Research On Sanding Prediction Method Based On Fluid-solid Coupling Theory In Reservoir For Oil Well

Unstressed sand reservoir is distributed widely, who accounts for a large percentage ofall the production, and sanding is a seriously problem of this reservoir. This paper carrys onresearch for critical requirements during the development of the resrvoir that solid particlesheds from the rock matrix, microscale sanding of well, plentiful sanding of well, migrationof fluid at everywhere of the reservoir at everytime.Actually, solid particle still cements on the rock matrix even when plastic failure hasoccurred on the rock matrix. This phenomenon shows that the rock matrix has residual stress.When the production condition reaches to a certain price, solid particle conquers the residualstress and sheds from the rock matrix. This paper focus on the research of the criticalrequirements of production codition, and has established the mathematical model in the viewof effective stress and equivalent plastic strsin. Still, this paper analysed the sensitivity ofinfluencing factors.Sand producted from the reservoir can be diveded into free sand and skeleton sand.When the velocity of the fluid reaches to a critical valus, the free sand starts to migration.Slight but steady sanding status emerges in the producing wells. At this conditon, we calledthe velocity of the fluid as threshold velocity. With the increse of the fluid velocity, the rockmatrix failes and products skeleton sand. Plentiful sanding status emerges in the producingwells. At this conditon, we called the velocity of the fluid as critical velocity. This paper hasestablished the mathematical models about the threshold velocity and critical velocity. Still,this paper analysed the sensitivity of influencing factors.Fluid-solid coupling always exists the development of the reservoir. Based on themechanics of flow through porous media, rock matrix deformation theory, coupling theoryand so on, this paper established the mathematical model of sanding prediction. With aim ofpredicting the velocity of the fluid, this paper solves the ploblem applyes the numericalsimulation.