Model Predictive Control of Flow and Pressure in Underbalanced Drilling

This paper presents a novel application of linear model predictive control (MPC) for pressure and flow control in underbalanced drilling operations. Coordinated control of pump flow and choke pressure is used to control the return flow rate, and the well pressure profile. The control system is verified using a high fidelity drilling simulator for some common drilling operations. The proposed solution shows promising results for operations close to the selected set-points, but the simple models employed have distinct limitations. The control solution is easily extendable to larger control problems, and can be augmented with better models.