Application Of Graded Sand Control Technique In The Later Sand-out Stage Of Oil-water Well

One of the most contradiction is oil reservoir sanding in unconsolidated sandstone oil reservoir.This paper put forward conception of classification sand control and series, gradation,grade order according to sand control characteristics in the later stage and carried on an indoor research also. Critical sanding pressure model and carry on an estimate to the strata accumulated sanding production and judge depletion radius of sand producing formation.It optimize gravel packing series by means of infiltrating fluid model formation of anisotropy and optimize classification sand control gradation by means of Saucier during gravel packing which not only attain the aim of both sand retention and sand prevention but also keep high permeability quotient utmostly.It predicted grade order through researching gravel movement processed borehole and stability of the sand arch and verified the accuracy of order prediction through the experiment also which attain the optimal sand control result. It uses physical model to carry on a verification of optimized classification sand control in the laboratory and obtain the result which sand control result which three series gravel packing is better than two series gravel packing,at the time,sand control result of order gravel packing is better than inverted order.particle diameter ratio is 6,8,10 respectively when the gravel segment 1,the gravel segment 2 and the gravel segment 3 compare with formation sand respectively. To enhance withstand fluid erosion of wellbore surrounding gravel packing zone to built up control sand artificial borehole wall of fibre net complex according to classification sand control theory.The paper supply a set of new method of sandcontrol for oil and water well of sanding relative seriously and major formation depletion.