The Effect Of Organic Chlorine In Oilfield Chemicals On The Organic Chlorine Of Crude Oil

The increase of oil additives in oil field has caused increase of organic chlorine content in crude oil,which had caused a variety of security risks and great economic losses.It is of great significance to study the influence of organic chlorine in the oil field chemical agent on the organic chlorine in crude oil.In this paper,the optimum conditions for the determination of inorganic chlorine and total chlorine in crude oil were investigated.The main existing forms of organic chlorine in crude oil were detected by gas chromatography-mass spectrometry.The effects of pH value of aqueous phase,water content of crude oil and different properties of crude oil on the residual law of all kinds of organic chlorine in crude oil were investigated.Then crude oil and all kinds of organic chlorine reaction system with oil were detected through FT-IR and GC-MS and the reaction mechanism of all kinds of organic chloride in crude oil were analyzed,which would provide theoretical basis for the selection of chemical agents in oil fields.The optimum experimental conditions for the determination of inorganic chlorine in crude oil 100 mg·L^-1 NaOH solution,crude oil extraction ratio 1000,11000 r·min^-1 high shear dispersion 4 min at 80?.The optimum experimental conditions for determination of total chlorine content in crude oil were Oxygen filling pressure 2.5 MPa,gas was absorbed with0.5 mol·L^-1 Na₂CO₃ of solution for 30 min.The difference of total chlorine content and inorganic chlorine content was the chlorine content.There were mainly alkanes,aromatics,olefins,alcohols,esters five forms of organic chlorine in oilfield chemical agents and in the crude oil there were mainly alkanes,aromatics,and aniline three forms of organic chlorine.The effects of different experimental conditions on the residual rate of five kinds of organic chlorine in crude oil were investigated,which were sym-dichloroethane,epichlorohydrin,1,2-dichlorobenzene,trichloroethylene,ethyl-2-Chloropropionate,five kinds of organic chlorine reagent as the research object.As OH^-is stronger than water as nuclear agent,so the hydrolysis reaction is easier to carry out and the residual rate of organic chlorine is the lowest under alkaline conditions.With the increase of water content,the contact area between organic chlorine and water is increased,which is favorable for the hydrolysis of organic chlorine in the reaction system of crude oil and organic chlorine residue shows a decreasing trend.The nature of crude oil affected the emulsion stability of the crude oil system,which affected the contact of the organic chlorine and aqueous phase in the process of organic chlorine hydrolysis.Through analyzing the reaction mechanism of all kinds of organic chlorine in crude oil,the conclusion is drawn.Alkanes organic chlorine can be gradually hydrolyzed and produce alcohol,which then transfer to the water phase and Industrial desalination and dehydration process can accelerate the hydrolysis.The hazard of alkanes organic chlorine is small.With the increase of carbon chain length,the difficulty of hydrolysis increased and the damage also increased.Alcohols organic chlorine can be gradually hydrolyzed to produce alcohol transfer to the water phase,which is less harmful,however,would increase with the increasing of the carbon chain length.Ring opening reaction of epichlorohydrin would increase concentration of organic chlorine,which is recommended to avoid using epichlorohydrin as the raw material for the production of oilfield chemicals.The harmfulness of chlorinated aromatic hydrocarbons is great.Chlorinated hydrocarbons are greatly hazardous because they can react with long chain alkanes in the crude oil and produce long chain organic chloride residues in the crude oil system.Carboxyl is an electron withdrawing group,which can form a relatively stable carbon positive ion and is conducive to the hydrolysis of organic chloride.The harm of the organic chlorine is not significant,however would grow with the increase of the carbon chain length.