Drilling derrick

drilling derrick

DRILLING DERRICK (EN: drillrig; DE: Bohrturm; FR: tour de sondage, tour de forage; ES: torre de sondeo, castillete; RU: буровая вышка) is the built structure, which is installed above the borehole, for the lowering and lifting of the drilling tools, downhole motors, and casing pipes. The drilling derrick is equipped with the stairway ladders, with the platform for the servicing of the crown block, and with the derrick platform for the top worker, which is purposed for the installation of the drilling stands, and ensures the safety during the tripping operations with the drilling string.

They distinguish the drilling derricks of the tower type (Figure), and of the A-shaped type. There have got the greatest distribution the sectional A-shaped drilling derricks, which are comprising the two supports, which are constrained in the vertical position with the help of the special tubular struts, or with the help of the built structure of the portal type with the guy ropes. The drilling derricks of the tower type are used during the drilling at the sea, and during the super-deep drilling (the depth is 8-10 thousand metres and more). The front plane of the tower is open, which ensures the delivery of the pipes and rods, and the ejection of them onto the receiving bridge. The height of the drilling derrick depends on the designed depth of the borehole, and amounts to 9-58 metres.

They transport the drilling derricks of the tower type in the assembled form (together with the base of the drilling derrick), or one aggregate at a time, while they transport the A-shaped derricks in the assembled form. The marking of the drilling derrick within the USSR includes the indication of the type of the derrick (VA is of the A-shaped type, VB is of the tower type), the distance from the base to crown block platform (in metres), and the maximal load-lifting capacity (in tonnes).