Research On Decision-making Of Key Equipment Renewal Of Offshore Oil Platform Based On Reliability

In the field of offshore oil,the maintenance and update of equipment are special.Limited by technology,tools,site and other conditions,offshore operators can only carry out simple maintenance.In case of serious failure,they must request technical support from engineers or dismantle the equipment for repair.Therefore,compared with land production enterprises,the equipment of offshore oil production platform needs higher reliability.In the management of key equipment,there are some problems,such as the lack of operability of the existing key classification methods of equipment,and the evaluation methods of renewal schemes are mostly based on experience.Therefore,this paper takes a platform in the east of the South China Sea and its ups update project as an example to study the equipment criticality evaluation and the key equipment update decision-making method.It is found that the key equipment of offshore oil platform mostly adopts a combined cold/hot standby system,including UPS,export pump,crane,etc.The average start-up time availability of key equipment is generally between 0.99974 and 0.99993.The key factors affecting the decision-making of offshore oil platform equipment renewal are the availability of equipment and the annual output of the platform.Therefore,the decision-making idea of platform key equipment renewal is to calculate the expected annual average cost of the equipment based on the availability of the equipment and the downtime loss,so as to obtain the most economic renewal plan through the comparison of the annual cost minimum method.The key point of operation is to collect the historical failure records of old equipment and new equipment in the market,and determine the output and decline rate of the platform.On the 30 old platforms with low output that have been put into operation for more than 15 years in China,when the availability of equipment has not significantly deteriorated,it is suggested that the expected purchase cost of new equipment should not be more than 2.21 million yuan.In the practice of UPS system renewal project,it shows that the method of minimum equipment renewal decision based on the expected annual average cost of availability is feasible and effective.In this project,compared with the original factory,the optimized domestic overall replacement scheme reduces the expected life cycle cost by 1.06 million yuan,with a cost change of 38.4%.The case study shows that the sensitivity of the expected annual average cost of equipment renewal scheme to the change of repair rate ? is 1.33,and the sensitivity is the highest.Therefore,it is suggested that no matter what the decision-making results are,measures should be taken to reduce the expected average repair time of new equipment by integrating the maintenance resources of manufacturers,absorbing the maintenance experience of other oilfields,training field personnel and preparing accessories in advance,so as to improve the repair rate and ensure the economy of the renewal scheme.