Optimization of drilling parameters using improved play-back methodology

Abstract

Drilling is one of the expensive operations in oil and gas production. The cost of drilling exponentially increases with an increase in non-productive time (NPT). Extending the drill bit life, reducing the NPT (minimizing downhole complications, round trips or bit trips, circulation time, etc.), and the total expended specific energy would reduce drilling costs. It can be achieved by increasing the rate of penetration (ROP) and optimizing drilling efficiency. This paper presents a novel approach for optimum drilling parameters based on real-time optimization of drilling rates, drilling efficiency, and bit hydraulics. And this can be visually substantiated by the play-back methodology employed on an exploratory well. To determine the inefficient drilling zones for different lithology, drilling specific energy (DSE), mechanical specific energy (MSE) was estimated at all operating conditions. The result shows that utilization of optimal drilling parameters reduces input power by nearly 75%. Further, in this study, a new metric termed hydraulic drilling impact (HDI) is introduced to optimize the drilling performance during real-time rotary drilling operations. Monitoring the HDI in actual field conditions can help the driller evaluate the ongoing drilling operation's reliability. Fallouts from the comparison disclose that the excessive energy spent for the low ROP was due to inappropriate drilling parameters chosen for a particular formation. This work can contribute to the effective and accurate evaluation of operating parameters and conditions by utilizing surface readings alone where no downhole sensors/equipment were employed. The proposed model was validated in a directional well that was drilled in the north-eastern parts of India. • The reverse-engineering technique and the input energy module are utilized to determine the optimal drilling parameters. • Surface measurements are adequate, avoiding the costly downhole sensors and equipment. • The hydraulic drilling impact (HDI) is proposed for real-time drilling evaluation. • The holistic approach can be implemented in directional wells that are driven by the potential of cost reduction.