A service rig is a piece of equipment which is used for servicing wells such as oil and gas wells. Service rigs are not intended for drilling, but for the completion of other tasks related to operating oil and gas wells. Some companies which operate wells maintain their own service rigs, while others prefer to rent them because they can be very expensive. Specialty crews run service rigs when they are needed for routine maintenance and emergencies.
Once a well is drilled and productive, it requires periodic maintenance. This is where a service rig comes in. When components need to be replaced or a well needs to be cleaned, it is done with a service rig. Likewise, when a well needs to be shut down for any reason, the crew uses a service rig to complete the tasks associated with shutting down the well and securing it for safety.
Service rigs are loaded on large vehicles which transport them to the well site. The rig itself is a telescoping tower secured with guy wires which keep it stationed in place. Attachments can be fitted to the service rig to complete various tasks associated with the well servicing activities. In special circumstances, attachments can be added to a service rig so that it can drill.
Also known as completions rigs, workover rigs, or pulling units, service rigs are run by a crew of people. The members of the crew assemble the rig, confirm that it is secure and working properly, and complete the assigned task on the well. It is necessary to have multiple people both for safety and because some tasks cannot be completed by a single person. People who are just starting out are known as roughnecks and they work their way into more advanced positions such as tool pushers.
Working on a service rig can be dangerous. The equipment is large and heavy and when it is not installed and maintained properly, it can pose safety risks. People are also exposed to the risk of electric shock when working with well maintenance equipment, and they can be endangered by environmental toxins which may be present around oil and gas wells. In recognition of the dangers, oil and gas occupations can come with very high salaries along with benefits. Employers also usually need to pay high liability and disability insurance because claims from workers are much more likely than with other trades.