Abstract: A well configuration is provided comprising an injection well (102) completed relatively high in an oil reservoir (100) and a production well (103-106) completed relatively low in the reservoir (100). The production well has a horizontal leg (107) oriented generally perpendicularly to a generally linear and laterally extending, upright combustion front propagated from the injection well (102). The leg (107) is positioned in the path of the advancing front. Oil upgrading catalyst has been emplaced along the horizontal leg. The production well (103-106) is maintained open, thereby providing a low pressure sink which induces the front to advance along the leg. The hot combustion gases react with the commingled oil over the catalyst to provide in situ upgrading.

Abstract: A well arrangement is used wherein the production wells are generally horizontal, positioned low in the reservoir and arranged generally perpendicularly to a laterally extending combustion front. The combustion front is propagated by a row of vertical air injection wells completed high in the reservoir. The open production wells function to cause the combustion front to advance along their lengths. The process is characterized by a generally upright combustion front having good vertical and lateral sweep.