Enhanced oil recovery through in-situ combustion: Kinetic modeling of light oil oxidation

Abstract

Crude oil remains one of the most important sources of fuels and energy globally for industry, transportation, and for heating purposes. It also provides raw materials for plastics and other petrochemical products. The significant growth in world's population and economies has led to a considerable increase in the global demand for oil. Enhanced Oil Recovery (EOR) techniques have been introduced to boost oil recovery and are central to the future development of oil industry. This research work is focused on a thermal EOR technique called In-situ combustion. In-situ combustion involves injecting oxygen rich air into a reservoir causing an ignition of the crude that develops into a combustion front which propagates outward thereby sweeping oil bank towards the production well. This combustion technique has significant potential for the recovery of light oil. This is due to the fact that it simultaneously offers some important aspects of flue gas (CO2) flood and a highly efficient thermal recovery. Light crude oil is composed of several hydrocarbons including aliphatics and aromatics. Surrogate fuels were selected to represent crude oil, and the reaction mechanisms for their combustion were developed and validated against experimental data from literature to ascertain the reliability of the model and to improve the combustion model. Furthermore, a simplistic study was carried out by using the model together with the surrogate fuel mixture to simulate the in-situ combustion process using monolith reactors to represent the reservoir. The effects of varying the fuel-air equivalence ratios on the peak temperature, volume of oil displaced, and the viscosity of the oil were investigated. For a constant injection rate, the volume of oil displaced are 1.77E10 cm3, 1.81E10 cm 3 and 2.08E10 cm3 for the equivalence ratios of 0.05, 0.1 and 0.2, respectively. Subsequently, the oil recovered in the reservoir due to volume displacement are 42.75%, 45.25% and 52.0 % for the equivalence ratios of 0.05, 0.1 and 0.2, respectively. Thus, the recovery rate increases with equivalence ratio. The light oil reaction mechanism developed in this work provide an excellent tool that can be used to optimize the process conditions used for in-situ combustion process in light oil reservoirs.

Date of Award	2016
Original language	American English
Supervisor	Abhijeet Raj Gupta (Supervisor)