Grant: Collaborative Research and Development Grants

This proposal relates to the design optimization of petroleum wells in thermal operations. Thermal operations are used in Alberta and around the globe to heat thick heavy oils (bitumen), reduce their viscosity and allow their flow into the wellbore at economical rates. There are two major technologies for thermal operations: Steam Assisted Gravity Drainage (SAGD) and Cyclic Steam Stimulation (CSS). These wells are drilled in uncemented sand reservoirs and will collapse unless supported by pipes which also act as screens that allow the passage of fluids, but keep the sand grains in the formation. These pipe screens are called stand alone screen liners, or simply liners.*There are different types of liners for thermal operations. These liners are supposed to prevent the reservoir sand from flowing into the wellbore, but allow the production of very fine materials (i.e. fine silts and clay) in the reservoir. Sand production in thermal wells, which usually are horizontal, will result in sand accumulation in the liner, requiring the wellbore to be frequently shut in for wellbore clean up. The sand, which is contaminated by oil, is costly to separate, clean, and dispose of once manually brought to the surface or transported by wellbore flow to the surface. The production of fines will result in higher wellbore productivity as, if they are not produced, they will plug the sand and the screen liner.*The design of liners that allow the production of fines, but keep the sand in the reservoir is a delicate task. Liner design criteria have been developed in the past, but are inadequate and conservative, resulting in lower wellbore productivity. In this research, we propose the development of criteria for the design of three different common types of liners. The proposed research takes a comprehensive approach in enhancing the liner design for heavy oil reservoirs through fundamental and applied research using physical and mathematical modeling and state-of-the-art laboratory facilities at the University of Alberta.*