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

摘要

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 with foam in vertical wells while keeping the bot-tomhole pressure at minimum. The new method can be easily used in the field to determine the best combination of gas-/liquid-injection rates and total-bit flow area (i.e., jet-nozzle sizes), such that the maximum drilling rate is achieved.