RU2448231C1 - Controlled drilling layout - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: controlled drilling layout comprising a bit and a downhole motor has a projection in the form of a blade on the housing, the periphery radius of which is larger than bit radius. The above projection is equipped with cutting-shearing elements on the side facing the bit, which cover the distance between periphery radii of projection and bit in radial direction. In order to improve stability of the layout in the well above the projection with cutting-shearing elements on opposite half of the downhole motor housing the provision is made for one more projection.

EFFECT: invention allows increasing technical and economic parameters at drilling of controlled directional wells and horizontal wells.

6 cl, 13 dwg

Description

The invention relates to drilling equipment and can be used in the layout of the bottom of the drill string when drilling directional and horizontal wells with a hydraulic downhole motor.

Various arrangements for directional drilling are known and widely used (Drilling rigs. Modern technologies and equipment. OMZ Uralmash-Izhora group, 2002, pp. 213-215), including a bit and a downhole diverter motor with a skew assembly made in the form of a curved sub .

The use of downhole assemblies with curved diverter motors is associated with a deterioration in controllability in a curved wellbore due to the high resistance to rotation of such an arrangement.

In addition, due to the expansion of the curved layout in a straight trunk, it is difficult to move along the well when the tool is lowered to the bottom.

The best conditions for moving in a straight borehole are achieved by direct arrangements with a decentralizer or with an eccentric pad on the nipple of the downhole diverter motor (Equipment, blowout preventer and wellhead. Reference manual, t.2 LLC IRTs Gazprom, 2007, pp. 211-212 ), in which the peripheral radius of the eccentric pad is smaller than the radius of the bit. The disadvantage of such downhole arrangements is the possibility of their use only in stable rocks, where the risk of jamming of the drilling tool is excluded.

The closest technical solution known is a turbo-baffle with an eccentric pad, the peripheral radius of which exceeds the radius of the bit (Yu.V. Vadetsky. Drilling oil and gas wells. Moscow, Nedra, 1973, p. 276, 277) (prototype).

The disadvantage of this device is the high probability of jamming of the bottomhole assembly in the well, especially when drilling in unstable rocks.

The present invention is aimed at eliminating these disadvantages and increasing the efficiency of drilling directional and horizontal wells.

This is achieved by the fact that the configuration for directional drilling, including a bit and a downhole motor having a protrusion in the form of a blade on the body, the radius of the periphery of which is greater than the radius of the bit, said protrusion from the side facing the bit, is equipped with at least one cutting-chipping an element overlapping in the radial direction the distance between the radii of the periphery of the protrusion and the bit.

To increase the stability of the layout in the well above the protrusion with cutting-cleaving elements, it is desirable to place another protrusion on the opposite half of the downhole motor housing.

It is advisable to cut-cleaving elements on the protrusion in the form of diamond carbide cutters with a cutting angle between the front plane of the cutter and the radius to its cutting edge, which is in the range of 5 ° -30 °.

The upper protrusion is most effective if it is formed by an arc of the radius of the bit at the maximum distance of the periphery of this protrusion from the axis equal to the radius of the periphery of the protrusion with cutting-cleaving elements.

One of the effective options is the layout design, in which the downhole motor housing below the protrusion with cutting-cleaving elements has a radius less than the radius of the housing located above the specified protrusion.

In addition, a rational arrangement in which a part of the downhole motor housing located above the protrusion with cutting-cleaving elements has a radius greater than the radius of the bit.

Figure 1, 1A, 1B shows a view of the proposed layout with a protrusion on the housing, equipped with cutting-shearing elements.

Figure 2, 2A, 2B shows a layout with a protrusion located in the opposite part of the body of the downhole motor, above the protrusion with cutting-shearing elements.

In Fig.3 shows a cross section of the layout in place of the protrusion with cutting-cleaving elements in the form of one blade, Fig.3A - in the form of two blades.

Figure 4 shows a cross-section of the layout in place of the protrusion located above the protrusion with cutting-cleaving elements.

On figa shows an embodiment of the upper protrusion.

Figure 5 shows the position of the layout in the well when it rotates from the surface to drive a straight section of the wellbore.

Figure 6 shows the position of the layout in the well without its rotation from the surface for the sinking of the curved section of the well.

Figure 7 shows the layout, a part of the body of which, located below the protrusion with the cutting elements, has a radius less than the radius of the body located above the specified protrusion.

The layout for directional drilling (Fig. 1) includes a downhole motor 1, the output shaft 2 of which is connected to the bit 3. The protrusion 4 is equipped with cutting-shearing elements 5, the peripheral radius r of which the cutting edge _BP is larger than the radius of the bit r _D (Fig. 1a). View B of the layout (figb) shows the location of the cutting-cleaving element 5 on the protrusion 4.

The layout (figure 2) in addition to the features (composition of elements) shown in figure 1, has a protrusion 7 located on the engine housing, above the protrusion 4. View B of the layout (figa, 2b) shows the location of the protrusion 7 on part 6 case, opposite ledge 4 with cutting and cleaving elements 5.

The cross-section AA of the arrangement in the place of the protrusion 4 with the cutting-cleaving elements 5 (Fig. 1 and Fig. 3) shows the installation of the elements 5. The cutting angle between the front plane 8 of the cutter 5 and the radius r _{BP of} its cutting edge r is within 5 ° -30 °. On figa presents an embodiment of the protrusion 4 in the form of two blades.

The cross-section _{BB of the} arrangement at the site of the protrusion 7 (FIG. 2 and FIG. 4) shows that said protrusion 7 is formed by an arc of the radius of the bit r _D at a maximum distance r _{BB of the} periphery of this protrusion from the axis equal to the radius r _{BP of the} periphery of the protrusion with the cutting shearing elements (r _BB = r _BP ). On figa presents an embodiment of the protrusion 7. The angle α of coverage of the peripheral surface of the protrusion is in the range of 45 ° -150 °.

Figure 5 shows the position of the layout in the well during its rotation from the surface. In this case, the diameter of the well D _SLE. = 2r _BP .

Figure 6 shows the position of the layout in the well without its rotation from the surface. In this case, a curved wellbore of radius R _well is drilled _. and well diameter D wells _. = 2r _D.

The layout is as follows. To start the device in work on the drill string in the downhole motor 1 (figure 2) is supplied with drilling fluid, leading to the rotation of the output shaft 2 of the engine with a bit 3.

For driving a straight section of the well (Fig. 5), the assembly of the drill string is rotated from the surface. In this case, a stepped wellbore is formed. The lower part of the wellbore from the bit 3 (Fig. 1) to the protrusion 4 with cutting and cleaving elements 5 has a radius r _D , and above it has a radius r _BP. Due to the increase in the transverse dimension of the wellbore, the layout can move uninterruptedly in the drilled well. In this case, the protrusion 7 (figure 2), located above the protrusion 4, acts as an additional centering element, provided that r _BP = r _BB . Depending on the category of rock drillability during the expansion of the wellbore, the installation angle of cutting-cleaving elements (diamond carbide cutters) 5 (Fig. 3) is selected within 5 ° -30 °. When driving highly abrasive, hard rocks, the cutting-chipping element can be made in the form of cones reinforced with carbide teeth. To increase the efficiency of drilling, the protrusion 4 with cutting-cleaving elements 5 can be made in the form of several blades (figa).

To penetrate the curved section of the well (Fig.6), the rotation of the drill string is stopped, which is fixed in the circumferential direction in the position corresponding to the combination of a given plane of curvature of the well with a plane passing through the layout axis and the middle of the protrusion 4 (Fig.3, 3a) with a cutting chipping elements. With the translational movement of the layout, a curved wellbore with a radius of R _SLE will be formed _. (6) and the diameter of the well D _SLE. = 2r _D. In this case, the protrusion 7 (Fig.2), located on the opposite half 6 (Fig.2A, 2b) of the body, will serve as a support, holding the layout in a given direction. For greater stability of the layout from the action of the reactive moment, the upper protrusion 7 in cross section has a radius of the peripheral surface equal to the radius of the bit r _D (figure 4). In addition, the protrusion 7 can be rotated to the left (view B) relative to the cutting protrusion at an angle of 30 ° -90 ° (Fig.2 and Fig.2b).

Subsequently, the formed curvilinear section of the well can be expanded to a diameter equal to 2r _BP by translationally moving the assembly with its rotation.

The intensity of the angle change, and hence the curvature radius, R, _SLE . the borehole can be changed depending on the values of r _BP and r _BB relative to r _D , L ₁ and L ₂ according to the formula

The proposed layout for directional drilling can also be used in a design where the lower part of the motor housing (from the bit to the protrusion with cutting elements) is smaller in diameter than the part of the body above the specified protrusion (Fig.7). This design allows the use of a more powerful working section with a radius r _KV > r _KN in a downhole hydraulic motor _.

Another special case may be the use of an assembly for directional drilling, when the radius of the part of the engine casing located above the protrusion with cutting elements is equal to or greater than the radius of the bit, which allows this arrangement to be used as a borehole expander with a powerful working section of the downhole motor.

The proposed layout for directional drilling can improve technical and economic performance when drilling directional and horizontal wells.

Claims (6)

1. An arrangement for directional drilling, including a chisel and a downhole motor interconnected, having a protrusion in the form of at least one blade, the radius of the periphery of which is greater than the radius of the chisel, characterized in that the protrusion on the side facing the bit is equipped at least one cutting-cleaving element, overlapping in the radial direction the distance between the radii of the periphery of the protrusion and the bit. 2. The directional drilling arrangement according to claim 1, characterized in that at least one more protrusion is placed above the protrusion with cutting-cleaving elements on the opposite half of the housing. 3. The layout for directional drilling according to claim 1, characterized in that the cutting-cleaving elements are made in the form of diamond carbide cutters, and the cutting angle between the front plane of the cutter and the radius to its cutting edge is in the range of 5-30 °. 4. The arrangement for directional drilling according to claim 2, characterized in that the upper protrusion in the cross section is formed by an arc of the radius of the bit at the maximum distance from the periphery of this protrusion from the axis, equal to the radius of the periphery of the protrusion with cutting-cleaving elements. 5. The layout for directional drilling according to claim 2, characterized in that the downhole motor housing below the protrusion with cutting-cleaving elements has a radius less than the radius of the housing located above the specified protrusion. 6. The layout for directional drilling according to claim 2, characterized in that the part of the body of the downhole motor above the protrusion with cutting-cleaving elements has a radius greater than the radius of the bit.

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