Arp's Hyperbolic Decline Model has been widely used to analyze production data and predict long-term well performance in conventional reservoirs. Due to its simplicity, it has been used in unconventional resource plays too. Because of ultralow permeability and multistage fracturing completion in unconventional resource plays, the "b" value in the hyperbolic model is higher than 1 at the beginning of production and may last for long time, but it will eventually be less than 1. By keeping "b>1" forever may greatly over-estimate ultimate well oil/gas recovery.
Here is a poster I prepared more than 6 years ago—still keeps me excited. The poster mathematically proves and physically explains why "b>1" can't last forever. The production data from one Eagle Ford well and one Bakken well demonstrate that the "b>1" can't last forever, and instead, the “b” value reduces with time. Thus, the poster recommends the best practices while applying the hyperbolic model, and proposes a way to determine a terminal decline rate and how to build multi-segment of production decline curves with multiple “b” values.
Hongjie Xiong is the senior engineering advisor for University Lands (UL), and focuses on the well performance vs. well spacing vs. completion designs on unconventional reservoirs. Xiong is passionate about enhancing hydrocarbon recovery from unconventional reservoirs. Before joining UL/Texas Oil and Gas Institute, he was the global reservoir engineering advisor for ConocoPhillips, where his main responsibilities were to evaluate companywide exploration and field development projects, advise senior management for funding approvals and project sanctions, and provide guidelines to appraise and develop unconventional reservoirs, including Bakken, Eagle Ford, Niobrara, Permian Basin, Montney, and Horn River. Xiong’s earlier positions include manager of production optimization for Schlumberger, engineering advisor for Burlington Resources, and petroleum engineer for S.A. Holditch & Associates. He is the author of more than 50 technical papers and is an adjunct professor in the petroleum engineering department at Texas A&M University, College Station. Xiong holds a PhD in petroleum engineering from Texas A&M University.