Method for improving bitumen recovery from oil sands by production of surfactants from bitumen asphaltenes

In a method for increasing the efficiency of bitumen recovery from oil sands, bitumen asphaltenes naturally present in the oil sands ore are treated with selected chemical agents to produce surfactants which reduce surface and interfacial tensions and promote the production of bitumen-water emulsions, thus facilitating the extraction and recovery of bitumen for use in producing synthetic crude oil. The agents react with the asphaltenes by oxidation, sulfonation, sulfoxidation, or sulfomethylation reactions, or by a combination of such reactions. These reactions may be initiated by adding selected agents into water-based oil sand slurries in process vessels or in pipelines. Alternatively, the agents may be injected directly into subsurface oil sand formations for in situ production of surfactants to enhance the efficiency of in situ thermal bitumen recovery processes. The methods of the invention may also be used to improve the stability of bitumen-water emulsions to facilitate transportation of the emulsions by pipeline, and to enhance the recoverability of bitumen from oil sands tailings.