3D experimental research of innovative VH-SAGD to enhance recovery of thin layer oil sand reservoirs

Abstract

In thin layer oil sand reservoirs, the vertical and horizontal combined wells steam assisted gravity drainage (VH-SAGD) can avoid validly the problems of low steam efficiency and the high heat loss induced by the traditional SAGD technology. However, there are few laboratory studies about steam chamber development and production performance on the VH-SAGD. To fill this gap, a 3D large-scale physical model with temperature sensors was designed based on the similarity criterion, the experiment was carried out to simulate the production process of VH-SAGD. Then the development characteristic of steam chamber was captured by monitoring the temperature distribution changes. Finally, the production performance at each steam chamber development stage was analyzed. The experimental results showed the steam chamber development experienced the formation stage, the longitudinal development stage, the lateral expansion stage and the stabilization stage. The formation of triangular cold oil area indicated the steam chamber is mature, and the appearance of smooth steam front funnel indicated the steam chamber stopped developing. This research revealed the steam chamber development characteristics and the production performance of VH-SAGD, which can provide a reference value for optimizing injection and production parameters and predicting recovery factor for VH-SAGD in thin layer oil sand reservoirs.