Studies On Numerical Simulation Of Gel Particle Profile Control To Enhance Recovery Of Oil Field After Polymer Flooding

Gel particle may block high capacity channel of reservoir, develop polymer flooding efficiency. Gel particle profile control technology is becoming a hot research point in recent years. However, study about this technology mainly focuses on principles of profile control in laboratory. Few study about numerical simulation has been made, there is still no report about gel particle profile control technology after polymer flooding. Lacking of modeling technology leads to blinding designs of profile control schemes and more not answering wells. This situation has made lots of unnecessary economic loss. So developing a suit of method to simulate gel particle profile control is very useful.In this thesis, works start with study of main principles of gel particle profile control in laboratory. A series of experiments are carried out, such as maturation pattern of gel particle in water and polymer solution; shearing break pattern of gel particle in porous media; deforming movement pattern of gel particle; relation between gel particle radius and pore-throat; affection of remained polymer in layers to profile control effection; affection of mix injecting systerm of gel particel and crosslink agent to profile control effection. Principles are made clear, such as particle size change, viscosity increasing, deforming to move etc. Analysis the affection of profile control time and injection system to profile control effection.Based on laboratory study, math descriptions about principles are developed, such as relations between suspention concention and water viscosity, particle size description, dynamic equations of gel particle movement in porous media. Propose that gel particle movement in porous media is divided into two parts: jamming and deforming to move, and both dynamic equations are developed separately. Initiatively develop the dynamic equation of deforming to move of gel particle, which accounts of pressure gradient, flowing rate, retention of particle, time etc. Radial flowing model is developed, movement pattern of gel particle around injection is studied.Based on researching conclusion of principles of gel particle profile control, theoretical conditions to develop three dimention three phase coupled model of gel particle profile control after polymer flooding are proposed. Under these conditions, coupled model is developed step by step, and the difference between three coupling methods is analysised. Analysis the difference between defferent difference scattering and linearing methods. A suit of numerical solution is developed, which contains solving pressure and saturation by using IMPSAT method, solving chemical components concentration in water phase by using Runge-Kutta method, solving gel particel concentration and retention amount by using operator splitting method. Additionally, special modelling method about recovering permeability of less permeable layers by using acid after completing gel particel injection is developed.In the end, developed model is validated and affection of several parameters to profile control effection is studied. Reliability of the developed model is confirmed by matching results of experiments and real developing data of oil field. Matched laboratory contents include:①Injecting pressure when gel particle is injected in cores with different permeability;②Injecting pressure when gel particle is injected in cores with different sequent water flooding degree after polymer flooding;③Injecting pressure when mix system of gel particle and crosslink agent is injected in cores after polymer flooding. Matched real oil field developing data includes liquid rate, oil rate, water cut pre- and post- gel particle profile control. Analysised parameters affecting profile control effection include profile control moment, concentration of injecting gel particle suspension, injecting rate, total amout of injecting suspension, ratio of vertical permeability to horizental permeability, permeability of high capacity channel. Results of validation of model and analysis of parameters indicate that developed model of gel particle profile control after polymer flooding has high degree of accuracy, may be used to simulate profile control process and optimize parameters for profile control schemes, and plays a guiding role for gel particle profile control technology.