The E_c-Factor: A New Correlation for Optimizing Completion Efficiency

The optimization of new wells completion designs will increasingly become a critical parameter for reducing development costs and maximizing wells potentials. This is particularly true as more and more reservoirs become mature with their associated complications resulting from increased water cuts and aging facilities. This paper presents a new method for optimizing the partial completion of oil wells. The optimization criterion is the minimization of well's combined skin due to the partial completion placement, the well deviation angle and the perforation skin effect. These skin components are different from the damage skin that may be negated through well stimulation. That's why the design of well partial completion is imperative. This work develops and presents simplified correlations for the different skin components associated with partial reservoir completions. The models presented employ uniform and consistent dimensionless variables. This should make the models easier to understand and apply for quantifying the flow efficiency of perforated completions. The efficiency of a partial completion design is represented here as the completion efficiency factor of a partially completed well, E _c. This efficiency factor is introduced as an optimizing parameter that can be quantified easily using the newly developed correlations as it captures all parameters affecting partially completed wells for a quick and handy way for engineers for optimizing a well completion. For any reservoir and wellbore geometry, the optimum perforation length is determined for any combination of well and perforation design.