An Integrated Well Performance Study for Shale Reservoir Systems - Application to the Marcellus Shale

Abstract

In this work we focus on the integration of two independent analyses, time-rate analysis and model-based production analysis, as an approach to resolve the uncertainty in estimating ultimate recovery (EUR) for wells in unconventional reservoirs. In particular, we seek to establish a relationship between time-rate parameters from modern time-rate models and the reservoir and completion properties obtained from model-based production analysis. Establishing agreement between these independent analyses will support the practice of EURs in unconventional reservoir systems.

In this work we provide a study of 55 (fifty-five) shale gas wells taken from the Marcellus shale (USA), complete with an integrated workflow of model-based production analysis and time-rate analysis accompanied by a discussion of challenges and methodologies. In addition, we present a study on pressure transient analysis (PTA) for selected pressure buildup tests conducted on a series of Marcellus shale wells. We include field cases complete with orientation, diagnostic, and analysis plots; as well as commentary on the observed behavior of the pressure transient tests themselves and what these pressure buildup tests may yield with regard to insight into the well/reservoir that production data in isolation cannot provide.