RU2485277C2 - Screw borer for rotary boring of wells - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: borer consists of a screw housing, in upper part of which there hinged are dampers, replaceable boring cutters, and a shaft for attachment of a pilot jumper bit. Screw housing is installed on support plates, in the centre of which there located is a shaft of the pilot jumper bit so that its upper cutting line is located below cutting line of the lowest cutter, and tops of extreme side cutters are located at one and the same distance from rotation axis and at the same height relative to horizontal plane. Internal lateral sides of cutters are parallel to the line attaching the top of the cutter to the rotation axis, and support plates are offset relative to each other trough angle α.

EFFECT: increasing operating efficiency of the borer.

3 dwg

Description

The invention relates to drilling equipment, and in particular to the design of a drilling tool for rotary drilling of shallow wells in soils of I-IV drillability categories according to SNIP IV-2-82 standards with solid inclusions, as well as in permafrost and seasonally frozen soils.

Known boring tools for rotary drilling machines, which are produced by the Alapaevsky Stroydormash plant, containing a two-way bladed body with a bore and cutting elements (cutters) installed in the lower part of the blades located in the same plane of rotation (Catalog of Drilling Machines and Instruments ”, Stroydormash OJSC, 2009). The disadvantage of these drills is that they have a large power consumption, a large specific consumption of hard alloy, the removal of the axis of the well when drilling wells with solid inclusions.

The closest analogue is the well-known drilling tool from RU 2004761 C1 for rotary drilling of wells, comprising a casing in the form of spiral blades and pivotally mounted dampers in the upper part, a bobbin coaxially mounted in the lower part of the blades and stepwise mounted to the blades along radial lines with the possibility of overlapping each other at different angles to the vertical plane, the central incisors and peripheral incisors mounted on the generators of the cone, the apex of which is located on the axis of the body in the lower part tee picker. In this case, the central incisors are located on the generatrices of the cone, the apex of which is located on the axis of the body in the upper part of the bore, and the generators of the cones of the peripheral and central incisors intersect at the installation site of the peripheral incisor closest to the center, located below the others, the cutting edges of the central and peripheral incisors are displaced around the circumference in the direction of rotation relative to the radial line of the peripheral cutter, and the upper edge of the cutting edge of the bail is located above the cutting edges of the central and peripheral x incisors.

The disadvantage of these drills is:

- the absence of a downward stepped well, which leads to an increase in axial pressure on the drill while drilling hard rock, which accordingly leads to rapid wear of the cutters;

- irrational use of drilling rig power and increased torque on the spindle of the machine;

- the ability to remove the axis of the well from a given value when drilling soft rocks with solid inclusions.

However, this drill tool has several disadvantages: firstly, extremely unfavorable working conditions of the cutters, and secondly, the irrational use of drive power.

The technical result consists in increasing the efficiency of the drill:

- improving the working conditions of the drill;

- formation of a well with a vertical axis and sealed walls;

- ensuring the stability of the drill when drilling vertical wells with solid inclusions when drilling soil with solid inclusions, i.e. the axis of the well does not go from the initial adjustment of the axis of the well to the side.

A drill is declared, consisting of a screw housing 1, in the upper part of which the shutters 2, drill interchangeable cutters 5, 6, 7, shaft 8 for fastening the pilot-bore 9 are pivotally fixed, characterized in that the screw housing 1 is mounted on the support plates 3, in the center of which is the shaft 8 of the pilot-bail 9 so that its upper cutting line is located below the cutting line of the lowest cutter, and the tops of the extreme side cutters are located at the same distance from the axis of rotation and at the same height relative to the horizontal plane, and the inner kovye cutters faces parallel line connecting the vertex with the cutter axis of rotation, and the support plates are displaced relative to each other by an angle α.

Figure 1 presents the inventive drill for rotary drilling, where:

1 - screw housing;

2 - shutter;

3 - base plate;

4 - pocket for mounting the cutter;

5, 6, 7 - incisors;

8 - shaft of the pilot-bail;

9 - pilot-zaburnik.

Figure 2 presents a diagram of the formation of a stepped bottom while drilling a well, where:

D is the diameter of the borehole;

d is the borehole diameter of the pilot pilot;

h is the distance between the lower cutting line of the cutters and the upper line of the pilot-bail.

Figure 3 presents the location of the cutters and the alignment of forces when cutting soil, where:

3 - base plates;

5 - side incisors;

6, 7 - incisors;

9 - pilot-zaburnik.

The claimed technical results are achieved as follows.

In order to ensure the stability of the drill during drilling of vertical wells with solid inclusions and the formation of a well with a vertical axis and compacted walls, the pilot bore 9 is installed in such a way that its upper cutting line is located below the cutting line of the lowest cutter, and the vertices of the extreme side cutters are located on one distance from the axis of rotation and at the same height relative to the horizontal plane, and the inner side faces of the cutters are parallel to the line connecting the tip of the cutter with the axis of rotation, while rennie side faces cuts the soil and it is discarded into the wellbore and the outer faces are cut and discarded ground it to the borehole wall, sealing it. Figure 2 shows how this happens. The upper cutting line of the pilot-borer is located below the lower cutting line of the incisors. When the drill rotates, the cutter, in contact with the soil, turns the spindle torque into a cutting force P and P ₁ , which are decomposed into two component forces: forces N and N ₁ , which cut the soil layer. Strength N ₁ presses the side wall of the borehole, and the force N discards cut into the layer of soil on the blade of the screw body 1. Forces Q and Q ₁ are involved in the abrasion at the cutting edge of the drill and equal to Q = f × P, Q ₁ = f × P ₁ . The support plates 3 are offset relative to each other by an angle α so as to provide maximum passage of the destroyed soil between the walls of the well and the plates. The destroyed soil, supported by the newly destroyed soil, is squeezed up onto the blades of the housing 1 and transported by them into the space above the shutters 2. In order for the soil to be lifted at a low axial pressure of the drill, it is necessary to provide the most passage area for the soil, which is supported by the base plates. Therefore, the support plates 3 are set so as to provide a minimum coefficient of overlap of the well area K = F plates / F wells ≤0.5. After the drill has been drilled to a certain depth, the drill is raised to the surface together with the destroyed soil, which is prevented by the shutters 2 waking up.

In order to improve the penetration of the drill into the soil, replaceable cutters 5, 6, 7 are installed in a stepwise pattern at a certain angle to the plane of rotation, and the cutting edge of the cutter has an optimal operating mode for this carbide. Moreover, the extreme incisors on one of the support plates 3 are located on the axis of rotation to form the diameter of the wells, and the other incisors are located with the possibility of loosening the soil according to the following scheme: first, the loosers are loosened by the soil located closer to the axis of rotation, then the following and so on to cover the entire area of the well . When the pilot-bored 9 meets hard inclusions, he rises, but does not leave his leading well, which allows the drill to remain on its vertical axis. Subsequently, the borehole 9 either drills a solid inclusion, or presses it sideways into a softer rock, where it will be delivered to the auger blades of the incisors.

The claimed technical solution allows to obtain an increase in operational characteristics, improve the working conditions of the drill, to form wells with a vertical axis and sealed walls, as well as to ensure the stability of the drill when drilling soil with solid inclusions.

Claims (1)

Drill, consisting of a screw housing 1, in the upper part of which the shutters 2, drilling interchangeable cutters 5, 6, 7, shaft 8 for fastening the pilot-bore 9 are pivotally fixed, characterized in that the screw housing is mounted on base plates 3, in the center of which the shaft of the pilot-bore 9 is located so that its upper cutting line is located below the cutting line of the lowermost cutter, and the vertices of the extreme lateral cutters are located at the same distance from the axis of rotation and at the same height relative to the horizontal plane, the inner side faces p cutters are parallel to the line connecting the tip of the cutter with the axis of rotation, and the support plates are offset relative to each other by an angle α.

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