RU2425945C1 - Three-cone rolling drilling bit - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: drilling bit includes legs with parallel offset inclined trunnions, which are installed on them by means of retaining bearing of conical cutter with a crown; cast or milled teeth of the above legs are installed at an angle to longitudinal axis of trunnion. Each conical cutter is provided with teeth with right-hand and left-hand inclination. The above teeth are made so that axial load on bearing assembly of each bit cutter, which appears as a result of rock destruction force of inclined teeth of one cutter crown, can be compensated with axial force which had the same value and was opposite in direction and which appeared simultaneously at operation of the rest crowns of the same cutter, i.e. total constituent of axial force appearing as a result of rock destruction force with cutter crowns with inclined teeth at its sliding along the bottomhole on each bearing assembly of the bit shall be equal to zero.

EFFECT: higher operating efficiency of the bit by providing the hole making in the specified direction.

2 dwg

Description

The invention relates to a rock cutting tool, and in particular to cone drill bits, primarily for drilling soft rocks and rocks of medium hardness category.

Known drilling cone bit, comprising a housing, conical cones with cast or milled teeth and side flushing units with interchangeable nozzles (see Maslennikov IK "Drilling tool". M: Nedra, 1989, p.141-142, Fig. 2.1.63).

The disadvantage of this bit is the low efficiency due to the imbalance of its two main systems - the geometry of weapons and support nodes.

The closest to the proposed technical essence and the achieved result is a three-cone drill bit, including paws with inclined trunnions mounted on them by means of a roller cone lock bearing, cast or milled teeth of which are located at an angle relative to the generatrix (see I. Maslennikov and Matveev, G.I., Tool for Drilling Wells, Moscow: Nedra, 1981, pp. 40-41).

This design of the bit due to the new tooth arrangement provides a more effective destruction of the face.

The disadvantages of this drilling tool include the probability of deviation of the bit from a given direction during drilling, since the proposed tooth arrangement does not eliminate the deflecting force on the bit, and also contributes to increased wear of the bearing assemblies associated with the occurrence of additional axial load in the bearing nodes of the bit due to the impact of the axial load on the bit, but also from the forces of destruction of the rock arising from the slipping of weapons in the face. This, in turn, reduces the efficiency of the drill bit and leads to higher cost of drilling operations.

In connection with the stated technical result of the invention is to increase the efficiency of the bit by increasing the service life of the bearing assemblies and optimizing the removal of cuttings from the drilling zone of the cone teeth while ensuring well penetration strictly in a given direction.

The technical result is achieved by the fact that in the three-cone drill bit, which includes paws with parallel shifted inclined pins, mounted on them by means of a locking roller cones with crowns, cast or milled teeth of which are mounted at an angle to the longitudinal axis of the axle, according to the invention, each cone is equipped with teeth with right and left tilt, designed so that the axial load on the bearing assembly of each bit cone, resulting from the rock breaking force nennyh cutter tooth crowns in one direction, offset by the same magnitude and opposite direction of axial load occurring simultaneously with the rest of rims on the same cone.

The invention is illustrated by drawings, figure 1 presents a General view of the bit; figure 2 - layout of weapons.

The drill bit contains a housing 1 with parallel inclined pins (not shown), on which conical cones 2 with cast or milled teeth 3 are installed, and flushing units 4 located between the cones 2 and guiding the flow of flushing fluid to the bottom of the well. In this case, the teeth 3 on each cone 2 are made with the opposite (i.e., left and right) inclination relative to the longitudinal axis of cone 2. The total axial components for each of the three cones N _A , N _B and N _C from the corresponding rock fracture forces F _A , F _B and F _{C of the} inclined teeth arising from their contact with the face must satisfy the following condition (equality):

N _A- N _A1 + N _A2 + N _A3 = 0;

N _B = N _B1 + N _B2 = 0;

N _C = N _C1 + N _C2 = 0;

Where:

N _A1 , N _A2 and N _A3 = axial load on the support nodes - A (1st bit cone) resulting from the rock breaking force - F _A1 , F _A2 , and F _A3 teeth with oblique arms of the first, second and third crowns, respectively cones - And when it slips along the face.

N _B1 and N _B2 = axial load on the support node - B (2nd bit cutter) resulting from the rock breaking force - F _B1 and F _{B2 of the} teeth with oblique armament of the first and second bit cutters - B when they slip along the bottom.

N _C1 and N _C2 = axial load on the support node - C (3rd bit cone) resulting from the rock breaking force - F _C1 and F _C2 teeth with oblique armament of the first and second cones - C when they slip over the bottom.

The fulfillment of this condition is achieved due to a number of design solutions, such as: changes in the number of inclined teeth; use along with the inclined teeth also the teeth oriented along the axis of the cone; a change in the angle of inclination of the teeth, as well as their length for each individual crown of each cone.

This implementation of the geometry of the weapons of the cones provides mutual cancellation of the forces acting along the axis of the cone bits and directed in opposite directions that occur when the rock is destroyed by the right and left-side teeth. This ensures an increase in the durability of the bearing units, as well as the preservation of a given direction of drilling.

The proposed armament scheme for drill bit cones can be used in bits with any number of cones.

The principle of operation of the bit is as follows. Under the action of axial load and torque, the teeth 3 of the cone 2 carry out the destruction of the bottom and calibration of the walls of the well. The destroyed rock is removed to the surface by flushing fluid supplied to the bottom of the well through flushing units 4. Due to the armament of the bit with the indicated parameters, there are no deflecting forces on the bit, and the well maintains the specified direction of drilling.

Thus, the use of the proposed bit will increase the efficiency of its work and thereby reduce the cost of drilling.

Claims (1)

Three-cone drill bit, including paws with parallel-shifted inclined pins, mounted on them using a roller cone lock bearing, cast or milled teeth of which are mounted at an angle to the axle longitudinal axis, characterized in that each roller cone is equipped with right and left pitch teeth so that the axial load on the bearing assembly of each bit cone, resulting from the destruction of the rock of the inclined teeth of the cones of one cone, compensate It was equal in magnitude and opposite in direction to the axial load that simultaneously arises when the other crowns work on the same cone.

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