Research On Injection Stimulation In Injection Wells Of ASP Flooding

With the oilfield development into the later period,Oil and gas development has entered into the high water cut-extra high water cut period,technique of tertiary has become a powerful guarantee to improve oil recovery and achieve sustained and stable production.ASP flooding field experiments confirmed that the asp flooding can obviously increase the reservoir producing extent and recovery.In recent years,the production technology development and perfect,could meet the needs of the oilfield development basically.But in the process of application of asp flooding found two or three types of reservoir into the process of asp system,low permeable formation is not fit to ASP,blocking and the low reservoir producing degree in the low permeability reservoir when using the same molecular weight displacement.Production well scaling or emulsifying phenomenon seriously,and the peak effect with scale height,significantly affect the production well production.The proppant migrates and the validity is short after fracturing in ASP flooding injection well,Alkali resistance of resin sand is poor,and so on.This article aims at the above problems,Analysis the blocking composition of ASP flooding,Screen and optimize of solution plugging agent formula on the base of indoor physical simulation experiment.the relationship between blocking and rate of injection pressure gradient and permeability recovery rate were analyzed to study on the influence of clogging on seepage characteristics.Results show: block of ASP flooding is made up of clay particles with small particle size,including water,hydrochloric acid solution?Ca CO₃?,hydrochloric acid insoluble matter?SiO₂?and alkali.The mineral composition is composed of two parts,organic matter and inorganic matter,Organic matters including polymers,Oils and surfactants,inorganic consist of CaCO₃,SiO₂,FeS,Al₂O₃ and so on."College Blocking Remover" formula is determined as: Oxidizing agent?0.4%ClO₂?compound acid?8%¹2%HCl+2%³%HF+1%CH3COOH+0.6%small cationic quaternary ammonium salt 0.5%YC-SY 0.5%KCl?,flooding with the order of Oxidation agent,composite acid,displacement fluid.Because the surfactant could extend the effective period of the blocking solution,1% surfactant was added into blocking remover.With flooding agent blockage particle content increased,the slug size increase of particles and the particle size increased,the injected into each stage core pressure gradient is increased,the solution was stable after plugging into high pressure,the permeability recovery rate is low.The permeability recovery rate increases with the increase of the plugging agent dosage,but the economic benefit is poor.Alkali resistant resin sand short-term flow conductivity is the best,and Resin cement sand's long-term flow conductivity in better than others.Comparing resistance to basic corrosion of the alkali quartz sand,resin sand,resin cement sand,the best one is resin cement sand,followed by alkali resistant resin sand,quartz sand is the worst.The sand ratio can be reduced by the combination of different supporting agents,the combination effect of quartz sand and walnut shell is better than that of the quartz sand and carbon fiber.