Drilling tools

DRILLING TOOLS (EN: drilling tool; DE: Bohrwerkzeug, Bohrgerate; FR: outil de forage; ES: herramientas de sondeo; RU: буровой инструмент) is the general name for the mechanisms and utilities, which are used during the drilling of the blastholes, and boreholes, and for the elimination of the accidents, which are emerging within the boreholes. According to the purpose, they distinguish the technological, auxiliary, emergency, and special drilling tools. Depending on the field for the usage (the drilling of the blasting, geological-exploratory, petroleum, or gas boreholes), on the method and diameter of the drilling, the nomenclature and structural peculiarities of the drilling tools within each group have the specific peculiarities.

The technology. They use the drilling tools for the performance of the works, which are immediately associated with the process of the drilling for the boreholes. There belong to the drilling tools the rock-destructing drilling tools, namely, the cutters, drilling crowns, drilling bits, and other tools, which are purposed for the mechanical (contact) destruction of the rocks within the bottomhole with the purpose to form the blasthole, or borehole, or for the drilling-out and retrieval of the core, and also the expanders, calibrators, and other tools for the destruction of the walls within the borehole, with the purpose to form there the required diameter and cross-section. Besides these purposes, they use the rock-destructing drilling tools for the conducting of the special works within the boreholes, for example, for the drilling through the cement plugs, metallic shoes, remainders of the pipes, and so on. There also belong to the technological drilling tools the tools, which are purposed for the mechanical and hydraulical linking of the rock-destructing tools with the ground surface drilling equipment, for the tripping operations, for the replacement of the rock-destructing tools, and for the maintenance of their work within the downhole. In case of the drilling of the boreholes for petroleum and gas, the tools are the directing, loaded drilling pipes, centralizers, and other elements of the drilling pipe string; in case of the drilling of the geological-exploratory boreholes, the tools are also the columnar pipes for the placement of the core, and the devices for the tearing of the core from the bottomhole; in case of the drilling of the blastholes or blasting boreholes, the tools are also the drilling stand, which comprises one or several drilling rods. In case of the geological-exploratory drilling, they name the combination of the technological tools, which are connected according to the determined sequence, as the drilling assembly.

The auxiliary drilling tools (wrenches, elevators, spiders, wedge grips, and others) are purposed for the assembly and disassembly (screwing and unscrewing) of the drilling pipe strings (of the drilling stands), and also for the dragging, lifting, lowering, and holding on the suspension, or on the table of the rotor, of the elements of the drilling pipe column, of the rods, and of the casing pipes.

They use the drilling tools for the elimination of the accidents (markers, bells, pipe catchers, pipe cutters, milling cutters, torpedoes, screw-jacks, and others) also in case of the emergence of the complications (the loss of the rock-destructing tools, the separation or stucking of the drilling pipe string, the stucking or removal of the casing pipes, and so on) during the process of the drilling of the boreholes (see the "Catching tools" article).

The special drilling tools serve for the orientation of the technological tools within the shaft of the borehole, with the purpose for the performance of the drilling of this borehole into the required direction, and includes the diverters of various structures (turbine diverters, spindle diverters, whipstock, stabilizers, and so on), and the means for the orientation of the borehole.