SAGD Well-Pair Completion Optimization Using Scab Liner and Steam Splitters

Abstract

Summary: The steam-assisted-gravity-drainage (SAGD) process has been widely used commercially in western Canada for bitumen production. Improving the oil-production rate and reducing the steam/oil ratio (SOR) have been the focus of the industry. In heterogeneous reservoirs, oil production could be impeded by steam breakthrough at one location of the producer and higher liquid level above the other sections of the producer. Various completion methods have been proposed to improve production efficiency. Outflow-control devices (OCDs), such as steam splitters, are used to match steam delivery to reservoir requirements, and inflow-control devices (ICDs) may be used in producers to maximize oil production. Scab liners are the most widely used type of ICD. In general, oil drainage into producers may need to be slowed at some locations and sped up at other locations of the well. In this study, we address how to design SAGD injector and producer completions using steam splitters and scab liners. Results from reservoir simulation with coupled wellbore hydraulics will be presented to show how a well pair could be optimized by attaining favorite pressure profiles inside the injector and producer liners. This investigation will also address sensitivities on steam-splitter location, size, and number of holes, as well as size and length of scab liners.