Optimizing Recovery in Unconventional Reservoirs by Advancing Fishbone Drilling Technology in the Bakken Formation, Williston Basin

Abstract

ABSTRACT: The integration of multi-stage hydraulic fracturing and extended horizontal drilling has markedly advanced oil extraction from the Bakken tight oil reservoir, a prominent unconventional reservoir in the United States. Despite these technological strides, the primary recovery rates from this tight formation have remained suboptimal, leaving a considerable volume of oil unrecovered. This challenge underscores the necessity for innovative Enhanced Oil Recovery (EOR) methods tailored to the unique conditions of the Bakken formation. While CO2 injection has been explored, its effectiveness is limited by the formation's heterogeneity. This study introduces an innovative approach through the application of Fishbone Drilling (FbD) technology, aimed at enhancing recovery efforts in the Bakken formation. Our investigation reveals that FbD, characterized by multiple minor holes branching from the main wellbore, significantly improves hydrocarbon recovery by enhancing reservoir contact and exploiting the existing natural fractures more effectively than traditional methods. The findings indicate that FbD not only promises an increase in hydrocarbon flow but also, through optimization of design parameters, aligns with economic viability over time despite higher initial costs. This paper presents a comprehensive analysis of FbD's optimal design and its efficacy in the Bakken formation, supported by data-driven insights that validate the technology's potential to revolutionize EOR strategies in unconventional reservoirs. Through detailed numerical simulations and comparative analyses, this study highlights the superior performance of FbD over conventional drilling and fracturing methods, proposing a promising avenue for future exploration and development within the unconventional reservoirs. 1. INTRODUCTION The quest for enhanced oil recovery (EOR) techniques in unconventional reservoirs has been a pivotal focus within the energy sector, driven by the imperative need to optimize hydrocarbon extraction from formations like the Bakken tight oil reservoir (Almousa et al., 2023a). Located in the Williston Basin, one of the United States' most expansive unconventional reservoirs, the Bakken formation presents a unique set of challenges and opportunities for EOR strategies (Helms et al., 2023). Hydraulic fracturing and re-fracturing contributed heavily in the oil and gas production in the Bakken as reported by (Dehdouh et al, 2023a). Despite the significant strides made through the integration of multi-stage hydraulic fracturing and extended horizontal drilling, these conventional methods have only marginally improved the primary recovery rates in such tight formations. This scenario underscores the substantial volume of oil that remains untapped, highlighting the critical need for innovative approaches to EOR as detailed by Merzoug et al. (2024).