Reliability of Power Supply in Remote BGV/RGV Stations Along the Pipeline, a Key Factor for Arctic Pipelines Operation

Abstract

1. INTRODUCTION One of the most serious problems in strategic pipeline projects is the need for reliable power for unattended stations in the severe environments under which these pipelines must continuously operate (temperatures as low as −55°C (−67°F) in winter, roads to the stations inaccessible for long periods of time making the stations inaccessible for maintenance crews, etc). The objectives for high reliability in RGV operation, telecommunications, cathodic protection and SCADA systems in strategic projects have become staggering. In areas not serviced by commercial power, the problems faced by the power systems designers are very stringent since power generators must operate continuously on a 24 hour-per-day basis 365 days per-year. The high reliability of the power supply in remote stations along the pipeline can be achieved by:–Selection of the most reliable remote power generators–Providing adequate redundancy of power generators Telecommunications, SCADA, cathodic protection facilities along oil and gas pipelines are mission-critical, carrying vital performance, telemetry and control data. The use of specially designed, arctic type, Closed Cycle Vapor Turbogenerators and their associated non-electric heating systems in arctic telecommunication systems has solved two of the most stringent problems of the pipeline operators: reliable remote power up to 4 kW is provided with maintenance requirements reduced to a visit only once in 6 months or more, and required temperature ranges in equipment shelters are maintained, assuring correct operation of the sensitive electronics, without any need of electrical power. This paper reviews the key criteria to consider in selecting power solutions for remote site applications and CCVT performance is reviewed. The paper goes on to present case histories, including the Alaska pipeline, that demonstrate the field reliability and performance of CCVTs over the last thirty five years. 2. CRITERIA FOR SELECTING POWER SOLUTIONS FOR REMOTE SITES There are a number of critical parameters which must be assessed when selecting a power solution for a network or a specific remote site. Reliability. Because these critical remote sites are difficult (and expensive) to reach - or are inaccessible for part of the year, reliable operation is extremely important. Reliability is typically measured in terms of Mean Time Between Failure (MTBF). CCVT technology has a proven performance history, demonstrating over 200,000 hours MTBF for the turbine and 30,000 hours MTBF for the entire system. These data are based on thirty seven years of field experience.