Field Demonstration of a New Method of the Automation of Continuous Circulation Drillpipe Connections

Abstract

Abstract Continuous circulation technology is used to maintain constant circulation of drilling fluid in a well by enabling the rig pumps to remain on during all steps of the drillpipe connection process. Continuous circulation is a managed pressure drilling (MPD) technique; it improves drilling success for difficult high-pressure high-temperature (HPHT), narrow pore pressure/fracture gradient, and extended reach horizontal wells. Traditionally, a continuous circulation system relies on a manifold connected into the rig standpipe, which diverts flow to and from the topdrive to a side port on a sub that is threaded into the top of each drilling stand. Historically, this side port flowline is connected manually by an operator, within the rig floor red zone, in a single barrier pressure environment. To enhance safety by removing exposure to any single barrier pressure applications, a new system was developed that automates and enhances the current manual process. The automated continuous circulation system includes a connection tool that is mounted on a manipulator arm; after it is delivered to the drillstring and clamped, it will use a human machine interface (HMI) to automatically and remotely remove a threaded side port safety cap, connect the side port flowline, and control the manifold flow diversion process. The system is controlled at the HMI by an advanced software system that is capable of functioning autonomously, with operator verification steps. Internal robotic mechanisms drive the system to perform the exact steps as a human without requiring modifications to the proven continuous ciruclation sub design, all while providing instantaneous feedback to the operator located at the remote HMI. A prototype tool was assembled and successfully tested in November 2016 in the Val D'Agri oilfield region in southern Italy. With a rapid technical development cycle of less than one year in a down market, a commercial tool was developed and deployed, including the implementation of all lessons learned. This system is the first in the industry to provide threaded engagement of the side port flowline, and a successful undermount delivery arm. This paper presents results from more than 1,000 diversion connections in both laboratory and field environments. With a 10-year track history of the manual system, the automated system enables the operator to improve upon proven technology to safely deploy continuous circulation capabilities in offshoreapplications, from fixed platforms to floaters, in areas with strict industry certification regulations, personnel in red zone limitations, and double pressure barrier requirements. The system reduces overall added connection time from typical manual systems, increases safety, and maintains the benefits of continuous circulation to reduce nonproductive time (NPT) and total drilling days.