Project Description

SPE 167788 Liquid-Rich Shale Versus Conventional Depletion Performance

Curtis Hays Whitson (Norwegian University of Science & Technology) | Guowen Lei (FMC Technologies) | Nan Cheng (Statoil)

SPE/EAGE European Unconventional Resources Conference and Exhibition, Vienna, Austria, 25-27 February 2014

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Description

This paper describes the major differences in production performance between liquid-rich shale reservoirs (LRSRs) and conventional reservoirs undergoing depletion recovery. We “map” the transition from conventional depletion performance (oil recovery and producing GOR) to “shale” depletion performance in terms of permeability. The recent research showed that depletion performance for LRSRs is fundamentally different from conventional reservoirs, which is well documented in the literature. This paper attempts to answer the questions – what differentiates conventional from (ultra-tight) shale depletion performance, and when is conventional performance invalid?

Application

Our understanding of LRSRs depletion performance is only now being understood, based on modeling studies and field performance. Quantifying differences in LRSRs depletion performance from conventional reservoirs is important for proper engineering and development of these new resources. Production forecasting and recovery enhancement is a direct result of quantified depletion performance.

Results, Observations, and Conclusions

In this study we compare depletion performance for permeabilities ranging from 10nD to 10D, with PVT and rock properties being the same for all cases. We define a similar “economic” well performance for each permeability-case studied. Our results show that conventional reservoir performance, depending somewhat on initial fluid system, is observed for k>0.5md, while ultra-tight “shale” performance is found for k Significance of subject matter