Improving SAGD by applying emulsion based reservoir conformance control method

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The proposed research directly addresses the conformance problem (i.e., uneven steam chamber development and therefore partial loss of available reservoir for bitumen recovery) in the Steam-Assisted Gravity Drainage (SAGD) process due to the heterogeneity of oil sands reservoirs. To improve the thermal efficiency and therefore the economics of SAGD operations in heterogeneous oil sands reservoirs, the low permeability zones need to be geo-mechanically dilated to make them permeable to steam. It is crucial to temporarily block the high-permeability zones during dilation of the low mobility zones. This project will develop an emulsion blocking technique for SAGD conformance control. In this project, thermally stable bitumen-in-water emulsions will be generated at temperatures up to typical steam temperature (~200oC). More than a 99.5% permeability reduction in high permeability zones will be realized, and a uniform growth of the SAGD steam chamber will be promoted. This project will target to generate stable emulsions under moderate interfacial tension conditions by utilizing the synergy between alkalis, surfactants, and nanoparticles in the emulsification of bitumen in brine. The performance of emulsions in SAGD conformance control will be evaluated and optimized by conducting various physical model tests. Mathematical and numerical models for permeability reduction and conformance control by emulsion blocking will be developed. Brion Energy and BitCan have agreed to support the herein proposed emulsion-based conformance management research, and to test the emulsion systems developed in this project in Brion's reservoirs. Reservoir simulation will be performed for field test design of SAGD conformance control operations and will be validated by analyzing field test results. The research outcomes of this project will be applicable to SAGD conformance controlled dilation start-up and SAGD conformance improvement after start-up operations in other oil sands reservoirs in Canada and to related processes globally. The anticipated benefits of implementing the proposed new technique for oil sands recovery are significant energy savings, reduced water consumption, and reduced greenhouse gas emissions.