When the oil and gas recovery equipment needs to be shut down for a long period due to reasons such as site renovation or business adjustment, it cannot simply be left unused. During the shutdown period, the equipment does not operate, but residual oil and gas in the pipelines will condense, seals will gradually deteriorate under pressure, and electrical components will become damp and accumulate dust. These issues are not visible during shutdown, but they will emerge collectively when the equipment is restarted. Proper sealing ensures smooth startup; careless sealing often requires several times the effort to deal with remaining issues during startup. This article explains the sealing measures before shutdown and the steps for restarting.
How to take sealing measures before decommissioning
The core idea of sealing involves three things: draining, powering off, and protecting. Draining involves cleaning up the residual oil and gas in the pipelines and pump bodies to prevent condensation, deterioration, and corrosion of the internal chambers during long-term storage. Powering off involves cutting off the equipment's power supply and tagging it to prevent accidental startup during downtime, as well as avoiding long-term standby with electrical components live. Protecting involves blocking and covering exposed interfaces and cable entrances to prevent the entry of moisture, dust, insects, and rodents. If these three things are done thoroughly before shutdown, it will be much easier to restart later.
The timing of sealing is also important: try to arrange for the equipment to be decommissioned after completing a round of routine maintenance, so that the equipment enters the storage period in good condition; if the equipment is decommissioned while it is still operating with defects, the problems will be carried over into the entire decommissioning period, making it more difficult to deal with when it is reactivated.
Five steps of sealing operation
- Drain the pipeline: Drain the residual liquid in the pipeline and pump body according to the operating instructions, and check and confirm the low-point areas one by one;
- Cleaning the internal chamber: Clean and dry the openable chamber to prevent residual oil from adhering to the inner wall for a long time;
- Power off and tag out: Cut off the power supply, and hang a tag indicating the suspension of use at the power distribution location, specifying the suspension date and contact person;
- Sealing and protection: All external interfaces should be sealed with cover plates or plugs, cable entrances should be resealed, and exposed pipe sections should be covered;
- Registration and archiving: Record the sealing date, executor, and equipment status before sealing in the equipment archive as a reference document for future use.
Inspection and commissioning before reactivation
After long-term disuse and re-use, avoid directly powering on and starting up. First, conduct a round of pre-startup inspection: remove the blockages one by one, confirm that the pipelines are unobstructed, and check whether the seals are hardened or cracked - rubber parts will age even if not used after being stored for many years. Replace any parts that have become hard and lose elasticity; for the electrical part, first check the insulation and the state of the wiring terminals, and confirm that there is no moisture before powering on. After powering on, conduct a no-load trial run, observe the operating sound and status indication, and gradually put it into actual operation after confirming its stability. The records during the disuse period come in handy at this time: comparing the state before sealing with the state when starting up, it is clear at a glance which changes are caused by storage.
| phase | project | key points |
|---|---|---|
| Before deactivation | Drain and clean | The residual liquid in the pipeline has been completely drained, and the cavity is clean and dry |
| Before deactivation | Power outage and identification | Cut off the power supply, hang a tag, and indicate the date of suspension |
| Before deactivation | Interface sealing | Seal the external interface and cable entry |
| During the downtime | regular inspection | Check the integrity of the sealing, and inspect for any water accumulation or rust stains |
| Before enabling | Sealing and electrical inspection | Replace the aged seals, confirm the insulation, and then power on |
| When enabled | No-load trial operation | Observe under no-load conditions first, and then proceed with actual operations after it becomes stable |
Suggestions on responsibility arrangement for sealing and enabling
The greatest concern in sealing and reactivation is "no one in charge": who performed the sealing and to what extent, no one can remember clearly after a few months. It is recommended to designate a specific person to be responsible for each sealing and reactivation, carry out the actions according to the checklist, and archive the results based on the records. For equipment that has been sealed for a long time, arrange for personnel to check periodically - to see if the sealing is intact, whether there is water accumulation or rust, and to handle any abnormalities promptly. This is much more labor-saving than handling them all at once when reactivating. For uncertain projects, hand over the archival records to the equipment manufacturer and ask them to provide inspection suggestions before reactivation.
Frequently Asked Questions
How long does it take to consider discontinuation as long-term?
In practice, equipment should be treated according to the sealing standards on a monthly basis. Equipment that is out of service for a few days can be handled as routine downtime; for equipment that is out of service for multiple months or even quarters, the effects of residual oil in the pipeline and aging seals will become apparent, and it is recommended to follow the sealing measures outlined in this article.
Is it okay to just stop using it without doing any maintenance before sealing it?
Not recommended. Discontinuing use with issues unresolved is akin to trapping the problem inside the device for several months. If you're pressed for time, at least ensure that the residual fluid is drained and the power is disconnected. For other tasks, catch up as soon as possible during the downtime.
Should we notify the manufacturer when re-enabling?
If the equipment has been out of use for more than half a year or if abnormalities are found during the pre-use inspection, it is recommended to contact the manufacturer first. Report the sealing records and the pre-use inspection results to the manufacturer, who can determine which parts need to be replaced first and which can be directly put into operation, thus avoiding blindly starting up and exacerbating the problem.
This article is compiled by Luoyang Wohong Petrochemical Equipment Co., Ltd. The company provides design and manufacturing, skid-mounted customization, installation and commissioning, as well as after-sales operation and maintenance services for three-time oil and gas recovery equipment to gas stations and oil depots. If you need on-site inspection or scheme configuration, please feel free to contact us for discussion.