Research Of Breaking Crude Heavy Oil Emulsion At Low Temperature

This text was prepared for heavy crude oil of Liaohe Oilfield, which was highlyviscous, highly temperature of demulsification, energy-consuming, andagent-consuming. Starts with research on demulsification mechanism, the molecularstructure of demulsifier, demusifier type, and the relationship between theirdemulsification effects. After zhe analysis of the oil group composition of ShuguangLiaohe Oil Field and the stabilization of heavy oil emulsion, according to laboratoryexperiments and on-site application, Research and development a new kind of lowtemperature demulsifier. This paper made the following research.The crude heavy oil was separated into the four components (asphaltene, resin,aromatic, saturated) by way of adsorption chromatogram, we studied through weightmeasurement and FI-IR spectrum analysis of heavy oil components. As well asanalyzed the composition and characteristics of wastewater, determination of lowtemperature oil-water emulsion viscosity-temperature curve. The results showed that:high resin and asphaltene content in the heavy oil, both have relatively high surfactant;The hydroxyl containing of asphaltene more than colloid, a strong intermolecularhydrogen bonding force, more prone to cause rising of crude oil viscosity.The demulsifier through the screening,mixing, and orthogonal experiment design.Compared with other types of demulsifier, to get the demulsification effect ofaromatic ring structure, high molecular weight and branched degree bigger demulsifiedemulsifier is better, get the best demulsification conditions as follows: thedemulsification temperature of85℃, the blending ratio of HG-11：HG-6=3:1, thedosage of demulsification was120ppm, dehydration rate was95.83%after five hours,After demulsification of crude oil moisture content for2.76%; Through theexperiment on the dosage of demulsification at low temperatures, the best dosage ofdemulsification was120ppm at85℃, the best dosage of demulsification was210ppmat80℃.Demulsifier is studied from the aspects of mechanism, measuring the surfacetension and interface tension of the demulsifier, critical micelle concentration ofdemulsifier is about100mg/L, this dosage of demulsification are very close to actual.Increases as the temperature rises, the oil/water interfacial tension was increased, withthe increase of demulsifier concentration, the oil/water interfacial tension wasincreased after lower, theory is that when reduced to low interfacial tension (100mg/L), Demulsification effect is the best.Through the experiment on colloid and asphaltene effect on viscosity of crude oil, Water/crude oil interfacial tension from crude oil emulsions in the presence of thedifferent concentrations of demulsifiers was measured, and the influence of colloid,asphaltene on the interfacial tension of heavy oil-in-water emulsion was investigated.The results showed that: with the increase of colloid and asphaltene content,emulsion of ultra-heavy oil dehydration rates were reduced and viscosity were low.When it contains1.97%asphaltene, the viscosity of crude oil was190.2mpa·s, Whenit contains attain2.5%asphaltene, he viscosity of crude oil rise to1410mpa·s. Whenit contains more than2.1%asphaltene or more than32%colloid, emulsion ofultra-heavy oil in demulsification is quite elusive; That colloid and asphaltene contentrises would involve interfacial tension between demulsifying agent water solution andcrude oil increase, Asphaltene content was increased0.7%has more effects on crudeoil interfacial tension than colloid content increased7%, so the increase of the contentof asphaltene has greater impact on interfacial tension between model oil and aqueousphase.