Modeling Frac Hits: Mechanisms for Damage Versus Uplift

Abstract

Parent/child interactions pose a critical challenge for oil and gas shale producers (Roussel et al., 2013; Yaich et al., 2014; Rimedio et al., 2015; Miller et al., 2016; King et al., 2017; Dhuldhoya and Dusterhoft, 2017; Cipolla et al., 2018; Whitfield et al., 2018; Rainbolt and Esco, 2018; Lindsay et al., 2018; Gale et al., 2018; Scherz et al., 2019; Guo et al., 2019; Jin and Zoback, 2019; Kumar et al., 2020; Zheng et al., 2020; Gupta et al., 2020). The industry has progressed significantly in its understanding of causes and mitigation. However, important uncertainties remain. Fracture driven interactions or more commonly, "frac hits", exhibit varied behaviors in different basins. In the majority of basins, parent wells exhibit production loses after a frac hit. We examine and contrast a case study in the Bakken where production uplift occurs to observations of production loss in a STACK case study in Oklahoma. We show the productivity enhancement in the Bakken case study is driven by proppant transport and fracture conductivity amplification, with no apparent skin or conductivity damage. This suggests that absent specific damage mechanisms, frac hits alone can improve productivity via repressurization and increased propped area. In the STACK case study, fracture conductivity damage reactions must be introduced in order to match the historical data. This suggests that in the STACK, and perhaps other basins, additional processes are occurring in the subsurface to hinder the productivity of wells after frac hits. We postulate that minerology, petrophysics, and reservoir condition differences between basins causes differences in impacts of the fracture driven interactions.