Abstract
Pursuing more cost-effective well construction and reduced surface footprint has prompted Western Canadian operators to explore extreme extended reach drilling (ERD) wells. However, this endeavor faces a critical challenge: most heavy oil reserves are relatively shallow, resulting in the unwrapped reach ratio (the total horizontal length when projected on the horizontal plane to true vertical depth (TVD)) of more than seven. Therefore, to drill ERD wells, two crucial technical challenges must be tackled: successful liner installation, and efficient steam distribution along these long laterals to enhance production.
This paper delves into the solutions for these challenges and a case study showcasing the recent drilling of a steam-assisted gravity drainage (SAGD) extreme ERD well. While floating liners are a known method for extending well reach, they are uncommon in SAGD wells. However, some companies have started exploring the use of floating liners in SAGD projects due to their potential to greatly expand lateral well length, reducing footprint and increasing the oil recovery from any one well pair. By floating the liner using plugged flow control devices (FCDs), gentler running procedures can be employed to achieve TD without risking the integrity of the liner. Moreover, utilizing FCDs in floating liners improves steam conformance and oil production while reducing the cumulative steam oil ratio (cSOR) during the production phase.
Modeling results can enhance our capabilities in planning shallower SAGD wells with longer productive sections in the future, with (as described herein) horizontal liner lengths of 1700m and true vertical depths of 240m. The modeling results show that floating liners using plugged FCDs reduce torque by an average of 22% and bottom hole torque by 28%, while also decreasing drag by 16% on average, and bottom hole drag by 17%. These findings indicate that floating liners with plugged FCDs offer a promising solution for SAGD and CSS extreme ERD wells limited by liner installation forces. Furthermore, wells with FCDs in uplifted cases displayed a remarkable upswing of 57%, while concurrently, cSOR demonstrated a noteworthy decrease of 18%. Uplifted cases are identified when wells were completed or retrofitted with FCDs and showed increased oil production compared to neighboring wells.
The successful implementation of floating liners with dissolvable or meltable plugs on FCDs enhances confidence in future SAGD extreme ERD wells. The implementation of FCDs in extreme ERD well designs could contribute to reduced greenhouse gas (GHG) emissions, aligning with efforts to combat climate change and minimize environmental impacts. The study's findings elaborated on driving paradigm shifts in the development of heavy oil resources as technology advances, while considering economic factors.
