Mathematical modeling of casing exit windowing by swirling abrasive jet

Abstract

Casing windowing constitutes a pivotal operation in the functionality of short-radius horizontal wells aimed at harnessing marginal reservoirs. The swirling abrasive jet (SAJ) windowing technology emerges as a notable candidate for windowing processes, distinguished by its rapid cutting abilities, elevated safety standards, and benign environmental impact. Nonetheless, the absence of comprehensive theoretical inquiry has obscured the understanding of the SAJ windowing mechanism, and the parameter selection process remains devoid of a theoretical framework, thus impeding its practical deployment. This investigation introduces a mathematical model for SAJ windowing, incorporating the influence of both jet and nozzle structural parameters on the efficiency of the windowing process. Specific jet parameters examined include jet pressure, standoff distance, and abrasive concentration, while nozzle characteristics are defined by nozzle diameter and impeller outlet angle. The theoretical model's fidelity is substantiated through experimental validation. Findings indicate that windowing duration diminishes exponentially as jet pressure, abrasive concentration, nozzle diameter, and impeller outlet angle increase, whereas the windowing diameter exhibits a linear augmentation with standoff distance and impeller outlet angle enhancements. Optimal conditions were identified as a jet pressure of 15 MPa, standoff distance of 35 mm, abrasive concentration of 5%, nozzle diameter of 4 mm, and an impeller outlet angle of 39°. This research furnishes theoretical underpinnings for parameter selection in the SAJ casing exit window cutting technique.