RU2115794C1 - Bore-hole drilling bit with replaceable sections - Google Patents

Abstract

FIELD: drilling machinery and equipment. SUBSTANCE: this relates to drilling deep bore-holes of large diameter by means of bits with replaceable rock-crushing sections. Drilling bit has body 1 which carries rock-crushing sections 2 fastened by means of locking and fastening units. Section 2 has shank with taper thread 3. Locking unit is represented by step 4 with faceted external surface on shank which is seated in faceted hole of body 1. Nut 6 of fastening unit has faceted shank 7. Thread 8 of nut 6 is of taper type. Installed in washing passages of body 1 are head-piece holders which can be turned for adjustment and dismantling. One or several head-pieces can be installed in respective head-piece holders. Head-pieces can be installed perpendicularly to work face surface or at angle to axis of drilling bit with possibility of dismantling. Aforesaid embodiment has locking unit of simple and reliable design. Fixing of rock-crushing section is more rigid and accurate with respect to drilling bit axis. EFFECT: higher efficiency. 7 dwg

Description

 The invention relates to the drilling and formation of deep wells of large diameter and can be used in the layout of bit drills and bits with replaceable rock-forming sections.

 Known drill bit for drilling wells with a removable rock cutting section, containing a housing with peripheral rock cutting elements and coaxially secured advancing removable rock cutting section [1].

 The disadvantages of the known device are the inability to replace the peripheral rock-forming elements when they are worn out and the time it takes to dismantle the removable section, which reduces the efficiency of the bit.

 Known drill bit for drilling wells with removable rock cutting sections, comprising a housing mounted on the housing rock cutting sections, through the locking nodes and fastening nodes in the form of threaded shanks of the section and nuts with internal thread [2].

 The disadvantages of the known device are the long time for dismantling the section associated with making nuts along the entire length of the fastening thread, the complexity of manufacturing and unreliability of the stop assemblies, the flushing unit does not provide for the removal of sludge from the bottom of the well and elimination of gland formation during drilling of rocks with various physical and mechanical properties, since stationary the location of the nozzles does not allow you to direct the flushing stream, if necessary, in various zones of accumulation of sludge and rock-forming elements.

 An object of the invention is to increase the efficiency of the bit and its durability by reducing the time to dismantle the rock cutting sections, the reliability of the stop assembly, better removal of sludge from the bottom of the well and the formation of the walls of the well.

 In a chisel for drilling wells with replaceable pro-cutting sections, comprising a body, rock-cutting sections attached to the body with threaded shanks by means of locking assemblies and fastening units having nuts and a flushing unit in the form of flushing channels with nozzles, for solving the technical problem, the threads on the shanks of the rock-cutting sections are made conical, each locking unit is made in the form of a step located on the shank under the threaded part, with a faceted outer surface, and placed in the execution In the case of a faceted hole with the possibility of interaction of the faces with each other, each nut of the mounting unit is made with a faceted shank on the outer surface located above the upper end of the nut, the thread of which is tapered, and the washing unit is equipped with nozzle holders installed in the washing channels, in which one is attached or several nozzles, and nozzles can be placed at different angles to the axis of the bit, and nozzle holders are fixed with the possibility of installation turns around their axles and the possibility of dismantling.

 The technical result of the technical problem to be solved is a simpler and more reliable design of the locking assembly, and the placement of the faceted surface of the step in the faceted hole of the housing gives a more rigid and precise fixation of the rock cutting section with respect to the axis of the bit.

 The technical result is also a quickly dismantled mounting unit with a simple and reliable design, since the tapered thread allows you to detach the section for several revolutions of the nut for its further replacement with a new section, and in addition, the tapered thread prevents thread breakage.

 The technical result is also a more complete removal of sludge from the bottom of the well and from stagnant zones and elimination of gland formation due to the fact that the nozzles can be rotated in any direction and their number in the nozzle holder can be different depending on the drilling conditions and rock properties.

 Also the technical result is the improvement of the flushing unit, which operates offline. This makes it possible to replace the rock cutting section if it is worn out without dismantling the washing unit, the design of the section itself is also simplified and its manufacture cheaper. Since the rock cutting sections wear out before other parts of the drill and are the most labor-intensive, simplifying the design gives a great economic effect.

 In FIG. 1 shows a drill bit for drilling wells with replaceable rock cutting sections; in FIG. 2 is a section AA of FIG. one; in FIG. 3 is a view B of FIG. one; in FIG. 4 is a layout of nozzle holders with nozzles providing direction of the tangential jets of the drilling fluid to the center of the well; in FIG. 5 is a location diagram of nozzle holders with nozzles providing direction of the tangential jets of the drilling fluid to the walls of the well; in FIG. 6 is a layout of nozzle holders with nozzles providing direction of tangential jets of drilling mud in one direction; in FIG. 7 is a diagram of the location of contact spots of tangentially curved jets of drilling fluid under the running part of the cones.

 A drill bit for drilling wells with replaceable rock cutting sections comprises a housing 1. In the housing 1, rock cutting sections 2 are fixed by means of locking and fixing units. Sections 2 have shanks with a tapered thread 3. The locking assembly is a step 4 with a faceted outer surface located under the thread 3 and placed in a faceted hole 5 made in the housing 1. The faces of the step and the holes interact with each other. The nut 6 of the mounting unit is made with a faceted shank 7. The thread 8 of the nut 6 is tapered. The shank 7 is located above the upper end of the nut 6.

 In the washing unit there are nozzle holders 9, which are installed in the washing channels 10 of the housing 1 with the possibility of installation turns and dismantling. In the nozzle holders 9, one or more nozzles 11 can be fixed 11. The nozzles 11 can be installed both normal to the bottom of the well, and at different angles to the axis 12 of the bit and the possibility of dismantling.

 The bit works as follows. Before lowering the bit into the well, the nozzle holders 9 are equipped with the necessary number of nozzles 10. Since the nozzle holders 9 have the possibility of installation turns, they can be installed in any position. Due to the fact that the nozzles 11 are removable, various combinations of nozzles 11 are possible according to the diameter of their outlet openings. Depending on the properties of the rock being drilled, the nozzles 11 can be located normal to the surface of the face or normal and at an angle to the axis of the bit, or only at an angle to the axis of the bit. Moreover, the angles of inclination of the nozzles 11 to the axis of the bit 12 can be different, and their outlet openings due to the rotation of the nozzle holders 9 can be directed in different directions.

 During the operation of the bit, the drilling fluid is directed through the flushing channels 10, then through the nozzle holders 9 and nozzles 11 to the bottom of the well. In this case, the drilling fluid flowing out of the nozzles 11 located normal to the surface of the face will produce rock destruction by its hydrodynamic effect.

 Since the rock particles are pressed to the bottom surface by the pressure difference between the pore and hydrostatic, in order to separate them from the bottom in this place, the hydrodynamic pressure of the mud streams must exceed the hydrostatic pressure of the barrel of this solution. In practice, these two pressure values often prevail one above the other, therefore, sometimes rock particles will separate from the bottom with some delay and move into the upward flow.

 The outflow of the drilling fluid from the inclined nozzles 11 contributes to a more effective flushing of the destroyed rock particles, since the hydrodynamic pressure in the tangentially directed jet exceeds the hydrostatic pressure in magnitude. Moreover, if the tangentially outgoing jets from the inclined nozzles 11 are directed from the center of the well to its walls, this contributes to a more efficient removal of sludge from the bottom of the well, since it increases the velocity head of the ascending slurry jet through the annulus.

 If the tangentially outgoing jets are directed towards the center of the well, this contributes to the effective removal of sludge from the central stagnant zone. This is the case in some designs of tricone bits with side flushing.

 If the tangentially outgoing jets of some nozzles 11 are directed to the center of the bottom, and others to the wall of the well, this will contribute to the effective destruction and removal of rock, for example, loose and some other rocks.

 Nozzles can be fixed in the nozzle holders, giving various combinations of outlet diameters. This makes it possible to redistribute the power of various flows at the bottom, taking into account specific drilling conditions.

 The nozzle holders 9 in the flushing channels 10 can be installed with different approximations of the nozzles 11 to the bottom of the well. As a result, drilling fluid can erode the topmost stagnant zones. Nozzles 11 can be close to the bottom at a distance determined by the specific drilling conditions.

 The tangentially outgoing jets of drilling fluid from the inclined nozzles 11 can be directed to the cones in the case of drilling rocks, creating increased omentum formation on cones. The mud flow erodes the oil seal and exposes the rock-cutting elements of the cone.

 Outgoing jets can be directed tangentially under the running part of the cones (Fig. 7), at a certain distance from them, to reduce the erosion of cones. In this case, the work of the rock-breaking elements of the cone is facilitated, since the hydrodynamic effect of the jet on the rock provides a more effective effect of the rock-breaking elements on the rock due to the timely removal of sludge. In FIG. 7 schematically shows the cone 13 of the rock cutting section 2, the contact patch 14 of the cone 13 with the face, the contact patch 15 of the tangentially outgoing jet of mud at the bottom of the hole under the incident part of the cone 13 with the bottom, the contact patch 16 of the normally outgoing jet of mud at the bottom of the well.

The proposed flushing unit, therefore, has a number of advantages over existing designs:
the degree of approach of nozzles to the bottom can be any;
the number of nozzles can be any;
there are conditions for setting nozzle holders for differentiated treatment of different zones of the face with both normal and tangential flows;
The washing unit is autonomous - not connected with rock-cutting sections. This allows you to simplify the design of the section and reduce the cost of its manufacture.

 After wear of the rock cutting section, it is replaced. The nut 6 for the shank 7 is screwed from the threaded shank 3 of section 2. The shank 7 can have any number of faces, starting from a minimum of two faces. At the same time, due to the conical thread, the fastening unit releases the section for several revolutions of the nut 6. This design of the fastening unit reduces the time for dismantling the section 2, thereby increasing the efficiency of the bit. Moreover, only one section can be replaced, the most worn out, with the still possible operability of other sections. The compact design of the bit allows you to fix the nut 6 on the shank 3 only for the shank 7.

 The time for dismantling section 2 is reduced by the simple design of the locking assembly. Placing the faceted step 4 in the faceted hole 5 of the housing 1 increases the rigidity of the mount and the accuracy of the assembly. Moreover, the number of faces can be different, starting from the minimum - two faces. Moreover, in the case of using three faces, the strength of the step decreases. With an increase in the number of faces, for example, eight or more, the faceted surface approaches a circle. As a result, the jamming moment of the locking device is reduced and there may be a risk of the section spinning around its axis when the torsion moment arising around the section axis from the operation of the bit exceeds the jamming moment in magnitude. Optimal can take two, four and six faces.

Claims (1)

 A drill bit for drilling wells with replaceable rock cutting sections, comprising a housing, rock cutting sections attached to the housing with threaded shanks by means of locking assemblies and fastening nodes having nuts and a flushing unit in the form of flushing channels with nozzles, characterized in that the thread on the shanks of the rock cutting sections is tapered , each locking unit is made in the form of a step located on the shank under the threaded part, with a faceted outer surface and placed in a housing with a faceted hole with the possibility of interaction of the faces with each other, each nut of the mounting unit is made with a faceted shank on the outer surface located above the upper end of the nut, the thread of which is tapered, and the washing unit is equipped with nozzle holders installed in the washing channels, in which one or more nozzles, moreover, nozzles can be placed both along the normal and the surface of the face, and at different angles to the axis of the bit and the possibility of dismantling, and the nozzle holders are fixed us with the possibility of adjusting rotation around their axes and removably, with flushing channels are arranged in the bit body between rock cutting sections.

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