Characteristics of shutdowns for inspection, maintenance, and renovation in oil refining enterprises

Thread Content

This post was last edited by Jinma Water Damage Control on 2025-5-16 07:47. Since the beginning of the 21st century, oil refining companies have grown in size, and competition in this industry has intensified; among them, Sinopec alone has seen the number of oil refineries with a capacity of tens of millions of tons increase from 2 to 11. CNOOC, CNPC, as well as private refineries with a refining capacity of over 10 million tons are also experiencing rapid development. From the perspective of the development of oil refining companies, current shutdowns for maintenance and renovation exhibit the following characteristics: 1) The scale of such maintenance work is continuously increasing. As competition intensifies, large-scale, multi-series, full-process operations have become a hallmark of oil refining companies. Shutdowns for maintenance have evolved from involving just one or a few units to encompassing dozens of units across the entire production process, that is, maintenance is carried out on a series of units. 2) The operating cycle is continuously lengthening. Currently, the average operating cycle for refineries in China is 3.6 years, with most having a cycle of 3 to 4 years; a few companies with excellent management can achieve an operating cycle of 4.5 years. In other words, a major shutdown for maintenance is carried out every 4 years on average. Other enterprises with multiple series and processes may conduct scheduled shutdown maintenance every 2 years. 3) The depth of maintenance increases gradually. As the operating cycle lengthens, wear and tear on the equipment during the previous cycle becomes more severe; to ensure reliability in the next operating cycle, the depth of maintenance is correspondingly increased. A major shutdown overhaul of a refining plant involves opening up all the equipment in the plant for inspection, fixing any defects that cannot be resolved during normal operation, and performing preventive maintenance on the internal components based on their service life and operating conditions. All relevant internal components must be thoroughly cleaned and reinstalled in accordance with standard requirements. For devices involving chemical reactions, dozens or hundreds of tons of catalysts also need to be loaded. Class A refining plants have approximately 200 to 300 pieces of equipment, while other plants generally have more than 100 pieces as well. Currently, the downtime for maintenance is generally around 40 days; in other words, all of this work must be completed within 40 days. During maintenance, the site is involved daily in various hazardous operations such as hot work, lifting, work in confined spaces, and work at heights, posing significant risks. 4) The number of renovation projects is increasing year by year. The product life cycles of refining and chemical enterprises change rapidly; in order to maintain profitability, it is generally necessary to renovate the facilities, optimize the product mix, and reduce operational energy consumption. At the same time, to enhance the safety of the equipment, it is also necessary to carry out hazard mitigation simultaneously in order to improve the intrinsic safety of the devices. All these tasks need to be carried out taking advantage of the shutdown for maintenance. Maintenance shutdown management includes the organization of plant shutdowns and restarts, the preparation of maintenance plans, inspections of special equipment, control of maintenance costs, selection of contractors, ordering of maintenance materials, the preparation and approval of construction plans, management of the construction site, control of construction quality, rectification of potential hazards in the plant, provision of logistical support for maintenance personnel, promotion of maintenance and renovation activities, control over the execution of maintenance work, and summarization and improvement of maintenance processes. It is a comprehensive set of tasks that places significant demands on a company’s management capabilities.