Abstract
A composite drill bit has one or more scraping-wheel cutting units disposed on fixed-blade. The drill bit comprises a bit body, fixed-blades, and scraping-wheels. The angular deflection of the scraping-wheel is in the range of 20||90. The scraping-wheel cutting unit has a scraping-wheel shaft and a scraping-wheel with cutters disposed thereon. The scraping-wheel cutting unit is disposed on the fixed-blade by a rotary connection.
Claims
1. A composite drill bit, comprising: a bit body and one or more composite cutting units disposed on the bit body, wherein each composite cutting unit comprises: a fixed-blade having a fixed-blade body and a plurality of fixed cutters disposed along a circumference of the fixed-blade body; and a scraping-wheel unit having a scraping-wheel rotatably affixed to the fixed-blade body through a shaft connecting the scraping-wheel and the fixed-blade body, wherein the scraping-wheel has a plurality of cutters disposed thereon, wherein the scraping-wheel has an angular deflection in the range of 20||90, wherein the plurality of cutters on the scraping-wheel form a first cutting profile and the plurality of cutters on the fixed-blade form a second cutting profile, wherein the first cutting profile substantially coincides with a portion of the second cutting profile, wherein, in the composite cutting unit, the fixed blade body comprises a first part and a second part separated from each other in a direction of travel about a center longitudinal axis of the composite drill bit by a slot, and further wherein the scraping-wheel unit is disposed in the slot, the shaft of the scraping-wheel unit extends through the scraping-wheel unit, and a first end of the shaft is affixed to the first part of the fixed blade body and a second end of the shaft is affixed to the second part of the fixed blade body.
2. The composite drill bit of claim 1, wherein, in the composite cutting unit, at least one of the plurality of fixed cutters disposed along the circumference of the fixed-blade body are located in the first part of the fixed blade body, the second part of the fixed blade body, or both.
3. The composite drill bit of claim 1, wherein, in the composite cutting unit, the plurality of fixed cutters on the fixed-blade body define a first imaginary surface by setting a boundary of the first imaginary surface and at least a portion the plurality of cutters on the scraping-wheel defines a second imaginary surface by setting a boundary of the second imaginary surface, wherein the second imaginary surface is perpendicular to the scraping-wheel shaft, wherein the first imaginary surface leads or trails the second imaginary surface in a direction of travel about the center longitudinal axis of the composite drill bit.
4. The composite drill bit of claim 3, wherein, in the composite cutting unit, a portion the scraping-wheel is disposed between the first imaginary surface and the second imaginary surface.
5. The composite drill bit of claim 1, wherein the composite cutting unit comprises two of the scraping-wheel units, wherein the fixed blade body has two slots and each slot receives one of the plurality of the scraping-wheel units.
6. The composite drill bit of claim 1, comprising two or more composite cutting units, wherein an angular deflection of the scraping-wheel in at least one of the two or more composite cutting units is different from an angular deflection of the scraping-wheel in at least another of the two or more composite cutting units.
7. The composite drill bit of claim 1, comprising two or more composite cutting units, wherein the scraping-wheel in at least one of the two or more composite cutting units has a positive angular deflection and the scraping-wheel in at least another of the two or more composite cutting units has a negative angular deflection.
8. The composite drill bit of claim 7, wherein the positive angular deflection equals the absolute value of the negative angular deflection.
9. The composite drill bit of claim 1, comprising two or more composite cutting units, wherein the first scraping-wheel in at least one of the two or more composite cutting units has a radial position on the composite drill bit that is different from a radial position of the scraping-wheel in at least another of the two or more composite cutting units.
10. The composite drill bit of claim 9, wherein diameters of the first scraping-wheel and the second scraping-wheel are not equal.
11. The composite drill bit of claim 1, wherein the scraping-wheel has more than one row of cutters.
12. The composite drill bit of claim 1, wherein, in the composite cutting unit, a cutting profile of the scraping-wheel is higher than a cutting profile of the fixed-blade.
13. The composite drill bit of claim 1, comprising two or more composite cutting units, wherein a cutting profile of the scraping-wheel in at least one of the two or more composite cutting units is lower than a cutting profile of the scraping-wheel in at least another of the two or more composite cutting units.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 is a schematic drawing of the rotary connection between the scraping-wheel and its shaft of existing technology;
(2) FIG. 2 is a schematic drawing of the rotary connection between the scraping-wheel (being disposed in front of the fixed-blade) and fixed-blade of an embodiment in present invention;
(3) FIG. 3 is a schematic drawing showing the geometric parameters of the scraping-wheel: offset distance s, arm of journal root center c, angular deflection and journal angle of an embodiment in present invention;
(4) FIG. 4 is a cross-section taking along the polar axis plane of the scraping-wheel, showing the rotary connection between the scraping-wheel and its shaft (of which both ends are fixed on the fixed-blade) of an embodiment in present invention;
(5) FIG. 5 is a break-out section of the fixed-blade, taking along the polar axis plane of the scraping-wheel, showing the fixed connection between the scraping-wheel and its shaft (of which both ends are disposed on fixed-blades with rotary connection) of an embodiment in present invention;
(6) FIG. 6 is a simplified plan view along the bit axis, showing the geometric parameters of relative positions s, c, of an embodiment in present invention, wherein, the offset and angular deflection of the scraping-wheel are both positive.
(7) FIG. 7 is a simplified plan view along the bit axis, showing the geometric parameters of relative positions s, c, of an embodiment in present invention, wherein, the offset and angular deflection of the scraping-wheel are both negative.
(8) FIG. 8 is a perspective view showing the bit in present invention, wherein, the scraping-wheel is disposed in the slot machined within the fixed-blade which is disposed with one row of fixed cutters.
(9) FIG. 9 is a plan view of the bit in FIG. 8 (taking along the bit axis from the cutting structure toward the connector of the bit).
(10) FIG. 10 is a plan view of the bit with the scraping-wheel cutting unit being disposed in front of the fixed-blade.
(11) FIG. 11 is a plan view of the bit with the scraping-wheel cutting unit being disposed at the back of the fixed-blade.
(12) FIG. 12 is a plan view of the bit similar to that in FIG. 8, wherein, the difference is that one cutters-row are disposed both in front and at the back of the scraping-wheel on the fixed-blade.
(13) FIG. 13 is a plan view of the bit in present invention, wherein, two cutters-rows are disposed in front of the scraping-wheel while one cutters-row is disposed at the back of the scraping-wheel on the fixed-blade.
(14) FIG. 14 is a plan view of the bit in present invention, wherein, each fixed-blade is configured with one cutters-row and two scraping-wheels, and the angular deflection of one scraping-wheel is positive while the other one is negative.
(15) FIG. 15 is a plan view of the bit similar to that in FIG. 14 with only the journal angle of the scraping-wheel being different.
(16) FIG. 16 is a plan view of the bit similar to that in FIG. 14, wherein, the difference is that the fixed-blade is disposed with multiple cutters-rows.
(17) FIG. 17 is a plan view of the bit similar to that in FIG. 16, wherein, the difference is that scraping-wheels are disposed on the fixed-blade with different radial positions of the bit.
(18) FIG. 18 is a plan view of the bit in present invention, wherein, the scraping-wheel disposed with multiple circles of cutters is located in front of the fixed-blade.
(19) FIG. 19 is a plan view of the bit in present invention, wherein, scraping-wheels are disposed both in front and at the back of the fixed-blade.
(20) FIG. 20 is a schematic drawing of the bit in the present invention, wherein, the scraping-wheel is disposed on its shaft with rotary connection, while the shaft is formed as an integrated structure with the fixed-blade.
(21) FIG. 21 is a plan view of the bit illustrated in FIG. 20.
(22) FIG. 22 is a perspective view of the bit similar to that in FIG. 21, wherein, the difference is that independent fixed-blade cutting units are disposed on the bit.
(23) FIG. 23 is a plan view of the bit similar to that in FIG. 21, wherein the difference is that independent fixed-blade cutting units are disposed on central area of the bit.
(24) FIG. 24 is a plan view of the bit in present invention, wherein, independent fixed-blade cutting units without scraping-wheels are disposed on the bit.
(25) FIG. 25 is a schematic drawing of the bit disposed with scraping-wheels of different angular deflections.
(26) FIG. 26 is a schematic drawing of the mesh-like cutting pattern created by both scraping-wheel and fixed-blade cutting units of an embodiment in present invention, wherein offset of the scraping-wheel is positive.
(27) FIG. 27 is a schematic drawing of the mesh-like cutting pattern created by both scraping-wheel and fixed-blade cutting units of an embodiment in present invention, wherein offset of the scraping-wheel is negative.
(28) FIG. 28 is a schematic drawing of the mesh-like cutting pattern created by both scraping-wheel and fixed-blade cutting units of an embodiment in present invention, wherein, offset of one scraping-wheel is positive while the other one is negative, and absolute values of the angular deflections of the two scraping-wheels are equal.
(29) FIG. 29 is a schematic drawing of the cutting profiles of an embodiment in the present invention, wherein, cutting profile of one scraping-wheel cutting unit is higher than that of other cutting units, while profile of the other scraping-wheel being partially matched with the profiles of fixed-blade cutting units.
(30) FIG. 30 is a schematic drawing of the cutting profiles of an embodiment in the present invention, wherein, cutting profile of one scraping-wheel cutting unit is higher than that of other cutting units.
(31) FIG. 31 is a schematic drawing of the scraping-wheel being configured with cutters of different diameters.
(32) FIG. 32 is a schematic drawing of the scraping-wheel being configured with non-circular section (elliptic section) cutters.
(33) FIG. 33 is a schematic drawing of the wedge-shaped cutter.
EMBODIMENTS
(34) The present disclosure is further illustrated in details in reference to the following figures. It is to be noted that the figures illustrates only some embodiments of the invention and therefore are not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.
Embodiment 1
(35) As illustrated in FIGS. 3, 4, 5, 6 and 7: A composite drill bit with a scraping-wheel cutting unit being disposed on the fixed-blade, comprising: a bit body (1), a fixed-blade (4) and a scraping-wheel (2). The fixed-blade (4) with cutters (41) fixed thereon is configured on the bit body (1). The angular deflection of the scraping-wheel (2) is in the range of 20||90. At least one scraping-wheel cutting unit, which comprises the scraping-wheel shaft (3) and the scraping-wheel (2) with cutters (21) disposed thereon, is configured on the bit body (1). At least one scraping-wheel (2) is disposed on the fixed-blade (4) forming a rotary connection. The fixed-blade (4) is machined with scraping-wheel slot in which the scraping-wheel (2) is disposed, one end or both ends of the scraping-wheel shaft (3) is disposed on the fixed-blade (4), and the scraping-wheel (2) is disposed on the fixed-blade (4) with rotary connection formed through the scraping-wheel shaft (3). With this structure, volume of the scraping-wheel cutting unit is largely reduced, and fixed-blades (4) in front and at the back of the scraping-wheel (2) could prevent it from axial movement or falling off the bit. For bearings of the same size, the bearing strength is larger and stress on the scraping-wheel shaft (3) is evener than the existing design (as illustrated in FIG. 1), so that the scraping-wheel bearing system of the present invention is safer, more reliable and more durable. The scraping-wheel (2) is disposed on the fixed-blade (4) with rotary connection through scraping-wheel shaft (3), among multiple connection methods, there are several priorities: First, as illustrated in FIG. 5, the scraping-wheel (2) is fixed on the scraping-wheel shaft (3) (through keys, splines or interference fit or even being formed as an integrated structure with each other etc.), and the scraping-wheel shaft (3) is disposed on the fixed-blade (4) with rotary connection, so that the scraping-wheel (2), together with the shaft (3), is able to rotate relative to the fixed-blade (4). Second, the scraping-wheel (2) is disposed on the scraping-wheel shaft (3) with rotary connection, and at least one end of the shaft (3) is fixed on the fixed-blade (4) (as illustrated in FIG. 4). Third, the scraping-wheel (2) is disposed on the scraping-wheel shaft (3) with rotary connection, both ends of the shaft (3) are fixed on the fixed-blade (4), and at least one circle of cutters (41) are fixed in front and/or at the back of the scraping-wheel (2). As illustrated in FIGS. 8, 9, 12 and 13, the fixed-blade (4) is configured with one to maximum three rows of cutters (41), making the bit more adaptable for drilling in hard and abrasive formation. As illustrated in FIG. 14, the fixed-blade is machined with two scraping-wheel slots extending from the top towards the root of it, wherein one slot is in front of the fixed cutters (41) and the other one at the back, and each slot is disposed with one scraping-wheel (2). As illustrated in FIG. 15, is a bit similar to the one in FIG. 14 with only the journal angle of the scraping-wheel (2) being different. As illustrated in FIG. 16, is a bit similar to the one in FIG. 14, wherein cutters (41) are disposed on the fixed-blade (4) in front of, at the back of and between the scraping-wheels (2). As illustrated in FIG. 17, is a bit similar to the one in FIG. 16, wherein the polar axis planes of the two scraping-wheels (2) on the same fixed-blade (4) are different. The combination of fixed cutters (41) and scraping-wheel cutting unit forms cross-cutting area in the bottomhole, which is of benefit for cutters effective penetrating in rocks, thus lowering the wear rate of cutters and increasing rock-breaking efficiency for the bit. FIG. 22 illustrates the mesh-like bottomhole pattern scraped by fixed cutters (41) and scraping-wheels with positive offset (as the structures illustrated in FIGS. 8, 9 and 13). FIG. 6 illustrates the concentric tracks (5) formed by fixed cutters and the spiral-like tracks (6) (from edge to center of the borehole) formed by the scraping-wheel with positive offset. As illustrated in FIG. 27, is the mesh-like bottomhole pattern scraped by fixed cutters (41) and scraping-wheels with negative offset (as the structures illustrated in FIG. 12). FIG. 7 illustrates the concentric tracks (5) formed by fixed cutters and the spiral tracks (7) (from center to edge of the borehole) formed by scraping-wheels with negative offset.
Embodiment 2
(36) This embodiment is generally the same as Embodiment 1, as illustrated in FIGS. 12, 22 and 24, wherein, the difference is that the bit body (1) is configured with independent fixed-blade cutting unit which consists of independent fixed-blade (4) and cutters (41) affixed thereon. Furtherly, the fixed-blade (4) disposed with scraping-wheel is configured with one row of cutters (41) (as illustrated in FIG. 22) or two rows of cutters (41) (as illustrated in FIGS. 12 and 24). Moreover, independent fixed-blade cutting unit (4) is disposed on the bit body (1) so that cutters distribution density is increased, making the bit to be more adaptable for the hard and abrasive formation.
Embodiment 3
(37) This embodiment is generally the same as Embodiment 1 or 2, wherein the difference is that scraping-wheels with both positive and negative offsets are disposed on the bit body (1). As illustrated in FIGS. 14, 15, 16 and 17, since two scraping-wheels (2) are disposed on the fixed-blade (4) with a close space, the corresponding ends of the scraping-wheel shaft (3) are disposed on the same part of the fixed-blade (4), so that the bit structure is more compact or, for the bit of the same size, more cutters can be configured, on the other hand, cutters (41) can be disposed on the fixed-blade (4) in front of, at the back of and between the scraping-wheels (2) to form fixed-blade cutting units in different areas of the fixed-blade. As illustrated in the figures, structure of the embodiment has enlarged the distribution space for the fixed cutters and enables more scraping-wheels to be disposed on the bit, and accordingly, making the bit smaller and more compact, which is favorable for the application of the bit in deep-hole and slim-hole wells drilling. FIG. 28 illustrates the cross-cutting or mesh-like bottomhole pattern scraped by fixed cutters (41) and scraping-wheels with both positive and negative offsets, wherein, the concentric tracks (5) are formed by fixed cutters, and the spiral-like tracks (6) (from the edge to center of the borehole) are formed by scraping-wheels with positive offset while the spiral-like tracks (7) (from center to edge of the borehole) are formed by scraping-wheels with negative offset. Multiple cross-cutting like this is of benefit for cutters effective penetrating in rocks, and consequently, increases the rock-breaking efficiency of the significantly.
Embodiment 4
(38) As illustrated in FIGS. 2, 10, 11, 18, 19, 20, 21, 22 and 23: A composite drill bit with a scraping-wheel cutting unit being disposed on the fixed-blade, comprising: a bit body (1), a fixed-blade (4) and a scraping-wheel (2). The fixed-blade (4) with cutters (41) fixed thereon is configured on the bit body (1). The angular deflection of the scraping-wheel (2) is in the range of 20 ||90. At least one scraping-wheel cutting unit, which comprises the scraping-wheel shaft (3) and the scraping-wheel (2) with cutters (21) disposed thereon, is configured on the bit body (1). At least one scraping-wheel (2) is disposed on the fixed-blade (4) forming a rotary connection. The scraping-wheel (2) is disposed in front or at the back of the fixed-blade (4), one end of the scraping-wheel shaft (3) is fixed with the scraping-wheel (2) and the other end forms a rotary connection within the fixed-blade (4) (as illustrated in FIG. 20). As illustrated in FIGS. 10 and 21, the scraping-wheel (2) is disposed in front of the fixed-blade (4), in FIG. 11, the scraping-wheel (2) is disposed at the back of the fixed-blade (4), and in FIG. 19, the scraping-wheels (2) are disposed both in front and at the back of the fixed-blade (4). As illustrated in FIG. 23, independent fixed-cutter cutting unit (401) fixed with cutters (411) is disposed on the central area of the bit. Furtherly, this embodiment could be hybridized with Embodiment 2.
Embodiment 5
(39) This embodiment is generally the same as Embodiment 1, 2, 3 or 4, wherein the difference is that at least two scraping-wheel (2) cutting units are disposed on the bit, the angular deflection of at least one scraping-wheel (2) differs from that of the others, as illustrated in FIG. 21, 12, furtherly, diameters of two scraping-wheels with different angular deflections are not equal.
Embodiment 6
(40) This embodiment is generally the same as Embodiment 1, 2, 3 or 4, wherein the difference is that at least two scraping-wheel cutting units are disposed on the bit, the cutting profile of at least one scraping-wheel is lower than the others. As illustrated in FIG. 29, the cutting profile (92) of one scraping-wheel (of which the cutters are labeled 212) is positioned higher than the cutting profile (8) of the fixed-blade and the cutting profile (91) of the other scraping-wheel (of which the cutters are labeled 211), meanwhile, the cutting profile (91) matches with the fixed cutting profile (8). As illustrated in FIG. 30, the cutting profile (91) of one scraping-wheel (of which the cutters are labeled 211) is positioned lower than the cutting profile (8) of the fixed-blade and the cutting profile (92) of the other scraping-wheel (of which the cutters are labeled 212).
Embodiment 7
(41) This embodiment is generally the same as Embodiment 1, 2, 3 or 4, as illustrated in FIG. 31, wherein the difference is that cutters (21) of different diameters are disposed on at least one scraping-wheel (2).
Embodiment 8
(42) This embodiment is generally the same as Embodiment 1, 2, 3 or 4, wherein the difference is that at least one scraping-wheel (2) is disposed with non-circular section cutters (21). FIG. 32 illustrates a scraping-wheel disposed with elliptic section cutters (21), and FIG. 31 illustrates a scraping-wheel disposed with noncircular section cutters (21) with salient point or salient area (such as wedge-shaped cutter).
Embodiment 9
(43) This embodiment is generally the same as Embodiment 1, 2, 3 or 4, wherein the difference is that two circles of cutters (21) are disposed on the same scraping-wheel (2), as illustrated in FIGS. 18, 21 and 23, the scraping-wheel (21) is disposed with two circles of cutters (21).
Embodiment 10
(44) This embodiment is generally the same as Embodiment 1, 2, 3 or 4, wherein the difference is that at least two scraping-wheels (2) cutting units are disposed on the bit, the radial position of at least one scraping-wheel (2) on the bit differs from that of the others. Furtherly, diameters of at least two scraping-wheels with different radial positions on the bit are not equal.
