Integrated spiral blade collar   

The present application provides an integrated spiral blade collar.

BACKGROUND OF THE INVENTION

A drill string generally has a bit connected to its lower end that drills a borehole through an earth formation as the drill string and the bit are rotated. The drill string typically includes a length of relatively heavy drill collars at its lower end to provide weight on the bit.

A drill collar generally is constructed to provide a predetermined radial spacing of the longitudinal axis of the drill string with respect to the borehole wall. Drill collars commonly have three or four “straight” blades that contact the formation. The straight blades generally run substantially parallel to the longitudinal axis along substantially the length of the drill collar.

Unfortunately, the contact area between the formation and the “straight” blades of such drill collars is relatively small. The relatively small contact area tends to provide only limited stabilization of the bottom-hole assembly (BHA). The contact between the “straight” blades and the formation can increase torque during drilling operations. The straight blades also generally do not significantly promote the lifting of cuttings up the borehole.

A need exists for collars with configurations that: (a) provide greater stabilization; (b) reduce torque; and, (c) promote the lifting of cuttings up the borehole.

SUMMARY

The present application provides an integrated spiral blade collar (“ISBC”).

In one embodiment, the application provides an ISBC comprising: a collar comprising a wall defining a bore, the collar having a longitudinal axis extending from a proximal end to a distal end; the collar comprising a first engagement mechanism at the proximal end and a second engagement mechanism at the distal end; the collar comprising one or more integral blades extending radially outward from an outer surface and forming a spiral around the longitudinal axis of the collar from at or near the proximal end to at or near the distal end of the collar, the spiral being at an angle of from 1° to 89° relative to the longitudinal axis of the collar.

In another embodiment, the application provides a method of increasing performance during drilling operations, the method comprising: mechanically engaging a bottom hole assembly (BHA) with a proximal end or a distal end of an ISBC comprising a wall defining a bore comprising a first engagement mechanism at a proximal end, a second engagement mechanism at a distal end, and a longitudinal axis extending therebetween, the ISBC comprising one or more integral blades extending from an outer surface of the ISBC and spiraling around the longitudinal axis from at or near the proximal end to at or near the distal end, the spiral being at an angle relative to the longitudinal axis; and, drilling through a formation to an improved final depth at which the ISBC must be replaced, the improved final depth being greater than the final depth to which a comparable straight blade collar or standard pack assembly drills through the same formation.

In yet another embodiment, the application provides a method of increasing performance during drilling operations, the method comprising: mechanically engaging a bottom hole assembly (BHA) with a proximal end or a distal end of an ISBC comprising a wall defining a bore comprising a first engagement mechanism at a proximal end, a second engagement mechanism at a distal end, and a longitudinal axis extending therebetween, the ISBC comprising one or more integral blades extending from an outer surface of the ISBC and spiraling around the longitudinal axis from at or near the proximal end to at or near the distal end, the spiral being at an angle relative to the longitudinal axis; and, rotating the ISBC at a rotation rate, thereby producing an improved rate of penetration of 1.5 times or more greater than the rate of penetration achieved using a comparable straight blade collar or standard pack assembly drilling through the same formation.

FIG. 1A is a schematic isometric view of one embodiment of a near bit integrated spiral blade collar (“ISBC”).

FIG. 1B is a schematic isometric view of a sting ISBC.

FIG. 2 is an enlarged view of the box 12 of the near bit ISBC of FIG. 1.

FIG. 3 is a longitudinal sectional view at line C-C in FIG. 2.

FIG. 4A is a cross sectional view along line B-B of FIG. 2.

FIG. 4B is a cross sectional view of an alternative embodiment along line B-B of FIG. 2.

FIG. 4C is a cross sectional view of another alternative embodiment along line B-B of FIG. 2.

FIG. 4D is a cross sectional view of another alternative embodiment along line B-B of FIG. 2.

FIG. 5 is an enlarged, truncated view of the ISBC of FIG. 1A.

FIG. 6 is a longitudinal sectional view at line D-D along the distal extension 21 in FIG. 5.

FIG. 7 is a graph of predictions and goals related to time required to drill to 13,500 feet through a formation using a straight blade tricollar vs. actual time required to drill using an integrated spiral blade collar.

DETAILED DESCRIPTION

The present application provides an integrated spiral blade collar (“ISBC”). The ISBC provides a number of advantages compared to straight blade collars. In one embodiment, the ISBC minimizes torque during drilling.

In one embodiment, the ISBC lifts more cuttings up the borehole than a comparable straight blade collar. In one embodiment, the ISBC stabilizes the BHA due to increased contact between the blades and the formation. In one embodiment, the ISBC provides more effective weight on the bit. In one embodiment, the ISBC reduces stresses on the bit. In one embodiment, the ISBC enhances bit life. In one embodiment, the ISBC increases the rate of penetration (ROP) of the ISBC. In one embodiment, the ISBC reduces the mechanical specific energy.

In one embodiment, the ISBC produces an improved rate of penetration through a given formation compared to the rate of penetration achieved using a comparable straight blade collar. During three runs, an ISBC having three blades (sometimes referred to as a tricollar ISBC) achieved 1.5 times the rate of penetration achieved using a straight blade collar having three blades.

A standard pack assembly generally comprises one or more stablizers, one or more straight tricollars, and/or one or more roller reamers. The tricollar ISBC achieved 2 or more times the rate of penetration achieved using a standard pack assembly during the three runs.

Hence, in one embodiment, the ISBC produces an improved rate of penetration of 1.5 times or more greater than the rate of penetration achieved using a comparable straight blade collar or standard pack assembly drilling through the same formation. In one embodiment, the ISBC produces an improved rate of penetration of 2 times or more greater than the rate of penetration achieved using a standard pack assembly drilling through the same formation.

During the three runs, the straight blade tricollar and the standard pack assembly had to be replaced after drilling 2500 feet. In contrast, the ISBC did not have to be replaced until reaching 4000 feet.

Hence, in one embodiment, the ISBC exhibits an extended life compared to a straight blade tricollar and/or standard pack assembly. In one embodiment, the ISBC drills to an improved final depth in a subterranean formation, at which point the ISBC must be replaced. In one embodiment, the improved final depth is greater than the final depth to which a comparable straight blade collar or standard pack assembly drills through the same formation. In one embodiment, the improved final depth is 2 or more times the final depth to which a standard pack assembly drills through the same formation.

Rather than having one or more straight blades, the ISBC comprises one or more spiral blades. In one embodiment, the ISBC comprises a plurality of spiral blades separating a plurality of substantially planar surfaces. The one or more spiral blades spiral from at or near the proximal end of the collar to at or near the distal end of the collar.

The number of blades may vary. In one embodiment, the ISBC comprises one blade. In one embodiment, the ISBC comprises a plurality of blades. In one embodiment, the ISBC comprises two blades. In one embodiment, the ISBC comprises three blades separating three substantially planar surfaces extending from at or near the proximal end of the collar to at or near the distal end of the collar.

The number of blades, the length of the blades, and/or the rotation rate, may be increased, if desired, in order to increase the lifting of cuttings up the borehole. Without limiting the application to a particular theory of operation, the increase in lifting of cuttings is believed to result from Archimedes theory of suction. The lifting of cuttings up the borehole using the ISBC may be increased even further by substantially planar surfaces that are somewhat concave. FIGS. 4B, 4C, and 4D are cross sections of ISBCs which have such concave surfaces.

ISBCs according to the present application will be better understood with reference to the Figures, which are illustrative only and should not be construed as limiting the claims.

FIG. 1A illustrates an exemplary embodiment of a “near bit” ISBC. Referring to FIG. 1A, the near bit ISBC comprises a collar 10 having a longitudinal axis 29-29. The near bit ISBC comprises a box 12, a proximal intervening segment 14, a proximal segment 16, an intermediate intervening segment 17, an intermediate segment 18, a distal intervening segment 19, a distal segment 20, and a distal extension 21. The proximal intervening segment 14 and the intermediate intervening segment 17 provide make-up and/or break-up space that may be used to apply torque to engage and/or disengage the ISBC. The distal extension 21 serves as a fishing neck for fishing the ISBC out of the borehole, if necessary.

In one embodiment, the box 12 comprises an engagement mechanism at a proximal end 46. In one embodiment, the box comprises an engagement mechanism at a distal end 46a adjacent to the proximal intervening segment 14.

Suitable engagement mechanisms for the ISBC, generally, engage the ISBC to a separate desired component in a fixed rotational relationship. The fixed rotational relationship may be permanent or temporary. In one embodiment, the engagement mechanism permanently engages the ISBC in a fixed rotational relationship with a separate component. In one embodiment, the engagement mechanism releasably engages the ISBC in a temporary fixed rotational relationship with a separate desired component. Suitable engagement mechanisms include, for example, mating threads, hooks and eyes, a matching slot and die, a welded engagement, and a fused engagement. In one embodiment, the engagement mechanism is external threads on a pin that mate with internal threads on a box.

In one embodiment, the box 12 comprises proximal box threads 48 (FIG. 3) adapted to engage the external threads of a pin on a desired component. The BHA often comprises externally threaded pins. For this reason, the embodiment in FIG. 1A comprising the box 12 is sometimes referred to as a “near bit” ISBC.

In one embodiment, the ISBC is a “sting” ISBC. A sting ISBC is depicted in FIG. 1B. The “sting” ISBC of FIG. 1B is substantially the same as the “near bit” ISBC of FIG. 1A except that there is no box 12. Instead, the proximal end 15 of the proximal intervening segment 14 is a pin 15 comprising exterior threads. In one embodiment, the pin 15 mates with a box 12, or with the distal inner threads 77 (FIG. 6) of another ISBC 10.

An enlarged view of an exemplary embodiment of the box 12 of FIG. 1A is seen in FIG. 2. The box 12 has the longitudinal axis 29-29.

FIG. 3 is a cross section taken along the longitudinal axis 29 at line C-C of FIG. 2. As seen from FIG. 3, in one embodiment, the proximal end 46 of the box 12 comprises proximal box threads 48. The proximal box threads 48 may be any suitable threads adapted to engage external threads on a desired pin. In one embodiment, the proximal box threads 48 are adapted to engage pin 15 of another ISBC 10. In one embodiment, the proximal box threads 48 are adapted to engage a pin in mechanical communication with the BHA.

In one embodiment, the edge 49 at the proximal end 46 of the box 12 is beveled at an angle. The angle relative to the longitudinal axis 29-29 may vary. In one embodiment, the edge 49 is beveled at an angle of from about 0° to 90°. In one embodiment, the edge 49 is beveled at an angle of from about 0° to 89°. In one embodiment, the edge 49 is beveled at an angle of from about 0° to 45°. In one embodiment, the edge 49 is beveled at an angle of about 45° relative to the longitudinal axis 29-29. The inner diameter 51 at the proximal end of the proximal box threads 48 may vary. In one embodiment, the ISBC comprises a bore 24. In one embodiment, the inner diameter 51 of the proximal box threads 48 is the same as the inner diameter 45 of the bore 24 (FIG. 4A).

In one embodiment, the bore 24 extends along the longitudinal axis along the length of the collar 10. In this embodiment, complimentary engagement mechanisms are engaged in or with the bore. The inner diameter 45 of the bore 24, extending from the proximal box threads 48 (FIG. 3) to the distal segment threaded section 77 (FIG. 6), may vary. In one embodiment, the inner diameter 45 of the bore 24 varies from about 5.7 cm (2.25 inches) to about 10.8 centimeters (4.25 inches). In one embodiment, the inner diameter of the bore 24 varies from about 5.7 cm (2.25 inches) to about 8.9 cm (3.5 inches). In one embodiment, the inner diameter of the bore 24 is about 5.7 cm (2.25 inches). In one embodiment, the inner diameter of the proximal box threads 48 also is 5.7 cm (2.25 inches). In one embodiment, the proximal box threads comprise an American Petroleum Institute (API) Reg Box with a 2F3R float bore.

In the frontal view of the box 12 (FIG. 2), the box blade 28 and the box blade 30 abut opposed edges of a box substantially planar surface 31. In FIG. 2, box blade 28 and the box blade 30 have rounded proximal ends 28a and 30a. In FIG. 2, box blade 30 extends from the rounded box proximal end 30a to a tapered box distal end 30b.

FIGS. 4A-4D are cross sections taken at line B-B of FIG. 2 showing alternative embodiments of the collar 10. In one embodiment, a cross section taken at any location distal to the proximal end of the proximal box hardface pad 100a (FIG. 5) and extending to the distal end 105 of the distal hardface pad 104c (FIG. 5) will have substantially the same outer surface configuration as that depicted in FIG. 4A-4D, depending upon the embodiment.

In the embodiment of FIG. 4A, the wall 26 defines a bore 24. The bore 24 depicted in FIG. 4A is substantially cylindrical. However, the bore 24 may have other configurations. Suitable configurations for the bore 24 include, for example, rectangular, triangular, oval, or any other suitable configuration. In one embodiment, the bore 24 is cylindrical.

The wall 26 may comprise any material having sufficient mechanical strength. Suitable materials include, for example, metal, metal alloys, or composites. In one embodiment, the wall 26 comprises iron or cast iron. In one embodiment, the wall 26 comprises stainless steel. In one embodiment, the wall 26 comprises tungsten carbide.

In the embodiment depicted in FIG. 4A, the wall 26 has first, second, and third box substantially planar surfaces 32, 34, and 36, respectively. In the embodiment depicted in FIG. 4A, lines 38a, 38b, and 38c drawn along the box substantially planar surfaces 32, 34, and 36 form a triangle. The angle “A” found at each corner of the triangle may vary. In the embodiment depicted in FIG. 4A-4D, the lines 38a, 38b, and 38c form a substantially equilateral triangle. In this embodiment, the angle “A” at each corner of the triangle is approximately 60°. The first, second, and third box substantially planar surfaces 32, 34, and 36, are separated by a first box blade 40, a second box blade 42, and a third box blade 44, respectively.

Unless specified to the contrary, a “substantially planar surface” is not a surface that necessarily is flat. For example, a substantially planar surface may be concave, convex, may have a “concave” or “convex” “V” structure, or may comprise notches, grooves, or other indentations or projections. As used herein, such configurations are substantially planar as long as lines drawn along their surfaces from a triangle, a rectangle, a pentangle, or similar closed geometric structure which corresponds to the number of blades on the ISBC.

Exemplary alternative embodiments comprising concave surfaces are depicted in FIGS. 4B-4D, in which like numbers indicate like parts. In FIGS. 4B-4D, the wall 26 has a first substantially concave surface 32, a second substantially concave surface 34, and a third substantially concave surface 36, separated by a first blade 40, a second blade 42, and a third blade 44, respectively.

In FIG. 4B, the blade edges 32a, 32b, 34a, 34b, 36a, 36b, are relatively sharp. In one embodiment, some of the edges 32a, 32b, 34a, 34b, 36a, 36b, are sharp and others are rounded.

In one embodiment, one or more of the blades 40, 42, 44 comprise hardface pads. In one embodiment, all of the blades 40, 42, 44 comprise hardface pads.

Suitable hardface pads comprise material that is harder than the material from which the wall 26 is made. In one embodiment, the hardface pads comprise a material that is harder than stainless steel. In one embodiment, the substantially planar surfaces comprise a plurality of spaced hardface pads comprising cobalt, tungsten carbide fragments. Hardface pads comprising cobalt, tungsten carbide fragments are commercially available from a variety of sources. For example, suitable hardface pads are commercially available from Vital Metals Ltd. The size of the hardface pads may vary. Increasing the size and the exposed surface area of the hardface pads tends to increase torque during drilling. Decreasing the size and the exposed surface area of the hardface pads tends to decrease torque during drilling. The hardface pads may be affixed to the blades using any suitable method. In one embodiment, the surface of the ISBC to which a hardface pad is to be affixed is heat melted and the hardface pad is bonded to the heat-melted surface.

In FIG. 4C, hardface pads cover substantially all of the cross-sectional surface of the first box blade 40, the second box blade 42, and the third box blade 44, leaving slightly rounded edges 32a, 32b, 34a, 34b, 36a, 36b adjacent to the hardface pads. Referring to FIG. 4D, hardface pads cover much of the cross-sectional surface of the first blade 40, the second blade 42, and the third blade 44, but an exposed area 41 remains adjacent to each of the rounded edges 32a, 32b, 34a, 34b, 36a, and 36b.

A triangle is formed when lines 38a, 38b, and 38c are drawn between the edges 32a-32b abutting surface 32, the edges 34a-34b abutting surface 34, and the edges 36a-36b abutting surface 36. The number of blades may be more or less than three. Lines drawn along the substantially planar surfaces between the blades will form the closed geometric structure corresponding to the number of blades of the ISBC>

Referring back to FIG. 2, in one embodiment, the box blades 28 and 30 (FIG. 3) comprise a plurality of box spaced hardface pads, designated in FIG. 2 as 31a, 31b, and 31c. In one embodiment, the box blades 28, 30 (FIG. 3A) comprise three box hardface pads 31a, 31b, and 31c, respectively, per blade.

In one embodiment, the blades 28, 30 do not comprise hardface pads. Where the blades do comprise hardface pads, the number, size, and spacing of the hardface pads may vary. In one embodiment, the entire cross-sectional surface of the blades is covered with hardface pads. In one embodiment, portions of the blades are not covered with hardface pads. In one embodiment, the hardface pads are longitudinally spaced. In one embodiment, the hardface pads do not cover small portions of the edges of the blades 28, 30. In one embodiment, the hardface pads are both longitudinally spaced and the hardface pads do not cover small portions of the edges of the blades.

The length of the hardface pads may vary. The pad-to-pad distance between the distal end of one hardface pad and the proximal end of an adjacent hardface pad also may vary. In one embodiment, the length of the hardface pads and the pad-to-pad distance is determined by the size of commercially available hardface pads. In one embodiment, the blades 28, 30 comprise three hardface pads each having a length of about 17.8 cm (7 inches). In one embodiment, the pad-to-pad distance is about 12.7 cm (5 inches).

The box length, which extends from the proximal end 47 of box hardface pad 31a to the distal end 35 of box hardface pad 31c, may vary. In one embodiment, the box length is about 78.7 cm (31 inches).

In one embodiment, the blades 28, 30 comprise distal ends 30b which taper inward at an angle relative to the longitudinal axis 29-29 to form the outer surface of the proximal intervening segment 14. The tapered angle may vary. In one embodiment, the tapered angle varies from about 10 to 89°. In one embodiment, the tapered angle varies from about 10 to 45°. In one embodiment, the tapered angle varies from about 10 to 20°. In one embodiment, the distal end 30b is tapered inward at an angle of about 12° relative to the longitudinal axis 29-29.

The outer surface of the proximal intervening segment 14 may have a variety of configurations. Examples of suitable configurations include cylindrical, rectangular, triangular, oval, or any other suitable configuration. In one embodiment, the outer surface of the proximal intervening segment 14 is cylindrical. As previously explained, the proximal intervening segment 14 provides make-up and/or break-up space that may be used to apply torque to engage and/or disengage the ISBC.

Referring again to FIG. 1A, the number of times that a blade (e.g., blade 30) spirals around the longitudinal axis from a proximal end to a distal end of the ISBC depends on the angle X formed between the longitudinal axis 29-29 and a line drawn along the longitudinal axis of the blade 30. In one embodiment, X is from 1° to 89°. In one embodiment, X is from 10 to 45°. In one embodiment, X is 450.

FIG. 5 is an enlarged, truncated view of the near bit ISBC 10 of FIG. 1a comprising the box 12, the proximal intervening segment 14, the proximal segment 16, the intermediate intervening segment 17, the intermediate segment 18, the distal intervening segment 19, and the distal segment 20.

As with the box 12, the presence or absence, size, and spacing of hardface pads on the proximal blades 63 may vary. In the embodiment of FIG. 5, the proximal blades 63 comprise proximal hardface pads 100a, 100b, and 100c. In one embodiment, the proximal blades 63 comprise proximal hardface pads 100a, 100b, and 100c, having similar dimensions and similar spacing to the box hardface pads 31a, 31b, and 31c.

In the embodiment of FIG. 5, the proximal ends 62a of the proximal blades 63 also are tapered inward at an angle relative to the longitudinal axis 29-29 to form the outer surface of the intermediate intervening segment 17. The angle of tapering may vary. In one embodiment, the proximal ends 62a of the proximal blades 63 are tapered inward at an angle of from about 0° to about 90° relative to the longitudinal axis. In one embodiment, the proximal ends 62a of the proximal blades 63 are tapered inward at an angle of from about 0° to about 45° relative to the longitudinal axis. In one embodiment, the proximal ends 62a of the proximal blades 63 are tapered inward at an angle of from about 0° to about 20° relative to the longitudinal axis. In one embodiment, the proximal ends 62a of the proximal blades 63 are tapered inward at an angle of about 12° relative to the longitudinal axis.

In the embodiment depicted in FIG. 5, the proximal blades 63 and the proximal substantially planar surfaces 62, 64 spiral distally to become the intermediate intervening blades 63a (FIG. 1A) and the intermediate intervening substantially planar surfaces 64a (FIG. 1A).

The intermediate intervening blades 63a and the intermediate intervening substantially planar surfaces 64a (FIG. 1A) spiral distally to become the intermediate blades 71 and the intermediate substantially planar surfaces 68, 70. As with the box 12, the presence or absence, size, and spacing of hardface pads on the intermediate blades 71 may vary. In the embodiment of FIG. 5, the intermediate blades 71 comprise intermediate hardface pads 102a, 102b, and 102c. In one embodiment, the intermediate blades 71 comprise intermediate hardface pads 102a, 102b, 102c having similar dimensions and similar spacing to the proximal hardface pads 31a, 31b, and 31c.

In the embodiment depicted in FIG. 5, the distal intermediate blades 71 and the intermediate substantially planar surfaces 68, 70 spiral distally to become the corresponding distal intervening blades 71a (FIG. 1A) and the distal intervening substantially planar surfaces 70a (FIG. 1A).

The distal intervening blades 71a and the distal intervening substantially planar surfaces 70a of the intervening distal segment 19 spiral distally to become the distal blades 73 and the distal substantially planar surfaces 72 of the distal segment 20, illustrated in FIG. 5.

As with the box 12, the presence or absence, size, and spacing of distal hardface pads 104a, 104b, 104c on the distal blades 73 of the distal segment 20 may vary. In the embodiment of FIG. 5, the distal blades 73 comprise distal hardface pads 104a, 104b, and 104c. In one embodiment, the distal blades 73 comprise distal hardface pads 104a, 104b, 104c having similar dimensions and similar spacing to the box hardface pads 31a, 31b, and 31c.

In one embodiment, the distal ends 73a of the distal blades 73 are tapered at an angle relative to the longitudinal axis 29-29. The angle of tapering may vary. In one embodiment, the tapered angle varies from about 10 to 90°. In one embodiment, the tapered angle varies from about 1° to 89°. In one embodiment, the tapered angle varies from about 1° to 45°. In one embodiment, the tapered angle varies from about 1° to 20°. In one embodiment, the distal ends 73a of the distal blades 73 are tapered at an angle of about 12° relative to the longitudinal axis 29-29.

Because the distal intervening section 19 is not tapered at either a proximal end or at a distal end, the configuration of the outer surface of the collar 10 extending from the proximal end 101 of the most proximal hardface pad 100a on the proximal segment 16 to the distal end 105 of the most distal hardface pad 104c on the distal segment 20 is substantially uniform.

FIG. 6 is a cross section through the distal extension 21 along line D-D of FIG. 5. The distal extension 21 illustrated in FIGS. 1, 5, and 6 is cylindrical. However, the distal extension 21 may have a variety of configurations. For example the outer surface of the distal extension 21 may form a cylinder, a rectangle, a triangle, an oval, or another geometric configuration. In one embodiment, the distal extension 21 is cylindrical. As explained previously, the distal extension 21 provides make-up and/or break-up space that may be used to apply torque to engage and/or disengage the ISBC.

As seen from FIG. 6, the distal end of the distal extension 21 comprises distal inner threads 77. The distal inner threads 77 may be any suitable threads. The distal inner threads 77 are adapted to engage a threaded pin on a desired component. In one embodiment, the desired component is a sting ISBC 10 (FIG. 1B), a roller reamer, or drill bit. In one embodiment, the distal inner threads 77 are adapted to engage a threaded pin 15 on a sting ISBC 10 (FIG. 1B) or on a drill bit. In one embodiment, the distal inner threads 77 are a 0.9 m (3½ inch) I.F. Box with 0.9 m (3½ inch) float bore.

The external diameter 76 of the distal extension 21 may vary. The external diameter 76 of the distal extension 21 may be the same as or different that the external diameter of the proximal intervening segment 14.

In one embodiment, the external diameter 76 of the distal extension 21 is substantially the same as the external diameter of the proximal intervening segment 14. In one embodiment, the external diameter 76 of the distal extension 21 is about 12.7 cm (5 inches).

The collar 10 may have a variety of lengths and dimensions. For example, the total length of the collar 10 from the proximal end 47 of the box hardface pad 31a (FIG. 2) to the distal end 105 of the distal hardface pad 104c may vary. In one embodiment, the total length of the collar 10 on the same basis is about 9.45 meters (31 feet).

The dimensions of the various segments of the collar 10 will vary with the length of the collar 10. In one embodiment, the segment length of the box 12, the proximal segment 16, the intermediate segment 18, and the distal segment 20 is different. In one embodiment, the segment length of the box 12, the proximal segment 16, the intermediate segment 18, and the distal segment 20 is the same. In one embodiment, each of the box 12, the proximal segment 16, the intermediate segment 18, and the distal segment 20 have a segment length of about 0.79 meters (31 inches).

The distance 13 (FIG. 5) between the most proximal portion of the rounded end 30a and the most distal portion of the tapered end 30b of the box blade 30 also will vary with the total length of the collar 10. In one embodiment, the distance 13 is about 0.85 meters (33.5 inches).

The length 23 of the proximal intervening segment 14 (FIG. 5), extending from the distal end 35 of the proximal hardface pad 31c to the proximal end 101 of the proximal hardface pad 100a, will vary depending upon the total length of the collar 10. In one embodiment, the length 23 of the proximal intervening segment 14 (FIG. 5) is approximately 0.4 meters (15.5 inches, or 15 17/32″).

The distance 23a between the box tapered end 30b and the proximal tapered end 62a will vary with the total length of the collar 10. In one embodiment, the distance 23a is about 0.3 meter (12 inches).

The intermediate intervening segment length 106 also will vary with the total length of the collar 10. In one embodiment, the intermediate intervening segment length 106 is about 2.3 meters (90.97 inches, or 7 feet, 6 and 31/32 inches).

The distal intervening segment length 108 will vary with the total length of the collar 10. The distal intervening segment length 108 may be the same as or different than the intermediate intervening segment length 106. In one embodiment, the distal intervening segment length 108 is about 2.3 meters (90.97 inches, or 7 feet, 6 and 31/32 inches).

The distal extension length 110 also will vary with the total length of the collar 10. In one embodiment, the distal extension length 110 is about 1.3 meter (49.75 inches).

The collar 10 may be formed in any suitable manner. In one embodiment, the surface of a suitable cylindrical bar or tube is milled to form the various segments using procedures familiar to a person of ordinary skill in the art.

In operation and use, the engagement mechanism at the distal end of the distal segment is engaged with a complimentary engagement mechanism on a desired component. In one embodiment, the engagement mechanism at the distal end (77) is engaged with a complimentary engagement mechanism of another ISBC 10. In one embodiment, an engagement mechanism at the distal end (77) is engaged, for example, with a complimentary engagement mechanism on the drill pipe, on a non-magnetic drill collar (Monel), on a mud motor, or on a heavy weighted drill pipe.

In one embodiment, the distal inner threads 77 are engaged with a pin on a desired component. In one embodiment, the distal inner threads 77 are engaged with the pin 15 of a sting ISBC 10 (FIG. 1B).

In one embodiment, the proximal box threads 48 are engaged with the distal inner threads 77 of a sting ISBC 10 (FIG. 1B). In one embodiment, the proximal box threads 48 are engaged with a complimentary externally threaded pin on the BHA. In one embodiment, the proximal box threads 48 are engaged with a pin on the drill pipe, on a non-magnetic drill collar (Monel), on a mud motor, or on a heavy weighted drill pipe.

The application will be better understood with reference to the following examples, which are illustrative only and not intended to limit the claims.

FIG. 7 is a graph of predictions and goals related to time required to drill to 13,500 feet through the Pinedale Anticline using a straight blade tricollar. The assumptions using the straight blade tricollar were (a) predicted progress under ideal conditions; (a) required progress to meet internal cost per foot target of $250/foot; and (b) required progress to remain within budget. FIG. 7 also graphs the depths actually achieved drilling through the formation using a ISBC.

As seen from FIG. 7, goals (a)-(c) were exceeded using the ISBC. Using the ISBC, 13,500 ft was reached two full days ahead of budget (b), and one full day ahead of the projected goal given ideal conditions (a).

Persons of ordinary skill in the art will recognize that many modifications may be made to the embodiments described herein. The embodiments described herein are meant to be illustrative only and should not be taken as limiting the invention, which will be defined in the claims.