Associating Polymer Structure Solution Flooding Validity

Along with the high speeding development of economic, the supply of china petroleum has been serious hard up, importation of petroleum including finished product oil exceeds a hundred million ton in 2004.The requirement of petroleum will exceed 4 hundred million ton a year to 2010 with the tempo of the moment china economic. Two petroleum yield can be guaranteed only according to the present produce position of petroleum and the gap will arrive at 2 hundred million ton. At that time china will be burdened heavily with petroleum. Using the present exploitation technology of oil, only 25-30% explored reserves can be got, and near 70% crude oil resorted under the earth can not be explored, so enhanced oil recovery(EOR) is the eternal task of china petroleum up to world oil field.Viscosity and anti-temperature and salt of water-soluble associating polymer has been approved universally, and it is hopeful that playing important role in EOR. But there are many question acquainted and settled before this kind of polymers were extended and applied cosmically. It is mostly that: associating polymer molecular structure and the network structure formed how to influence its' solution viscosity and visco-elasticity and which molecular structure will bring the best visco-elasticity effect; what difference of rheology characteristics in porous medium and visco-elasticity it is between associating polymer structure solution and linear ultra-high molecular weight PAM solution; if associating polymer structure solution has better injection characteristics or not and if it can be injected in the deep of oil layer favorably.The associating polymer network structure solution will be subjected to the high speed shear near injection well borehole and whether the network structure can be kept availably or not and its' structure solution visco-elasticity and rheology are changed. If it can retain inherent network structure solution rehology on the condition of low speed fluid flow through porous medium deep the oil layer through high speed injection shear associating polymer solution, it is that if can establish bigger resistance factor andresidual resistance factor?For resolving and understanding the above-mentioned problem, this thesis study rheology characteristics especially viscoelasticity of associating polymers solution of different molecule structure from associating polymer structure solution peculiarity, and study the. rheology in the porous medium contrast different molecule structure associating polymers to high molecular weight resist-salt polypropylene amide. Study and investigate primarily the law of fluid flow through porous medium and displacement using microcosmic-transparent emulated putty model. Study and analyze quantitatively viscoelasticity of associating polymer solution contributed to displacement efficiency using visco-glycerin as reference compound. At the same time, research the differences of injection characteristic of associating polymer and super-high molecular weight PAM solution and study contra-shear capability ofassociating polymer structure solution from simulating shot hole shear contrast to the super-high molecular weight PAM .This paper determine rheology parameters of different molecular structure associating polymer solution and PAM: storage modulusG ' , loss modulusG" and the first normal stress difference N through using HAAKE RS600 rheometer to processing dynamic shear flow and steady state shear flow experiment to descript and token the rheology characteristics of associating polymer solution especially the visco-elasticity . Processed the experiment of fluid flow through porous medium and displacement using Berea standard core and man-made plane core produced in USA. Stimulated fluid flow state in oil layer through self-determination - design instrument and observed displacement process of associating polymer using microcosmic photograph technology. Established adding press screen coefficient standard to study and describe the injection characteristics difference between associating polymer structure solution and linear ultra-high molecular weight PAM solution. Stimulated high speed fluid flow through porous medium shear near borehole stratum to study and describe the resist shear characteristics.We can draw some conclusions from researches as follows:1) The associating polymers become the structure of the super-molecule network through associating at these molecule, and make its solution to show the extremely higher elasticity-respond than molecular weight KYPAM, the associating polymers which contain appropriate associating may make this kind of advantage develop the better state.2) The associating polymers of solution high viscosity prove that flowing in the core is valid, it expresses a higher resistance factor and residual resistance factor and efficiency viscosity. Solution of the associating polymers whether is high molecular weight or high molecular weight and whether high hydrophobe or low hydrophobe content express the behavior of swell-flows. And efficiency viscosity of associating polymers higher than that of KYPAM under the condition that the same apparent viscocity,which express network structure of associating polymers of solution have the more intelligent and stronger elasticity than single molecule clew of general polyacrylamide.3)The solution of associating polymers which have low molecular weight and high hydrophobe content higher than that is high molecular weight and low hydrophobe content under the low injection speed and the same apparent viscocity ,but that is contrary under the high infusion speed. This made out that the elasticity respond show more prominence when the solution of the much network structure was at the low speed flow of tension,but ssociating polymers of low molecular weight was broken out the small structure,as a result the elasticity respond became bad.4)Associating polymers of high molecular weight and low hydrophobe content werechoosed at the condition of high injection speed and low permeability from the infusion, resistance factor and residual resistance factor.5) The displacement efficiency is better of high-viscosity and high-elasticity polymer solution which was formed with network structure6)The associating polymer solution appears the furthest displacement speed within the scope of study. The furthest displacement speed is 2m/d—3m/d and displacement efficiency attains max. at the speed when permeability of core is 400md and apparent viscosity of polymer is 50mPa.s.7) High-viscosity associating polymer solution shows better fluidity contrast to the super-high molecular weight PAM at high-flow differential pressure ,but shows even more flow resistance at low-flow differential pressure.8)Associating polymer structure solution rheological characteristic excelled to super-macromolecule weight polyacrylamide when they are simulated to sheared by core of embrasure neighborhood.Through the above-mentioned research work, further confirmed that associating polymer structure solution is efficiency at displace oil;The first step we can acquires the relation of associating polymer structure solution and it's rheology(visco-elastic especially),the relation of solution and seepage flow andcharacteristic of displace oil, and finally made out the relation of displacement efficiency,at the same time it can afford foundation of theory for designing molecule-structure of associating polymers possess better rheology capability of adapting to displace oil in oil field,and provide to coaching of theory for choosing associating polymer of appropriate molecule structure. Knew the difference of injection's characteristic of associating polymer structure-solution and super-macromolecule weight polyacrylamide,discovered high-viscosity associating polymer solution can gain to perfection balance between better injection and establishing efficiency flow's resisitence, thereby eliminated misgiving of injectionable at associating polymer structure solution at technics .knew associating polymer structure solution possess better capability of anti-shear, thereby eliminated misgiving whether associating polymer structure solution can maintain capability of rheology through injecting of high-speed pumb and high-speed shear in fluid flow through porous medium nearby well.