Acid Sludge Formation Mechanism And Anti-sludge Agent Formulation Optimization

In the process of acid stimulation,the formation of acid slag will block the formation and cause permanent damage.In this paper,on the basis of predecessors'research,the acid slag formation mechanism and influencing factors were fully analyzed.Mainly aimed at the crude oil of Iran's oil field,using quality standard to determine acid residue generation,based on acid slag generation and the generation of acid slag trend analysis,we get the conclusion:Resin asphaltene and acid is the necessary conditions for the formation of acid slag.When resin asphaltene content is more than 8.8%,we must attach importance to the change of recovery factor caused by acid slag.Acid type and concentration affects the generation of acid slug.Ferric iron is important external factors for the generation of acid slag.ferric iron ions content The higher ferric iron content is,the greater the acid slug generation is.At the same time acid slag generated fast,therefore,we should not only focus the reduction effect,but also the reaction time.In this paper,after choosing from the common 7 kinds of surfactants,10 kinds of iron stabilizer and three kinds of catalyst optimization,we developed the anti-sludge agent composed of ABS and SAS-60 as the main surfactant composition,C6H7NaO6·H2O and modified sodium sulfide as the main reducer composition,CuI as catalyst composition.Through combinatorial optimization,it is concluded that three kinds of acid slag system.System is mainly applied to ferric iron ion content as small oil Wells.The main agent is surface active agent.It can prevent resin asphaltene assemble by by adsorption and dispersion effect.Join modified sulfide at the same time so that when there is a small amount of ferric iron in the well,reducing agent can be timely to control of ferric iron,leading to more effective anti-sludge effect.System 2 is suitable for the oil Wells containing iron minerals(such as siderite,chlorite,pyrite,etc.).This system mainly used the reducing agent,so the biggest advantage of this system is to efficiently control the ferric iron ions,effectively solve the problem that the generation of acid slag caused by existence of ferric iron.At the same time,joining the catalyst increase reduction reaction speed greatly and solve the problem that as soon as conditions are,acid slag will produce a lot.The system has certain acid solubility,no special smell,no strong corrosion to equipment,and construction need special method is used for configuration,adding acid,injected into formation can be.System 3 is suitable for the well conversion well,injection in front of acidizing,mainly used as pickling pretreatment liquid.The system main function is isolation,block the resin and asphaltene in crude oil and acid contact.By making evaluation on this formula's surface tension-lowering ability,compatibility,acid solubility and acid sludge-resisting performance.It turned out this new antisludge formula is efficient to resist forming acid sludge and it has also other impressive performance,by which the formula system can be a chemical addictive to prevent Iran's oil fields acid sludge during acidizing treatment.