Experimental Study On Sand Control Effect Of Pasted Gravel

In the process of oil,gas wells,and water supply pipe wells,most of them are faced with the problems of how to improve the infiltration effect and prevent the silt from blocking.Research on sand control was started.In practical production,gravel packing sand control is the most common sand control method,but gravel packing sand control also has certain deficiencies.For example,it has poor sand control effect in high-pressure formations and fine sand formations,and it is relatively complicated to operate in some special formations.Requires professional filling equipment,which is uneconomical in terms of time and cost.Meanwhile,gravel packing and sand control also need to pay attention to the problem of gravel loss,obstruction and permeability decline.Gravel filtration sand control is based on gravel packing sand control and is an improvement and supplement to the insufficiency of gravel packing sand control methods.The gravel pasted filter sand stratum is in the sand control parameters and optimize the structure,to find out the optimal way of sand control.The filter layer is divided into a surface layer and a bottom layer,and the size of the bottom gravel is increased and the integrated porosity is increased on the basis that the surface layer can effectively prevent sand.The sand control test was carried out on different crushed stone structures.Considering the conditions of sand production,and infiltration rate,the pebble structure suitable for the sand control requirements of fine sand was comprehensively considered and the filtration mechanism of pebble filtration was analyzed.By comparing the results of the specific surface area of the filter with different sizes and the test results of the same filter,and the relationship between the strength of the gravel structure under different particle sizes is predicted.Through simulation experiments and theoretical derivation,the following conclusions have been drawn:1.The average particle size of the filter media has the greatest effect on the surface area value of the filter media,and the volume ratio of the surface area determines the amount of binder required to reach the highest strength.2.In the simulated sand control experiment for fine sand formations,the gravel structure with a filter particle size of 0.25-0.27 mm has a better sand control effect.Both the single layer and the double-layer gravel structure can better prevent the exudation of the ground sand.3.On the basis of sand control,the double-layer gravel structure increases the penetration effect of the whole gravel structure compared with the monolayer gravel structure,which has high porosity and permeability coefficient,and the permeability attenuation rate is much lower than that of single layer gravel structure.4.Through the analysis of the pore structure size formed by the accumulation of gravel filter material,the mechanism of sand control is analyzed,and the reasons for the optimum sand control effect of the double-layer gravel structure are explained.