An Analytical Model for Predicting Composite Inflow Performance Relationship (IPR) for Fishbone Drilling Technology with N-Number of Ribholes

Abstract Fishbone drilling has gained significant attention globally, with numerous applications and successes in many oil and gas fields. This technology offers a more environmentally friendly alternative to fracking, reducing induced seismic activities in critically stressed regions. In addition, fishbone wells increase production, connect natural fractures, and bypass damaged zones. However, despite its benefits, few models accurately predict production rates from fishbone wells, hindering informed technical and economic decisions. Existing models, such as Guo's, are often complex and difficult to apply, especially in new fields lacking historical production data. This study presents a simplified mathematical model, building on furui et al work, ribholes are assumed to be a conduit inclined at an angle, θ, to the horizontal in the development of the model. The analytical model combines flow in the matrix with the flow in the ribhole considering pressure drop due to friction and accumulation along the ribhole sections. The governing equations and the solution procedures are included in the work to enable readers to reproduce all results. The model was validated by applying it to the fishbone stimulation in the Austin Chalk carbonate reservoir in Texas. A reasonable agreement was observed between the field measurement and the calculated production rate using the present model outperforming both Guo's et al and A. Abdulazeem's models. The excellent result of the new model is attributed to the included pressure drop terms in its development. The sensitivity analysis of the present model showed that the angle of inclination, the number and size of the ribholes are the major variables that influence the performance of fishbone wells while the length of the ribholes have the least effect on production. Finally, the present model will ensure both technical and economic decisions are taken within the shortest time period. This model can be extended for predicting production from fishbone drilling in geothermal reservoirs.