A year ago, this feature noted the continued languishing of crude-oil prices and the low margins in tight and very tight reservoir asset developments and the resulting substantial reduction in new-well drilling and completion. Little has changed since then. In the meantime, technology advancements have enabled a greater number of hydraulic fractures in long horizontal completions in such reservoirs, for example, resulting in more-cost-effective completions and greater initial oil-production rates. But low primary oil recovery and steep initial-production-rate declines still present overriding limitations. These tight and very tight oil-bearing reservoirs are typically characterized by oil-recovery factors of approximately 10%. However, on a positive note, in addition to improvements in completion efficiencies, recent advancements also have been made in the understanding and application of enhanced-oil-recovery (EOR) methods in such reservoirs.
While enhancing oil production from multizone, hydraulically fractured completions in tight reservoirs is not straightforward, recent studies, including field trial programs, have shown that applications such as gas injection and waterflooding, including smart water injection, have the potential to create significant improvement in oil recovery.
The three papers featured this month are from Canada. All address the importance of wettability and wettability alteration in improving sweep efficiency and oil extraction by use of gas injection or water injection. Both laboratory studies and field application, in the case of waterflooding, are discussed. Each, with their unique perspectives and approaches, provides understanding of EOR fluids; formation interactions; and the benefits and present limitations of gas injection, conventional waterflooding, and smart water injection.
SPE 185037 EOR in Tight Reservoirs—Technical and Economic Feasibility by K. Joslin, Computer Modelling Group, et al.
SPE 185680 Compositional-Simulation Evaluation of Miscible-Gas-Injection Performance in Tight Oil Formation by Ahmed Mansour, Texas Tech University, et al.
SPE 180284 The Use of Propellants To Stimulate and Enhance Productivity From Tight, Damaged, and Low-Quality Reservoirs by J. Gilliat, Baker Hughes, et al.
New-Frontier Reservoirs II
Leonard Kalfayan, SPE, Global Production-Engineering Adviser, Hess Corporation
01 October 2017