Drill rod for small hole window side drilling and manufacturing method thereof

Abstract

The invention discloses a drill rod for side drilling of small well windows and a manufacturing method thereof, the drill rod comprises an upper joint, a drill rod body composed of multiple rod sections and a lower joint; the bottom end of the upper joint, the top and bottom ends of each rod section and the top end of the lower joint are all reduced in diameter by a conical shoulder to form small outer diameter ends with the same outer diameter; an annular wear-resistant belt composed of two staggered annular wear-resistant layers is respectively provided on the outer wall adjacent to the conical shoulder of the upper joint, the outer wall adjacent to the conical shoulder of the lower joint and the outer wall adjacent to the top and bottom ends of each rod section; a plurality of groups of flow-turbulating structures are uniformly distributed along the circumferential direction on the outer wall of each rod section, and a plurality of sand-cleaning spiral grooves are uniformly distributed along the circumferential direction on the annular wear-resistant belt located at the upper joint and the lower joint; the drill rod can increase the side drilling annular space and generate a strong vortex in the annular space, so as to throw the rock cuttings deposited on the bottom edge of the wellbore to the large annular space, thereby improving the downhole sand carrying capacity and having a long service life.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling tools, in particular to a drill rod for small-hole window sidetracking and a manufacturing method thereof. Background Art

[0002] Long-term exploitation of old oilfields has resulted in severe bottom depletion. Window drilling and sidetracking often encounter loose, sandy formations. Slimholes have limited space, low displacement, and poor sand-carrying capacity. The pressure generated by the active drilling tool is significant, easily causing wellbore fragments to fall. During horizontal drilling, fallen cuttings can easily form shoulders and sand bridges, leading to sand jams or sticking, seriously impacting drilling safety and effectiveness. Therefore, timely and effective removal of the cuttings bed is an urgent issue.

[0003] At present, most of the wellbore cleaning tools developed at home and abroad are developed for large wellbore drilling. Their shortcomings include:

[0004] 1. The outer diameter of the spiral groove of the tool is large, so it can effectively remove the cuttings in the wellbore in large wellbores. However, in window drilling operations, since the wellbore is generally small, the wellbore cleaning tool cannot be used;

[0005] 2. The outer diameter of the spiral groove of the wellbore cleaning tool is larger than that of the drill pipe. During the rotary drilling operation, friction, extrusion and collision between the tool and the wellbore wall or casing can easily induce complex downhole conditions. The downhole friction is high, which results in the wellbore cleaning tool only being used at a rate of one tool every 200m, seriously affecting the sand cleaning effect.

[0006] 3. Due to the thick wall thickness of the wellbore cleaning tool, the hardness cannot be adjusted too high during heat treatment, resulting in poor wear resistance of the pipe wall. Especially in high sand content and small wellbore environments, the service life is too short.

[0007] 4. Wellbore cleaning tools need to be managed separately and cannot be repaired after wear, which greatly increases management and use costs.

[0008] In addition, the upper directional inclination section of deep slim-hole sidetracking is short and the well inclination is large, so the inclination rate must be greater than 8° / 30m. This leads to increased alternating stress on the drill pipe. When ordinary drill pipe is used in this environment, the wear-resistant belt will wear rapidly to the point of joint degradation, and there is a risk of fatigue failure of the drill pipe.

[0009] Therefore, in response to the above-mentioned problems, it is urgent to design a drill pipe with a long-life sand cleaning function that can be used in a small hole environment. Summary of the Invention

[0010] The purpose of the present invention is to provide a drill pipe for small hole window sidetracking that solves the sand cleaning problem, rapid wear of drill pipe joints and premature fatigue failure of drill pipe in a small hole drilling environment.

[0011] Another object of the present invention is to provide a method for manufacturing a drill pipe for sidetracking through window opening in a slim wellbore.

[0012] To this end, the technical solution of the present invention is as follows:

[0013] A drill pipe for sidetracking through a small hole is formed by an upper joint, a drill pipe body and a lower joint connected in sequence from top to bottom; wherein,

[0014] The upper joint is a female joint, the bottom end of which is reduced by a conical shoulder to form a small outer diameter end; the drill pipe body is composed of multiple rod sections with the same structure and size; the top and bottom ends of each rod section are reduced by a conical shoulder to form a small outer diameter end; the lower joint is a male joint, the top end of which is reduced by a conical shoulder to form a small outer diameter end; the outer diameters of the small outer diameter ends on the upper joint, each rod section, and the lower joint are all the same;

[0015] An annular wear-resistant belt is provided on the outer wall adjacent to the conical shoulder of the upper joint, on the outer wall adjacent to the conical shoulder of the lower joint, and on the outer wall adjacent to the top and bottom ends of each section rod body; each annular wear-resistant belt is composed of a first annular wear-resistant layer and a second annular wear-resistant layer, wherein the first annular wear-resistant layer is welded and fixed in an annular welding groove opened adjacent to the conical shoulder, and its thickness is slightly greater than the groove depth of the annular welding groove, and the second annular wear-resistant layer is welded and fixed on the outer surface of the first annular wear-resistant layer, and is offset from one end of the first annular wear-resistant layer adjacent to the conical shoulder;

[0016] A plurality of groups of spoiler structures are evenly distributed along the circumferential direction on the outer wall of each section of the rod body, and each group of spoiler structures is composed of a main spoiler groove and several branch groove groups evenly distributed and spaced along the extension direction of the main spoiler groove; each branch groove group is composed of two branch grooves, and the two are symmetrically arranged on both sides of the main spoiler groove and connected to the main spoiler groove; the main spoiler groove is a through groove opened from the top wear-resistant layer to the bottom wear-resistant layer along the axial direction of the rod body, and each branch groove is opened obliquely downward from the main spoiler groove, one end of which is connected to the main spoiler groove, and the other end is adjacent to the other end of the branch groove at the same position of the spoiler structure on the adjacent side; a plurality of sand cleaning spiral grooves are evenly distributed along the circumferential direction on the annular wear-resistant belts located at the upper joint and the lower joint; each sand cleaning spiral groove is a through groove opened in a broken line shape from the end surface of the wear-resistant belt away from the conical shoulder to the end surface of the adjacent conical shoulder.

[0017] Furthermore, the inclination angles of the conical shoulders on the upper joint, the rod body and the lower joint are all 18°.

[0018] Furthermore, the outer diameter of the upper joint, the outer diameter of each rod section, and the outer diameter of the lower joint are all the same, and the thread taper of the internal thread processed on the inner wall of the upper joint and the external thread processed on the outer wall of the lower joint are the same, both 1:16.

[0019] Furthermore, the annular welding groove is opened at a distance of 10 mm from the conical shoulder, and its groove depth is 2.4 mm; the thickness of the annular wear-resistant belt is 5.6±0.4 mm, the length of the annular wear-resistant belt located on the female joint is 154.5 mm, and the length of the annular wear-resistant belt located on the male joint is 76.2 mm; the length of the annular wear-resistant belt located at both ends of the rod body is 154.5 mm; the second annular wear-resistant layer has an offset distance of 25.4 mm from the first annular wear-resistant layer adjacent to the conical shoulder.

[0020] Furthermore, in each group of spoiler structures, the main spoiler groove is a through groove with an asymmetric V-shape in radial cross-section, and each branch groove is a groove with an asymmetric V-shape in radial cross-section; the left groove wall of each groove in the clockwise direction is an arc-shaped groove, and the right groove wall is sloped, and the projected area of ​​the left groove wall on the vertical plane is smaller than the projected area of ​​the right groove wall on the vertical plane; the groove width of the branch groove is smaller than the groove width of the main spoiler groove.

[0021] Furthermore, the radial cross-section of the sand cleaning spiral groove is an asymmetric V-shape, wherein the left groove wall in the clockwise direction is an arc-shaped groove and the right groove wall is a slope, and the projected area of ​​the left groove wall on the vertical plane is smaller than the projected area of ​​the right groove wall on the vertical plane.

[0022] Furthermore, the length of the inner transition zone inside the drill rod is greater than 100 mm.

[0023] A method for manufacturing the drill pipe for slim hole window sidetracking comprises the following steps:

[0024] S1. Select multiple non-quenched and tempered seamless round tubes to make the drill pipe body, and select thick-walled tubes of corresponding length and thickness as pipe body joints;

[0025] S2. performing end thickening treatment on a plurality of seamless round tubes, the steps comprising:

[0026] S201, subjecting each seamless pipe end to two high-frequency heatings and one soaking treatment; wherein, the first high-frequency heating temperature is 700-1100°C, the second high-frequency heating temperature is 1100-1250°C, and the soaking furnace heating pad temperature is 1100-1250°C; each high-frequency heating and soaking time is 20-30s;

[0027] S202, after heating, thicken the ends of each seamless pipe to an outer diameter and an inner diameter slightly larger than the design size, and the length of each pipe body is adapted to the design length;

[0028] S3, quenching and tempering the tube body in sequence; wherein the quenching temperature is 870-890°C, the quenching time is 55 minutes; the tempering temperature is 585-598°C, and the tempering time is 78 minutes;

[0029] S4. The connecting ends of the heat-treated pipe bodies are turned until the outer and inner diameters are consistent with the designed dimensions. The pipe bodies are then sequentially connected by friction welding to form the drill pipe body. The drill pipe welds are then annealed, the outer and inner weld rings are removed, and magnetic particle and ultrasonic testing are performed. The annealing temperature is 680-695°C, and the annealing time is 170 seconds.

[0030] S5. The welds of the drill pipe body are quenched and tempered in sequence, wherein the quenching temperature is 930-975°C and the heating time is 20s; the tempering temperature is 620-665°C and the tempering time is 120s;

[0031] S6. Turning the thick-walled tube selected in step S2 into an upper joint and a lower joint, respectively, and performing magnetic particle inspection on both joints;

[0032] S7, quenching and tempering the turned upper and lower joints; wherein the quenching temperature is 870-890°C, the quenching time is 102 minutes; the tempering temperature is 575-630°C, and the tempering time is 123 minutes;

[0033] S8. Turning an internal thread and an external thread on the upper joint and the lower joint respectively, and turning an annular welding groove;

[0034] S9. Turn the upper and lower joints to the ends of the drill pipe body to the specified dimensions and connect them by friction welding to form the drill pipe. Anneal the welds of the drill pipe, remove the outer and inner weld rings, quench and temper the welds, and then perform magnetic particle and ultrasonic testing. The annealing temperature is 680-695°C, and the annealing time is 170 seconds. The quenching temperature is 930-975°C, and the heating time is 20 seconds. The tempering temperature is 620-665°C, and the tempering time is 120 seconds.

[0035] S10, welding a first wear-resistant layer at corresponding positions of the upper joint, each rod section, and the lower joint, then grinding and removing impurities on the first wear-resistant layer and quickly welding the second wear-resistant layer; wherein, the preheating temperature before welding the first wear-resistant layer is 100-130°C, and when welding the second wear-resistant strip, the temperature of the first wear-resistant layer is not less than 100°C;

[0036] S11. Mill sand-cleaning spiral grooves on the outer walls of the wear-resistant belts of the upper and lower joints, mill flow-turbine structures on the outer walls of each rod section, and perform magnetic particle inspection on the wear-resistant belts.

[0037] Compared with the existing technology, the drill pipe for small hole window side drilling is suitable for side drilling recovery operations of casing damaged wells and accident wells in deep reservoirs in the field of oil and gas field development, and can be used in operating environments with large sand content; wherein, the structural design of the drill pipe: 1) by simultaneously improving the outer diameter and thread taper of the upper and lower joints to ensure that the torsional strength of the joints remains unchanged, the side drilling annulus space is greatly increased and the downhole sand carrying capacity is improved; 2) by providing multiple groups of disturbing flow structures on the drill pipe body, and arranging sand cleaning spiral grooves on the upper and lower joints to cooperate with the disturbing flow structures, the drill pipe can create a strong The swirl not only effectively flushes the cuttings deposited at the bottom of the wellbore, but also helps to throw the cuttings into the large annulus, thereby improving the downhole sand carrying capacity and reducing the phenomenon of downhole drill sticking and drilling stagnation; 3) By setting multiple annular wear-resistant belts at intervals on the upper joint, lower joint and drill pipe body, the outer wall of the drill pipe and the corresponding flow disturbance structure and sand cleaning structure are effectively protected to prevent the wear and degradation of the joints, thereby greatly improving the life of the drill pipe joints. At the same time, the second layer is welded with a 25.4mm offset to prevent the high-sand content drilling fluid from forming a scouring groove when flowing through the position where the wear-resistant belt disappears during window side drilling, which leads to premature failure and degradation of the joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic structural diagram of a drill pipe for slim hole window sidetracking according to the present invention;

[0039] Figure 2 A cross-sectional view of an upper joint of a drill pipe for sidetracking through a slim hole window according to the present invention;

[0040] Figure 3 It is a partially enlarged schematic diagram of the wear-resistant belt of the upper joint of the drill pipe used for slim hole window sidetracking of the present invention;

[0041] Figure 4 Schematic diagram of conventional drill pipe under fluid erosion;

[0042] Figure 5 Schematic diagram of a drill pipe for slim hole window sidetracking under fluid erosion according to the present invention;

[0043] Figure 6 A cross-sectional view of a lower joint of a drill pipe for slim hole window sidetracking according to the present invention;

[0044] Figure 7 It is a partially enlarged schematic diagram of the wear-resistant belt of the lower joint of the drill pipe used for slim hole window sidetracking of the present invention;

[0045] Figure 8 This is a schematic structural diagram of a sand-cleaning spiral groove provided on the wear-resistant belt of the upper joint of a drill pipe for sidetracking through window opening in a slim hole according to the present invention;

[0046] Figure 9 for Figure 8 A-A' cross-sectional view;

[0047] Figure 10 This is a schematic structural diagram of the transition zone on the inner wall of the lower joint of the drill pipe used for slim hole window sidetracking of the present invention;

[0048] Figure 11 This is a schematic structural diagram of a single-section drill pipe for slim hole window sidetracking according to the present invention;

[0049] Figure 12 It is a partial enlarged view of a single-section rod end of a drill rod for slim hole window sidetracking of the present invention;

[0050] Figure 13 for Figure 11 BB' cross-sectional view;

[0051] Figure 14 A partially enlarged view of a flow-disturbing structure provided on the surface of a single section of a drill pipe for sidetracking through a slim hole according to the present invention;

[0052] Figure 15 for Figure 11 C-C' cross-sectional view. DETAILED DESCRIPTION

[0053] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention in any way.

[0054] Example 1

[0055] like Figure 1 As shown, the drill pipe used for small hole window sidetracking is modified from a conventional S-grade steel 2-inch 7-type special buckle drill pipe; specifically, the drill pipe is integrally formed by an upper joint, a drill pipe body, and a lower joint connected in sequence from top to bottom; wherein,

[0056] like Figure 2 As shown, the upper joint is a female joint, and its outer diameter is reduced from the conventional 111.1mm to 88.9mm. Accordingly, the thread taper of the internal thread machined on the inner wall of its top is 1:16. This reduces the outer diameter of the upper joint to increase the sidetracking annulus space while maintaining the torsional strength unchanged. The inner diameter of the center through hole of the upper joint is maintained at 41.3mm.

[0057] The bottom end of the upper joint is reduced in diameter to 73 mm via a conical shoulder structure, allowing for an integrated connection with the bottom end of the drill pipe body. Specifically, the angle between the inclined surface of the conical shoulder and the vertical surface is changed from 35° to 18°, which cooperates with the flow-disturbing structure provided on the drill pipe body to further improve the drill pipe's downhole sand-carrying capacity, avoid drill sticking and holding, and facilitate stress dispersion.

[0058] like Figure 3 As shown, an annular wear-resistant belt is provided on the outer wall of the upper joint above the shoulder, which is composed of a first annular wear-resistant layer a and a second annular wear-resistant layer b; specifically, an annular welding groove with a groove depth of 2.4 mm and an axial length of 154.5 mm is opened at a distance of 10 mm from the top side of the shoulder; the first annular wear-resistant layer a is welded and fixed in the annular welding groove, and its thickness exceeds the depth of the annular welding groove by 0.8 mm; the second annular wear-resistant layer b is welded and fixed on the outer surface of the first annular wear-resistant layer a, and its end adjacent to the shoulder is 25.4 mm offset from the end adjacent to the shoulder of the first annular wear-resistant layer a, while its end away from the shoulder is aligned with the end of the first annular wear-resistant layer a away from the shoulder; the thickness of the second annular wear-resistant layer b satisfies: the second annular wear-resistant layer b protrudes 3.2 mm from the outer wall of the upper joint; wherein, the first wear-resistant layer a and the second wear-resistant layer b are both welded with the same material as the wear-resistant layer welded on the conventional drill pipe;

[0059] like Figure 4 and Figure 5 As shown, compared with the wear-resistant belt welded on the outer wall of the conventional drill pipe joint, the thickness of the annular wear-resistant belt of the present application is increased from the original 2.8mm to 5.6mm, and the axial length is extended from the original 76.2mm to 154.5mm. The advantages of this dimensional improvement are: the thickness of the wear-resistant belt is increased without increasing the outer diameter of the joint, better ensuring the downhole annulus, while extending the length of the wear-resistant belt. After the second wear-resistant layer is worn, the first wear-resistant layer can still play a role in protecting the joint, so that it can better protect the joint when used in high sand content formation environment, and increase the service life of the drill pipe joint by more than 2 times.

[0060] and Figure 4 In comparison, Figure 5 As shown, the structural design of the annular wear-resistant belt of this embodiment can cause a strong vortex in the casing annulus and generate a strong vortex near the spiral groove. On the one hand, it can effectively flush the cuttings deposited at the bottom edge of the wellbore, and on the other hand, it can make the fluid flow from the small annulus to the large annulus. At the same time, the fluid in the small annulus forms a low-pressure area near the hook angle of the spiral groove, which is conducive to drawing the cuttings into the spiral groove and throwing the cuttings to the large annulus under the action of the centrifugal force generated by the rotation of the drill pipe; at the same time, the annular wear-resistant belt is welded with a second layer offset of 25.4mm to prevent the high-sand drilling fluid from forming a scouring groove when flowing through the disappearance position of the wear-resistant belt during window side drilling, resulting in premature failure and degradation of the joint.

[0061] like Figure 8 and Figure 9As shown, four sand-cleaning spiral grooves are evenly distributed along the circumferential direction on the outer wall of the annular wear-resistant belt of the upper joint; each sand-cleaning spiral groove is a through groove opened in a broken line shape from the end surface of the wear-resistant belt away from the shoulder to the end surface adjacent to the shoulder, and the radial cross-section of the through groove is an asymmetric V-shape, that is, the left groove wall in the clockwise direction is an arc-shaped groove, and the right groove wall is sloped, and the projected area of ​​the left groove wall on the vertical plane is smaller than the projected area of ​​the right groove wall on the vertical plane; specifically, the arc radius of the arc corner of the broken line through groove is 22.2 mm, the groove width of the through groove is 17.2 mm, the left groove wall is an arc-shaped groove with an arc radius of 3.2 mm, and the maximum groove depth is 3.2 mm;

[0062] The sand-cleaning spiral groove is provided on the annular wear-resistant belt, which increases the hardness of the groove by 50% compared with ordinary downhole tools, thereby significantly improving the life of the spiral groove. At the same time, even if the groove is worn during use, the spiral groove can be repaired by re-welding the wear-resistant belt so that it can be reused multiple times. In addition, the sand-cleaning spiral groove is provided on the second wear-resistant layer, so that the groove structure protrudes out of the joint body and maintains the same height as ordinary joints, which will not affect the annulus in the well and can be used throughout the well column.

[0063] like Figure 1 As shown in the figure, the drill pipe body consists of three sections with identical structures and dimensions. Each section has a length of 1527 mm, an outer diameter of 88.9 mm, and an inner diameter of 41.3 mm. At the same time, the diameter of each end of the rod body is reduced to 73 mm by a conical shoulder structure, with an inner diameter of 54.6 mm. Specifically, the inclination angle between the inclined surface of the conical shoulder of the lower joint and the vertical surface is changed from 35° to 18° to cooperate with the flow-disturbing structure provided on the rod body, further improving the downhole sand-carrying capacity of the drill pipe, avoiding the occurrence of stuck drill and holding drill, and at the same time, more conducive to stress dispersion.

[0064] like Figure 11 As shown, each section of the rod body is provided with an annular wear-resistant belt on the outer wall near the top and bottom ends; the annular wear-resistant belt is composed of a first annular wear-resistant layer a and a second annular wear-resistant layer b; the first wear-resistant layer a and the second wear-resistant layer b are both welded with the same material as the wear-resistant layer welded on the conventional drill pipe; specifically,

[0065] An annular welding groove with a depth of 2.4 mm and an axial length of 152.4 mm is provided 10 mm from the bottom side of the shoulder at the top of the rod body; the first annular wear-resistant layer a is welded and fixed in the annular welding groove, and its thickness exceeds the depth of the annular welding groove by 0.8 mm; the second annular wear-resistant layer b is welded and fixed to the outer surface of the first annular wear-resistant layer a, and its end adjacent to the shoulder is offset by 25.4 mm from the end adjacent to the shoulder of the first annular wear-resistant layer a, while its end away from the shoulder is aligned with the end of the first annular wear-resistant layer a away from the shoulder; the thickness of the second annular wear-resistant layer b satisfies the requirement that the second annular wear-resistant layer b protrudes 3.2 mm from the outer wall of the upper joint;

[0066] An annular welding groove with a depth of 2.4 mm and an axial length of 154.5 mm is provided 10 mm from the top side of the shoulder at the bottom end of the rod body; the first annular wear-resistant layer a is welded and fixed in the annular welding groove, and its thickness exceeds the depth of the annular welding groove by 0.8 mm; the second annular wear-resistant layer b is welded and fixed to the outer surface of the first annular wear-resistant layer a, and its end adjacent to the shoulder is offset by 25.4 mm from the end adjacent to the shoulder of the first annular wear-resistant layer a, while its end away from the shoulder is aligned with the end of the first annular wear-resistant layer a away from the shoulder; the thickness of the second annular wear-resistant layer b satisfies the requirement that the second annular wear-resistant layer b protrudes 3.2 mm from the outer wall of the upper joint;

[0067] like Figure 11 、 Figure 12 and Figure 14 As shown, three groups of spoiler structures are evenly distributed along the circumferential direction on the outer wall of each rod section. Each group of spoiler structures consists of a main spoiler groove and eight branch groove groups evenly distributed and spaced along the extension direction of the main spoiler groove. Each branch groove group consists of two branch grooves, which are symmetrically arranged on both sides of the main spoiler groove and connected to the main spoiler groove.

[0068] The main spoiler groove is a through groove extending from the top wear-resistant layer to the bottom wear-resistant layer along the axial direction of the rod body, and the radial cross-section of the through groove is an asymmetric V-shape, that is, the left groove wall in the clockwise direction is an arc-shaped groove, and the right groove wall is a slope, and the projected area of ​​the left groove wall on the vertical plane is smaller than the projected area of ​​the right groove wall on the vertical plane; specifically, Figure 13 and Figure 15 As shown, the left side of the through groove is an arc-shaped groove with an arc radius of 9.9 mm, and the slope angle of the right side of the sloped groove wall is 31°; the maximum groove depth of the main spoiler groove located on the wear-resistant belt is 12.9 mm, and the maximum groove depth of the main spoiler groove located on the rod body is 10 mm;

[0069] The branch groove is opened obliquely downward from the main spoiler groove, one end of which is connected to the main spoiler groove, and the length of the branch groove is such that the other end is adjacent to the other end of the branch groove located at the same position of the spoiler structure on the adjacent side; the radial cross-section of the branch groove is an asymmetric V-shape, that is, the left groove wall in the clockwise direction is an arc-shaped groove, and the right groove wall is sloped, and the projected area of ​​the left groove wall on the vertical plane is smaller than the projected area of ​​the right groove wall on the vertical plane; specifically, Figure 15 As shown, the maximum groove depth of the through groove is 5 mm, the left groove wall is an arc-shaped groove with an arc radius of 6.1 mm, and the slope angle of the right sloped groove wall is 30°;

[0070] As described above, each groove of the flow-disrupting structure provided on each rod body adopts a hook-like groove structure from the perspective of radial cross-section, so that the drill rod can produce a flow-disrupting effect on the drilling fluid during its rotation, and the disturbed drilling fluid rolls up the rock cuttings deposited in the lower part of the wellbore to prevent the accumulation of rock cuttings at the bottom of the well; at the same time, each branch groove group adopts a herringbone distribution, so that the drilling fluid is accelerated during the confluence process, and the rock cuttings are accelerated to be drained and finally discharged quickly; in this embodiment, the flow-disrupting structure is combined with the three-section rod body to form a three-section design, so that the fluid can immediately enter the second flow-disrupting groove after flowing out of the flow-disrupting structure and briefly decelerating at the small outer diameter end, so that the rock cuttings can be discharged at a high speed all the time; and the annular wear-resistant belts provided on both sides of the flow-disrupting structure are used to prevent the wear of the flow-disrupting structure and extend its service life;

[0071] The turbulent scaling arranged on the rod body cooperates with the multiple sand cleaning spiral grooves arranged on the upper joint and the lower joint to create a strong swirl in the annulus and generate a strong vortex near the spiral groove. On the one hand, it can effectively flush the cuttings deposited on the bottom edge of the wellbore, and on the other hand, it can make the fluid flow from the small annulus to the large annulus. At the same time, the fluid in the small annulus forms a low-pressure area near the hook angle of the spiral groove, which is conducive to drawing the cuttings into the spiral groove and throwing the cuttings to the large annulus under the action of the centrifugal force generated by the rotation of the drill rod.

[0072] like Figure 6 As shown, the lower joint is a male joint, and its outer diameter and inner diameter remain unchanged at 88.9mm and 41.3mm respectively. Among them, the top of the lower joint is reduced to 73mm by a conical shoulder structure, and the inner diameter is 54.6mm. Specifically, the inclination angle between the inclined surface of the conical shoulder of the lower joint and the vertical surface is changed from 35° to 18°, so as to cooperate with the spoiler structure provided on the drill pipe body, further improve the downhole sand carrying capacity of the drill pipe, avoid the phenomenon of stuck drill and holding drill, and at the same time be more conducive to stress dispersion. At the same time, the thread taper of the internal and external threads machined on the outer wall of the bottom end of the lower joint is 1:16, keeping the torsion resistance of the joint at 0.8 of the pipe body.

[0073] like Figure 7As shown, an annular wear-resistant belt is provided on the outer wall of the lower joint below the shoulder, which consists of a first annular wear-resistant layer a and a second annular wear-resistant layer b; specifically, an annular welding groove with a groove depth of 2.4 mm and an axial length of 76.2 mm is opened at a distance of 10 mm from the bottom side of the shoulder; the first annular wear-resistant layer a is welded and fixed in the annular welding groove, and its thickness exceeds the depth of the annular welding groove by 0.8 mm; the second annular wear-resistant layer b is welded and fixed on the outer surface of the first annular wear-resistant layer a, and its end adjacent to the shoulder and the end of the first annular wear-resistant layer a adjacent to the shoulder have an offset distance of 25.4 mm, while its end away from the shoulder is aligned with the end of the first annular wear-resistant layer a away from the shoulder; the thickness of the second annular wear-resistant layer b satisfies: the second annular wear-resistant layer b protrudes 3.2 mm from the outer wall of the upper joint; wherein, the first wear-resistant layer a and the second wear-resistant layer b are both welded with the same material as the wear-resistant layer welded on the conventional drill pipe.

[0074] Similar to the upper joint, four sand-cleaning spiral grooves are evenly distributed along the circumferential direction on the outer wall of the annular wear-resistant belt of the lower joint; each sand-cleaning spiral groove is a through groove opened in a broken line shape from the end face of the wear-resistant belt away from the shoulder to the end face adjacent to the shoulder, and the radial cross-section of the through groove is an asymmetric V-shape, that is, the left groove wall in the clockwise direction is an arc-shaped groove, and the right groove wall is sloped, and the projected area of ​​the left groove wall on the vertical plane is smaller than the projected area of ​​the right groove wall on the vertical plane; specifically, the arc radius of the arc corner of the broken line through groove is 22.2 mm, the groove width of the through groove is 17.2 mm, the left groove wall is an arc-shaped groove with an arc radius of 3.2 mm, and the maximum groove depth is 3.2 mm.

[0075] Compared with conventional drill pipes, the wear-resistant strips on the upper and lower joints have been improved in structure and their length has been increased to better protect the joints under large curvature conditions and prevent wear and degradation of the joints, thereby greatly improving the life of the drill pipe joints. The reason why the wear-resistant strips formed by the double-layer wear-resistant layer structure are arranged at intervals on the upper joint, lower joint and drill pipe body is that when window side drilling is performed, the rock formation hardness can reach Mohs hardness 7.5. When the high-sand drilling fluid flows through the position where the wear-resistant strip disappears, a scouring groove will appear, causing premature failure of the joint. The double-layer and staggered welding method can prevent premature wear and degradation at the position where the wear-resistant strip disappears.

[0076] As a preferred technical solution of this embodiment, Figure 10As shown, the length of each inner transition zone on the inner wall of the drill pipe has been extended from 50mm to 100mm, allowing the drilling fluid to flow smoothly at the variable diameter section inside the drill pipe, effectively reducing the internal pressure loss of the drilling fluid. The reason for this preferred structural improvement is that the upper directional buildup section of deep small-hole sidetracking is small and the wellbore inclination is large, requiring a buildup rate greater than 8° / 30m, which increases the alternating stress on the drill pipe. The weakest point of the pipe body is the inner transition zone, where stress is concentrated. Ordinary drill pipe has a steep extension of only 50mm, and puncture leakage often occurs at this location. Based on this, in this embodiment, the inner transition zone of the window sidetracking sand cleaning drill pipe is extended to a length of more than 100mm, which can effectively disperse the stress concentration in the inner transition zone and effectively prevent pipe puncture.

[0077] Example 2

[0078] A method for manufacturing the drill pipe for slim hole window sidetracking, the specific steps are as follows:

[0079] S1. Select four non-quenched and tempered seamless round tubes of corresponding length as the drill pipe body and perform flaw detection on the tubes to prevent defects; select thick-walled tubes of corresponding length as the pipe body joints and perform flaw detection on the thick-walled tubes to prevent defects;

[0080] S2, performing end thickening treatment on the four seamless round tubes selected in step S1, the steps comprising:

[0081] S201, subjecting the ends of four seamless pipes to two high-frequency heatings and one soaking treatment; wherein, the temperature of the first high-frequency heating is 700-1100°C, the temperature of the second high-frequency heating is 1100-1250°C, and the temperature of the soaking furnace heating pad is 1100-1250°C to ensure uniform temperature of the pipe ends; each high-frequency heating and soaking time is 20-30 seconds;

[0082] S202. After heating, the outer diameters of both ends of the two tubes are thickened to 92.0 mm, the inner diameters are thickened to 39.0 mm, and the lengths are 780 mm. One end of the other two tubes is upset until the outer diameters are thickened to 92.0 mm and the inner diameters are thickened to 39.0 mm, and the other ends of the tubes are thickened to 80.0 mm and the inner diameters are thickened to 33.0 mm, and the lengths are 80.0 mm.

[0083] S3. Quenching and tempering the tube body in sequence, and testing its physical and chemical properties, the steps include:

[0084] S301, quenching treatment: quenching temperature is 870 ~ 890 ℃, quenching time is 55min;

[0085] S302, tempering treatment: tempering temperature is 585 ~ 598 ℃, tempering time is 78min;

[0086] S303, physical and chemical properties test: The test results require that the yield strength of the remaining parts, excluding the weld, must be ≥930MPa, the tensile strength must be ≥1000MPa, the elongation must be ≥13, and the impact energy (10×10×55mm, 21±3℃) of three pieces must be ≥60J, and the single value must be ≥50J. If any performance is unqualified, the batch of pipes must be reheat treated to achieve the above performance.

[0087] S4, connecting the thickened pipe body processed and tested in step S3, the steps include:

[0088] S401, turning one end of the tube body with an outer diameter thickened to 92.0 mm and an inner diameter thickened to 39.0 mm, specifically: turning the outer diameter to 88.9 mm, turning the inner diameter to 41.3 mm, and turning the end face to a depth of 5 mm;

[0089] S402, frictionally pressing the ends of the turned pipe body in sequence to form a drill pipe body;

[0090] S403, annealing the welding ring at the welding seam at an annealing temperature of 680-695°C for 170 seconds;

[0091] S404. Remove the outer weld ring by turning, remove the inner weld ring by drilling, and grind the weld to a roughness of 3.2 μm.

[0092] S5, heat treating the weld processed in step S4 and testing its physical and chemical properties, the steps comprising:

[0093] S501, quenching the weld: quenching temperature is 930 ~ 975 ℃, heating time is 20s;

[0094] S502, tempering the weld: the tempering temperature is 620-665°C, and the tempering time is 120s;

[0095] S503. Conduct a destructive test on each batch or 100 pipes. The test results should meet the following requirements: weld yield strength ≥ 750MPa, tensile strength ≥ 820MPa, elongation ≥ 13, impact energy (10×10×55mm, 21±3℃) of three pieces average ≥ 35J, single value ≥ 30J. If any performance failure occurs, the batch of pipes needs to be reheat treated until the above performance is met.

[0096] S504, performing magnetic particle and ultrasonic testing on the welds that have undergone the above heat treatment and passed the test;

[0097] S6, cutting the thick-walled tube selected in step S2 internally and externally until the upper and lower joints are formed, and performing magnetic particle inspection on the upper and lower joints after turning;

[0098] S7, heat treating the upper joint and the lower joint after turning and testing their physical and chemical properties, the steps comprising:

[0099] S701, quench the joint: the quenching temperature is 870 ~ 890 ° C, and the quenching time is 102 minutes;

[0100] S702, tempering the joint: the tempering temperature is 575-630℃, and the tempering time is 123min;

[0101] S703. Conduct physical and chemical property tests on heat-treated joints: Conduct a destructive test on each batch or every 100 pairs of joints. The weld yield strength must be ≥850 MPa, the tensile strength must be ≥1000 MPa, the elongation must be ≥13, and the impact energy (10×10×55 mm, 21±3°C) of three pieces must be ≥60 J, with a single value of ≥50 J. If any performance fails, the batch of joints must be reheat treated to achieve the above-mentioned properties.

[0102] S8. Turning an internal thread and an external thread on the upper joint and the lower joint respectively, and turning an annular welding groove;

[0103] S9, frictionally pressing the upper joint and the lower joint to the top and bottom ends of the drill pipe body, heat treating, and conducting physical and chemical property tests, respectively, the steps comprising:

[0104] S901. Turn the upper joint, lower joint, and both ends of the drill pipe body, specifically turning the outer diameter of the connecting end to 76.2 mm and the inner diameter of the connecting end to 41.3 mm. Simultaneously, turn the end face of the connecting end to a turning depth of 5 mm.

[0105] S902, friction-pressing the turned upper joint, lower joint, and both ends of the drill pipe body;

[0106] S903, annealing the welding ring at a temperature of 680-695°C for 170 seconds;

[0107] S904. Remove the outer weld ring by turning, remove the inner weld ring by drilling, and grind the weld to a roughness of 3.2 μm.

[0108] S905, quench the weld: the quenching temperature is 930 ~ 975 ° C, and the heating time is 20s;

[0109] S906, tempering the weld: the tempering temperature is 620 ~ 665 ° C, and the tempering time is 120s;

[0110] S907. Conduct a destructive test on each batch or 100 rods, requiring the weld yield strength to be ≥750MPa, tensile strength to be ≥820MPa, elongation to be ≥13, and impact energy (10×10×55mm, 21±3℃) of three pieces to be ≥35J, with a single value to be ≥30J. If any performance fails, the batch of rods must be reheat treated to achieve the above performance.

[0111] S908. Conduct magnetic particle and ultrasonic testing on the welds after heat treatment;

[0112] S10, welding a first wear-resistant layer at corresponding positions of the upper joint, each rod section, and the lower joint, then grinding and removing impurities on the first wear-resistant layer and quickly welding the second wear-resistant layer; wherein, the preheating temperature before welding the first wear-resistant layer is 100-130°C, and when welding the second wear-resistant strip, the temperature of the first wear-resistant layer is not less than 100°C;

[0113] S11. Mill sand-cleaning spiral grooves on the outer walls of the wear-resistant belts of the upper and lower joints, mill flow-turbine structures on the outer walls of each rod section, and perform magnetic particle inspection on the wear-resistant belts to prevent cracks.

Claims

1. A drill pipe for sidetracking in a slim hole, comprising an upper joint, a drill pipe body, and a lower joint connected in sequence from top to bottom, formed in one piece; characterized in that: The upper joint is a female joint, the bottom end of which is reduced by a conical shoulder to form a small outer diameter end; the drill pipe body is composed of multiple rod sections with the same structure and size; the top and bottom ends of each rod section are reduced by a conical shoulder to form a small outer diameter end; the lower joint is a male joint, the top end of which is reduced by a conical shoulder to form a small outer diameter end; the outer diameters of the small outer diameter ends on the upper joint, each rod section, and the lower joint are all the same; An annular wear-resistant belt is provided on the outer wall adjacent to the conical shoulder of the upper joint, on the outer wall adjacent to the conical shoulder of the lower joint, and on the outer wall adjacent to the top and bottom ends of each section rod body; each annular wear-resistant belt is composed of a first annular wear-resistant layer and a second annular wear-resistant layer, wherein the first annular wear-resistant layer is welded and fixed in an annular welding groove opened adjacent to the conical shoulder, and its thickness is slightly greater than the groove depth of the annular welding groove, and the second annular wear-resistant layer is welded and fixed on the outer surface of the first annular wear-resistant layer, and is offset from one end of the first annular wear-resistant layer adjacent to the conical shoulder; A plurality of groups of spoiler structures are evenly distributed along the circumferential direction on the outer wall of each section of the rod body, and each group of spoiler structures is composed of a main spoiler groove and several branch groove groups evenly distributed and spaced along the extension direction of the main spoiler groove; each branch groove group is composed of two branch grooves, and the two are symmetrically arranged on both sides of the main spoiler groove and connected to the main spoiler groove; the main spoiler groove is a through groove opened from the top wear-resistant layer to the bottom wear-resistant layer along the axial direction of the rod body, and each branch groove is opened obliquely downward from the main spoiler groove, one end of which is connected to the main spoiler groove, and the other end is adjacent to the other end of the branch groove at the same position of the spoiler structure on the adjacent side; a plurality of sand cleaning spiral grooves are evenly distributed along the circumferential direction on the annular wear-resistant belts located at the upper joint and the lower joint; each sand cleaning spiral groove is a through groove opened in a broken line shape from the end surface of the wear-resistant belt away from the conical shoulder to the end surface of the adjacent conical shoulder.

2. The drill pipe for slim hole window sidetracking according to claim 1, characterized in that: The inclination angle of the conical shoulders on the upper joint, the rod body and the lower joint is 18°.

3. The drill pipe for slim hole window sidetracking according to claim 1, characterized in that: The outer diameter of the upper joint, the outer diameter of each rod section, and the outer diameter of the lower joint are all the same, and the thread taper of the internal thread processed on the inner wall of the upper joint and the external thread processed on the outer wall of the lower joint are the same, both of which are 1:

16.

4. The drill pipe for slim hole window sidetracking according to claim 1, characterized in that: The annular welding groove is opened at a distance of 10mm from the conical shoulder, and its groove depth is 2.4mm; the thickness of the annular wear-resistant belt is 5.6±0.4mm, the length of the annular wear-resistant belt on the female joint is 154.5mm, and the length of the annular wear-resistant belt on the male joint is 76.2mm; the length of the annular wear-resistant belt at both ends of the rod body is 154.5mm; the second annular wear-resistant layer has an offset distance of 25.4mm with the first annular wear-resistant layer adjacent to the conical shoulder.

5. The drill pipe for slim hole window sidetracking according to claim 1, characterized in that: In each group of spoiler structures, the main spoiler groove is a through groove with an asymmetric V-shape in radial cross-section, and each branch groove is a groove with an asymmetric V-shape in radial cross-section; the left groove wall of each groove in the clockwise direction is an arc-shaped groove, and the right groove wall is sloped, and the projected area of ​​the left groove wall on the vertical plane is smaller than the projected area of ​​the right groove wall on the vertical plane; the groove width of the branch groove is smaller than the groove width of the main spoiler groove.

6. The drill pipe for slim hole window sidetracking according to claim 1, characterized in that: The radial cross-section of the sand cleaning spiral groove is an asymmetric V-shape, wherein the left groove wall in the clockwise direction is an arc-shaped groove and the right groove wall is a slope, and the projected area of ​​the left groove wall on the vertical plane is smaller than the projected area of ​​the right groove wall on the vertical plane.

7. The drill pipe for slim hole window sidetracking according to claim 1, characterized in that: The length of the inner transition zone inside the drill pipe is greater than 100 mm.

8. A method for manufacturing a drill pipe for slim hole window sidetracking according to claim 1, characterized in that: Here are the steps: S1. Select multiple non-quenched and tempered seamless round tubes to make the drill pipe body, and select thick-walled tubes of corresponding length and thickness as pipe body joints; S2. performing end thickening treatment on a plurality of seamless round tubes, the steps comprising: S201, subjecting each seamless pipe end to two high-frequency heatings and one soaking treatment; wherein, the first high-frequency heating temperature is 700-1100°C, the second high-frequency heating temperature is 1100-1250°C, and the soaking furnace heating pad temperature is 1100-1250°C; each high-frequency heating and soaking time is 20-30s; S202, after heating, thicken the ends of each seamless pipe to an outer diameter and an inner diameter slightly larger than the design size, and the length of each pipe body is adapted to the design length; S3, quenching and tempering the tube body in sequence; wherein the quenching temperature is 870-890°C, the quenching time is 55 minutes; the tempering temperature is 585-598°C, and the tempering time is 78 minutes; S4. The connecting ends of the heat-treated pipe bodies are turned until the outer and inner diameters are consistent with the designed dimensions. The pipe bodies are then sequentially connected by friction welding to form the drill pipe body. The drill pipe welds are then annealed, the outer and inner weld rings are removed, and magnetic particle and ultrasonic testing are performed. The annealing temperature is 680-695°C, and the annealing time is 170 seconds. S5. The welds of the drill pipe body are quenched and tempered in sequence, wherein the quenching temperature is 930-975°C and the heating time is 20s; the tempering temperature is 620-665°C and the tempering time is 120s; S6. Turning the thick-walled tube selected in step S2 into an upper joint and a lower joint, respectively, and performing magnetic particle inspection on the two joints; S7, quenching and tempering the turned upper and lower joints; wherein the quenching temperature is 870-890°C, the quenching time is 102 minutes; the tempering temperature is 575-630°C, and the tempering time is 123 minutes; S8. Turning an internal thread and an external thread on the upper joint and the lower joint respectively, and turning an annular welding groove; S9. Turn the upper and lower joints to the ends of the drill pipe body to the specified dimensions and connect them by friction welding to form the drill pipe. Anneal the welds of the drill pipe, remove the outer and inner weld rings, quench and temper the welds, and then perform magnetic particle and ultrasonic testing. The annealing temperature is 680-695°C, and the annealing time is 170 seconds. The quenching temperature is 930-975°C, and the heating time is 20 seconds. The tempering temperature is 620-665°C, and the tempering time is 120 seconds. S10, welding a first wear-resistant layer at corresponding positions of the upper joint, each rod section, and the lower joint, then grinding and removing impurities on the first wear-resistant layer and quickly welding the second wear-resistant layer; wherein, the preheating temperature before welding the first wear-resistant layer is 100-130°C, and when welding the second wear-resistant strip, the temperature of the first wear-resistant layer is not less than 100°C; S11. Mill sand-cleaning spiral grooves on the outer walls of the wear-resistant belts of the upper and lower joints, mill flow-turbine structures on the outer walls of each rod section, and perform magnetic particle inspection on the wear-resistant belts.

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