Canyon Express Deepwater Umbilical and Control System: Design and Installation

Abstract

Abstract This paper presents an overview of the Canyon Express umbilical and control system which extends 56 miles from a host platform in Main Pass Block 261 to connect three deepwater gas fields in the Mississippi Canyon and Desoto Canyon Areas of the Gulf of Mexico - King's Peak (6500 fsw), Aconcagua (7000 fsw), and Camden Hills (7200 fsw) - operated by BP, TotalFinaElf, and Marathon Oil, respectively. The Canyon Express control system is a hybrid fiber optic / electro-hydraulic multiplex system designed for 11 wells, with the primary operator interface being a dual PC Master Control Station (MCS) installed at the host facility. The umbilical system, which connects the host facility to each subsea well, provides for electrical power, signal control, hydraulic supply, chemical injection, well annulus monitoring, servicing via dedicated service line, and methanol injection (infield umbilicals only). Methanol supply to each field is via a separate Single Methanol Distribution Line (SMDL) and powered system of subsea metering valves. The paper will emphasize technical challenges and lessons-learned during the design, manufacture, and installation of this deepwater umbilical and control system. The technical challenges and lessons presented in this paper can be directly applied to future subsea oil and gas developments, particularly long offsets in deepwater. Canyon Express demonstrates that the state of technology existing in the industry today is generally in line with the control system requirements of such projects. However, improvements can be made in the design, qualification and testing of components to enhance reliability in deepwater applications. Lessons-learned on this project include issues relating to electrical and electro-optical connectors, umbilical cable terminations, chemical metering valves, and testing during installation. This paper enhances industry knowledge by focusing on the specific issues related to the successful deployment of a deepwater umbilical and control system. Specifically, consideration is given to how lessons-learned relate to system design issues such as reliability and redundancy. Component qualification, interface management, integration of umbilical terminations, installation challenges, and field fault finding, are also considered. The lessons presented can be used to improve deployment of similar systems for future subsea developments. Introduction The Canyon Express deepwater umbilical and control system, which originates from the Canyon Station platform in Main Pass Block 261, is designed to monitor and control subsea production from three deepwater gas fields in the Mississippi Canyon and Desoto Canyon Areas of the Gulf of Mexico " King's Peak, Aconcagua, and Camden Hills " operated by BP, TotalFinaElf, and Marathon Oil, respectively. Water depth along the 56-mile route varies from 300 to 7,200 feet. The umbilical and control system is comprised of the following subsystems:Surface equipment including the Master Control Station (MCS), Electrical Power Unit (EPU), Uninterruptible Power Supply (UPS), Hydraulic Power Unit (HPU), methanol and chemical injection pump skids, Topside Umbilical Termination Box (TUTB), and associated tubing, cabling and appurtenances.Subsea control pods mounted on each subsea tree and associated instrumentation.Network of twelve main and infield electro-hydraulic steel tube umbilicals, varying in length from 0.4 to 41 miles in length, complete with subsea umbilical terminations