Summary
The Bakken is one of the most prolific plays in North America, but even with the deployment of horizontal wells and hydraulic fracturing, anticipated recovery factors under primary depletion are usually in the range of 10% to 20%. Waterflooding has been a nearly ubiquitously deployed technology in conventional reservoirs to enhance recovery beyond primary depletion. However, the Bakken's ultra-tight, largely oil-wet nature limits the potential of waterflooding. Moreover, the challenges associated with sweep after the formation has been hydraulically stimulated must also be overcome. To address these challenges an optimally-spaced well to well surfactant flooding technology is proposed. Optimal well spacing, from a flooding perspective, can mitigate rapid breakthrough while minimizing the distance through the matrix that the injection fluid must travel. An optimally designed chemical system can enhance imbibition rates and favorably alter wettability to enable economic recovery. Moreover, environmental and community benefits can be realized by utilizing abundant produced water to operate a surfactant flooding process in the Bakken.
This paper discusses a comprehensive experimental program exploring the potential of surfactant flooding in the Bakken along with a field communication study and corresponding scaled-up, well-to-well flooding models for an optimized surfactant flooding process. Results from the experimental program are provided which showcase the potential of advanced chemical systems. A brief overview of a core-scale natural fracture study and field-scale well-to-well communication study is provided. Lastly, up-scaled models, showing the potential societal and economic benefits that can be attained from an optimally designed surfactant flood, are presented.
