Evaluating Extended Needles Designs in Fishbone Stimulation Technology: Impact on Oil Production Across Heterogeneous Tight Reservoir

Abstract Fishbone stimulation technology represents an innovative approach to enhancing oil recovery in tight formation reservoirs by improving permeability and reservoir connectivity. Acknowledging its potential, this study aims to propose and evaluate new fishbone designs by increasing needle lengths from 40 feet to 60 feet and 80 feet. The objective is to determine the optimal needle lengths and spacing configurations that maximize hydrocarbons production across different reservoir permeability ranges. Numerical reservoir simulation models were utilized to model two fishbone wells within different needle lengths (40 feet, 60 feet, 80 feet) and corresponding distances between needles in a benchmark reservoir model. A multilateral approach and Local Grid Refinement (LGR) was employed to accurately represent the complex geometry of the fishbone wells. The simulations were conducted across heterogenous reservoir with different ranges of permeabilities to assess performance of each design under different geological conditions, focusing on cumulative oil production. The simulation results indicate that in low-permeability reservoirs, the original fishbone design with 40 feet needles and 40 feet spacing is more effective in enhancing oil production compared to new designs with longer needles. The shorter needles allow for an increased numbers of subs and needles, enhancing connectivity and improving in oil recovery in tight formations. These simulation results were over the 10-year simulation period. As reservoir permeability increases, the difference in cumulative oil production between the new suggest design (60 feet and 80 feet needles) becomes marginal. The extended needle lengths did not significantly enhance production, indicating that longer needles may not be economically justified in such scenarios. The study concludes that the effectiveness of fishbone stimulation design is highly dependent on reservoir permeability. For low-permeability reservoirs, increasing the number of shorter needles can lead to more efficiency in terms of oil production, while in higher-permeability reservoirs, longer needles do not provide substantial advantages. These findings assist in optimizing fishbone well designs to improve production efficiency and cost-effectiveness. This study introduces a novel exploration of extended needle lengths and provides new insight into optimizing fishbone stimulation technology by traditional and extended needle lengths, emphasizing their impact on production efficiency in tight formation reservoirs. By demonstrating when longer needles may not offer significant benefits for enhancing hydrocarbon recovery. This contributes to the existing literature and offers practical guidelines for engineers optimizing well designs in tight formation reservoirs.