cross Fractures

Hydraulic fracturing is a stimulation measure used in the exploitation of unconventional oil and gas resources.The proppant distribution in the fracture network generated by this technology has a great influence on the fracture conductivity,which in turn affects the oil and gas production.Therefore,it is very important to study the migration law of proppant.In this paper,the sedimentation mechanism of proppant particles is firstly analyzed,and the influence of particle size and density parameters on the proppant sedimentation law is analyzed by using the sedimentation experimental device.The effects of proppant particle size and density,proppant mixed liquid-sand ratio parameters on the proppant migration law in a single flow channel were studied through the proppant migration experimental device.The effects of the shear rate of the mixed liquid,the included angle of the flow channel,and the particle size of the proppant on the migration law of the proppant in the cross flow channel were studied through the proppant migration experimental device.Finally,Fluent software was used to analyze the proppant migration law in single flow channel and cross flow channel,and the main influencing factors were determined.The results show that the acceleration and equilibrium velocity of proppant are negatively correlated with particle size and positively correlated with density.In a single channel,the equilibrium height and volume of the sand bank are positively correlated with particle size,density and sand ratio,respectively.In a single flow channel,the distance between the equilibrium height position and the proppant inlet is negatively correlated with particle size and density,and positively correlated with sand ratio.In the cross flow channel,with the increase of shear rate,the equilibrium height of the sand bank in the main channel and the sub channel and the volume of the sand bank in the sub channel first increase and then decrease,the volume of the main channel sand decreases,and the distance from proppant import to the position of the equilibrium height of the main channel Increased.with the increase of the included angle of the flow channel,the sand bank parameters did not change significantly.With the increase of proppant particle size,the variation law of sand bank parameters of main channel and distributary channel is consistent with that of single channel.The numerical simulation results are in good agreement with the results obtained from the proppant migration experiments.