A new recovery process which uses concentric coiled tubing has been developed to improve production capabilities in heavy oil. The process, called Single Well - Steam Assisted Gravity Drainage PatPend (SW SAGD) relies on continuous injection of high quality steam into the toe of a horizontal well while simultaneously producing mobilized oil from the same wellbore. The well is therefore dual completed with both, production tubulars and Insulated Concentric Coiled Tubing PatPend (ICCT). Having completed an extensive study into the design and fabrication of ICCT, a number of single well, SAGD installations have already been completed and are in production. This paper will review this process and will document production results from some of these early wells.
A number of innovative methods have been developed to enhance and extend the productive life of heavy oil reserves in Canada. Many of these incorporate steam injection to help reduce viscosity and therefore improve the in-situ now characteristics of the oil. Requiring extensive capital for development and operation, these projects are often limited by economic considerations.
Single Well SAGD is a new steaming technique which offers both lower completion costs and lower operating costs due to more efficient placement of the steam. In order to deliver high quality steam to the reservoir, insulated concentric coiled tubing was developed with specific thermal performance issues and completion requirements in mind.
Preliminary results from the first generation of SWSAGD completed wells have been very good. The process has been successfully implemented in a few different areas indicating that the principles of SWSAGD may be applied to a range of heavy oil reservoirs.