An Experimental Study of Emulsion Phase Behavior and Viscosity for Athabasca Bitumen/Diethylamine/Brine Mixtures

Autor: Upali P. Weerasooriya, Kai Sheng, Ryosuke Okuno, Himanshu Sharma, Kwang Hoon Baek, Francisco J. Argüelles-Vivas
Rok vydání: 2018
Předmět:
Zdroj: SPE Reservoir Evaluation & Engineering. 22:628-641
ISSN: 1930-0212
1094-6470
Popis: Summary Water is the most dominant component in steam-based oil-recovery methods, such as steam-assisted gravity drainage (SAGD). The central question that motivated this research is whether in-situ bitumen transport in SAGD can be substantially enhanced by generating oil-in-water emulsion, in which the water-continuous phase acts as an effective bitumen carrier. As part of the initial stage of the research project, the main objective of this paper is to present the ability of organic alkali to form oil-in-water emulsions that are substantially less viscous than the original bitumen. Diethylamine (DEA) was used as the organic alkali in this research. Experimental studies were conducted for emulsion phase behavior and viscosity for mixtures of Athabasca bitumen, DEA, and sodium chloride (NaCl) brine. Experimental variables included brine salinity, alkali concentration, water/oil ratio (WOR), temperature, and sample-aging time. The phase-behavior study indicated that conditions conducive to oil-in-water emulsions are low alkali concentrations at salinities less than 1,000 ppm. For example, a single phase of oil-in-water emulsion was observed for 0.5, 1.0, 2.0, and 5.0 wt% DEA with WOR of 7:3 with no NaCl. The emulsion for 0.5 wt% DEA, 1,000 ppm NaCl, and WOR of 7:3 was a single-phase oil-in-water emulsion at temperatures up to 403 K at 35 bar. At lower temperatures, 323 and 298 K, flocculation of emulsions in these samples resulted in the separation between the bitumen-rich and water-rich oil-in-water emulsions. However, essentially all bitumen content was measured from the bitumen-rich oil-in-water emulsion. The oil contents in these emulsions were more than 70 vol% at 298 K and 57 vol% at 323 K. Viscosities of these oil-in-water emulsions ranged between 85 and 115 cp at 1.0 seconds–1 and between 31 and 34 cp at 10.0 seconds–1, at 323 K. At 298 K, they ranged between 105 and 250 cp at 1.0 seconds–1 and between 48 and 74 cp at 10.0 seconds–1. Results in this research show that, compared with the original bitumen, bitumen-rich oil-in-water emulsions were less viscous by three to four orders of magnitude at 298 K, and less viscous by two orders of magnitude at 323 K.
Databáze: OpenAIRE