Machinery Vibration on Offshore Platforms
Authors: Monk R.G. 
Published: December 2007

Machine failures can be prevented by regular monitoring of machine vibration levels. This paper presents details of recent field experiences indicating quantitatively that regular monitoring reduces equipment failure and increases equipment reliability.

Introduction

Useful inspection techniques developed recently are condition monitoring, particularly vibration monitoring and analysis of operating equipment.

These techniques were developed mainly by the oil and petrochemical industries. For long-term, continuous operation of machinery, they saw the advantages of detecting incipient failures in machinery without frequent shutdown and inspection. Correct application of the techniques has led to a reduction in the number of machinery breakdowns in onshore installations. This reduction, in turn, yields considerable cost savings inthe production sector, where unplanned shutdown time caused by inoperative equipment virtually can be eliminated, andthe maintenance sector, where repair costs are reduced because of fewer breakdowns.

Fewer breakdowns, particularly in hazardous areas, mean less risk of fire or explosion, which leads to improved safety standards, This benefit from vibration monitoring is considered rarely, but is of vital importance in today's emphasis on safety. All these benefits are important to offshore installations, and operators should be aware of the financial and engineering advantages gained from using vibration monitoring.

However, the approach to vibration monitoring in onshore installations is not uniform and there is no single philosophy that can be defined and applied directly to philosophy that can be defined and applied directly to offshore platforms. Major differences exist in the dynamic environment offshore that significantly affect the technology.

This study describes vibration monitoring programs onshore and machinery vibration investigation for offshore installations. Based on this experience, we have developed a rationale for machinery vibration monitoring on offshore platforms.

Philosophy Behind Vibration Monitoring Philosophy Behind Vibration Monitoring A recent survey estimated that for industries with a high capital investment in plant and machinery per employee and with a high added-value output per employee, condition monitoring in general and vibration monitoring in particular can save about 1 percent of the total added-value particular can save about 1 percent of the total added-value output per year. Of this saving, approximately 65 percent will be related to output and 35 percent will be percent will be related to output and 35 percent will be related to maintenance.

The oil industry both onshore and offshore has a high added-value output per employee, with much processing equipment per location, including centrifugal pumps, fans, compressors, and generator plants. This makes it an ideal industry to apply vibration monitoring. Because of the extremely high, unscheduled downtime penalties, increasing maintenance costs, and decreasing margins, investment in vibration monitoring is becoming more essential. Protection of productive capacity is usually the most important application for vibration monitoring, and operating equipment for a refinery can be categorized in ten-ns of priority to production.

Critical Equipment

Turbo-compressors and generators are the most important equipment and are used unsparingly. Any breakdown of this critical equipment would cause a total loss of plant throughput.

JPT

P. 627