METHOD FOR TREATING CARBONATE RESERVOIRS

摘要

A method is disclosed for treating hydrocarbon reservoirs to alter surface wettability of carbonate reservoirs for improved recovery of heavy oil or bitumen. In one embodiment, recovery operations involving solvents and/or steam to mobilize heavy hydrocarbons are addressed, such as oil-wet reservoir matrices of the Grosmont Carbonates. Gases may be added, such as carbon dioxide, sulfur dioxide and/or nitrogen dioxide, to form acidic liquids or vapors when combined with water or steam as injected during in-situ recovery operations. Acid-producing gases adhere to matrix rock surfaces as the gases condense/dissolve; condensed vapors react with carbonate rocks, such as limestone and dolomite, and alter the surfaces from oil-wet towards water- wet. The method's effectiveness may be monitored by analyzing the recovered fluids and/or applying cased-hole diagnostics in observation wells. Compressed flue gases or carbon dioxide gas recovered from other surface plant processes may be added to the injected steam.