Study On The Flow Of Supercritical CO₂ Fracturing Fluid In Wellbore And The Law Of Carrying Sand

Hydraulic fracturing technology have existed problems such as poor flowback and fracturing stimulation effect,environmental pollution and so on.Due to its own advantage,supercritical carbon dioxide fracturing is expected to replace hydraulic fracturing and become a new generation of fracturing fluid.Therefore,in order to predict the effect of supercritical carbon dioxide fracturing more accurate and improve the recovery rate.In order to further analyze the process of supercritical carbon dioxide fracturing fracture mechanism,the optimum size of the proppant and the condition of the proppant from the main crack into the seaming network,clarified the rheological behavior of supercritical carbon dioxide fracturing fluid in horizontal well and the migration rule of the internal proppant in supercritical carbon dioxide fracturing fluid,The research and application of supercritical carbon dioxide fracturing technology are instructive to construction operations.Firstly,the flow of supercritical carbon dioxide fracturing fluid in wellbore is studied.In the process of fracturing of unconventional oil and gas,in order to meet the required displacement and fracturing fluid quality,the ground construction pressure,gas injection rate and base fluid injection rate must be adjusted in real time.Preliminary stage,As the cracks extend to the deeper part of the strata,the pressure,flow and the quality of the fracturing fluid are constantly changing,which will affect the construction parameters on the ground.Secondly,in order to analyze the supercritical carbon dioxide fracturing effect of hydraulic fracture,to know the proppant in supercritical carbon dioxide fluid in the wellbore formation of fluidized bed of the stress distribution,and the force under the action of proppant particles migration,need through the forces between particles and particles,particles and fluid drag force,lift,virtual mass force.Basset force,as well as the fluid force of particles were analyzed.And using the euler-euler based on the theory of the particle kinetics model of multiphase flow,to simulate the particles in the construction of the fluidized bed under the condition of supercritical carbon dioxide fluid inside the fluidization model and the settlement of particles trajectory.Finally,consider to the interaction between particles?particles and fluid?fluid and wall,we build supercritical carbon dioxide fluid carrier migration of computational fluid dynamics model,to study the the migration of proppant in horizontal wellbore settlement rule,use quantitative characterization of fracture surface friction influence on the whole fracturing fluid system.considering the proppant settlement,do prepare for the study of simulate fracturing fluid carrier open fracture process,explore the proppant migration rule in the crack,analysis of proppant parameters,viscosity of fracturing fluid,fracturing fluid injection parameters on the proppant movement within the fracture morphology of impact.