CN203008793U - Resistance reduction pup joint for drill - Google Patents

Abstract

The utility model discloses a drag reducing nipple of a drilling tool, which comprises a mandrel body and a drag reducer. The mandrel body has a central hole, and an annular groove is arranged on the outer periphery of the middle part of the mandrel body. The groove is used to assemble the drag reducer; the drag reducer is mainly composed of a bearing sleeve and multiple pairs of drag reducing rollers, the bearing sleeve is a combined bearing sleeve, and the first half-ring bearing sleeve and the second half-ring bearing sleeve are connected The inner diameter of the bearing sleeve is slightly larger than the outer diameter of the annular groove of the mandrel body. There are multiple roller grooves on the outer circumference of the bearing sleeve. Each roller groove is equipped with a pair of drag-reducing rollers through a pin shaft to reduce drag. The highest point of the roller on the circumference of the bearing sleeve is greater than the outer diameters of the mandrel body and the bearing sleeve. The utility model can effectively convert the contact friction resistance generated during the rotation of the drilling tool into rolling friction resistance, so as to achieve the purpose of reducing friction and resistance. It has the advantages of simple structure, low processing cost, high reliability and overall strength, and strong practicability Features.

Description

A drag reducing nipple of a drilling tool

technical field

The utility model relates to a drilling and production tool for oil and gas wells, in particular to a drag reducing nipple of a drilling tool.

Background technique

Drilling tool is one of the important equipment for drilling and production of oil and gas wells. The two ends of the drilling tool are respectively connected with the drill bit and the power equipment at the wellhead. Rotation is realized in the pipe, so as to transmit drilling pressure to the drill bit and drive the drill bit to perform drilling operations. However, the drilling tool will generate frictional resistance with the well wall and casing during the rotation process, and the frictional resistance will increase sharply with the increase of the well depth of the oil and gas well. When the frictional resistance is greater than the yield pressure of the drilling tool, the drilling tool will be stuck , The drilling pressure cannot be transmitted to the drill bit, so that the drilling operation of the oil and gas well comes to a standstill. For this reason, it is necessary to add a drag reducing tool to the drilling tool, and reduce the frictional resistance generated by the drilling tool in the well wall and casing through the drag reducing tool. There are many kinds of existing drag reduction tool structures, all of which convert the contact friction resistance generated by the drilling tool with the well wall and casing into rolling friction resistance through the rollers or balls set on the body, thereby reducing the frictional resistance of the drilling tool during drilling. The frictional resistance generated in the process. However, in order to realize the assembly of these drag reducing tools on the drilling tool, the drag reducing tool needs to be processed into multiple sections or multiple splits. The structure is very complicated, the processing cost is high, the reliability and overall strength are poor, and the service life is short.

Contents of the invention

The purpose of this utility model is to provide a simple structure, low processing cost, high reliability and overall strength, which can effectively convert the contact friction resistance generated during the rotation of the drilling tool into rolling friction. The resistance of the drilling tool drag reducing sub.

The technical solution adopted by the utility model is: a drag reducing nipple of a drilling tool, including a mandrel body and a drag reducer, the mandrel body has a central hole, and an annular groove is arranged on the outer periphery of the middle part of the mandrel body , the annular groove is used to assemble the drag reducer; the drag reducer is mainly composed of a bearing sleeve and multiple pairs of drag reducing rollers, the bearing sleeve is a combined bearing sleeve, and the first half-ring bearing sleeve and the second half-ring The bearing sleeve is composed of connecting parts. The inner diameter of the bearing sleeve is slightly larger than the outer diameter of the annular groove of the mandrel body. There are multiple roller grooves on the outer circumference of the bearing sleeve. Each roller groove is equipped with a pair of drag reduction through the pin shaft. Roller, the highest point of the drag reducing roller on the circumference of the bearing sleeve is greater than the outer diameter of the mandrel body and the bearing sleeve.

The first half-ring bearing sleeve and the second half-ring bearing sleeve are special-shaped bodies of half-ring structure respectively, one combined end side of the two is a straight side, and the other combined end side is a stepped side, and the stepped sides of the two are connected to each other. match.

The top and bottom ends of the first half-ring bearing sleeve and the second half-ring bearing sleeve are provided with stop ring grooves that do not penetrate to the circumferential end, and bolt holes are provided at the circumferential end of each stop ring groove , the bolt holes on the top and bottom ring grooves of the first half-ring bearing sleeve correspond to and match the bolt holes on the top and bottom end ring grooves of the second half-ring bearing sleeve respectively, and pass through the bolt holes of the two Insert the bolts to combine the two into one.

The inner wall of the bearing sleeve is provided with at least one wear indicating groove.

The drag reducer is assembled in the annular groove of the mandrel body through the thrust rings at both ends and the gap adjustment ring.

The roller grooves on the bearing sleeve are divided into three groups longitudinally, and these three groups of roller grooves are evenly distributed on the circumference of the bearing sleeve.

Each pair of drag-reducing rollers in the plurality of pairs of drag-reducing rollers is composed of two rollers that do not interfere with each other when rotating, and each roller is elliptical.

The outer wall of the annular groove of the mandrel body and the inner wall of the bearing sleeve are respectively provided with a wear-resistant layer, and the hardness of the wear-resistant layer on the outer wall of the annular groove of the mandrel body is greater than that of the inner wall of the bearing sleeve.

The outer walls of the upper part and the lower part of the mandrel body are respectively provided with spiral guide grooves, and the upper part of the mandrel body is provided with a hanging tong fastening part.

The top and bottom ends of the mandrel body are respectively provided with a first taper thread and a second taper thread for connection. The bottom end of the outer wall of the mandrel body.

The beneficial effects of the utility model are: the above-mentioned drag reducing nipple is composed of the mandrel body and the drag reducer, and is reliably connected with the drilling tool through the mandrel body; The ring bearing sleeve is composed of multiple pairs of drag-reducing rollers. The two half-ring bearing sleeves are not simple tile-shaped structures, but two special-shaped half-ring bearing sleeves similar to Tai Chi patterns. The two half-ring bearing sleeves can It is easy to assemble on the mandrel body, the assembly is reliable, firm, and high in strength, and it can reliably withstand both axial and radial forces. The design of the drag reducing roller is elliptical, which effectively avoids the deformation of the roller and the impact on the downhole. Tool wear (such as cylindrical rollers) and accidents embedded in the well wall (such as spherical rollers) occur, and the drag-reducing rollers can effectively convert the contact friction resistance generated during the rotation of the drilling tool into rolling friction resistance, thereby realizing For the purpose of reducing friction and drag, the overall structure is simple, high reliability and strength, strong practicability, and low processing cost; in addition, the assembly surface of the mandrel body and the drag reducer is provided with a wear-resistant layer, and the wear-resistant layer on the mandrel body The hardness of the layer is greater than the hardness of the wear-resistant layer on the drag reducer. The drag reducer is used as the sacrificed side to avoid the wear of the mandrel body. The replacement of the drag reducer is convenient for the maintenance and replacement of drilling tools. There are wear indicator grooves on the inner wall of the two half-ring bearing sleeves, through which the wear of the drag reducer can be observed, and lubricating oil can be injected through the grooves, which helps to reduce the friction coefficient between the drag reducer and the mandrel body , prolong the service life of the entire drag reducing sub.

Description of drawings

Below in conjunction with accompanying drawing, the utility model is further described.

Fig. 1 is a kind of structural representation of the utility model.

Fig. 2 is the A-A view of Fig. 1 .

Fig. 3 is a B-B view of Fig. 1 .

Fig. 4 is a C-C view of Fig. 1 .

FIG. 5 is an enlarged view of part D of FIG. 3 .

Fig. 6 is a schematic structural view of the first half-ring bearing sleeve in Fig. 1 .

Fig. 7 is a schematic structural view of the second half-ring bearing sleeve in Fig. 1 .

The meaning of the codes in the figure: 1—mandrel body; 2—thrust ring; 3—gap adjustment ring; 4—drag reduction roller; 5—pin shaft; 6—first half ring bearing sleeve; 7—second half ring bearing 8—spiral guide groove; 9—wear indicator groove; 10—roller groove; 11—center hole; 12—first taper thread; 13—second taper thread; 14—bolt hole; 15—stop ring groove.

Detailed ways

Referring to Fig. 1 to Fig. 7: the utility model includes a mandrel body 1 and a drag reducer.

Wherein, the mandrel body 1 is an axially hollow pipe, and its hollow part is the central hole 11, which is used to circulate the drilling gas and liquid; The first tapered thread 12 and the second tapered thread 13 used to connect the drilling tool (the first tapered thread 12 and the second tapered thread 13 are both API standard tapered threads), the first tapered thread 12 is set in the center hole of the mandrel body 1 11, the second taper thread 13 is located at the bottom of the outer wall of the mandrel body 1. There is an annular groove in the middle of the outer wall of the mandrel body 1. The length and depth of the annular groove should correspond to the height and thickness of the drag reducer. A high-strength wear-resistant layer is surfacing on the outer wall of the annular groove. (such as surfacing AL2O3), the mandrel body 1 is equipped with a drag reducer through the annular groove, there is a gap between the two ends of the drag reducer and the two ends of the annular groove, and the thrust ring 2 and the thrust ring are installed in the gap at both ends. The clearance adjustment ring 3 and the thrust ring 2 are close to the end of the annular groove, and the clearance adjustment ring 3 is close to the end of the drag reducer. On the outer wall of the mandrel body 1 above and below the annular groove (that is, the upper and lower parts of the outer wall of the mandrel body 1), there are respectively provided with spiral diversion grooves 8, and the spiral diversion grooves 8 are used to quickly carry bottom cuttings, And the upper part of the outer wall of the mandrel body 1 is provided with a fastening part of the hanging tongs (at the upper spiral diversion groove), and the fastening part of the hanging tongs is used for the operation of mechanical buckling and loosening.

The drag reducer is mainly composed of bearing sleeves and six pairs of drag reducing rollers 4 . The bearing sleeve is a combined bearing sleeve, which is composed of the first half-ring bearing sleeve 6 and the second half-ring bearing sleeve 7 via connectors (ie, bolts). The specific structure of the bearing sleeve is that the first half-ring bearing sleeve 6 and the second half-ring bearing sleeve 7 are special-shaped bodies with a half-ring structure, that is, one combined end side of the two is a straight side, and the other combined end side is a step. side, the stepped side of the first half-ring bearing sleeve 6 is a positive step, and the stepped side of the second half-ring bearing sleeve 7 is a reverse step, and the stepped sides of the two should match each other to ensure that they can be overlapped and meshed when combined. Together, the combination of the first half-ring bearing sleeve 6 and the second half-ring bearing sleeve 7 is similar to the Taiji pattern, which can help improve the firmness and reliability of the assembly of the two, with high strength, regardless of axial force, Or the radial force can be reliably borne; the top and bottom ends of the first half-ring bearing sleeve 6 and the second half-ring bearing sleeve 7 are provided with stop ring grooves 15 that do not penetrate to the circumferential ends. Bolt holes 14 are provided at the circumferential end of the first half-ring bearing sleeve 15, and the bolt holes on the top and bottom ring-stop grooves of the first half-ring bearing sleeve 6 are connected with the top and bottom ring-stop grooves of the second half-ring bearing sleeve 7 respectively. The bolt holes on the top are corresponding and matched, and the first half-ring bearing sleeve 6 and the second half-ring bearing sleeve 7 are combined by passing bolts through the bolt holes of the first half-ring bearing sleeve 6 and the second half-ring bearing sleeve 7 Integrate to form a complete bearing sleeve. The inner diameter of the bearing sleeve is slightly larger than the outer diameter of the annular groove of the mandrel body 1, and a high-strength wear-resistant layer is surfacing on the inner wall of the bearing sleeve. The hardness of the wear-resistant layer should be smaller than that of the annular groove of the mandrel body 1. The hardness of the wear-resistant layer is high, because in the combination process of the drag reducer and the mandrel body 1, the drag reducer is required to be the one that is sacrificed for wear, thereby reducing the difficulty and workload of the replacement of the mandrel body 1; on the inner wall of the bearing sleeve There are multiple wear indicating grooves 9 (the number depends on the specific design requirements), through which the wear of the drag reducer can be observed, and the assembly of the drag reducer and the mandrel body 1 can also be made through the wear indicating groove 9 Lubricating oil is injected into the combined surface to reduce the friction coefficient between the drag reducer and the mandrel body 1 . Six roller grooves 10 are arranged on the outer circumference of the bearing sleeve, three of which are distributed on the upper part of the outer wall of the bearing sleeve, and the other three are distributed on the lower part of the outer wall of the bearing sleeve, and the three roller grooves 10 on the upper part are Corresponding to the three roller grooves 10 in the lower part, the two roller grooves 10 corresponding to the upper and lower pairs form a group. In this case, the six roller grooves 10 on the outer circumference of the bearing sleeve are divided into three groups in the longitudinal direction. The three sets of roller grooves 10 are evenly distributed on the circumference of the bearing sleeve, that is, the angle between the radial centerlines of two adjacent groups of roller grooves 10 is 120°; due to the special structure of the bearing sleeve, the distribution of the aforementioned three sets of roller grooves 10 On the first half-ring bearing sleeve 6 and the second half-ring bearing sleeve 7, one and a half groups are respectively distributed on the first half-ring bearing sleeve 6 and the second half-ring bearing sleeve 7, and the half group (ie one) is at the first Near the step edge of the half-ring bearing sleeve 6 and the second half-ring bearing sleeve 7; each roller groove 10 is equipped with a pair of drag-reducing rollers 4 through the pin shaft 5, and the drag-reducing rollers 4 assembled in the roller groove 10 are mounted on the bearing The highest point on the sleeve circumference should be greater than the outer diameter of the mandrel body 1 and the bearing sleeve. The aforementioned pair of drag-reducing rollers 4 is composed of two rollers that do not interfere with each other when rotating. Each roller is assembled on the roller groove 10 through its own pin shaft 5. Each roller is oval and made of hard alloy. , such a roller structure can effectively eliminate the defects of cylindrical rollers and spherical rollers, and has high strength and hardness and wear resistance.

In addition to the above-mentioned design, the forward and reverse directions of the stepped sides of the first half-ring bearing sleeve 6 and the second half-ring bearing sleeve 7 can also be reversed, that is, the first half-ring bearing sleeve The step side of 6 is a reverse step, and the step side of the second half-ring bearing sleeve 7 is a forward step, as long as the step sides of the two match each other, they can be overlapped and meshed together when combined. the

In addition to the use of bolts, the combined connectors of the first half-ring bearing sleeve 6 and the second half-ring bearing sleeve 7 can also be welded (that is, the combined sides of the two are directly welded into one body) or hinge pins (that is, the joints of the two are directly welded together). The combined sides are designed as interlaced hinges, and the pin shafts can be inserted into the interlaced hinges). If welding is used as the combined connector, it is not conducive to subsequent equipment maintenance and replacement; if the hinge pin is used as the combined connector, the processing difficulty of the drag reducer will be increased, and the reliability and firmness of the combination will be poor. Therefore, bolts are preferred for the combined connection of the first half-ring bearing sleeve 6 and the second half-ring bearing sleeve 7 .

The number of drag-reducing rollers and the number of roller grooves mentioned above are not specific values, and may be more, such as eight roller grooves, ten roller grooves, etc., and the number of drag-reducing rollers should correspond to the number of roller grooves.

Claims (10)

1. A drag-reducing sub-joint of a drilling tool, comprising a mandrel body (1) and a drag reducer, the mandrel body (1) has a central hole (11) on the middle outer periphery of the mandrel body (1) An annular groove is provided, and the annular groove is used for assembling the drag reducer; the characteristic is that the drag reducer is mainly composed of a bearing sleeve and multiple pairs of drag reducing rollers (4), and the bearing sleeve is a combined bearing sleeve, It is composed of the first half-ring bearing sleeve (6) and the second half-ring bearing sleeve (7) through connecting parts. The inner diameter of the bearing sleeve is slightly larger than the outer diameter of the annular groove of the mandrel body (1). There are multiple roller grooves (10) on the top, and a pair of drag-reducing rollers (4) are installed in each roller groove (10) through a pin shaft (5). The highest point of the drag-reducing rollers (4) on the circumference of the bearing sleeve is greater than The outer diameter of the mandrel body (1) and the bearing sleeve. 2. The drag-reducing sub-joint of a drilling tool according to claim 1, characterized in that: the first half-ring bearing sleeve (6) and the second half-ring bearing sleeve (7) are special-shaped bodies with a half-ring structure, and the two One of the combined end sides of the latter is a straight side, and the other combined end side is a stepped side, and the stepped sides of the two match. 3. The drag-reducing sub-joint of the drilling tool according to claim 2, characterized in that: the top and bottom ends of the first half-ring bearing sleeve (6) and the second half-ring bearing sleeve (7) are provided with non-through joints. To the stop ring groove (15) at the circumferential end, bolt holes (14) are provided at the circumferential end of each stop ring groove (15), and the top and bottom stop rings of the first half-ring bearing sleeve (6) The bolt holes on the groove correspond to and match with the bolt holes on the top and bottom stop ring grooves of the second half-ring bearing sleeve (7) respectively, and the two are combined into one body by penetrating bolts in the bolt holes of the two. 4. The drag-reducing sub-joint of a drilling tool according to claim 1, characterized in that: at least one wear indicator groove (9) is provided on the inner wall of the bearing sleeve. 5. The drag reducing sub-joint of the drilling tool according to claim 1, characterized in that: the drag reducer is assembled on the annular ring of the mandrel body (1) through the thrust ring (2) and the gap adjustment ring (3) at both ends. inside the groove. 6. The drag-reducing sub-joint of the drilling tool according to claim 1, characterized in that: the roller grooves (10) on the bearing sleeve are divided into three groups in the longitudinal direction, and the three groups of roller grooves (10) are evenly distributed on the bearing sleeve on the circumference of . 7. The drag-reducing sub-joint of a drilling tool according to claim 1, characterized in that: each pair of drag-reducing rollers in the multiple pairs of drag-reducing rollers (4) is composed of two rollers that do not interfere with each other when rotating, each The first roller is oval in shape. 8. The drag-reducing nipple of a drilling tool according to claim 1, characterized in that: the outer wall of the annular groove of the mandrel body (1) and the inner wall of the bearing sleeve are respectively provided with wear-resistant layers, and the mandrel body (1) ) The hardness of the wear-resistant layer on the outer wall of the annular groove is greater than the hardness of the wear-resistant layer on the inner wall of the bearing sleeve. 9. The drag-reducing sub-joint of a drilling tool according to claim 1, characterized in that: the outer walls of the upper and lower parts of the mandrel body (1) are respectively provided with spiral diversion grooves (8), and the mandrel body (1) ) is provided with a clamp fastening part on the upper part. 10. The drag-reducing pup joint of the drilling tool according to claim 1, characterized in that: the top and bottom ends of the mandrel body (1) are respectively provided with a first taper thread (12) and a second taper thread for connection (13), the first tapered thread (12) is provided at the top of the central hole (11) of the mandrel body (1), and the second tapered thread (13) is provided at the bottom end of the outer wall of the mandrel body (1) .

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