The Continuous Circulation System—From Prototype to Commercial Tool

Abstract

Abstract This paper follows the evolution of the Continuous Circulation System (CCS™) from the prototype to the first models available for commercial application. It reviews the mechanical and control system changes introduced following the prototype trials to make the CCS more user friendly and mechanically reliable. It also discusses the approach of the constructor to the introduction of the system to the drilling industry and its determination to provide reliable and fit for purpose equipment. Utilisation of the CCS could significantly change the way that drilling operations are carried out in certain "difficult to drill" formations. The ability to maintain uninterrupted circulation while making connections with jointed drillpipe is of considerable benefit when drilling formations where there is a narrow margin between fracture pressure and pore pressure gradients. With continuous circulation a steady ECD can be maintained and the positive and negative pressure surges, associated with making a connection under normal drilling conditions, avoided. Improved hole cleaning and the elimination of connection gas kicks can also be achieved.