The Medicine Hat Glauconitic C reservoir contains medium heavy oil, and was put on production in 1985. In 1993, a waterflood pilot was initiated; in 1996, several horizontal wells were drilled as producers, and they resulted in a spectacular increase in oil production. In 2001 a conventional field-wide waterflood was implemented. The waterflood included seven Toe-To-Heel Waterflooding (TTHW) modules involving 10 injectors and 18 horizontal producers, out of a total of 52 injectors and 100 producers.

Five of these modules that utilized vertical wells as injectors performed well; oil rate increased 2 to 11 times, as increases in oil production continued for several years, or stabilized. During the same period, the performance of conventional waterflood modules was characterized by reductions in decline of oil production trends. Two TTHW modules that used horizontal injectors performed similar to conventional waterflood modules.

The best performance was shown by Module # 5 (involving two horizontal producers and two vertical injectors), located in the best quality reservoir. Compared to conventional waterflood pilot area nearby, the performance of Module #5 was superior, with oil production rates increasing 7-11-folds, while in the pilot area this was only 2-3 times; the water injected/oil produced ratio was 12–15 m3/m3 for Module #5, while it was 24–44 m3/m3 for the pilot area. The incremental oil recovery due to waterflooding from the TTH module # 5 was estimated at about 7%, and 5% from a nearby conventional waterflood area.

A statistical analysis for the whole field revealed that TTH horizontal wells produced at oil rates 30% higher than the non-TTH configuration horizontal producers.

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