A Study on Heavy Oil Recovery by in-Situ Catalytic Aquathermal Cracking

Four catalysts are developed for use in aquathermal cracking of heavy crude oil in reservoir strata. One of them(transition metal salts) is selected as the most effective and the optimal conditions of catalytic aquathermal cracking(CATC) in laboratory are established. For three heavy crude oils from Liahe CATC with 0.2% catalyst at 240℃ over 24 hrs leads to reduction in viscosity at 50℃ by 89.9—77.7% and to variation in composition: significant increase of saturated and aromatic hydrocarbon contents and decrease of resin and asphaltene contents and displacement of hydrocarbon distribution to direction of lower carbon number. The field tests on in situ CATC of reservoir heavy oil are successful: after injecting a proper catalyst into 3 steam huff puff wells the viscosities of produced heavy crudes are notably decreased.