"Service work"; "Workover"; and "Completion".
Service work consists of using the rig to pull downhole pumps from the wellbore so that the pump can be repaired and the well can begin pumping again. These pumps are attached to "rods" which go from the surface of the ground all the way to the pump at the bottom of the wellbore. This distance is anywhere from several hundred feet to 10,000 feet below the surface, or deeper. The rig is used to pull these rods from the wellbore. Often, the rods are inside of production tubing (steel pipe) which also has to be pulled from the wellbore to repair leaks. A rig also does this. Basically, "service work" involves using the rig to assist in repairing a well to return it to producing oil and gas.
A "workover" occurs when an oil and gas producer decides to try to produce a well from a new producing zone - other than the one from which the well is currently producing. A well service rig is used to pull the tubing from the well, run it back in the well and assist in the testing of the new zone. The rig can also be used to pull fluids from the wellbore using a technique called "swabbing".
A "completion" is the attempt to make a newly drilled well into a productive oil and gas well. A well service rig is used to pull tubing, run it back in the well and assist in the testing of the new well - much like a "workover" except that a completion is performed upon a newly drilled well.
In addition, some well service rigs are used to plug wells and perform other services to oil and gas wells.
The well service industry has a trade group which represents its industry in many ways. This group is called the Association of Energy Service Companies and is located in Houston, Texas.
© Genie Well Service 2024