In this paper we will present the evolution of well construction in the Montney play, technical and economical challenges, and the new synergy developed between drilling and completions.
The financial driver that all operators are facing today is to lower well construction costs. The drilling and completions processes should not be looked at as separate entities but rather as an integrated team. This will allow for the achievement of an optimal solution for overall well construction, a solution that cannot be achieved by either discipline in isolation. This paper demonstrates the evolution of a unique completion system that lowers costs in a technically challenging area.
Case histories of two completion methods, swellable packers and cemented sliding sleeve technologies are discussed in detail. The cemented sliding sleeve systems were deployed at a field scale for the first time in North America in the Pouce Coupe area of Alberta, Canada in December 2008.
The Montney formation is a prolific tight gas reservoir located in the Western Canadian Sedimentary Basin in both Alberta and British Columbia. In the Peace River Arch area, horizontal wells with multiple fractures are the key to achieving economic success. Using various area drilling and completion techniques as a starting point, lowering the installation cost without affecting the completion or production results was the driver for the next generation of completions. Swellable packer systems with ball-drop actuated sliding sleeves were initially run in various openhole configurations to allow multiple fracture treatments to be pumped in one operation, a significant savings from multiple day operations. From these successes, a drive to further reduce costs led to cemented ball-drop sliding sleeves with a hydraulic fracture initiator sleeve at the toe of the horizontal well.
After having installed the cemented sleeves on eight horizontal wells and continuously improving the process, it has been concluded that the system can reduce drilling and completion costs by 25% when compared to swellable packer systems with intermediate casing and 50% over traditional cemented liners with perforated completions. These savings are accomplished without negatively affecting well performance. This paper will also present micro-seismic data, production logging, rate transient analysis and tracer logging comparing the openhole and cemented sliding sleeve designs. Production results to date comparing cemented stimulation sleeves to an openhole swellable packer completion system do not show any material difference favoring one method or the other.
To date, the Operator has completed six wells using cemented sliding sleeves. Initially there were various technical challenges to overcome and the confidence level has increased dramatically with the last three completions. The Operator has made continuous improvements on the first wells to overcome operational challenges and the last two wells had a combined fourteen fracture treatments that were completed in only five days.