Reamer Wear Protection Assembly and Method

Abstract

Embodiments of a reamer of the present invention generally include a front end containing components, such as pie wedge-shaped corebuster components, that are substantially axially disposed with respect to the axis of rotation of the reamer, wherein the pie wedges include abrasion-resistant inserts, which may be cylindrical in shape, oriented substantially longitudinally with respect to the axis of rotation of the reamer. Embodiments of a method of using an apparatus of the present invention are also provided.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 63/033,481, filed on Jun. 2, 2020, which application is incorporated herein by reference as if reproduced in full below.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

This invention relates to an apparatus and method for sub-surface Horizontal Directional Drilling (HDD). HDD is utilized to create an underground pathway without excavation. An example of HDD may be found in U.S. Pat. No. 5,242,026 to Deken, et al., which is incorporated herein by reference in its entirety. One type of apparatus utilized in HDD is a borehole cutter, also known as a “reamer.” Examples of reamers may be found in U.S. Pat. No. 6,386,302 to Beaton, and U.S. Pat. No. 10,428,586 to Wagner et al., which are incorporated herein by reference in their entirety.

DESCRIPTION OF THE RELATED ART

Within the HDD industry, the underground pathways (bores or holes) are usually not straight and need to be steered to create the necessary profile to avoid surface and sub-surface obstacles. Typically, a bore is created by first constructing a pilot hole using guidance means and a downhole excavating assembly comprising a pilot bit or small-diameter reamer with a bend in or adjacent thereto to steer the bore in a desired direction. The excavating assembly is usually powered by an above-ground, motorized unit (rig) to provide rotational and/or down-hole force. The pilot hole may then be opened using a larger diameter tool, such as a reamer, in one or more multiple passes to create a progressively larger diameter hole. The reamers can be pushed and/or pulled and do not require steering as they follow the profile of the original pilot hole. In order for the larger reamers to follow the previously drilled hole, it is necessary for the reamer to be centralized in the hole so that it can cut fresh rock and create a hole substantially concentric to the original hole.

A typical reamer will comprise several major components, including a collar, cutting elements, front-end, fluid chamber, and supporting gussets. The reamer is designed to concurrently apply load to and fracture the rock, as well as direct drilling fluid, such as mud or water, to flush the cuttings away and expose fresh rock to be drilled. A reamer may be comprised of tubular steel, with forged, cast and/or machined components, and steel plates. The reamer components, such as the main and rear plates, as well as the gussets, are assembled and typically welded together to complete a single assembly that is able to transfer the rig-supplied load to the rock.

In various embodiments, prior art reamers contain a front end and collar that are designed to fit into the previously drilled hole in order to centralize the reamer segments so that the bore can be outwardly concentrically expanded in relation to the previously drilled hole. In one configuration, the front end comprises a plurality of gussets that forms a circular stabilizing body and is beveled outwardly from the collar toward the section of the reamer containing the cutting elements, to enable the collar to follow the previously drilled hole. The front-end may comprise replaceable, sacrificial components, often collectively referred to as a “corebuster,” which are usually disposed circumferentially about the front-end proximate its maximum diameter section.

A corebuster may comprise an annular component, either in the form of a singular solid component, or the annular component may comprise a plurality of segments (e.g., “pie wedges”) which cooperatively form a continuous annular structure. Typically, a corebuster comprises one or more abrasive surfaces designed to contact the rock being drilled. Such abrasive surfaces may be on the pie wedges and/or sections of the gussets. In one aspect, when the corebuster rotates and is forced against the previously drilled hole, it provides guidance so that the reamer follows the previously drilled hole and simultaneously provides stabilization to the reamer. In operation, rotational friction between the outer surface of the corebuster and the rock being drilled results in abrasion of the outer surface of the corebuster. Accordingly, corebusters possess a limited operational lifetime. While corebusters may be readily replaced, greater drilling efficiency is achieved when the corebuster maintains its outer surface integrity as long as possible during a drilling operation. To this end, prior art reamers have frequently employed corebusters which have had an abrasion-resistant (hardmetal) coating applied to the outer surface of the corebuster, or which have had abrasion-resistant inserts (e.g., carbides) at least partially inserted into the outer surface of the corebuster. In the prior art, such inserts are typically inserted into holes drilled perpendicular to the axis of rotation of the reamer. While these modifications often increase useful lifetimes of the corebusters, it would be desirable to even further increase the robustness of the corebuster and extend the useful lifetime thereof.

BRIEF SUMMARY OF THE INVENTION

Embodiments of an apparatus of the present invention generally include a reamer comprising a corebuster, wherein a plurality of inserts comprising an abrasion-resistant material is disposed at least partially within the outer surface of the corebuster in an orientation substantially parallel to the axis of rotation of the reamer. Embodiments of a method of utilizing an apparatus of the present invention are also provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a depiction of an embodiment of a prior art reamer.

FIG. 2 is a depiction of an embodiment of a reamer of the present invention.

FIG. 3 is another depiction of the embodiment of the reamer of the present invention depicted in FIG. 2.

FIG. 4 is a depiction of an embodiment of a front end of the present invention.

FIG. 5A is a depiction of an embodiment of a portion of the present invention wherein a pie wedge is equipped with a plurality of abrasion-resistant inserts.

FIG. 5B is a depiction of an embodiment of a portion of the present invention wherein a pie wedge is equipped with a plurality of abrasion-resistant inserts.

FIG. 5C is a depiction of an embodiment of a portion of the present invention wherein a pie wedge is equipped with a plurality of abrasion-resistant inserts.

FIG. 5D is a depiction of an embodiment of a portion of the present invention wherein a pie wedge is equipped with a plurality of abrasion-resistant inserts.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

The exemplary embodiments are best understood by referring to the drawings with like numerals being used for like and corresponding parts of the various drawings. As used herein, longitudinal refers to the axis A-A identified in FIGS. 1 and 2 (i.e., the axis of rotation of the reamer), and axial refers to a direction perpendicular to axis A-A of FIGS. 1 and 2. The directions top and bottom as used in this specification are used for descriptive purposes only, and other orientations are contemplated.

Referring to FIG. 1, a prior art reamer 1 is depicted. As shown in FIG. 1, reamer 1 comprises an up-hole pipe section 3, up-hole gussets 5, fluid chambers 7, cutting elements 9, front end 11, and a down-hole pipe section (collar) 21. In the reamer depicted in FIG. 1, front end 11 comprises front-end gussets 13, longitudinal corebuster components 17, and axial corebuster components (“pie wedges”) 15. Longitudinal corebuster components 17 and/or pie wedges 15 may comprise a plurality of wear-resistant inserts 19 embedded in a portion of the exterior surface thereof. As would be understood by one skilled in the art, longitudinal corebuster components 17, and pie wedges 15 are subject to wear during drilling operations and must be periodically replaced.

Referring now to FIG. 2, an embodiment of a reamer 100 of the present invention is depicted. As shown in the embodiment of FIG. 2, reamer 100, like prior art reamer 1, comprises an up-hole pipe section 3, up-hole gussets 5, fluid chambers 7, cutting elements 9, front end 11, collar 21, with front end 11 comprising front-end gussets 13, longitudinal corebuster components 17, and axial corebuster components (“pie wedges”) 15. In various embodiments of a reamer 100, axial corebuster components 15 may comprise a plurality of wear-resistant inserts 119 embedded longitudinally (i.e., substantially parallel to the axis of rotation of the reamer) into a portion of an exterior surface 25 thereof. In various embodiments, one or more substantially longitudinally oriented wear resistant inserts 119 comprises a substantially cylindrical component, although the invention is not so limited and other geometries of inserts 119 may be employed. In one embodiment, an insert 119 may be greater in length than in diameter. In one embodiment, an insert 119 comprises a singular component, while in other embodiments (e.g., FIG. 5C, described below), an insert 119 may comprise a plurality of components cooperatively arranged. FIG. 3 depicts a different view of the embodiment of the reamer 100 depicted in FIG. 2.

In various embodiments, one or more inserts 119 are positioned proximate or penetrating an outer surface 27 of the pie wedge 15 (see FIG. 4) so that they make can make contact with the pilot hole wall as wear occurs to the front-end during the reaming process. In various embodiments, inserts 119 may be retained at least partially within pie wedge 15 by interference fit, shrink fit, a brazing process (e.g., silver solder), or may be mechanically captivated, although the invention is not so limited and other methods of retainment may be employed, as would be understood by one skilled in the art. In other embodiments of the present invention (not shown), one or more abrasion-resistant inserts 119 may be positioned longitudinally at least partially within an exterior surface 23 of longitudinal corebuster component 17. In various such embodiments, one or more abrasion-resistant inserts 119 may be so positioned at least partially within a beveled section 24A of exterior surface 23 of longitudinal corebuster component 17, and/or within a substantially non-beveled section 24B of exterior surface 23 of longitudinal corebuster component 17.

In various embodiments, abrasive inserts 119 may comprise materials such as, but not limited to, tungsten carbide, tungsten carbide/cobalt alloys, nickel based alloys (e.g., Hastelloy® or Inconel®), cobalt alloys (e.g., Stellite®), cobalt/carbide hardfacing (e.g., applying a cobalt & carbide matrix by various welding processes including, but not limited to, tig, mig, spray & arc), copper alloys (e.g., beryllium copper), titanium, iron based alloys (e.g., standard, hardened, case-hardened, through-hardened), hardenable stainless steel alloys (e.g., 400 series and 17-4), and natural and polycrystalline diamond (e.g., PCD and PDC).

FIG. 4 depicts an embodiment of a front end of a reamer 100. As shown in the embodiment of FIG. 4, an insert 119 may be partially exposed from outer exterior surface 27 of pie wedge 15. In one embodiment, exposure of a portion of an insert 119 from outer exterior surface 27 of pie wedge 15 may comprise exposure from a beveled section 31 of outer exterior surface 27. In various embodiments, beveled section 31 of outer exterior surface 27 may be disposed proximate a lower exterior surface 29 of a pie wedge 15, or pie wedge 15 lower exterior surface 29 may comprise beveled section 31 of outer exterior surface 27.

FIGS. 5A, 5B, 5C, and 5D depict various embodiments of the present invention wherein a pie wedge 15 is equipped with inserts 119. In the embodiment of FIG. 5A, abrasion-resistant inserts 119 are partially contained within outer surface 27 of pie wedge 15, wherein at least a portion of the inserts 119 protrudes axially outwardly from outer surface 27, and wherein at least a portion of the inserts 119 protrudes longitudinally outwardly from beveled section 31 of outer surface 27.

In the embodiment of FIG. 5B, inserts 119 are partially contained within outer surface 27 of pie wedge 15, wherein at least a portion of the inserts 119 protrude axially outwardly from outer surface 27, and wherein inserts 119 are disposed in a recessed position with regard to beveled section 31 of outer exterior surface 27.

In the embodiment of FIG. 5C, inserts 119 each comprise a plurality of abrasion-resistant insert segments (not individually labeled). Although the insert segments depicted in FIG. 5C are of approximately the same length and diameter, the invention is not so limited and other geometries may be employed. In addition, although in FIG. 5C the insert segments are depicted as abutting each other, the invention is not so limited, and adjacent insert segments may be separated, such as by spacers, or be otherwise non-abutting.

In the embodiment of FIG. 5D, inserts 119 (drawn predominantly in phantom) are disposed substantially completely within pie wedge 15, proximate outer surface 27, wherein a portion of the inserts 119 protrudes longitudinally outwardly from beveled section 31 of outer surface 27.

The embodiments depicted in FIGS. 5A-5D disclose various aspects regarding employment of abrasion-resistant inserts 119; however, these examples are merely exemplary and other embodiments, including, but not limited to, other types of inserts and positioning thereof, may include combinations of such features of a particular pie wedge 15 or one or more pie wedges 15 of a front end 11.

Method

In various embodiments, a method of utilizing embodiments of the present invention comprises the following steps:

A Reamer Provision Step, comprising providing a reamer, such as a reamer 100, wherein one or more abrasion-resistant inserts, such as insert 119, are embedded in an exterior surface, such as exterior surface 27, of one or more pie wedge components oriented substantially axially to an axis of rotation of the reamer, such as pie wedge component 15, wherein the inserts are oriented substantially longitudinally to the axis of rotation of the reamer; and

A Reamer Operation Step, comprising introducing the reamer downhole and operating the reamer to expand the circumference of a hole.

Operation

In operation, an embodiment of a reamer 100 of the present invention is provided in a pilot hole; thereupon, the reamer 100 may be rotated and pulled back through, and/or pushed through, the pilot hole to enlarge the diameter thereof as may be desired. As corebuster sections 15 and/or 17 of the reamer 100 are worn, the front end 11, or sections thereof, such as one or more pie wedges 15 and/or one or more longitudinal corebuster components 17, may be replaced and operations may then be resumed.

As would be understood by one skilled in the art, during operation of the reamer 100 as described herein, wear to the corebuster typically involves wearing down of pie wedges 15 and/or or longitudinal corebuster components 17 through degradation of outer exterior surface 27 of the pie wedges 15 and/or exterior surface 23 of the longitudinal corebuster components 17. Thus, provision of abrasion-resistant inserts 119 as described herein allows for resistant wear thereof to occur along the length of abrasion-resistant inserts 119. Accordingly, the inserts 119, as positioned in various embodiments of the present invention, provide for the provision of contiguous lengths of abrasion-resistant material circumferentially about the corebuster during substantially the entirety of the working life of the pie wedges 15 and/or longitudinal corebuster components 17, and therefore the corebuster.

While the present invention has been disclosed and discussed in connection with the foregoing embodiments, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications, and substitutions of parts and elements without departing from the spirit and scope of the invention.

Claims

1. A reamer for horizontal directional drilling comprising:

a front end comprising one or more components oriented substantially axially to an axis of rotation of said reamer;

wherein:

at least one said axially oriented component is equipped with one or more abrasion-resistant members that is at least partially embedded in an outer exterior surface thereof, and that is oriented substantially longitudinally with respect to said axis of rotation of said reamer.

2. The reamer for horizontal directional drilling of claim 1, wherein at least one of said one or more front end components comprises a pie wedge.

3. The reamer for horizontal directional drilling of claim 2, wherein an abrasion-resistant member at least partially protrudes through an exterior surface of a pie wedge in which it is at least partially embedded.

4. The reamer for horizontal directional drilling of claim 1, wherein at least one of said one or more abrasion-resistant members comprises a substantially cylindrical component.

5. The reamer for horizontal directional drilling of claim 4, wherein said cylindrical component comprises a plurality of components cooperatively arranged.

6. The reamer for horizontal directional drilling of claim 1, wherein at least a portion of an exterior surface of at least one said one or more front end components is beveled.

7. The reamer for horizontal directional drilling of claim 6, wherein at least one of said one or more abrasion-resistant members at least partially protrudes through said beveled exterior surface.

8. A reamer for horizontal directional drilling comprising:

a front end comprising one or more components oriented substantially longitudinally to an axis of rotation of said reamer;

wherein:

at least one said axially oriented component is equipped with one or more abrasion-resistant members that is at least partially embedded in an outer exterior surface thereof, and that is oriented substantially longitudinally with respect to said axis of rotation of said reamer.

9. The reamer for horizontal directional drilling of claim 8, wherein at least one of said one or more front end components comprises a longitudinal corebuster component.

10. The reamer for horizontal directional drilling of claim 8, wherein an abrasion-resistant member at least partially protrudes through an exterior surface of a longitudinal corebuster component in which it is at least partially embedded.

11. The reamer for horizontal directional drilling of claim 8, wherein at least one of said one or more abrasion-resistant members comprises a substantially cylindrical component.

12. The reamer for horizontal directional drilling of claim 11, wherein said cylindrical component comprises a plurality of components cooperatively arranged.

13. The reamer for horizontal directional drilling of claim 8, wherein at least a portion of an exterior surface of at least one said one or more front end components is beveled.

14. The reamer for horizontal directional drilling of claim 8, wherein at least one of said one or more abrasion-resistant members at least partially protrudes through said beveled exterior surface.

15. A method of using a reamer for horizontal directional drilling comprising:

providing a reamer for horizontal directional drilling, wherein said reamer comprises: a front end comprising one or more components oriented substantially axially to an axis of rotation of said reamer; wherein: at least one said axially oriented component is equipped with one or more abrasion-resistant members that is at least partially embedded in an outer exterior surface thereof, and that is oriented substantially longitudinally with respect to said axis of rotation of said reamer; and.

operating said reamer to enlarge the diameter of a subsurface hole.

16. The method of using a reamer for horizontal directional drilling of claim 15, wherein at least one of said one or more front end components comprises a pie wedge.

17. The method of using a reamer for horizontal directional drilling of claim 15, wherein an abrasion-resistant member at least partially protrudes through an exterior surface of a pie wedge in which it is at least partially embedded.

18. The method of using a reamer for horizontal directional drilling of claim 15, wherein at least one of said one or more abrasion-resistant members comprises a substantially cylindrical component.

19. The method of using a reamer for horizontal directional drilling of claim 18, wherein said cylindrical component comprises a plurality of components cooperatively arranged.

20. The method of using a reamer for horizontal directional drilling of claim 15, wherein:

at least a portion of an exterior surface of at least one said one or more front end components is beveled; and

at least one of said one or more abrasion-resistant members at least partially protrudes through said beveled exterior surface.