Downhole drilling assembly.

(54) Title: DRILLING SET OF THE WELL FUND.

(54) Title: DOWNHOLE DRILLING ASSEMBLY.

(57) Summary

A downhole stabilizer (5), such as a drill motor stabilizer, is disclosed, comprising at least reaming means and / or reinforcing means (10). The present invention is also concerned with an assembly (30), such as a downhole drilling assembly (31), comprising at least one of such stabilizers (5) and / or a drilling bit (40, 41) comprising a calibration bit (42) at or near a drilling end (45) thereof and connecting means (46) for connecting the drilling bit (40, 41) to a drilling motor assembly ( 60), wherein the drill bit calibration bit 42 comprises a substantially cylindrical portion having a length less than or equal to about 1.0 times the nominal bit diameter. The present invention is also concerned with a new fixing mechanism (80), such as a lock and key mechanism, to allow the fixing of a shaft (70), for example a motor drive shaft (71 ') by means of or together with a stabilizer (5).

(57) Abstract

A downhole stabilizer (5), such as a drill motor stabilizer, comprises at least one reaming means and / or reinforcing means (10). The present invention also relates to an assembly (30), such as a downhole drilling assembly (31), comprising at least one such stabilizer (5) and / or a drill bit (40.41) comprising a gauge bit (42) at or near a drilling end (45) thereof, and a connection means (46) for connecting the drill bit (40.41) to a drill motor assembly (60), where the drill bit gauge (42) comprises a substantially cylindrical portion having a length less than or equal to approximately 1.0 times the nominal bit diameter. The present invention also relates to a novel locking mechanism (80), such as a lock and key mechanism, to allow locking of a shaft (70 '), eg a motor drive shaft (71'), through or together with a stabilizer ( 5').

DRILLING SET OF THE WELL FUND

FIELD OF THE INVENTION

The present invention is concerned with a downhole stabilizer such as a drill motor stabilizer and with a downhole assembly comprising such a stabilizer.

<td>The</td><td>present invention</td><td>too</td><td>it is</td><td>concerning with</td>

<td>devices</td><td>stabilization</td><td colspan="2">improved</td><td>for engines</td>

<td>drilling</td><td>and in particular</td><td>but no</td><td colspan="2">exclusively with</td>

<td>devices</td><td>stabilization</td><td>for use</td><td>with</td><td>high motors</td>

Addressable speed for operation in a hole.

The present invention is also concerned with a new fixing mechanism, such as a lock and key mechanism to allow the fixing of a shaft, for example, a motor drive shaft, by means of or together with a stabilizer, for example a drilling motor stabilizer and in particular, although not exclusively, for the attachment, removal and / or securing of a drilling trepan, such as a short gauge drill trepan to / from a lower end of the tree.

BACKGROUND OF THE INVENTION

Various types of downhole motors, including positive displacement motors and turbo drills, may be suitable for driving a drill bit into a hole, for example, during hole drilling. Addressable high-speed motors, also known as turbo drills or turbines, are a commonly used type of downhole motor and have become well known in the downhole drilling field. During development of high-speed airship

<td>During the</td><td>development of</td><td>motors</td><td>of</td><td>high speed</td>

<td>addressable, it</td><td>recognized that</td><td>at high</td><td colspan="2">speeds was</td>

<td>necessary that the</td><td>engine and the</td><td>joint</td><td>of</td><td>trepan</td>

stabilized in order to reduce or eliminate the tortuosity of the hole - commonly known as spiral formation. This spiral movement that can occur at high speeds can seriously reduce drilling speed, as well as causing excessive wear on the various parts of the motor assembly. This spiral effect can be particularly severe in the case of certain types of geological formations in which the hole is formed.

In a typical drill assembly the drill bit is connected to a motor shaft located inside a motor body.

The direction of hole formation can be controlled, for example by providing a bend, a deflection device, or an eccentric stabilizer located in an appropriate position of the assembly.

During normal drilling, the motor body portion is rotated at a lower speed than the drilling trepan speed, thereby mitigating the effect of the deflection device. On the other hand, when directional or lateral drilling is required, the assembly deflection device is adjusted in a desired direction and kept stationary, with the drill bit being rotated at high speed by the motor down the hole.

In order to maximize the deviation of the hole, the so-called trephine pendant (that is, the distance from the lower end, for example lower bearing or lower stabilizer, on the motor body housing to the operating face to the drilling trepan) It should be kept to a minimum.

Commonly most drill bits comprise a bolt connection (male) with an API thread to match an API thread socket (female) connection on the coupling component, which may be a drill collar, sub or motor shaft. However, in turbine drilling it has become common practice for the threaded connection to be reversed, the trepan is provided with the box connection.

In downhole drilling, the terms short gauge trepan or long gauge trepan refer to the stabilizing or guide portion of the outside diameter that is used for the purposes of final trimming and guide the trepan within the hole created by the trepan. The gauge may include a sleeve to extend the guide portion of the trepan to a longer length. This sleeve can be manufactured as an integral part of the trepan structure. The extended sleeve portion commonly has a diameter of + - 1/32 of the nominal trepan diameter.

In the art, a short gauge trepan is understood to mean a drill trepan with an outer cylindrical portion, the length of which is approximately one inch to 1.0 times the nominal trepan diameter. This is in contrast to the so-called long bore bits that can have cylindrical portions, the lengths of which are in excess of the diameter of trepan. In addition, so-called long-caliber drills are frequently made of. separate pieces and have a short cylindrical portion, which is part of the trepan head, and a second cylindrical portion formed by a separate sleeve

<td>and united</td><td>to the head</td><td>of the</td><td>trepan. It is understood that</td><td>the,</td><td>two</td>

<td>servings</td><td>cylindrical</td><td>I know</td><td>combine in such a way</td><td>than</td><td>the</td>

<td>length</td><td>of the portion</td><td colspan="3">cylindrical is in excess of once</td><td>the</td>

nominal trepan diameter. The two cylindrical portions are substantially the same diameter but may be slightly different; a difference of about 1/32 is possible due to normal manufacturing tolerance variations.

Short gauge drills have been used in drilling sets. However, known assemblies comprising a short gauge trephine involve the use of a stabilizer between the gauge trephine at the end of the motor body. As this type of arrangement is effective in stabilizing the trephine, the trephine pendant is significantly increased, thereby reducing the directionality of the motor assembly.

Current turbines tend to employ drilling bits that have long total gauge lengths, commonly from one see nominal trepan diameter to more than twice the nominal trepan diameter. This has made it necessary to ensure that a smooth hole is produced. However, this introduces a risk that the drill bit can stick to the hole and also increases the cost of the drill bit.

Recent developments in drill bits have led to motor assemblies that no longer require the presence of a trepan box between the lower end of the motor shaft and the drill bit. Such an arrangement is described in U.S. Patent 5,853,053 (GILCHRIST et al.) While the assembly disclosed therein provides a reduction in trepan pendant, some of the associated disadvantages may include premature wear of the stabilizer and a relatively high risk of the long gauge drill bit can be glued into the hole.

It is an object of at least one embodiment of at least one aspect of the present invention to eliminate and / or mitigate one or more disadvantages in the prior art.

It is an object of at least one embodiment of at least one aspect of the present invention to provide a downhole drill motor stabilizer comprising reaming elements or reaming means provided in or near at least a portion center of at least one stabilizer blade.

It is an object of at least one embodiment of at least one aspect of the present invention to provide a piercing trephine comprising a gauge trephine, for example a short gauge trephine and connecting means for connecting the piercing trephine to one set of drilling motor.

It is an object of at least one embodiment of at least one aspect of the present invention to provide a downhole drilling assembly comprising an improved stabilizer and optionally a drilling trephine such as a short bore drill bit and a motor assembly.

It is an object of at least one embodiment of at least one aspect of the present invention to provide fastening means or a lock and key mechanism for attaching an engine drive shaft by means of or in conjunction with an engine stabilizer and beneficially permit use of driving and attaching and / or removing a drill bit to / from the motor drive shaft.

It is an object of at least one embodiment of at least one aspect of the present invention to provide a downhole drilling assembly comprising the fastening means or lock and key mechanism.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with a first aspect of the present invention, a stabilizer is provided comprising at least one reaming means and / or reinforcing means.

In art, the term stabilizer is known and understood. However, it will be understood that other equivalent terms can be used in the art, for example centralizer.

The stabilizer may comprise a downhole stabilizer. Advantageously, the stabilizer may be a drill motor stabilizer.

The stabilizer may comprise one or more blades, for example a plurality of blades, for example blades extending longitudinally, on or around an external surface thereof, circumferentially spaced.

Alternatively, the one or more sheets, for example a plurality of sheets, may be profiled, for example oblique or wavy relative to an axis of rotation of the stabilizer.

The stabilizer may comprise a cylindrical body and the outer surface may comprise an outer surface of the cylindrical body.

Each blade can comprise at least an upper portion or outer surface.

Each blade may also comprise at least a sloping or sloping portion or surface extending between the at least one upper or outer portion or surface of the blade and a portion of the body or end portion of the stabilizer, for example the cylindrical body at or near a first lower end or piercing end and / or a second end or upper end thereof.

Commonly, each blade may comprise at least one edge between the at least one upper portion or surface and the at least one portion or inclined surface thereof.

Beneficially, the reaming means can be provided on at least one stabilizer sheet.

The stabilizer may comprise at least a first reaming means and / or reinforcing means provided at least at or near a first portion or portion of the lower end of the stabilizer, such first end being closer to a piercing end thereof. , in service. By such provision, any variations and / or imperfections in the drilling profile arising from the displacement of the drilling trepan by a central axis during drilling can be corrected by reaming the hole by the centralizer, thereby improving the quality of the hole.

The stabilizer may further comprise at least second reaming means and / or reinforcing means provided at least at or near a second end portion or upper end portion of the stabilizer, such second end being farthest from a piercing end. of it in service. By such provision, additional reaming of the hole can be effected by rotation of the stabilizer during removal of a drilling or hole pulling assembly ('POOH').

Preferably, the first and / or second reaming means may comprise means, for example reaming blocks, which protrude or extend at least partially from an upper surface of at least one blade on or on an inclined surface thereof.

The first and / or second reaming means can each have an external surface that can be substantially flat. A portion of the outermost surface of the first and / or second reaming means may be substantially level or flush with the outer surface of. the blade (s) in which they are provided. An additional portion of the outermost surface of the first and / or second reaming means may be provided radially external to the respective inclined surface.

The stabilizer may further comprise at least third reaming means and or reinforcing means provided on at least one portion, for example the inclined portion, of at least one blade. By such provision, in service, the inclined portion of a blade can be protected from excessive or premature wear, for example by undercutting.

The stabilizer may further comprise at least fourth reaming means and / or reinforcing means provided on at least a portion or upper surface of at least one blade thereof.

Commonly, the third and fourth reaming means and / or reinforcing means may be partially level or flush with an external surface of at least one stabilizer blade.

The stabilizer may further comprise at least fifth reaming means and / or reinforcing means provided at least partially along at least one longitudinal edge of at least one blade.

Conveniently, the at least fifth reaming means and / or reinforcing means may be provided at least partially along or near a longitudinal edge of at least one blade facing substantially towards a direction of rotation of the stabilizer, in service.

By such provision, reaming performance can be improved and / or the at least one blade can be protected from excessive or premature wear, for example by undercutting.

Commonly, the first, second, third and fifth reaming means and / or reinforcing means may comprise blocks and / or may be made of a diamond impregnated material, for example a diamond impregnated tungsten carbide material.

Commonly, the fourth reaming means and / or reinforcing means may be made of an optionally diamond impregnated tungsten carbide material.

Beneficially, the fourth reaming means and / or reinforcing means may comprise blocks, for example a mixture of formed blocks, such blocks may be made of a tungsten carbide material and / or a diamond impregnated tungsten carbide material .

Reaming block or reinforcing blocks made of different materials can be provided in different shapes.

Commonly, reaming blocks made of a diamond impregnated tungsten carbide material are provided in a circular, hexagonal or octagonal shape and reinforcing blocks made of an unreinforced tungsten carbide material can be provided in a rectangular shape.

Preferably, the reaming means and / or reinforcing means can be provided on a stabilizer blade.

Alternatively, the reaming means and / or reinforcing means may be provided on more than one sheet, for example one sheet yes and another sheet no, of the stabilizer.

Preferably, the reaming means and / or. reinforcing means can be provided on the stabilizer blade itself.

Alternatively, each of the first, second, third, fourth and fifth reaming means and / or reinforcing means may be independently provided on one or more stabilizer blades.

The first, second, third, fourth, and / or fifth reaming means and / or reinforcing means may comprise combined reaming and reinforcing means.

It will be understood that the reaming elements provided on the stabilizer of the present invention can fulfill their function when the stabilizer is in rotational motion, for example during the normal drilling mode.

Advantageously, the first, second, third, fourth and / or fifth reaming means and / or reinforcing means can be made of a harder material than in the body of the stabilizer.

Commonly, the stabilizer can be made of a low carbon alloy steel, for example steel

AISI4145.

Advantageously, the stabilizer may be a downhole drill motor stabilizer.

In accordance with a second aspect of the present invention, a drilling trepan is provided comprising a calibration trepan at or near a drilling end thereof and connection means for connecting the drilling trepan to a drilling motor assembly , wherein the piercing trepan gauge may comprise a substantially cylindrical portion having a length less than or equal to about 1.0 times the nominal trepan diameter and commonly in the range of 2.5 cm (one inch) to 1.0 times the nominal trepan diameter. .

By such an arrangement the drilling trepan can be termed a short calibration trepan. The drill trepan gauge can be in the range of 2.5 cm (one inch) to 20 cm (8 inches), commonly 5 cm (2 inches) to 15 cm (6 inches).

Beneficially, the drill trepan can be devoid of a trepan sleeve. By such provision, the drilling trepan can rely solely on the integral matrix gauge for stabilization. In addition, the trepan pendant can be significantly reduced, thereby improving the addressability of the motor assembly and decreasing the likelihood that the drilling trepan will jam. Still further, in the event that the drill bit is jammed, the force required to release the drill bit can be reduced. In the event that the drilling trephine cannot be released, the repetitive application of a pulling and / or jerking force on the drilling trephine may cause the drilling trepan to break, thereby avoiding the need to abandon a section of the bottom hole and / or auger assembly, thus reducing operating costs in such circumstances.

The connection means, for example a threaded connection, can connect the drilling trepan to a motor shaft of the drilling motor assembly.

Commonly, the connection means, for example a threaded connection, may comprise an externally threaded bolt configured to engage and connect and the connection to a receiving portion, for example internal threading of a portion of the lower end of the shaft. By such provision, the need for a connector, for example a trepan box, between the drilling trepan and the end of the drilling motor assembly, for example the motor shaft, is eliminated.

Conveniently, the piercing trephine may further comprise a neck portion provided for example at or near an upper end of the calibration trephine to allow clamping, for example, by a clamp on the trephine.

Commonly, the drilling trepan is made from a diamond impregnated carbide material with a suitable binder material.

In accordance with a third aspect of the present invention, there is provided an assembly, such as a downhole assembly, comprising at least one stabilizer according to the first aspect of the present invention and / or comprising a trepan. drilling according to the second aspect of the present invention.

Advantageously, the assembly may comprise a perforation assembly.

The assembly may further comprise a drilling motor assembly.

Preferably, the stabilizer can be provided at a lower end of the drill motor assembly, this is an end closer to a drill end thereof.

Typically, the drill motor assembly may comprise a tubular motor body portion capable of selective rotational movement, a motor shaft provided within or within the tubular motor body portion, and drilling trepan attachment means provided in or near a portion of the lower end of the motor shaft.

Commonly also, the body portion of the tubular motor can be attached and / or rotationally connected to the stabilizer. By such provision, rotational movement of the motor body portion can cause rotational movement of the stabilizer, for example during normal drilling. Conversely, in the absence of rotational motion of the motor body portion, for example during directional or lateral drilling, it may cause the stabilizer to remain stationary relative to the motor shaft.

Commonly, a portion of the lower end of the shaft may be provided with a receiving portion, for example an internal thread to which the connection means are received, for example a threaded connection such as an internally externally threaded drill bit.

The assembly may be devoid of a connector, for example a trepan box, between the drilling trepan and a lower end or drilling end of the drilling motor assembly, eg motor shaft.

Conveniently, a lower end portion of the stabilizer can be substantially level or level with a lower end portion of the motor shaft and / or portion of the motor body.

Conveniently, the piercing trephine may further comprise a neck portion provided, for example at or near an upper end of the piercing trephine to allow grip eg by a trephine fastener.

The shape of the stabilizer can be substantially concentric relative to the motor shaft and / or portion of the motor body.

Alternatively, the shape of the stabilizer can be acentric or eccentric relative to the motor shaft and / or motor body portion.

The stabilizer outer diameter may be substantially identical to the full bore diameter of the drill trepan, that is, 0 to 0.32 cm (1/8 inch) of the nominal hole size.

Alternatively, the stabilizer may show an offset, such that at least one offset blade of the stabilizer can sweep a radius equal to or greater than the radius of calibration of the trepan. Commonly, the radius of displacement can be 0 to +3 mm from the radius of the trepan gauge.

The drilling motor assembly may comprise a deflection device, for example, an offset stabilizer or a bend.

Advantageously, when the shape of the stabilizer of the present invention is acentric or eccentric relative to the motor shaft and / or portion of the motor body, the acentric or eccentric stabilizer can be aligned with and / or relative to the deflection device. By such provision, the deflection of the drill assembly can be adjusted, improved and / or increased by the deflection device, by aligning the acentric or eccentric stabilizer with and / or relative to the deflection device.

Beneficially, the drill trepan can be devoid of a trepan sleeve. By such provision the drilling trepan can depend solely on the integral matrix gauge for stabilization and the trepan pendant can be significantly reduced, thereby improving the addressability of the motor assembly.

Commonly, the drilling trepanne may comprise a substantially cylindrical portion having a length less than or equal to about 1.0 times the diameter of nominal trepan and commonly in the range of 2.5 cm (one inch) to 1.0 times the diameter of nominal trepan. By such provision, the drilling trepan can be referred to as a short gauge trepan.

The drill trepan gauge can be in the range of 2.5 cm (one inch) to 20 cm (8 inches), commonly 5 cm (two inches) to 15 cm (6 inches).

Commonly, the distance between a lower end or piercing end of the motor body, for example motor shaft and / or stabilizer shaft and the trephine gauge can be of the order of 2.5 cm (one inch) to 20 cm (8 inches) , commonly 2 inches (5 cm) to 6 inches (15 cm).

Commonly, the drilling trepan is made from a diamond impregnated carbide material with a suitable binder material.

Commonly, the drill assembly can be a downhole drill assembly.

In accordance with a fourth aspect of the present invention, fixing means or a lock and key mechanism suitable for fixing a drive shaft by means is provided, together with or in relation to a stabilizer.

The fixing means are beneficially suitable for temporarily and / or releasably fixing the drive shaft and the stabilizer.

Advantageously, the drive shaft is a motor drive shaft and / or the stabilizer is a drill motor stabilizer.

By such provision, a portion of the lower end of the shaft provided below or within the stabilizer can be held in position while a drill bit is attached to or detached from / to the shaft.

Commonly, the. fixing means or lock and key mechanisms may comprise locking means and key means.

The locking means may comprise at least one opening, hole or slot provided in or through a stabilizer portion of at least one receiving or fixing portion provided on at least a portion of the motor drive shaft.

Conveniently, in service, the one of at least one stabilizer opening may be aligned with the at least one receiving or fixing portion of the motor shaft.

The at least one opening can be covered or protected so that it can be opened by covering means, for example a flap or cover. Such an element may seek to prevent, in service, the ingress, egress, or accumulation of debris or drilling particles into or near the opening.

Commonly, the key means may comprise at least one handling portion and at least one coupling portion.

Conveniently, the shape and size of the at least one opening portion can be such that the at least one engaging portion of the key means can be inserted therethrough.

Conveniently, the at least one receiving portion or shaft fixing portion may be capable of receiving the at least one engaging portion of the key means.

Typically, the at least one receiving portion or shaft fixing portion may comprise for example a slot and the at least one engaging portion of the key means may be, for example, T-shaped.

Commonly, the shaft can be provided with one or more, for example two receiving or fixing portions, optionally diametrically opposed to each other.

Commonly also, the stabilizer can be provided with one or more, for example two openings.

Preferably, the fastening means or lock and key mechanism may be suitable for a downhole drilling motor assembly.

Preferably, the stabilizer of the drilling motor can be a stabilizer according to the first aspect of the present invention.

In accordance with a fifth aspect of the present invention, a downhole drilling assembly is provided comprising at least one fixing means or lock and key mechanism according to the fourth aspect of the present invention.

Preferably, the downhole drilling assembly may further comprise a stabilizer according to the first aspect of the present invention and / or a drilling trepan according to the second aspect of the present invention and optionally a drilling assembly the motor.

In accordance with a sixth aspect of the present invention, there is provided a stabilizer comprising at least one opening, hole or slot of the lock fixing means of the fixing means or lock and key mechanism according to the fourth to aspect of the present invention.

Preferably, the stabilizer is a stabilizer in accordance with the first aspect of the present invention.

In accordance with a seventh aspect of the present invention, the key means for fixing a drive shaft is provided by means of, together with or in connection with a stabilizer.

In accordance with an eighth aspect of the present invention, there is provided a shaft comprising at least one receiving portion or fixing portion, for example a groove, capable of receiving at least a coupling portion of the locking key means. the fixing means or lock and key mechanism according to the fourth aspect of the present invention.

BRIEF DESCRIPTION OF THE FIGURES

Modalities of the present invention will now be described by way of example only and with reference to the accompanying figures, which are:

FIG. 1 is a side view of a drill motor stabilizer in accordance with a first embodiment of the present invention;

Figure 2 is an enlarged side view of a piercing end of the stabilizer of Figure 1;

Figure 2a is an enlarged cross-sectional view of part of the piercing end of Figure 2;

Figure 3 is a perspective view of an upper part of the stabilizer of Figure 1;

Figure 4 is a side view of an alternative embodiment of the drill motor stabilizer of Figure 1, showing an eccentric stabilizer.

Figure 5 is a perspective view of a drilling trepan in accordance with a second embodiment of the present invention;

Figure 6 is a side view of a first drilling assembly comprising the stabilizer of the.

Figure 1 and the drilling trepan of Figure 5;

<td></td><td>the</td><td>figure 7 is</td><td>a</td><td>side view</td><td>for a second</td>

<td>joint</td><td>of</td><td>drilling</td><td>than</td><td>comprises a</td><td>stabilizer</td>

<td colspan="3">modified similar to that</td><td>of the</td><td>stabilizer</td><td>figure 1;</td>

<td></td><td>the</td><td>figure 8 is</td><td>a</td><td>side view</td><td>additional</td>

<td>joint</td><td>of</td><td colspan="2">drilling the</td><td>figure 7 with</td><td>a trepan of</td>

drilling removed and wrench means in a mated position;

Figure 9 is a front perspective view of a lower end of a motor drive shaft and stabilizer of the drilling assembly of Figure 7, showing the key means coupled with fixing means;

Figure 10 is a sectional side view of a lower end of the drilling assembly (stabilizer no.

<td>shown)</td><td>of</td><td>the</td><td>figure</td><td> 7,</td><td>which shows the</td><td>key means</td>

<td>coupled</td><td>with</td><td>the</td><td>media</td><td>of</td><td>fixing and</td><td></td>

<td></td><td>the</td><td colspan="2">figure 11</td><td>it is</td><td>a side view</td><td>of the set of</td>

Drill Figure 6 or Figure 7 with a drill bit removed.

DETAILED DESCRIPTION OF THE FIGURES

Referring to Figures 1 to 4, a drill motor stabilizer 5 according to a first embodiment of the present invention is shown.

The stabilizer 5 comprises reaming means and / or reinforcing means 10.

The stabilizer 5 comprises a plurality of blades 20, for example blades extending longitudinally on or around an external surface 4 thereof, for example circumferentially spaced.

The stabilizer 5 comprises a cylindrical body 8 and the outer surface 4 comprises an outer surface of the cylindrical body 8. Each blade 20 comprises at least an upper or outermost portion or surface 22.

Each blade 20 also comprises at least a sloping or sloping portion or surface 23 extending between the at least one or outermost portion or surface 22 of blade 20 and a body portion 8 or end portion 9 of the stabilizer of 5, for example of the cylindrical body, at or near a first end or lower end or perforation end 6 and / or a second end or upper end 7 thereof.

Commonly, each blade 20 comprises at least one edge 21 between the at least one upper portion or surface 22 and the at least one portion or inclined surface 23 thereof.

Beneficially, the reaming means and / or reinforcing means 10 are provided on at least one blade 20 of the stabilizer 5.

The stabilizer 5 comprises first reaming means 11 provided at least in or near a first portion or portion of the lower end 6 of the stabilizer 5, such first end 6 being closer to a piercing end thereof, in service.

The stabilizer 5 further comprises second reaming means 12 provided at least at or near a second end portion or upper end portion 7 of the stabilizer 5, such second end 7 being further from the piercing end thereof, in service .

As can be seen in Figures 2 and 3, in this embodiment the first and / or second reaming means 11,12 comprise reaming blocks lia, 12a prominent or at least partially extending from one end of an upper surface 22 of at least one blade 20 on or to an inclined surface 23 thereof.

The first and / or second reaming means 11, 12 each have a more external surface, which is substantially flat. A portion of the outermost surface of the first and second reaming means 11, 12 is substantially level or flush with the outermost surface 22 of the blade (s) 20 on which they are provided. An additional portion of the outermost surface of the first and / or second reaming means 11,12 is provided radially outward from the respective inclined surface 23.

In another embodiment, the stabilizer 5 optionally further comprises third reaming means or reinforcing means 13 provided on at least one portion, for example the inclined portion 23, of at least one blade 20. By such provision the inclined portion 23 of a blade 20 is protected, in service, from excessive or premature wear, for example by undercutting.

The stabilizer 5 further comprises fourth reaming means 14a or reinforcing means 14b provided on at least a portion or upper surface 22 of at least one blade 20 thereof.

Commonly, the third 13 and fourth 14a, 14b reaming and / or reinforcing means are substantially level or

<td>leveled with</td><td>a surface</td><td>external 25 so</td><td>less</td><td>a</td>

<td colspan="2">stabilizer blade 20</td><td> 5.</td><td></td><td></td>

<td>How</td><td>it shows</td><td>in figures 1</td><td>and 2,</td><td>the</td>

<td>stabilizer</td><td colspan="2">further comprises at least fifths</td><td>media</td><td>of</td>

<td>reaming and / or</td><td colspan="2">reinforcing means 15 provided by</td><td colspan="2">least</td>

<td>partially to</td><td>along the</td><td>longitudinal edge 26</td><td>of for</td><td>the</td>

minus one blade 20.

In this embodiment, the at least fifth reaming means and / or reinforcing means 15 are provided at least partially along a longitudinal edge 26 facing substantially 'toward a direction of rotation of the stabilizer 5, in service. By such provision, reaming performance is improved and / or the at least one blade 20 is protected from excessive or premature wear, for example, by undercutting.

Commonly, the first 11, second 12, third 13 and fifth 15 reaming and / or reinforcing means comprise blocks and / or are made of a diamond impregnated material, for example a diamond impregnated tungsten carbide material.

Typically, the fourth reaming means 14a or reinforcing means 14b are made of an optionally diamond impregnated tungsten carbide material.

The fourth reaming means 14a or reinforcing means 14b comprise blocks 14c made of a diamond impregnated tungsten carbide material and blocks 14d made of a tungsten carbide material.

In this embodiment, reaming blocks or reinforcing blocks 14d made of different materials are provided in different shapes.

Reaming blocks 14c made of a diamond impregnated tungsten carbide material are provided in a circular, hexagonal or octagonal shape and reinforcing blocks 14d made of an unreinforced tungsten carbide material are provided in a rectangular shape.

In this embodiment, the reaming and / or reinforcing means 11, 12, 13, 14a, 15 comprise combined reaming and reinforcing means, for example they provide both a reaming and reinforcing function, while the reinforcing means 14b provide a function reinforcement.

In this embodiment, the reaming and / or reinforcing means 11, 12, 13, 14a, 15 and / or the reinforcing means 14b are provided on a blade 20 of the stabilizer 5.

In an alternative embodiment, the reaming and / or reinforcing means 11, 12, 13, 14a, 15 and / or the reinforcing means 14b are provided on more than one blade 20, for example each blade of the stabilizer 5.

In this embodiment, the reaming and / or reinforcing means 11, 12, 13, 14a, 15 and / or the reinforcing means 14b are provided on the same blade 20 of the stabilizer 5.

In another embodiment, each of the first, second, third, fourth and fifth reaming and / or reinforcing means 11, 12, 13, 14a, 15 and / or the reinforcing means 14b are independently provided on one or more blades of the stabilizer.

It will be understood that the reaming means 10 provided on the stabilizer 5 of the present invention can fulfill its function when the stabilizer 5 is in rotational motion, for example during the normal drilling method.

The reaming and / or reinforcing means 11, 12, 13, 14a, 15 and / or the reinforcing means 14b are made of a material harder than the material of the body 8 of the stabilizer 5.

Commonly, stabilizer 5 is made of a low carbon alloy steel, for example a steel

AISI4145.

Advantageously, stabilizer 5 is a downhole drill motor stabilizer. '

Referring to Figure 5, a drill bit in accordance with a second embodiment of the present invention 40 is provided comprising a calibration drill bit 42 at or near a drilling end 45 thereof, and connection means 46 for connecting the drill bit 40 to a drill motor assembly. Connecting means 46, for example a threaded connection, is provided to connect drilling bit 40 to a motor shaft of the drilling motor assembly.

In this embodiment, the connection means 46 comprise a threaded connection, for example an externally threaded bolt 47 configured to engage and connect to a receiving portion, for example internal threading of a portion of the lower end of the shaft. By such provision, the need for a connector, for example a drill bit case, between the drilling bit 40 and the end of the motor body, for example motor shaft, is eliminated.

Conveniently, the piercing bit also comprises a neck portion 50 provided at or near an upper end of the calibration bit 42 to allow for grip, for example by a bit holder.

In this embodiment, the neck portion 50 comprises two flat diametrically opposed portions 55 to allow grip, for example by a burr clamp.

Advantageously, drill bit 40 is devoid of a drill bit sleeve.

Commonly, drill bit 40 comprises a substantially cylindrical portion gauge 42 having a length less than or equal to about 1.0 times the nominal bit diameter, and commonly in the range of 2.5 cm (1 inch) to 1.0 times the diameter of nominal bit.

By such provision, the drill bit 40 may be referred to as a short gauge bit 41.

<td>The</td><td>Caliper</td><td>trephine</td><td colspan="2">drilling 42</td><td>can</td>

<td colspan="2">have a length in the</td><td>interval 2</td><td>. 5 cm</td><td>(1 inch)</td><td>to 20</td>

<td>centimeters</td><td>(8 inches)</td><td>commonly 5</td><td>cm (2</td><td>inches)</td><td>to 15</td>

centimeters (6 inches).

Commonly, the drill bit 42 can be made of a diamond impregnated carbide material with a suitable binder material.

Referring now to Figure 6, there is provided a joint drill assembly 30 comprising a stabilizer 5 in accordance with the first embodiment of the present invention, a drill bit 40 in accordance with the second embodiment of the present invention, and an assembly drilling motor 60.

Stabilizer 5 is provided at a lower end of drill motor assembly 60, that is, an end closer to a drill end 45 thereof.

Commonly, the drilling motor assembly 60 comprises a tubular motor body portion 65 capable of selective rotational movement, a motor shaft provided within or within the tubular motor body portion, and drilling bit attachment means provided on or near a portion of the lower end of the motor shaft.

Also commonly, the body portion of the tubular motor 65 is rotationally attached and / or connected to the stabilizer 5. By such provision, rotational movement of the body portion of the motor 65 causes rotational movement of the stabilizer 5, for example during normal drilling . Conversely, the absence of rotational movement of the motor body portion 65, for example during directional or lateral drilling, causes the stabilizer 5 to remain stationary relative to the motor shaft.

Commonly, a portion of the lower end of the. Shaft is provided with internal threading to which an externally threaded bolt 47 is received from drill bit 40.

The assembly is devoid of a connector, for example a drill bit case, between the drilling bit 40 and a lower or drilling end of the motor body 65, for example the motor shaft.

Conveniently, a lower end portion of the stabilizer 5 is substantially level or level with a lower end portion of the motor shaft.

Preferably, drill bit 40 is a short bore 41 drill bit. In the art, a short drill bit is understood to mean a drill bit with an outer cylindrical portion, the length of which measures less than or equal to approximately 1.0 times the nominal trephine diameter, and commonly, in the range of 2.5 cm (1 inch) to 1.0 times the nominal trephine diameter.

Conveniently, the piercing bit 40, 41 comprises a neck portion 50 to allow grip, for example by a bit holder.

In one implementation, as shown in Figures 1 to 3, the shape of the stabilizer 5 is substantially concentric relative to the motor shaft.

In this embodiment, the outer diameter of the diameter of the stabilizer 5 is substantially identical to the full bore diameter of the drill bit 40, 41, that is 0 to

0.32 cm (1/8 inch), nominal hole size.

In another implementation, as shown in Figure 4, the shape of the stabilizer 5 is acentric or eccentric relative to the motor shaft. The stabilizer 5 shows an offset, such that an offset blade 20a of the stabilizer 5 sweeps a radius equal to or greater than the radius of the bit diameter. Commonly, the radius of displacement is 0 to +3 mm from the bore radius of the bit.

Beneficially, drill bit 40, 41 is devoid of a drill bit sleeve. By such provision, the drill bit depends only on the integral die gauge for stabilization and the bit bit is significantly reduced, thereby improving the addressability of the motor assembly.

The drill bit 42 gauge has a length in the range of 2.5 cm (1 inch) to 20 cm (8 inches), commonly 5 cm (2 inches) to 15 cm (6 inches).

The distance between a lower end or piercing end of the body 65 motor, for example the motor shaft and / or the stabilizer 5 and the bit gauge 42 is in the range of 2.5 cm (1 inch) to 20 cm (8 inches) , commonly 5 cm (2 inches) to 15 cm (6 inches).

Commonly, the drill bit 40, 41 is made of a diamond impregnated carbide material with a suitable binder material.

Commonly, drill assembly 30 is a downhole drill assembly 31.

Referring to Figures 7-10, a drilling assembly 30 'is provided comprising a stabilizer 5' in accordance with a third embodiment of the present invention. The stabilizer 5 'comprises fixing means or a lock and key mechanism 80.

The fixing means or lock and key mechanism 80 are suitable for temporarily and / or releasably fixing a drive shaft 70 'by means of or together with a drilling motor stabilizer 5'.

Advantageously, drive shaft 70 'is a motor drive shaft 71' and / or stabilizer 5 'is a drill motor stabilizer.

By such provision, a portion of the lower end of the shaft 70 'provided below or within the stabilizer 5' can be held in position as long as a drill bit 40 'is attached to or detaches from / from the shaft

70' .

Commonly, the fastening means or lock and key mechanism comprise locking means 90 and key means 100.

The lock means 90 comprise at least one opening, hole or slot 91 provided in or through a portion of the stabilizer 5 ', and at least one receiving portion or lock portion 95 provided on at least a portion of the shaft motor impeller 70 '.

Conveniently in service, the one of the at least one of the openings 91 of the stabilizer 5 'is aligned with the at least one of the receiving or fixing portions 95 of the motor shaft 70'.

The at least one opening 91 is covered or protected so that it can be opened by means of cover 92, for example a flap or cover. Such an element may seek to prevent, in service, the entry, exit or accumulation of debris or drilling particles in or near the opening

91.

Commonly, the key means 100 comprise at least a handling portion 101 and at least a coupling portion 102.

Conveniently, the shape and size of the at least one opening portion 91 is such that the at least one engaging portion 102 of the key means 100 can be inserted therethrough.

Conveniently, the at least one receiving portion or fixing portion 95 of the shaft 70 'is capable of receiving the at least one engaging portion 102 of the key means 100.

Typically, the at least one receiving portion or lock portion 95 of the shaft 70 'comprises for example a slot, and the at least one engaging portion 102 of the key means 100 is for example T-shaped.

Commonly, shaft 70 'is provided with one or more, for example two receiving or fixing portions 95, optionally diametrically opposed to each other.

Commonly also, the stabilizer 5 'is provided with one or more, for example two openings 91.

Preferably, the stabilizer of the drilling motor 5 'is a stabilizer according to the first embodiment of the present invention.

Preferably, the fastening means or lock and key mechanism 80 are suitable for a downhole drill motor assembly 31 '.

Preferably, the downhole drill assembly 31 'comprises a stabilizer 5', a drill bit 40 ', and a drill motor assembly 60'.

Referring now to Figure 11, a drilling assembly 30, 30 'is provided comprising a stabilizer 5.5' in accordance with a first or third embodiment of the present invention, a drilling motor assembly 60, 60 ', and a drill bit in accordance with a second embodiment of the present invention (not shown).

In one implementation, 'the drilling motor assembly 60, 60' comprises a deflection device 110, 110 ', for example an offset stabilizer or a bend.

When the shape of the stabilizer 5.5 'of the present invention is eccentric or eccentric relative to the motor shaft 70.70' and / or motor body portion 65, 65 ', the acentric or eccentric stabilizer 5.5' it can be aligned with and / or in relation to the deflection device 110,110 '.

By such provision, the offset of the drilling assembly 30, 30 'can be adjusted, enhanced and / or implemented by the offset device 110,110' by aligning the 5.5 'acentric or eccentric stabilizer with and / or relative to the device deviation 110, 110 '. Typically, the deflection will occur in an opposite direction to the offset blades 20a of the stabilizer 5.5 '.

It will be appreciated that the embodiments of the present invention described herein above are given by way of example only and are not intended to limit the scope thereof in any way.