Application of Coal Combustion Solid Wastes (CCSWs) as a New Economical Solution for Enhanced Oil Recovery

Enhanced oil recovery (EOR) methods are common for many oil reservoirs to continue their economical production, and gas injection has shown to be a promising EOR method widely used in the UKCS. Fingering effects and gravity override are drawbacks of gas injection process which result in an early breakthrough and a poor sweep efficiency in many cases. Water Alternating Gas (WAG) is currently used in different fields of the North Sea such as Miller, Ula, and Magnus among others, to control the mobility of gas and improve its performance.

However, it is difficult to control gas fingering and its breakthrough as displacing slugs travel in the porous media and become mature. This is due to fact that water and gas are immiscible and reservoir heterogeneity and dispersivity can expedite gas fingering through water slug. Foam flooding seems to be a good alternative for WAG injection as gas and water can be miscible which cause viscosity enhancement and favourable interfacial interactions that can reduce the issues of early breakthrough and low sweep efficiency in WAG process. However, the main issue with foam flooding which directly affects its performance, is stability of foam in porous media. Different chemicals such as foam boosters, polymers and nanoparticles are suggested to improve the foam stability.

However, these recommended methods make the process more expensive and as such they might not be a viable solution with the current oil prices. In this study, we examine the feasibility of using inexpensive nanoparticles as an economical alternative to expensive chemicals and foam boosters. Specifically, we study the improvements in the quality, texture and rheological properties of WAG and foam through the use of these materials, both in bulk and porous media at high temperature conditions. The rate of particle transport and retention in porous media, heat transfer changes and the effect of these nanomaterials on bubble disjoining pressures and coalescence will also be investigated.

Finally, prior to applying this method to the North Sea fields, the effects of monovalent and divalent ions and their concentrations on the stability of the generated displacing fluid, in the presence of hydrocarbon molecules will be explored.

The successful candidate should have, or expect to have, an Honours Degree at 2.1 or above (or equivalent) in Petroleum Engineering or Chemical Engineering or Chemistry or Physics

Knowledge of: Chemistry, Reservoir Engineering, Enhanced Oil Recovery, Nano Materials