Abstract: Affected by the heterogeneity of the reservoir, the SAGD steam chamber in super-thick massive extra-heavy oil reservoir with no interlayer and top-edge water was unevenly developed in the vertical direction, with a risk of top-edge water drainage. In response to this problem, the spatial distribution characteristics of the steam chamber were three-dimensionally characterized based on the detailed description of the SAGD steam chamber in Block Du 84 of Liaohe Oilfield, steam injection interruption, steam injection reduction, intermittent steam injection and non-condensate gas injection were optimized and compared through numerical simulation, the impact of different development modes on the expansion of steam chamber was demonstrated, and the SAGD steam chamber balance control strategy was proposed. The results showed that the four control methods all restrained the steam chamber from expanding upward, and the intermittent steam injection was easier to balance the steam chamber, reduce steam consumption, extend the development period, with the production characteristics of high oil-steam ratio and high net oil production. There is much for technical guiding significance of this study to the description and control technology of SAGD steam chamber.

Key words: water-cap reservoir, extra-heavy oil reservoir, SAGD, steam chamber description, numerical simulation, steam chamber control, Block Du 84