into new formations by drilling horizontal or lateral wellbores, sealing off depleted production zones and accessing previously bypassed production zones, converting former production wells into injection wells for enhanced recovery operations and conducting major subsurface repairs due to equipment failures. Workover services may last from a few days to several weeks, depending on the complexity of the workover.
Maintenance services provided with our rig fleet are generally required throughout the life cycle of an oil or natural gas well. Examples of these maintenance services include routine mechanical repairs to the pumps, tubing and other equipment, removing debris and formation material from wellbores, and pulling rods and other downhole equipment from wellbores to identify and resolve production problems. Maintenance services are generally less complicated than completion and workover related services and require less time to perform.
Our rig fleet is also used in the process of permanently shutting-in oil or natural gas wells that are at the end of their productive lives. These plugging and abandonment services generally require auxiliary equipment in addition to a well servicing rig. The demand for plugging and abandonment services is not significantly impacted by the demand for oil and natural gas because well operators are required by state regulations to plug wells that are no longer productive.
Fluid Management Services
We provide transportation and well-site storage services for various fluids utilized in connection with drilling, completions, workover and maintenance activities. We also provide disposal services for fluids produced subsequent to well completion. These fluids are removed from the well site and transported for disposal in saltwater disposal wells owned by us or a third party. In addition, we operate a fleet of hot oilers capable of pumping heated fluids used to clear soluble restrictions in a wellbore. Demand and pricing for these services generally correspond to demand for our well service rigs.
Coiled Tubing Services
Coiled Tubing Services involve the use of a continuous metal pipe spooled onto a large reel which is then deployed into oil and natural gas wells to perform various applications, such as wellbore clean-outs, nitrogen jet lifts, through-tubing fishing, and formation stimulations utilizing acid and chemical treatments. Coiled tubing is also used for a number of horizontal well applications such as milling temporary isolation plugs that separate frac zones, and various other pre- and post-hydraulic fracturing well preparation services.
Fishing and Rental Services
We offer a full line of fishing services and rental equipment designed for use in providing drilling and workover services. Fishing services involve recovering lost or stuck equipment in the wellbore utilizing a broad array of “fishing tools.” Our rental tool inventory consists of drill pipe, tubulars, handling tools (including our patented Hydra-Walk® pipe-handling units and services), pressure-control equipment, pumps, power swivels, reversing units, foam air units, proppants, oil and natural gas. We sold our well testing assets and our frac stack equipment used to support hydraulic fracturing operations and the associated flowback of frac fluids in the second quarter of 2017.
Demand for our fishing and rental services is closely related to capital spending by oil and natural gas producers, which is generally a function of oil and natural gas prices.
In April 2015, we announced our decision to exit markets in which we participate outside of North America. During the third quarter of 2017, second quarter of 2017 and the fourth quarter of 2016, we completed the sale of our businesses in Russia, Canada and Mexico, respectively. We provided rig-based services such as the maintenance, workover, recompletion of existing oil wells, completion of newly-drilled wells and plugging and abandonment of wells at the end of their useful lives in each of our international markets. In addition, in Mexico we provided drilling, coiled tubing, wireline and project management and consulting services. Our Canadian business was focused on the development of hardware and software related to oilfield service equipment controls, data acquisition and digital information flow.
Our Functional Support segment includes unallocated overhead costs associated with administrative support for our U.S. and International reporting segments.