DOI: 10.5593/SGEM2014/B11/S6.102


C. Saiwan, R. Prurapark, A. Klayhan
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-07-0 / ISSN 1314-2704, June 19-25, 2014, Book 1, Vol. 1, 785-792 pp

Directional drilling reduces the number of vertical wells needed, thus reducing
operation time. It is a way to economically access and produce of unconventional
resources such as shale oil, shale gas, tight oil, etc. However, torque and drag (T&D) is a limiting factor in directional drilling because drilling equipment can be damaged prior to reaching a target depth due to excessive T&D. Therefore, T&D analysis is an essential in the well planning phase to insure efficient, economical, and safe planning. An advanced technology using process and simulation of T&D during drilling has extraordinary potential to improve drilling performance and reduce unexpected risks and drilling costs. In this study, T&D analysis was performed using a soft-string model to develop program via the graphic user interface (GUI) of MATLAB. The program can run multiple scenarios of operation modes: rotating off-bottom, rotating on-bottom, pulling out of the hole, and running into the hole; and then update well planning at the site with real-time data to rapidly improve operation efficiency. Furthermore, it can be applied to almost all wellbore types, such as build, hold, drop, and horizontal. The well trajectory can be illustrated in three-dimension. Additionally, the normal contact force, axial force, buckling and torque can be presented in graphical form. This program has the capability to evaluate an example field in Thailand with a reasonably accurate prediction of T&D values, including reduced drilling operation risks, such as bucking, stuck pipe, and wellbore instability. The program can detect torque measurement with greater accuracy which is rarely available, and also help determine a more accurate confined compressive strength (CCS) that can be used to evaluate the rock formation from the drilling parameters. This program is also user friendly. A user can predict T&D values through wellbore data and drilling parameter input. Consequently, it will help engineers identify feasible well designs and define drilling limitation for particular field developments as well as provide data for the new wells in the same field with improved efficiency and safety, while protecting health and environment.

Keywords:torque and drag, well planning, directional drilling, horizontal drilling,