Abstract: After steam breakthrough, intermittent steam injection process can control steam channeling, enhance steam specific volume, sweep volume, steam quality, oil phase relative permeability and thermal efficiency, and establish the mechanism of imbibition displacement. It performed well while used in the pilot Area 0 of Jinglou oilfield. Field test and numerical simulation study showed that the optimized intermittent steam injection cycle is 30 days in thin heavy oil reservoir and steam injection rate should be 1. 5 times as continus steam injection rate; in a large sized waterflooding block, the injection wells at a row are designed as a unit, and the injection period in two adjacent rows of steam injection well should superimpose by 50%.

Key words: Heavy oil reservoir, Steamflooding, Discontiuity, Steam injection, Mechanism