Research On Gravel Packing Sand Control Mechanism And Effect Evaluation

Graded gravel packing sand control technology can solve the problem of blockage of gravel layer caused by fine sand effectively,prolonging the effective period of sand control,increasing the seepage capacity near the wellbore after sand control,and increasing the production of oil wells.Therefore,the clear sand-retaining mechanism of graded gravel packing and sand control technology can provide an optimization method for systematically graded gravel packing and sand control technology,which is of great significance to oil well production.In this paper,theoretical derivation,experiments and numerical simulations are used to establish an optimization method for low-pressure differential grade gravel pack sand control technology that satisfies sand control requirements for different types of reservoirs.A mathematical model for graded gravel pack sand control is established based on experiments.Firstly,the mechanism and research methods of sand-blasting with gravel packing were investigated,and the factors affecting the permeability change of the front of the gravel mixed belt and the effect of multi-level gravel packing on sand control were analyzed;then a set of gravel packing sand-control seepage flow simulation experiment equipment was established.The influence of formation sand median,fine sand content,homogeneity,and fluid properties on the permeability of gravel layer;design of a visualized experimental device for sand-sand retaining by graded gravel layer,and visual observation of the formation of sand between gravel layers.The law has studied the dynamic property permeability changes of gravel layer permeability with the sand production process.Finally,according to the liquid-solid two-phase flow theory in porous media,the vertical deposition and horizontal direction of mobile sand in the pores are considered.Influencing,,a dynamic model of the gravel pack's physical parameters was proposed,and the fluid-solid coupling deformation field equation and the seepage field equation of the formation were established.The solid deformation and seepage were considered.And the coupled effects of the variable mass flow in the wellbore,a finite element model for graded gravel packing and sand control was established,with the aid of finite element methods.To solve it.