A service rig is a mobile platform loaded with oil industry service equipment that can be driven long distances within the oil fields to service wells. Unlike drilling rigs, service rigs return to a particular well many times. There are several specialized types of service rigs: the carrier, the pumptruck, the doghouse, a 5-ton. .
The Rig, or Carrier, is a mobile truck with a derrick and a cab for one driver. The carrier can also be trailer-mounted, enabling it to be. .
The crew members on service rigs each have specialized experience and expertise. The entry-level workers are junior floor hands.
[pdf] Before any workover, the well must first be . Since workovers are long planned in advance, there would be much time to plan the and so the reverse circulation would be common. The intense nature of this operation often requires no less than the capabilities of a . The workover begins by killing the well then removing the wellhead and possibly the flow line, then installing a B.O.P. commonly known as a , then lifting the fr.
[pdf] NOV's two main predecessors, Oilwell Supply and National Supply, were founded in 1862 and 1893, respectively. These two companies manufactured and distributed pumps and derricks. In 1930, acquired Oilwell Supply. In 1958, merged with National Supply. In 1987, National Supply merged with USS Oilwell to become "National Oilwell". Varco was founded as Abegg and Reinhold Company by Walter Abegg and Baldwin Reinhold i.
[pdf] 
