A model-based optimization and control method of slide drilling operations

Abstract

Conventional toolface control during slide drilling is very labor intensive and time-consuming, and greatly rely on drillers’ experience, with aspects that have been described as more art than science. Optimized control of slide drilling operations can improve control performance, but most deployed methods in the field focus on utilizing historical data from regional databases to generate operation instructions, which is, however, often infeasible in new drilling blocks. In order to further improve slide drilling performance, this paper proposes a model-based optimization and control method to facilitate operations like toolface orientation setting and correction. A set of new operating procedures based on the surface rocking-pipe-assisted drilling technique are introduced in the method. For different slide drilling operations, the proposed method combines a drillstring dynamics model with different objective functions and manipulated variables to determine the best control inputs. The presented simulation case studies demonstrate that, both for toolface setting off-bottom and correction on-bottom, the proposed method can achieve control goals within a short time. A toolface change during rocking-pipe-assisted drilling can be delivered quickly, and the method can also help determine optimum surface rocking parameters to reduce friction along the wellbore. Finally, the proposed method shows a promising future in practical uses and helps the transformation from experience-based drilling to scientific drilling.