Hydraulic Optimization of Foam Drilling For Maximum Drilling Rate in Vertical Wells

Abstract

Summary A transient-mechanistic model of cuttings transport with foam has been recently developed and solved numerically. In this study, the new model has been used to revisit the classical theory of hydraulic optimization (i.e.,maximum bit-hydraulic-horsepower/jet-impact-force criteria). A new methodology has been suggested to determine the optimum gas-/liquid-injection rates for maximizing drilling rates when drilling withfoam in vertical wells while keeping the bottomhole pressure at minimum. The new method can be easily used in the field to determine the bestcombination of gas-/liquid-injection rates and total-bit flow area (i.e.,jet-nozzle sizes), such that the maximum drilling rate is achieved.