Nabors owns and operates the largest land-based drilling rig fleet in the world and has one of the largest workover and well servicing rig fleets in the
Canada . Our company also is a leading provider of offshore platform workover and drilling rigs in the
Canada and multiple international markets. A general representation of the types of drilling and workover rigs available within our fleet follows:
DRILLING RIGS: Land-based drilling rigs generally consist of engines, a drawworks, a mast (or derrick), pumps to circulate the drilling fluid (mud) under various pressures, blowout preventers, drill string and related equipment. The engines power the different pieces of equipment, including a rotary table or top drive that turns the drill string, causing the drill bit to bore through the subsurface rock layers. Rock cuttings are carried to the surface by the circulating drilling fluid. The intended well depth, bore hole diameter and drilling site conditions are the principal factors that determine the size and type of rig most suitable for a particular drilling job.
WORKOVER RIGS: Land-based workover rigs (commonly referred to as well servicing rigs) consist of a mobile carrier, engine, drawworks and a mast. The primary function of a workover rig is to act as a hoist so that pipe, sucker rods and down-hole equipment can be run into and out of a well. Land-based workover rigs are easier to move between well sites and different geographical areas of operations than drilling rigs. Typically, the rigs are self-propelled and have less auxillary equipment to move. Because of size and cost considerations, workover rigs are used for these operations rather than the larger drilling rigs.
PLATFORM RIGS: A platform is a stationary offshore oil and/or gas production facility. Platform rigs are designed to provide offshore workover, drilling and re-entry services at these facilities. Our platform rigs have drilling and/or workover equipment and machinery arranged in modular packages that are transported to, and assembled and installed on, fixed offshore platforms owned by the customer. Fixed offshore platforms are steel-like structures that either stand on the ocean floor or are moored floating structures. The top portion, or platform, sits above the water level and provides the foundation upon which the rig is placed.
JACK-UP RIGS: Jack-up rigs are mobile, self-elevating, offshore drilling and workover platforms equipped with legs that can be lowered to the ocean floor until a foundation is established to support the hull, which contains the drilling and/or workover equipment, jacking system, crew quarters, loading and unloading facilities, storage areas for bulk and liquid materials, helicopter landing deck and other related equipment. Many of our jack-up rigs are of cantilever design, a feature that permits the drilling platform to be extended out from the hull, allowing it to perform drilling or workover operations over adjacent, fixed platforms. The water depth limit of a particular rig is determined by the length of the rig’s legs and the operating environment. Moving a rig from one drill site to another involves lowering the hull down into the water until it is afloat and then jacking up its legs with the hull floating. The jack-up rig is then towed to the new drilling site.
INLAND BARGE RIGS: Inland barge rigs are mobile, self-contained, drilling and/or workover vessels. When moved from one location to another, the barge floats; when stationed on the drill or workover site, the barge is submerged to rest on the bottom. Typically, inland barge rigs are used to drill or workover wells in marshes, shallow inland bays and offshore where the water covering the drill site is not too deep. Our barge rigs can operate at depths between three and 25 feet.
Click here to view our operational map.