Data are available for four SAGD projects and two CSS projects operating in the Clearwater formation at Cold Lake. This paper uses these data to compare the energy efficiency and recovery performance of SAGD and CSS.

For the conditions outlined in this paper, field data demonstrate that:

  1. Bitumen recovery using SAGD is generally uneconomic in the Clearwater formation.

  2. Bitumen recovery using CSS in the Clearwater formation:

    • Produces as much as 50% or more bitumen/m3 external gas consumed than SAGD; and

    • Will result in significantly higher overall bitumen recoveries (as a percentage of OBIP) than SAGD.

These observations are consistent with industry experience in non-Clearwater SAGD and CSS operations.

In addition, operating and design data for commercial SAGD and CSS projects is used to demonstrate that:

  1. Due to differences in steam quality, SOR is not an appropriate indicator of energy efficiency. Energy efficiency comparisons are more appropriately based on the quantity of external gas required to produce 1-m3 of bitumen.

  2. To convert SOR data to an external gas requirement, the following conversion factors are proposed:

    • 1-m3 wet (80% quality) steam requires approximately 60-m3 gas.

    • 1-m3 dry (100% quality) steam requires approximately 75-m3 gas.

  3. The use of project specific EBIP, versus OBIP, in calculating recovery makes meaningful comparisons difficult.

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