Synthesis And Properties Of Polyether Demulsifiers

Demulsification of crude oil emulsion is very important in the process of oil exploration. With the implementation of tertiary oil recovery technology, it becomes more and more difficult to separate the water from crude oil due to the enhancement of emulsion’s stability. As a result, people require higher demulsification performance. It is of great significance to synthesize a novel type of demulsifier with high efficiency and wide applicability.In this paper two kinds of new polyether demulsifiers were synthesized and their aggregation behaviors were investigated. And the ability of demulsification was studied and the factors of demulsification were explored. Moreover the production of demulsifier-EDP603 was enlarged and its ability of demulsification at oilfield was investigated. The main content is as follows:1. A novel type of phenol-amine resin was prepared using environment-friendly cardanol, formaldehyde and tetraethylenepentamine as raw material. Then five kinds of block polyethers (CT) were synthesized by polymerization reaction with propylene oxide (PO) and ethylene oxide (EO) using phenol-amine resin as initiator. The structure of polyethers was identified by 1H-NMR and IR spectra. The molecular weight was measured by static laser light scattering. The cloud point, RSN, water number of different polyethers (CT) were determined and HLB value was calculated through the cloud point method. The aggregation behaviors at the air/water interface was studied by the means of equilibrium surface tension and the influence of inorganic salt and temperature on the aggregation behaviors was investigated. The results indicated that the cloud point, HLB value, water number and RSN increased with the content of EO and decreased with the increasing content of PO. The results showed that block polyethers (CT) have excellent surface activity. Their critical micellization concentration (cmc) increased with the content of EO and decreased with the increasing content of PO. The results demonstrated that the addition of salting-out inorganic salt or the increase of temperature can reduce surface tension.2. The demulsification ability of block polyethers (CT) was studied via bottle testing method at oilfield. The effect of concentration, temperature, inorganic salt, pH and modification on demulsification was investigated at laboratory. The results showed that demulsification was improved with the increase of concentration before the cmc. The demulsification got better when temperature rose. The addition of salting-out inorganic salt dramatically reduced the demulsification while the addition of salting-in inorganic salt slightly increased the demulsification. There was an appropriate pH range for particular crude oil emulsion. The demulsification of CT 18620 modified by silicone oil was improved and there was an appropriate scope for the addition of crosslinkers.3. A series of block polyethers (APE) were prepared using allyl alcohol as initiator via polymerization reaction of propylene oxide (PO) and ethylene oxide (EO). Then five novel kinds of polyether demulsifiers (PAPE-AMPS) were synthesized by copolymerization reaction of the APE and 2-acrylanmido-2-methylpropanesulfonic acid (AMPS). The structure of copolymer was characterized by 1H-NMR and IR. spectra. The molecular weight was measured through gel permeation chromatography. The demulsification ability of PAPE-AMPS was investigated by bottle testing method at laboratory. The instability of crude oil emulsion was studied by Turbiscan Lab stability analyzer. The results proved the occurrence of copolymerization of APE and AMPS. The molecular weight was large and had a wide range. The PAPE-AMPS had good demulsification performance and demulsification got enhanced with the increase of concentration.4. The results of pilot scale test showed that EDP603 had good demulsification performance. Not only the water content of output oil was further reduced, but also the quality of sewage got better. The application of EDP603 can be promoted.