Technical Field

The present invention relates generally to the drill industries, and, in particular, to a drill apparatus and a method of making the tool joint of a drill apparatus.

Background Drilling into the surface of the earth's crust for oil, gas, water, steam or other similar applications is typically done by assembling lengths of threaded tubular drill pipes into a so called drill string. Each individual length of tubular drill pipe also has what is known as an upset, or thicker and wider section, at each joint or end where the threads are located. These upsets are designed to provide sufficient drill pipe integrity in the abrasive environment presented by an open earth bore to the overall string to both hold the weight of the drill string when assembled together and suspended from the drilling rig, but also to prevent the wall thickness from wearing through during the drilling operation when the drill string comes into contact with the open bore hole. If there is excessive wear, creating thinning in the wall thickness of the drill pipe itself, due to rotational or axial movement when abrading against the bore hole, the drill string can be subjected to separation and the dropping of a drill string into the bored hole.

As the necessary drill string length to reach the desired natural resources is becoming farther down and often father away from the drilling rig itself, often on a horizontal axis as well, especially in the context of the oil and gas industry, there have been multiple proposed solutions to protect the tool joints of each individual piece of pipe in the drill string to promote overall string integrity. It is known in the art to provide components or additions to the drill pipe to remedy this inherent deficiency in the materials integrity of the drill string itself. For many decades one of these additions has been the welding on of some form of so called hard banding, which is made of various combinations of tungsten carbide or other similar harder metals welded on at each tool joint upset. This hard banding operation is most often carried out off-site at a specialized location, where very expensive technicians engage in time and equipment intensive remediation to bring each tool joint back into serviceable condition. As the drill string is one of the most expensive capital investments in the drilling of a well of any kind, taking the drill string out of service to apply hard banding can shut down a natural resources exploitation operation until the drill string can be brought back on site and put back into service. To be able to operate continuously, which is the desired and preferred method in the industry, this automatically doubles the drill string capital costs for any private or government natural resource operation and does not even include the additional expense and time lost in an off-shore natural resources exploitation environment where there is also a need to ship or barge the drill string to a shore base for remediation. Another inherent problem with hard banding alone as a proposed solution is that the harder tungsten carbide metals are capable of wearing through the casing placed into the crust of the earth as part of these drilling operations, especially in areas where a well is transitioning from the vertical to the horizontal.

So called casing is larger bore pipe designed to be placed in a well and cemented in place after an earth bore has reached a desired depth. Most often wells will have subsequently smaller multiple sizes of casing placed as the drilling operation progresses to deeper depths. After a casing operation is completed to a certain depth, the drilling, with a smaller diameter drill string, will then continue again inside of the casing already permanently cemented in place. So, while the use of hard banding as recognized in the art has a substantially useful benefit while in a vertical environment to prevent wear to the drill string, such hard banding can be substantially destructive to the casing, especially in a transition or horizontal portion of a well, often causing catastrophic failure requiring abandoning of a well, where the casing creating the permanently placed well bore is abraded through during the drilling operation. Abrasion on the drill pipe and casing in the area known as the cutting bed is also substantially problematic. The so called cutting bed is the area of an earth bore where a hole transitions from the vertical to the horizontal, which may or may not yet have casing placed at that depth, where the drilled materials are deposited and are not easily carried away to the surface by the drilling mud. Due to the weight of the drill pipe itself, laying on and rotating in the detritus of the hole during drilling operations, substantial wear to the drill pipe and casing can be exacerbated if that detritus is not loosened and pushed towards the surface of the hole. The detritus or cuttings also can accumulate sufficiently to increase ECD (equivalent circulating density) of the drilling mud, limiting normal operating procedures. It is known in the art to apply such wear resistant, torque reducing and drag reducing materials as have been heretofore described above and that such wear resistant materials are going to have a certain wear life before they will have to be inspected, serviced and / or replaced to ensure drill string safety and integrity are maintained. Current use in the arts on the number of pieces of pipe deployed in any drill string and the safety and inspection protocols are still managed by means of a pencil and paper tally sheet created on the rig floor as each piece of drill pipe is added to the string and deployed into the bore hole. This method of tallying or tracking allows an operation to count how many meters of pipe are deploying in any drilling operation, but there is no means to specifically identify the number of times any individual piece of pipe has been deployed nor is there a way to remove the possible human error in that currently used system.

From the foregoing, it will be understood that certain limitations on previous methods of tool joint protection and also drill apparatus, such as casing wear protection, torque reduction, drag reduction, field replacement and automatic tallying to track each individual piece of the drill string and to remove human error from that calculation must be noted.

Summary

According to an aspect of the invention, there is provided a drill apparatus, which can enhance the protection. A drill apparatus, comprise a tool joint, at least one undercut, which is on the surface of the thicker and wider section of the said tool joint, and the undercut's longitudinal axis is parallel to the axis of the tool joint; at least one insert, which can be inserted into and removed from the undercut, the insert can be securely retained by the undercut.

In one embodiment, the drill apparatus further comprise at least one end cap; the said undercut is a dovetail groove, and the insert is securely locked in the dovetail groove by the end cap.

In other embodiment, the insert is thicker than the end cap. In another embodiment, a machined pocket is located on the reverse side of the inserts. The drill apparatus further comprise a radio frequency identifier, the radio frequency identifier is embedded in the machined pocket, and the radio frequency identifier is used for remote tallying, location and number of trips each individual piece of tool joint has been run into and out of the artesian well.

In one embodiment, the drill apparatus further comprise at least one stirring rib; the stirring rib is on the surface of the insert, overmolded by high lubricity bearing coating cap. The stirring rib consists of hard materials, wherein, the hard materials comprise at least one of the following materials: the tungsten carbide compound, Polycrystalline Diamond

Compact, Thermally Stable Polycrystalline Compact.

In other embodiment, the undercuts are created on the drilling site with a pneumatic, hydraulic, or electric milling machine In another embodiment, the number of the insert is at least two; taper wedge is fabricated on the face of the first insert, which can be fitted in the taper boring on the face of the adjacent insert.

In one embodiment, the surface of the insert consists of hard materials or high lubricity bearing materials. In other embodiment, the insert is designed to fragment and separate each segment into manageable non-destructive drillable pieces in the event of catastrophic failure.

In accordance with another aspect of the invention, there is provided a method of making the tool joint of a drill apparatus, comprise the following steps:cut at least one undercut on the surface of the thicker and wider section of the said tool joint, and the undercut's longitudinal axis is parallel to the axis of the tool joint.

In one embodiment, the undercut is made by the following steps: cut normal to the surface of the thicker and wider section of the said tool joint, then a path is cut axially along the length of the pipe to create dovetail groove.

In other embodiment, the said undercut is made with a pneumatic, hydraulic, or electric milling machine in the drilling site field. The said milling machine is portable.

Brief Description of the Drawings

So, that the manner in which the above recited features, advantages and objects of the invention, as well as others which will become apparent, are attained and can be understood in detail, a more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the appended drawings illustrate only the typical embodiments of the invention and are not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

Embodiments of the invention are described hereinafter with reference to the drawings, in which: Fig. 1 is a perspective view of the drill apparatus's tool joint in accordance with an embodiment of the invention;

Fig. 2 is a schematic front view of the drill apparatus's tool joint in accordance with an embodiment of the invention;

Fig. 3 is a schematic A-A section view in accordance with Fig.2; Fig. 4 is a schematic B-B section view in accordance with Fig.3;

Fig. 5 is a schematic top view of the first insert according to an embodiment of the invention;

Fig. 6 is a schematic B-B section view in accordance with Fig.5;

Fig. 7 is a schematic side view of the first insert in accordance with an embodiment of the invention;

Fig. 8 is a schematic top view of the second insert according to an embodiment of the invention;

Fig. 9 is a schematic C-C section view in accordance with Fig.5;

Fig. 10 is a schematic side view of the second insert in accordance with an embodiment of the invention;

Fig. 11 is a schematic top view of the third insert according to an embodiment of the invention;

Fig. 12 is a schematic C-C section view in accordance with Fig.5;

Fig. 13 is a schematic side view of the third insert in accordance with an embodiment of the invention;

Fig. 14 is a schematic section view of the insert with high lubricity bearing materials surface in accordance with an embodiment of the invention;

Fig. 15 is a schematic top view of the insert with high lubricity bearing materials surface in accordance with an embodiment of the invention; Fig. 16 is a schematic section view of the insert with stirring rib on the surface in accordance with an embodiment of the invention;

Fig. 17 is a schematic top view of the insert with stirring rib on the surface in accordance with an embodiment of the invention; Fig. 18 is a schematic section view of the insert with a machined pocket on the reverse side in accordance with an embodiment of the invention;

Fig. 19 is a schematic top view of the insert with a machined pocket on the reverse side in accordance with an embodiment of the invention; Fig. 20 is a schematic exploded view of the milling machine in accordance with an embodiment of the invention; and

Fig. 21 is a schematic perspective view of the milling machine in accordance with an embodiment of the invention.

Detailed Description

The present invention is more specifically described in the following paragraphs by reference to the figures attached only by way of example.

One embodiment of the drill apparatus's tool jointl is shown in Fig. 1. The tool jointl comprise at least one undercut4 and at least one insert2. The undercut4 is on the surface of the thicker and wider section of the said tool jointl , and the undercuts s longitudinal axis is parallel to the axis of the tool joint. The insert2 can be inserted into and removed from the undercut4; the insert2 can be securely retained by the undercut4.

The drill apparatus further comprise at least one end cap; the end cap comprise the compact clump 3 and the bolt5. In one embodiment, the said undercut4 is a dovetail groove, and the insert2 is securely locked in the dovetail groove by the end cap.

As shown in Fig 3, the insert2 is slightly thicker than the end cap. During the drilling operation, the inset2 will bear the wear and drag due to the contact with the bore hole or the casing. The end cap 3 will not experience a substantial amount of wear and drag. Therefore, the bolt 5 will not bear shear. So called casing is larger bore pipe designed to be placed in a well and cemented in place after an earth bore has reached a desired depth. Most often wells will have subsequently smaller multiple sizes of casing placed as the drilling operation progresses to deeper depths. After a casing operation is completed to a certain depth, the drilling, with a smaller diameter drill string, will then continue again inside of the casing already permanently cemented in place. The invention can provide protection for the drill spring and casing in the

Please see Figures 1-4, the insert2 is designed to fragment and separate each segment into manageable non-destructive drillable pieces in the event of catastrophic failure. The insert2 also can contain any functional materials to facilitate the drilling operation, and/or the detection and/or r extraction of natural resources of any kind.

Please see Figures5-13, in an embodiment of the invention, the inserts2 in each undercut4 comprise the first insert21, the second insert22 and the third insert23. The taper wedge7 is fabricated on the face of the first insert, which can be fitted in the taper boringβ on the face of the adjacent insert (i.e. the second insert22). The taper wedge7 is fabricated on the face of the third insert23, which can be fitted in the taper boringβ on the face of the adjacent insert (i.e. the second insert22). This will ensure the inserts in the undercut will not drop out. Especially, four taper wedges 7 are fabricated on the sides of the middle insert 22, which are fitted in the taper borings 6 cut into the sides of the adjacent inserts 21 and 23. Therefore, the inserts can be firmly fitted and seated to the dovetailed groove 4. The segmented inserts 2 are designed to fragment and separate each segment into manageable non-destructive pieces in the event of catastrophic failure. The person skilled in the art knows that number of the inserts2 in each undercut4 can be changed according to requirement, such as two, four, five or more.

As shown in Figuresl-13, in one embodiment of the invention, the surface of the inserts consists of hard materials. The hard materials can consist of the tungsten carbide compound, or Poly crystalline Diamond Compact (PDC), or Thermally Stable Poly crystalline Compact (TSP), or other similar hard materials. This kind of insert2 has high wear resistance, and is preferred chosen by the operator on the sections of a drill string that will rotate in an earth bore hole where no casing has yet been set and cemented. This invention can reduce the torque and drag suffered by the drill string. Thus the maximum drill string geometry can get by the same force. This invention can realize the least amount of wear and destruction of the drill string and casing, provide maximum usable life of the hard faced inserts drill string and casing.

As shown in Figurel4, 15, in other embodiment of the invention, the surface of the insert2 consists of high lubricity bearing materials.

The high lubricity bearing materials can consist of the high lubricity polymer bearing material in an embodiment to form a series of drillable segmented friction bearing inserts. This type of inserts can be used with the drill strings that always stay in the cased hole, to reduce the drag and torque between the casing and the drill string. The insert 2 consists of the metal insert base 13 and high lubricity bearing materials 12 which is overmolded into the metal insert base 13 to form a high lubircity face. The high lubricity bearing materials can also consist of the high lubricity polymer bearing material in another embodiment. Such insert is desirable as chosen by the operator on the sections of a drill string that will rotate in an transition bore hole from the vertical to the horizontal where casing has already been set and cemented. As shown in Figureslβ, 17, the surface of the insert2 consists of stirring ribll. This kind of insert 2 can be chosen in the so called cutting bed section of the drill string to assist agitation of so called cutting beds to mix with the flow of drilling mud to upset and drive to the surface otherwise stagnant detritus. The stirring ribll usually are hard face. The hard face materials comprise at least one of the following materials: the tungsten carbide compound, Poly crystalline Diamond Compact, Thermally Stable Poly crystalline Compact. In one embodiment, on the surface of the stirring ribll is overmolded by high lubricity bearing coating cap 15. Such inserts are firmly fitted and seated by means of a seat and compression fitting, where such insert is desirable as chosen by the operator on the sections of a drill string that will rotate in a transition bore hole from the vertical to the horizontal where casing has already been set and cemented. When this type of insert is used in the cased hole, the overmolded cap 15 can protect the casing and the drill string with least amount of torque drag and wear. As the drilling progresses, this type of inserts may advance into the transition bore hole from the vertical to the horizontal. The overmolded cap 15 will wear off quickly, and the hard facing stirring rib 11 will not only protect the tools joint, but also stir up the deposited drilled materials so that the drilling mud can carry the drilled materials away to the surface easily.

As shown in Figs 18-19, a machined pocketl4 is located on the reverse side of the inserts2. Any sensor or inspect device can be placed in the machined pocketl4. For example, the sensor used for detect gas, or the inspect device used for inspect the chemical constituents of the rock. This senor and inspect device can facilitate the drilling operation, and the detection and/or or extraction of natural resources of any kind. In a embodiment, a excitable Radio Frequency Identifier (RFID) can be embedded inside the machined pocketl4, allowing for remote tallying, location and number of trips each individual piece of pipe has been run into and out of the hole. As shown in Figures 20, 21, A method of making the tool joint of a drill apparatus, comprise the following steps: cut at least one undercut on the surface of the thicker and wider section of the said tool joint, and the undercut's longitudinal axis is parallel to the axis of the tool joint. The undercut is made by the following steps: cut normal to the surface of the thicker and wider section of the said tool joint, then a path is cut axially along the length of the pipe to create dovetail groove. The said undercut is made with a pneumatic, hydraulic, or electric milling machine in the drilling site field, the said milling machine is portable. As shown in Figures 20, 21, the undercuts are created on the drilling site with a pneumatic, hydraulic, or electric portable milling machine by ordinary technician. The milling machine 16 can be easily mounted on drilling pipe on the drilling site with the clamping system comprised of the machine bed 17, machine clamp 18, and the index ring 19. By changing the three bolts 20 the milling machine can be rotated to different positions to cut the plurality of linear parallel dovetailed grooves 4.

As shown in Figuresl-21, the insert2 can slide into the dovetail groove from the first normal cut and is then locked in location by the placement of an end cap in the initial normal cut location, the insert2 are easily inserted or removed with simple hand tools by roustabout personnel on the rig floor, on-site in the field, eliminating the need to remove the drill string from the work location or even take the string out of service, as inserts can be replace when the pipe is being so called run into and out of the hole during routine bit changing operations.

Industrial Applicability The arrangements described are applicable to the drill industries.

The foregoing describes only some embodiments of the present invention, and modifications and/or changes can be made thereto without departing from the scope and spirit of the invention, the embodiments being illustrative and not restrictive.