A new air injection technique, low temperature oxidation (LTO) process for residual light oil recovery, is described. Improved oil recovery from deep, light oil reservoirs is achieved by removing the oxygen in the injected air by LTO reactions with the residual oil in the reservoir. The product of the LTO reactions is a "flue gas", which displaces the oil. Preliminary results of LTO reaction kinetics and oil recovery have been obtained using four North Sea light oils.
THAI - "Toe-to-Heel" Air Injection, is a new EOR process, which integrates advanced reservoir technology and horizontal well concepts, to achieve potentially very high recovery of heavy oil. It can also realise very substantial in situ upgrading by thermal cracking, producing upgraded oil to the surface. The process operates in a gravity stabilised manner by restricting drainage to a narrow mobile zone. This causes the flow of mobilised fluids to enter directly into the exposed section of a horizontal production well. The process can be operated on primary production, as a new technology, as a follow-up to existing technologies, or as a co-process where the advantages of high thermal efficiency are required. This is achieved by concentrating the energy required for oil mobilisation, recovery and thermal upgrading in the reservoir.
Combined with clean technology design, THAI offers a pathway to future economic success for the heavy oil industry.