Application of Torque and Drag Models to Prevent Real-Time Operational Problems

Abstract

Real-time drilling data is an essential tool to increase performance and operational safety, especially when operating in challenging environments. In this scenario, it is highly attractive to use new tools that can anticipate possible risks to the operation, aiding in decision making in order to guarantee operational efficiency and safety. The present work aims to present the new technologies developed in a real-time monitoring software (GANDELMAN ET AL., 2013), which automatic diagnosis drilling problem, from the calculations of loads alongthe drill string and the contact of the column with the borehole wall. Torque and drag models are used to support well planning. The aim is to ensure the feasibility of theoperation and to assist in the prediction and prevention of operational problems during drilling. Directional wells require even more attention, since, as their inclination increases, additional forces are observed due to the enhanced contact of the drill string with the borehole wall. Since these forces are cumulative, the deeper the well, the larger will be the contact forces and, consequently, the torque and drag values. A comprehensive torque and drag model was implemented to estimate the wear level on the casing, in real-time, due its contact with the drillstring. The purpose of this development is to automatically warn when the calculated wear approaches the expected and / or permitted wear. Still using the T&D model implemented in the real-time monitoring software (GANDELMAN ET AL., 2013), a module was developed for a more accurate detection of the tubular element that is passing through each of the BOP (blowout preventer) rams when drilling from floating vessels. The main objective of this new technology is to assist the operation in a possible emergency disconnection. The main focus would be to precisely define the moment to actuate a RAM, minimizing the risk of reaching a non-shearable component of the drillstring. Therefore, a logic of tracking each element of the column in front of the BOP rams was created, which takes into account the effect of axial elongation due to real-time tension and compression.