Abstract:
Torque and drag (T&D) analysis is considered essentially in the well planning phase to ensure the efficient, economical, and safe planning, especially in directional drilling because drilling equipment can be damaged or buckled prior to reaching a target depth due to excessive T&D. The T&D analysis was performed using a soft-string model to develop software via the graphic user interface (GUI) of MATLAB. The software runs multiple scenarios of operation modes, rotating off- bottom, rotating on-bottom, pulling of the hole, and running into the hole. The well planning can be updated with new data to rapidly improve the operation efficiency. Furthermore, it can be applied to almost all wellbore types, such as build, hold, drop, and horizontal. The well trajectory model can be illustrated in three-dimension. The normal contact force, axial force, buckling and torque can be presented in graphical form. Additionally, the effect of weight on bit (WOB), density of drilling fluid (DF), and heavy weight drill pipe (HWDP) on T&D values at the surface were investigated by the software. The increase in WOB increases the axial force and torque at the surface as the same as the direction of the HWDPs placed. While the axial tension force was increased due to the increase of MW. the torque of rotating on-bottom at the surface was decreased. These effects will also help avoid the buckling problem. The software was also evaluated T&D values using the actual field data in Thailand with the reasonably accurate prediction.
