The Hybrid Drilling System: Incorporating Composite Coiled Tubing and Hydraulic Workover Technologies into One Integrated Drilling System

Abstract

Historically well drilling operations have been based exclusively on steel pipe. Recently a drilling system that combines composite coiled tubing technology and hydraulic workover technology has been introduced. This paper examines the operating experience for the system and its implications for the future.By using composite pipe with embedded conductors, the system achieved uninterrupted real-time two-way communication with the downhole tools. This allowed a stepchange improvement in the knowledge of dynamic wellbore conditions and in the control over downhole systems. New procedures were developed to assimilate and use this increased functionality. These procedures include both geosteering and real-time system diagnostics from remote locations.Incorporating a hydraulic workover (HWO) jacking system as an integral part of the drilling unit also expanded the operating envelope and functionality of the entire drilling system. This revolutionary full-system development encountered numerous challenges, many of which are related to the unique properties of composite pipe in difficult hole conditions. The technological solutions to these challenges are examined in depth.