Major Sources of Uncertainty in Geochemical Production Allocation, and Some Mitigating Strategies, in Unconventional Plays

Abstract

Allocation of production, using the compositions of the contributing fluids and the aggregate production streams, is a mature technology in conventional fields worldwide, particularly in offshore fields (Kaufman et al., 1987 and 1990; Hwang et al., 2000; Milkov et al., 2007; Dolle et al., 2007; Chuparova et al., 2010; Elsinger et al., 2010; Schafer et al. 2011; McCaffrey et al., 2010 and 2011; Van Bergen and Gordon, 2018). In onshore unconventional plays, this technique can enable a clearer picture of the subsurface, and effectiveness of engineering decisions in accessing reserves (Kornacki et al., 2017; Liu et al., 2017). For example, it can enable the deductions of fracture height, contribution from particular formations, impact of re-stimulation activities, and interference from adjacent penetrations (Jweda et al., 2017; Lareau et al., 2016). Despite the potential for impact on a range of development decisions, there remains significant scope for wider adoption among operators. There are several reasons for this under- utilization, one of which is the uncertainty inherent to unconventional prospects, which, unless considered in interpretations, can lead to conclusions which are equivocal at best, or misleading at worst. Uncertainty (error) in data exists independent of the efforts to characterize and quantify it. However, unless steps are taken to assess and minimize these uncertainties, the associated scatter propagates to any models calibrated with these datasets, and to the business decisions informed by those models. This paper discusses the options central to identification and mitigation of the main uncertainties: core and production sample planning, sample handling hygiene, and integration of petrophysical and production data in interpretations.

AAPG Datapages/Search and Discovery Article #90349 © 2019 AAPG Hedberg Conference, The Evolution of Petroleum Systems Analysis: Changing of the Guard from Late Mature Experts to Peak Generating Staff, Houston, Texas, March 4-6, 2019