An empirical model for the drilling performance prediction for roller-cone drill bits

Abstract

The drilling process is a challenge in the oil and gas industry. These challenges are usually associated with the high costs involved in this process. Technological advances in the past few years, specifically in the drilling process, have allowed the exploitation of oil and gas fields that were uneconomical before. The economic feasibility of drilling a well is directly associated with the accuracy of the plan before the drilling starts, called “well planning”. Therefore, an accurate drilling performance prediction is crucial. Usually, the approaches to drilling performance prediction are divided into two categories: physics-based and data-driven models. Physics-based prediction models, or traditional models, are based on laboratory experiments, being empirical models designed for specific types of drilling parameters. Data-driven models are based purely on data, incorporating either machine learning or the implementation of neural networks to predict the rate of penetration. de Moura et al. (de Moura et al., 2020) developed a new drilling performance prediction model that includes the founder point location for fixed cutter drill bit operations. This model was based on the physics-based prediction approach because it usually presents low complexities and good accuracy. Based on several drilling datasets, the applicability and accuracy of the new model for roller-cone bit operations is discussed. Based on an analysis of the drilling data-sets from drill-off tests and field operations, the linear relationship between the “drillability constant” of the Maurer model and the weight on bit (WOB) was confirmed. The results of this study show that the new model presented high accuracy to predict the drilling performance in 25 distinct scenarios that included roller-cone bits with diameters that varied between 63.50 and 444.50 mm and in different rock specimens with rock strength varying between 30 and 317.16 MPa. • The development of a drilling performance prediction model that includes the location of the founding point is essential for the planning of wells. • Physics-based prediction models have low complexity and good accuracy. • This model showed high accuracy for roller-cone drill bits. • The Maurer's model is restricted to predicting drilling performance before the founding point. • The drillability constant has a linear dependence on the WOB.