Tapered Tubing Well Completion for Enhanced Production: a Study of Internal Diameter Tubing String

Conventional Well Completion involves usually a single, internal diameter (ID) tubing for producing oil from the subsurface reservoir. As the oil flows vertically upward, the flowing pressure decreases as a function of depth. This reduction in flowing pressure causes more and more dissolved gases to come out. Consequently, the flow stream, especially free gas, expands in volume per unit mass flow rate. The motivation of the present study is to investigate the effect of gradually increasing the tubing inside diameter (ID) as the fluid moves up the string. We call this Tapered ID Tubing Well Completion (TTWC), which is expected to give higher flow rates of oil. Thus, we performed numerous studies using nodal analysis for various tubing size combination, and also economic analysis over the entire producing life of the well. The study reveals that the higher flow rates possible through TTWC not only offsets the additional capital expenditure, butalso gives significant economic benefits compared tothe conventional single tubing completion.