Circulation of steam during the start-up of a well pair is required for the SAGD process where there is limited fluid mobility, as it helps establish communication for flow between the injector and producer well. The majority of the modeling encountered to date for the circulation period either assumed a source/sink constraint, used a horizontal discretized wellbore model with sand face coupling, or used a pseudo-steady state wellbore flow model only. The above methodologies do not take into account 1) the heat transfers and pressure behavior among the different tubing strings, 2) the change in conditions from sand face to wellhead, and 3) the fluid interaction between the wellbore and reservoir.
Using a thermally-coupled wellbore-reservoir simulator, a discretized wellbore model was constructed to allow a detailed history matching for the circulation period of the M-well pair at the Hangingstone Demo pilot. The history-matched circulation period helped better understand the effects of hydraulics, heat transfers between tubing strings and the impact of fluid losses on reservoir heating. This knowledge will help Japan Canada Oil Sands Limited (JACOS) design the operating philosophy for the Hangingstone Expansion wells. The paper will discuss how the matching was achieved along with the observations made.