Study On Mechanism And Function Of Small Molecular Oil Fluidity Improver

In this paper,the components of crude oil and their interactions were studied firstly.Column chromatography,thin layer chromatography(TLC),fourier infrared spectrum,ultraviolet spectrophotometry,differential scanning calorimetry,thermogravimetric analysis(DSC)and polarized light microscopy methods were used to study the components and effects on the wax precipitation process of three kinds of crude oil from Jinghe Oilfield.The result indicated:(1)due to the differences of crude oil,the interactions betweencomponents lead tothe decrease of wax crystal formation rate amongcrude oil with high wax content.(2)With the increasing of polarity for crude oil,the number of condensed ring of aromatic compounds components increases.(3)The high polar components to crude oil could increase the number of wax crystal particlesand weaken the dimensions of the wax particles during the cooling crystallization process,which prevented the particles from contacting and crosslinking each other and forming bulk wax crystal aggregation.(4)During the process of weight loss,cracking reactions and condensation reactionsoccurred alternately.What is more,the more content of colloid asphalteneresults in the less reactive,the slower the rate of weight loss and the harder of the reaction,the higher temperature to the peak correspondingly.(5)After adding the remaining components of different polarity to the C1,the point of wax precipitation,volume of wax deposition and the peak temperature of the wax precipitation were declined.After the addition of polar components of C8,wax precipitation point declines by2.4?,wax-peak declines by3.2?.Secondly,small molecules of crude oil flow improver has been investigated:(1)Acetal ketone compoundshave been synthesized withketones and different types of alcohol as a raw material in accordance with the molar ratio of carbonyl and hydroxyl group.(2)Three different types of spiro ring compounds have been synthesized with benzaldehyde and pentaerythritol,cyclohexanone,lauric acid monoglyceride ester and boric acid as raw materials.Then the two types of synthesizedcompounds including acetal ketone compounds and spiro ring compounds were used as crude oil flow improver to evaluate their impacts on the respective pour point and viscosity of crude oil,and the results showed:(a)Ketal compounds have good viscosity reducing and pour point depressant effect on Suiyuan crude oil.At 20?,usingKL-1 and KL-4with an amount of 0.10%,the viscosity reduction rate can reach up to 60% and 65%,respectively.At 30?,usingKL-3 with an amount of 0.05%,the viscosity reduction rate can reach up to 42%.UsingKL-2 with an amount of 0.02%,the pour point was dipressed by8.7 ?.Using KL-1 with an amount of 0.1%,the pour point was dipressed by7.7?.KL-4,KL-7 and KL-8 with an amount of 0.01% can dipress the pour pointby7.6?,7.9? and 8.4?,respectively.(b)Spiro ring compounds as pour viscosity reducer were effective for Suiyuan crude oil.At 20?,when the dosages of KL-17 is 0.1% and 0.05%,the viscosity reduction rate can achieve to 53.3% and 38.4%,respectively.KL-18 with 0.15% can reduce the viscosity by 45.7%,and KL-19 with an amount of 0.15% and 0.10% can reduce the viscosity by 50.5% and 42%,respectively.KL-17 with an amount of 0.10% can dipress its pour point by13.8?.KL-18 with an amount of 0.1%,0.15% depressed the pour point by12.0? and 12.2?,respectively.KL-19 were used in an amount 0.05%,0.10% and 0.15%,corresponding to reducing the pour point for 10.0?,8.0? and 9.5?.(c)For the three kinds of representative crude oil with high content of wax,saturated hydrocarbons and resin,respectively,ccetal ketone compounds have a good effect on reducing viscosity of the first two kinds,but they does not work well for the last one.Spiro compounds are fit for the first and the last one,but they are not suitable for the second.(d)Finally,the relationship between synthetic fluidity improvers and the peak temperature of the wax,wax precipitation point,the distribution of the wax crystals of crude oil have been systematically investigated by using the polarized light microscopy and differential scanning calorimetry(DSC).It has been demonstrated that acetal ketones and spiro compounds are favourable to reducing the wax precipitation point and the peak temperature of the wax,which lead to the decrease ofwax crystalparticle size,reducing of the coupling strength between the wax crystals,and suppressing their association to form large wax crystal aggregates.In addition,different types of surfactants and some compounds with benzene ring have been investigated to screen its impacts on viscosity and pour point of crude oil.The results show that Suiyuan crude oil has a good response to the compounds with benzene ring.