Expert Viewpoint – THAI in situ combustion
HeavyOilinfo.com spoke to Professor Malcolm Greaves, principal inventor of the THAI process for heavy oil recovery and co-inventor of the CAPRI process for downhole catalytic upgrading.
Toe to Heel Air Injection (THAI), invented in 1993, combines a vertical air injection well with a horizontal production well oriented in line to the vertical well. Fed by air from the injection well, a combustion front sweeps the oil from the toe to the heel of the horizontal producing well. Estimates from experimental tests indicate that the process can recover 80% of original oil-in-place (ooip) while partially upgrading the crude oil in situ.
CAPRI is a variant of the THAI process that adds an annular sheath of solid catalyst surrounding the horizontal producer well. Thermally cracked oil produced by THAI passes through the layer of catalyst en-route to the horizontal producer well. Laboratory tests indicate that the combination of THAI and CAPRI can achieve very significant upgrading, virtually transforming heavy oil into light oil.
THAI and CAPRI are trademarks of Petrobank Energy and Resources Ltd.
The development of THAI
