Booking reserves for unconventional, multi-frac wells is a critical business process, but to be done effectively, often requires significant time investment and multiple interpretation techniques. Although reserves can be estimated quickly with decline curve analysis (DCA) alone, the subjectivity in DCA makes it challenging for evaluators to estimate reserves with appropriate levels of uncertainty and maintain consistency between evaluators. The objective of this paper is to present a fast, systematic, yet rigorous methodology for estimating 1P, 2P and 3P estimated ultimate recoveries (EURs) for new wells. This methodology utilizes regression to correlate easy to obtain, early life indicators of well performance to 2P EURs, which have been estimated from more detailed interpretations. Multiple methodologies are presented for estimating 1P and 3P EURs.
Number of Pages
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Clarkson, C.R. 2013. Production data analysis of unconventional gas wells. International Journal of Coal Geology Volumes 109–110, 1 April 2013, Pages 101–146.
McDonald, Ian. 2019. Estimated Ultimate Recoverable (EUR) vs Technically Recoverable Resources (TRR). CNOOC International. Presented at SPE Workshop: Petroleum Resources Evaluations and Reporting: In Pursuit of a Common Understanding. May 2019.
Society of Petroleum Engineers. 2018. Petroleum Resources Management System.
Society of Petroleum Evaluation Engineers. 2016. "Estimating Ultimate Recovery of Developed Wells in Low-Permeability Reservoirs", Monograph 4.
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