| Polymer flooding crude oil emulsion is stable, it is difficulty to breaking. Especially for offshore oil field, since the space is small, process time is short, the impact of emulsion breaking dehydration, making the high moisture content of the oil, which can easily lead to the power tripped off when electric dehydration and such a series of problems,which would affecting the gathering and transportation efficiency. There is an urgent need to study a new type of fast demulsifier.Currently used demulsifiers is ethylene oxide-propylene oxide block polyether-based surfactants, which has high stability, good compatibility in water, but it has been difficult to meet the recovery solution containing poly for breaking requirements. In this paper, by using a bisphenolA-formaldehydde resin, an amine, aphenol-formaldehyde resin tetraethylenepenta-mine,tetraethylenepentamine, tetrahydrofuran as polymerization initiators, with butylene oxide, propylene oxide, ethylene oxide as a comonomer, synthesized four new series of demulsifiers.,which were named AE Series, DW Series, TEPA series, PA series.Bohai Oil Field SZ36-1block produced fluid to be processed, synthesized demulsifiers for breaking performance was evaluated, screened out of the sample with good breaking effect, breaking through the mechanism of these samples were compared research system.Take the1hour dehydrated dehydration and dehydrated rate as indicators, all samples were screened by bottle test, found that demulsifier has a good breaking effect of:AE-1, DW-1, TEPA-1and PA113. Then study the effects of temperature, concentration, and the aqueous phase demulsifier HMPAM residual polymer concentration on their breaking performance. Comprehensive survey found that AE-1breaking the best performance, with decreasing temperature, breaking performance of AE-1slow down, but still better than several other demulsifiers; residual polymer concentration increased emulsion stability makes increasing difficulty breaking, AE-1remains the dehydration rate higher than85%.In DW-1, AE-1, PA113and TEPA-1of the study (the four typical demulsifier herein), to determine their partition coefficient and the saturation adsorption amount to cover their oil-water interface and the area of a single molecule, the results showed that, AE-1basic does not exist in the aqueous phase, it may be oil-water interface and the oil phase, and may be more in the oil-water interface.Asphaltene content measured at different simulated dynamic interfacial tension of oil in water containing residual polymer in conventional demulsifiers SP169(excluding BO) of the reference samples are analyzed for their ability to replace the original oil-water interface of the active substance was found to contain when BO segment demulsifier replace ability. In addition, the effects of different demulsifiers from the bulk to the interface diffusion of thermodynamics, enthalpy change of AE-1discovery diffusion process and higher, AE-1has the greatest spontaneity in the oil phase has the greatest tendency to spread, after arriving interface, occupy the film more easily leave the discharge of the "blank" area, which shows a strong effect of the active material to replace the interface.Finally, this paper presents the differences between segments with BO-BO segments with and without demulsifier demulsifier breaking procedure:When the demulsifier molecules containing lipophilic groups BO segment, demulsifiers replace existing active substances after the oil-water interface, EO segment is inserted in the aqueous phase, some PO segment "multi-point" adsorbed water interface, but because BO strong hydrophobic segments more random mix of PO and BO is inserted into the oil phase. Close to each other when water droplets collide, mixing segment relative to random segments of pure PO, PO and BO with a lot of meth, stronger intermolecular interactions, different demulsifier molecules more winding, narrow the distance droplets, thereby conducive to breaking. |
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