Identifying the water producing section of a horizontal well completed with a slotted liner in Extra Heavy Oil (EHO) proves by itself to be a challenge. Being able to isolate that same interval and selectively injecting a water shut off treatment is even more challenging. To properly isolate the selected section, the annulars (open hole / slotted liner) above and below must be sealed; those annular may or may not be filled with formation sand.

This paper describes the water shut off experience in the Sincor Field in an EHO environment. Initially, the water producing interval was identified through the use of temperature measurements performed with a fiber optic. Then the zone to be treated was isolated using cement rings placed in the annulus, combined with the use of cement retainers. Following the isolation of the zone, a gel solution that polymerizes in situ followed by a tail slurry of micro-matrix cement were selectively injected. The idea behind the treatment is to create an impermeable barrier to the unwanted water production coming from the end of the well. The well treated had an initial water cut of 85%, and after the treatment the water cut was decreased to almost zero and the oil production boosted up by a 250%, compared to hydrated production period. Additionally, the final well productivity index (PI) indicates that the treatment effectively treated only the selected section.

In horizontal wells and EHO environment, the fiber optic tool proved to be a simple and reliable technology to assess the water production zone along the drain. An associated water shut off operation using cement and gel may then be implemented to reduce the water cut and to increase significantly the oil production rate.

You can access this article if you purchase or spend a download.