Anti-collision analysis has been becoming even more important in the past few years with the increasing amount of wells drilled in highly congested fields. The separation factor (SF) is a critical safety parameter to avoid wellbore collisions, where the pedal curve method (PCM) is the commonly used way for the SF calculation. However, such method may be conservative in many situations and possibly triggers an unnecessary early stop drilling due to its conservation. In this study, our work aims to evaluate and compare the different types of the SF models. In addition, an alternative and supplement method of the PCM, called as elliptic cylinder of uncertainty (ECoU) method, is proposed. The radius of the ECoU considers the distance of the intersecting points of the center-to-center line and the cylinder surfaces of both reference and offset wells. By introducing the cylinder surfaces into the SF calculation, it could extend the collision avoidance along the whole well path to reduce multiple-points collision possibility. The findings in the study help us for better understanding of the SF analysis and also show that using the ECoU indication has a great potential in fields applications as a viable method to keep the drilling operations’ safety.
Tripping, the process whereby a string is moved in either axial direction makes up 30% of the well construction time and is therefore responsible for a significant portion of capital expenditure by operators. Typically, the focus in the industry in optimizing this segment of the operation has centered on minimizing the slips-to-slips connection time. This references the time taken to swing in and make-up, or breakout and rack-back a stand before engaging elevators to either run-in or pull-out with the next component. This required both human-process optimization through training and technological development of topside equipment, first in isolation and then through systems automation. This paper recognizes these optimization efforts but identifies additional potential to significantly reduce invisible-lost-time (ILT) during tripping operations even further by reducing out-of-slips running time in tripping operations, all while keeping wellbore pressures within the safe operating envelope. Physics-based steady-state fluid dynamics models have been in use for decades to define boundary conditions for these operations. These swab and surge calculations output a velocity limit for moving pipe. Models that are more complex have begun to diffuse into the commercial environment over the last decade and enhance borehole protection by providing a coupled acceleration limit. Acceleration and velocity are inherently linked so an optimization must be performed to arrive at the optimum velocity-time curve. In this paper we present real-time engineering simulations to create a digital twin of the downhole environment and calculate optimum tripping parameters for every stand. The parameters are then passed as set-points to automated rig control systems. The paper summarizes the physics-based modelling as well as the mathematical optimization. The system, including interfaces required to implement control in the context of drilling systems automation is also described. Field examples are presented whereby exposing actual real-time measurements and derived tripping boundary conditions in an intuitive, accessible user interface can lead to performance improvements. The ability to calculate the optimum velocity-time curve is the essential ingredient in gaining efficiency while out-of-slips during tripping operations, and simultaneously staying within a safe operating envelope. The resulting reduction in invisible-lost-time demonstrated, and associated reduction in rig time has obvious financial implications for operators and increasingly more important, helps achieve critical ESG targets. Finally, the paper will touch the need, and applicability of such technology in the energy transition new frontiers, specifically geothermal.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.