Synthesis and laboratory evaluation ofiso‐tridecyloxypolyethylene glycol acrylate copolymers as potential viscosity reducers for heavy oil

Abstract

As driven by the increase in global fuel demand and decrease in worldwide reserves of conventional oil, it is important to develop new production technologies for heavy oil. In this work, copolymers PAAI7, PAAI10, and PAAI15 were synthesized and evaluated as potential viscosity reducers for heavy oil. iso‐Tridecyloxypolyethylene glycol acrylates (I13CxAA, x = 7, 10, 15), acrylic amide (AM), and 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) were polymerized to give the copolymers PAAIx, respectively. Copolymers PAAIx were characterized by FTIR, 1H NMR spectroscopy, and TGA and showed good thermal stabilities as the decomposition temperature was above 350°C. Their viscosity‐average molecular weights were measured as in the range between 6.53 × 106 and 10.58 × 106 g/mol. The effects of temperature, shear rate, and salinity on the viscosity of polymer solutions were studied, and PAAIx had reasonable rheological properties. The solutions of PAAIx in formation water could emulsify heavy oil sample to form oil‐in‐water emulsion when mass ratio of oil:water was in the range of 6:4‐2:8, respectively. The rates of reduction in viscosity of emulsions compared with that of original oil sample were 53.5%‐97.5% at 50°C under shear rate of 20 s−1. The effects of oil:water ratio, emulsifying temperature, and shear rate on the viscosities of emulsions were extensively studied, and the effect of the polymer structure on the emulsification and viscosity reduction of heavy oil was also discussed. Among three copolymers, PAAI15 formed the most stable emulsion with heavy oil and the emulsion had the lowest viscosity. PAAI15 had the potential for further study.

Novel Strategy of Polymers in Combination with Silica Particles for Reversible Control of Oil–Water Interface

“…Furthermore, the mixed system (0.05 wt % polymer/0.1 wt % SiO 2 ) has a similar viscosity reduction rate (92.2%) compared to the heavy oil/water emulsions stabilized by 0.2 wt % polymers, indicating that fewer polymers are demanded to emulsify the heavy oil to achieve the viscosity reduction. The Ashby chart in Figure S21 has compared its benefit with other polymeric emulsifiers for heavy oil reduction, such as PTVR, PAAL, PALS, etc. − Under homogenization and pH manipulation, the emulsions prepared by mixed systems showed good behavior in emulsification and demulsification in cyclic utilization (Figures b and S22). The droplet size does not change a lot in the first four cycles, but in the fifth cycle, it contains the lumpy heavy oil in the emulsions, meaning the performance degradation in emulsification due to the accumulation of salt ions.…”

Preparation and evaluation of double‐hydrophilic diblock copolymer as viscosity reducers for heavy oil

“…Macromolecular surfactants have been extensively used in the heavy oil viscosity reductions for their low interfacial tension (IFT) and high displacement efficiency heavy oil. [40][41][42][43][44][45][46][47][48] These chemical agents could greatly reduce the oil/water IFT and form heavy oil in water emulsions. However, their high interfacial activity usually makes heavy oil emulsions difficult to dehydrate and will be greatly increase the cost of subsequent treatment.…”

“…Compared with small molecules, this kind of amphiphilic molecules could have lower foaming properties and higher mechanical stabilities, and a number of amphiphilic copolymers have been successfully developed to stabilize emulsions, 31–34 foams, 35 and nanoparticles 36–39 in composite systems. Macromolecular surfactants have been extensively used in the heavy oil viscosity reductions for their low interfacial tension (IFT) and high displacement efficiency heavy oil 40–48 . These chemical agents could greatly reduce the oil/water IFT and form heavy oil in water emulsions.…”

New Amphiphilic Macromolecule as Viscosity Reducer with Both Asphaltene Dispersion and Emulsifying Capacity for Offshore Heavy Oil

“…Low-molecular-weight surfactants have been adapted in the research of some scholars, and their results illustrated that they can reduce heavy oil viscosity by 80–90%. , Meanwhile, in recent years, more attention is focused on synthesizing high-molecular-weight amphiphilic polymers. Researchers have incorporated various groups onto high molecular chains, including line-type, star-type, and net type. − …”