Study On The Sand Control System Of Foaming/Emulsified Resin And Its Adaptability

At present,there are some problems of mechanical sand control in the oilfield.On the one hand,this method can only block but can not consolidate sand,therefore it is unable to fundamentally solve the problem of sand production.On the other hand,the effect of fine-silty sand is poor.Based on analyzing reasons of sand production in sandstone reservoirs.Above all,a chemical consolidation system based on Pickering emulsion was researched.A stable Pickering resin emulsion was prepared by ultrasonic dispersing method.The optimum concentration of nano-SiO₂ emulsifier is 1w%in the condition of 1:2 water-oil ratio,the apparent density of the system reaches 0.93-1.05g/cm³ at room temperature.Furthermore,Sand consolidation experiments are employed by direct injection method,the formula of Pickering emulsion sand control system was:25w%Pickering emulsion+0.3w%curing agent+0.2w%coupling agent,after curing for 12h at 60?,the strength of consolidated core reached up to 4.6-5.82MPa,and its permeability ranges from 3.1?m² to 5.3?m².Moreover,the consolidated core of Pickering resin emulsions shows excellent water,oil and alkali as well as salt resistance.In addition,a foam chemical sand control system of amino resin was investigated in lab.By introducing foaming agent and stabilizing agent,a stable foaming resin system was prepared by Warning Blender method.Ultimately,the formula of foaming sand control system was optimized by means of direct injection:25w%foaming resin systems+0.5w%curing agents+0.2w%coupling agents,whose density is 0.56-0.63g/cm³.Meanwhile,the strength of consolidated core was up to 4.60⁶.28MPa after curing for 12h at 60?,and its permeability was 0.92².70?m².Moreover,orthogonal test L₂₅?5⁶?was used to obtain the primary and secondary relation among several influence factors on strength and permeability of consolidated core,which included concentration of curing agent,coupling agent and foam system.The characteristics of foam migration and sand control mechanism were discussed by visual and plate model.It is important to note that the Pickering resin emulsion and foam resin system were especially suitable for sand control in horizontal wells and heterogeneous reservoirs?...