Patent ID: 8528638
Filing Date: 2013-09-10
Classification: E21B

Abstract:
1. A method for steam assisted gravity drainage production, comprising: a) drilling, casing and inserting a tubing string in a wellbore; b) perforating both an upper portion and a lower portion of the casing and forming an upper horizontal fracture and a lower horizontal fracture to establish communication between the wellbore with the upper horizontal fracture and the lower horizontal fracture; c) inserting a retrievable packer or a seal assembly horizontally between the tubing string and the casing and vertically between the upper horizontal fracture and the lower horizontal fracture for isolation; d) injecting steam into the wellbore both into the upper horizontal fracture and the lower horizontal fracture; and e) producing heavy oil from the lower horizontal fracture while injecting steam into the upper horizontal fracture and maintaining subcool drainage control to prevent steam production through the lower horizontal fracture that would otherwise occur due to distance between the fractures without the subcool drainage control.