Modeling Frac-Hits Using Reservoir Geomechanics and Phase Field Finite Element

ABSTRACT Frac-hits can have a significant negative impact on hydrocarbon production by reducing mobility efficiency and modifying pressure profiles around wells, particularly with increased infill drilling. However, the relationship between operational fracturing parameters and frac-hit events is still not well defined. To address this issue, this study presents an integrated simulation model that combines reservoir geomechanics and phase field finite element methods to simulate frac-hits events. This model considers reservoir and fracturing parameters for multiple horizontal wells in a drilling spacing unit. It was cross-validated with Molina's (2019) analytical model and Morales’ (2020) mechanical testing apparatus, enabling the evaluation of hydraulic and mechanical interactions, such as pressure communication, fracture merging while propagation, and stress shadowing (Molina, 2019; Morales, 2020). This approach provides valuable insights into optimal well and fracture placement, fracture behavior in relation to pre-existing fractures, and the impact of operational parameters on frac-hits. Ultimately, this research represents an effective tool for improving fracture designs and mitigating frac-hits, thereby enhancing field performance. INTRODUCTION Infill well development has become a widely used strategy for hydrocarbon production in unconventional reservoirs, with an increasing number of "infill" wells being drilled offset to one or more existing producers. However, the proximity of these new wells ("child" wells) to existing producers ("parent" wells) often leads to negative impacts on production due to "fracture driven interactions" (FDI's) or "frac-hits" (Daneshy et al., 2019; King, 2012). The severity of the impact depends on factors such as well spacing and the age of the parent well (Gupta et al., 2020; Lindsay et al., 2018; McDowell et al., 2019), and impacts are highly variable between different shale plays (Esquivel et al., 2017; Gupta et al., 2020; Miller et al., 2016). Various techniques have been applied to mitigate impacts from parent/child well interaction, such as preloading the parent well by injecting into it prior to the offset frac, varying well spacing, varying fracture sequencing, cube (or tank) development, chemical treatments, refracturing, and far-field diverter (Bommer et al., 2018; Haustveit et al., 2020; McDowell et al., 2019; Miller et al., 2016; Nieto et al., 2018; Patel et al., 2016; Sani et al., 2015; Swanson et al., 2018; Vidma et al., 2018; Whitfield et al., 2018; Zhang et al., 2019). Although these strategies have been successful, there is no universal solution, as each technique comes with different costs and benefits.