Integrated Analytical Trajectory Control Model

Abstract

Abstract Typical trajectory-monitoring models only consider the geometrical approach, without considering the rock mechanics and operational constraints in a single algorithm. Trajectory corrections could compromise the wellbore stability and drilling efficiency. For this reason, an integrated analytical model is needed to couple the trajectory-control model with the rock mechanics and mechanical, rotational and hydraulic effects in the trajectory correction. This integrated approach allows to visualize the "big picture" when returning to the designed well path. The paper provides a roadmap so that the directional driller can use in the field in real-time. The geomechanics validation ensures that the wellbore stability is not compromised so that the correction results in trouble-free drilling. The HMSE evaluation enables to analyze the drilling efficiency in terms of mechanical, rotational and hydraulic energy to identify dysfunctions and other operational causes and effects on the trajectory. To validate the integrated model different deviation scenarios are simulated using the information of real wells already drilled. The results have proven that the smoothest correction path calculated is not always the best path as it may result in operational problems. The use of this integrated model allows to anticipate and mitigate operational problems which translate in improved drilling efficiency. This paper aims to bridge this existing knowledge gap and provides a comprehensive treatise on well trajectory control and, more in general, estimations and their underlying model parameters. The paper describes the details and the new calculation methodology of coupling these various models. The paper presents specific field examples with and without these models where there were wellbore stability problems.