The Effect of Fractures on the Steam-Assisted Gravity Drainage Process

Abstract

This study presents an experimental investigation of the effect of fractures and well configurations on the steam-assisted gravity drainage (SAGD) process in a three-dimensional model, using 12.4°API gravity crude oil. A total of eight runs were conducted, using a 30 cm × 30 cm × 10 cm rectangular-shaped box model. Temperature distributions were observed using 25 thermocouples. Three different well configurations were investigateda horizontal injection and production well pair, a vertical injection−vertical production well pair, and a vertical injection−horizontal production well pairwith and without fractures that provided a vertical path through the horizontal producer. The influence of fracture distribution on the steam−oil ratio (SOR) and oil recovery was analyzed using the horizontal well pair scheme, a vertical injection−horizontal production well pair, and a vertical injection and vertical production well scheme. The experimental results indicated that vertical fractures improved SAGD. Maximum oil recovery was observed during the horizontal injection−horizontal production well scheme with a fractured model, because of the favorable steam-chamber geometry. Runs showed that the location of the fractures affects the performance of the process. During the early stages of the runs, the fractured model gave significantly higher SORs than those observed in the uniform-permeability reservoir.