Mass transfer studies in heavy oil recovery using solvents

"Heavy oil, sometimes called bitumen, is known for its high viscosity (above 100 cp) and low API gravity (below 22⁰). In most cases, viscosity reduction is needed for the final product. There is a considerable amount of heavy oil in Alberta, Canada and the world's largest heavy oil deposit is in Venezuela. Yet less than 1% of it can be recovered because of its high viscosity. For shallow reservoirs, it is possible to resort to open cast mining. For deeper reservoirs, steam is used at ~ 350 ⁰C which gets the oil viscosity reduced to 1cp, which can now be drained out. This process requires large amount of water to make steam, the used water cannot be reused due to presence of high levels of bitumen in it and is currently leading to pollution. The recovered bitumen being highly viscous needs a diluent like naphtha for transportation. Therefore another method is devised which involves using gaseous or liquid solvents directly to bring down the viscosity of bitumen. One such method, vapor extraction (VAPEX) process uses gaseous solvents like hydrocarbon solvents and CO₂ to reduce bitumen viscosity. Vaporized solvents is introduced laterally to bitumen to reduce its viscosity and the less viscous bitumen drains under gravity. Solubility of solvents in bitumen is analyzed first. As solvents solubilize, it diffuses into bitumen and the diffusivity is strongly concentration dependent. The concentration dependence of solvent diffusivity in bitumen is measured next. Knowing the solubility and diffusivity of solvents, a model is used next to simulate oil recovery. It predicts an optimum solvent for this oil recovery process"--Abstract, page iv.

Name thesis:degree_name

Ph. D. in Chemical Engineering

Grantor

Missouri University of Science and Technology

Author dc:creator

• Mohan, Vijitha

• Concentration Dependent Diffusivities
• Flory-Huggins Solution Theory
• Heavy Oil Recovery
• Mass Transfer
• Swelling Factor
• VAPEX Process
• Chemical Engineering
• Petroleum Engineering

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/2566

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-3571