Investigation of initial water mobility on steam-assisted gravity drainage performance using a two-dimensional physical model

Steam-assisted gravity drainage (SAGD) has become a primary commercial in-situ recovery method for oil sands in Alberta, Canada. Industrial field studies have found that the initial water mobility in oil sands has an impact on the SAGD process. However, no experimental research has been conducted to investigate such effects on SAGD performance. In this study, a novel two-dimensional (2-D) physical model with a water-flow boundary is designed for the first time to simulate the flow of initial water in oil sands during the SAGD process. The model investigates the impact of initial water mobility on the steam chamber shape and captures the growth of the steam chamber at different times. The experimental results show that low initial water mobility can promote vertical and lateral growth of the steam chamber, compared to immobile initial water, while high initial water mobility results in accelerated vertical expansion of the steam chamber in the SAGD process. The oil recovery in the scenario of low initial water mobility is 6.6% higher than that of immobile initial water scenario, and is 12.6% higher than that of high initial water mobility scenario. Subsequently, the numerical simulation study for the experiments is conducted in order to acquire insight into the effects of initial water mobility on SAGD performance. Results show that initial water mobility has a great influence on water movement profiles and water distribution along the steam chamber boundary in the SAGD process.