Self-locking while-drilling reaming device and application thereof

Abstract

The application provides a self-locking while-drilling reaming device and application thereof, wherein the while-drilling reaming device comprises a barrel, a core pipe, a blade wing assembly, an extension assembly and a retraction self-locking assembly, the core pipe is arranged in the barrel, a groove is arranged on the barrel and penetrates the inner and outer walls of the barrel, the blade wing assembly is arranged in the groove and comprises telescopic reaming blade wings and upper and lower shift forks, the upper and lower shift forks are respectively arranged at the two ends of the telescopic reaming blade wings; the extension assembly is fixedly connected with one end of the blade wing assembly and arranged between the core pipe and the barrel, the extension assembly can move in the axial direction under the pressure of drilling fluid to push the telescopic reaming blade wings to extend out of the groove; the retraction self-locking assembly is fixedly connected with the other end of the blade wing assembly and can lock after the telescopic reaming blade wings extend out, and can reversely push the telescopic reaming blade wings to be retracted. The cam mechanism is adopted to lock the blade wing, the well diameter of the reaming section is not irregular due to the fluctuation of the drilling fluid pressure, and the telescopic reaming blade wings are of integral type, high strength and long service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas drilling equipment tools, in particular to a self-locking while-drilling reaming device and application thereof. BACKGROUND

[0002] With the development of oil and gas exploration and development to deep strata, the stratum structure and wellbore structure are more and more complex, and the challenges encountered in drilling are gradually increasing, including small hole size, poor rock drillability, large annular pressure loss, etc. Small hole drilling can reduce the cost of oil field exploration and development, saving 30% of the cost, and the application of small hole technology in remote exploration wells or areas with difficult logistics supply can save 50% to 75% of the cost. However, small hole cannot add a centralizer due to the small annular gap between the hole and the casing string, and the mud cake and hole shrinkage in the hole make the casing difficult to center, resulting in a thin cement sheath, large annular pressure loss during construction, high cement injection pressure, and easy to lose formation, which leads to low displacement efficiency and seriously affects the wellbore cementing quality. SUMMARY

[0003] The present application aims to solve at least one of the above-mentioned deficiencies in the prior art. For example, one of the purposes of the present application is to provide a self-locking while-drilling reaming device and application thereof, which can perform hole enlargement operation on small gap open hole sections, ultra-deep open hole sections and salt-gypsum layer shrinkage sections, effectively improve the resistance to stratum creep and sealing capacity of the cement sheath system, and achieve the purpose of improving the cementing quality.

[0004] To achieve the above-mentioned purposes, the present application provides a self-locking while-drilling reaming device, which can include a barrel, a core tube, a blade assembly, an extension assembly and a retraction self-locking assembly. The core tube can be arranged in the barrel, and a groove penetrating the inner and outer walls of the barrel can be formed on the barrel. The blade assembly can be arranged in the groove and can include telescopic reaming blades and upper and lower shift forks, which can be arranged at both ends of the telescopic reaming blades. The extension assembly is fixedly connected to one end of the blade assembly and can be arranged between the core tube and the barrel. The extension assembly can move axially under the pressure of drilling fluid to push the telescopic reaming blades out of the groove. The retraction self-locking assembly is fixedly connected to the other end of the blade assembly and can lock the telescopic reaming blades after they are extended, and can also push the telescopic reaming blades in the opposite direction to retract them.

[0005] Alternatively, the reaming device can further include a limiting seat arranged between the core tube and the barrel and connected to one end of the extension assembly. An annular space is formed between the limiting seat, the extension assembly and the core tube. A plurality of first liquid passages are formed on the side wall of the core tube to communicate the inner cavity of the core tube with the annular space, so that the drilling fluid enters the annular space from the inner cavity of the core tube through the first liquid passages.

[0006] Optionally, the extending assembly can comprise a pressure-bearing cap, a pressure-bearing piston and a first elastic member, one end of the pressure-bearing piston is fixedly connected with the lower shift fork, the other end is connected with the limiting seat, the pressure-bearing cap and the first elastic member are both arranged in the pressure-bearing piston, and two ends of the first elastic member are respectively in abutment with a step of an inner wall of the pressure-bearing piston and an end face of the pressure-bearing cap.

[0007] Optionally, the retracting self-locking assembly can comprise a flow guide ring, a second elastic member and a cam mechanism arranged in sequence along the axial direction, the cam mechanism comprises a cam control rod and a cam body, a sliding groove is formed in a side wall of the cam body, one end of the cam control rod is fixedly connected with the cylinder body, the other end is embedded in the sliding groove, the cam body can move along the axial direction and rotate in one direction in the cylinder body under the cooperation of the cam control rod and the sliding groove, so as to realize two states of axial locking and unlocking.

[0008] Optionally, the retracting self-locking assembly can further comprise a spring protection sleeve, at least two groups of axial thrust bearings and a moving sleeve, two ends of the second elastic member are respectively in abutment with the flow guide ring and the spring protection sleeve, the moving sleeve is fixedly connected with the upper end of the blade assembly, one group of the two groups of axial thrust bearings is located between the moving sleeve and the cam body, and the other group is located between the cam body and the spring protection sleeve.

[0009] Optionally, a plurality of second liquid passing holes can be formed in the side wall of the pressure-bearing piston, a plurality of third liquid passing holes are formed in the side wall of the cylinder body, a nozzle is arranged in each third liquid passing hole, and the second liquid passing holes can communicate the annular space with the third liquid passing holes, so that the drilling fluid in the annular space enters the third liquid passing holes along the second liquid passing holes and is discharged from the nozzles.

[0010] Optionally, the blade assembly can further comprise an upper shift fork limiting block and a lower shift fork limiting block, the upper shift fork limiting block is fixedly installed at the upper end of the upper shift fork, and the lower shift fork limiting block is fixedly installed at the lower end of the lower shift fork.

[0011] Optionally, the reaming device can further comprise a sliding mandrel, the sliding mandrel is sleeved on the core pipe, and the spring protection sleeve, the axial thrust bearings, the cam body, the moving sleeve, the blade assembly and the extending assembly are all sleeved on the sliding mandrel and can move along the axial direction together with the sliding mandrel.

[0012] Optionally, a shearing hole can be formed in the sliding mandrel, and the blade assembly and the extending assembly can move along the axial direction to shear the sliding mandrel at the shearing hole, so that the telescopic reaming blade assembly is recovered.

[0013] Another aspect of the present application provides the use of the self-locking while-drilling reamer in the wellhead reaming operation, the use comprising: when the telescopic reamer wing is in the retracted state, increasing the drilling fluid flow rate to 20-23 L / s, the telescopic reamer wing can be extended out of the groove; when the drilling fluid flow rate is increased to 30-33 L / s, the telescopic reamer wing can be extended to the maximum reaming diameter; when the telescopic reamer wing is in the locked state and the drilling fluid flow rate is increased to 40-43 L / s, the telescopic reamer wing can be triggered to unlock; when the telescopic reamer wing is in the unlocked state and the drilling fluid flow rate is increased to 40-43 L / s, the telescopic reamer wing can be triggered to lock; when the telescopic reamer wing is in the triggered unlocked state and the drilling fluid flow rate is reduced to less than 20-23 L / s, the telescopic reamer wing can be retracted.

[0014] Compared with the prior art, the present application has the following beneficial effects:

[0015] (1) The present application can effectively enlarge the wellbore diameter, which is beneficial to downhole testing and casing operation, can optimize the casing program, reduce the amount of casing steel and cement used for cementing, and reduce the operation cost, and can solve the exploration and drilling problems caused by salt-cement layer creep and extrusion.

[0016] (2) The present application uses drilling fluid as the driving force, which has the advantages of simple operation and obvious state indication of the reamer.

[0017] (3) The present application uses a cam mechanism to lock the telescopic reamer wing, which effectively avoids the problem of irregular reaming section diameter caused by drilling fluid pressure fluctuation.

[0018] (4) The present application uses a sliding mandrel fracture method to forcibly retract the telescopic reamer wing, which effectively avoids the problem of stuck pipe caused by failure of the telescopic reamer wing to retract.

[0019] (5) The present application uses an integral telescopic reamer wing, which has the advantages of high strength and long service life. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above and other objects and / or characteristics of the present application will become more apparent from the following description with reference to the attached drawings, wherein:

[0021] Figure 1 Fig. 1 shows the overall structure state diagram of the telescopic reamer wing of the self-locking while-drilling reamer of the present application when the telescopic reamer wing is not extended.

[0022] Figure 2 Fig. 2 shows the overall structure state diagram of the telescopic reamer wing of the self-locking while-drilling reamer of the present application after the telescopic reamer wing is extended.

[0023] Figure 3 A structural diagram of a cam body in the self-locking while-drilling reaming device of the exemplary embodiment 1 of the present application is shown.

[0024] Figure 4 A control principle diagram of a cam mechanism in the self-locking while-drilling reaming device of the exemplary embodiment 1 of the present application is shown.

[0025] Figure 5 A fracture position diagram of a sliding mandrel in the self-locking while-drilling reaming device of the exemplary embodiment 1 of the present application is shown.

[0026] BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 1-cylinder, 11-third liquid passage, 12-nozzle, 2-core tube, 21-first liquid passage, 3-blade assembly, 31-telescopic reaming blade, 32-upper yoke, 33-lower yoke, 34-upper yoke limiting block, 35-lower yoke limiting block, 4-extension assembly, 41-pressure bearing piston, 411-second liquid passage, 42-pressure bearing cap, 43-first elastic member, 5-retraction self-locking assembly, 51-cam mechanism, 511-cam body, 5111-slotted guide, 512-cam control rod, 52-flow guide ring, 53-second elastic member, 54-spring protection sleeve, 55-axial thrust bearing, 56-moving sleeve, 6-limiting seat, 7-sliding mandrel, 71-shear cut, 72-upper step surface. DETAILED DESCRIPTION

[0028] In the following, the self-locking while-drilling reaming device of the present application and its application will be described in detail in conjunction with exemplary embodiments.

[0029] In the description of the present application, it needs to be understood that the orientations or positional relationships indicated by the terms “center”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer” and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0030] The terms “first”, “second” are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with “first”, “second” can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of “multiple” is two or more.

[0031] In the description of the present application, it should be noted that unless specifically defined and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be directly connected, or indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] In the operation of small hole drilling, due to the small annular gap between the wellbore and the casing string and the inability to add a centralizer, the mud cake in the wellbore and the wellbore diameter reduction make the casing not easy to be centered, resulting in a thin cement sheath, a large annular pressure loss during construction, a high cementing construction pressure, and an easy pressure leakage of the formation, resulting in low displacement efficiency and other problems, which seriously affect the wellbore cementing quality.

[0033] Based on this, the present application provides a self-locking while-drilling hole expanding device and its application, wherein the self-locking while-drilling hole expanding device comprises a barrel, a core pipe, a blade wing assembly, an extension assembly and a retraction self-locking assembly, wherein the core pipe is arranged in the barrel, a groove penetrating the inner and outer walls of the barrel is formed on the barrel, the blade wing assembly is arranged in the groove and comprises a telescopic hole expanding blade wing and upper and lower shift forks, the upper and lower shift forks are arranged at the two ends of the telescopic hole expanding blade wing respectively; the extension assembly is fixedly connected with one end of the blade wing assembly and arranged between the core pipe and the barrel, the extension assembly can move in the axial direction under the pressure of the drilling fluid to push the telescopic hole expanding blade wing to extend out of the groove; the retraction self-locking assembly is fixedly connected with the other end of the blade wing assembly and can lock after the telescopic hole expanding blade wing extends out, and can also reversely push the telescopic hole expanding blade wing to retract.

[0034] The present application can effectively expand the wellbore, which is beneficial to downhole testing and casing operation, can optimize the casing program, reduce the use of casing steel and cementing cement, and reduce the operation cost, can solve the exploration and drilling problems caused by the creep and extrusion of salt and gypsum layers; the drilling fluid is used as the driving force, which has the advantages of simple operation and obvious state indication of the hole expanding device; the cam mechanism is used to lock the telescopic hole expanding blade wing, which effectively avoids the problem of irregular hole diameter of the hole expanding section caused by the fluctuation of the drilling fluid pressure; the telescopic hole expanding blade wing is forcibly retracted by the sliding mandrel breaking mode, which effectively avoids the sticking accident caused by the failure of the telescopic hole expanding blade wing retraction; the telescopic hole expanding blade wing has the advantages of high strength and long service life.

[0035] Example Embodiment 1

[0036] The present example embodiment provides a self-locking while-drilling hole expanding device.

[0037] Figure 1 The overall structure state diagram of the telescopic hole expanding blade wing of the self-locking while-drilling hole expanding device of the present example embodiment 1 is shown;Figure 2 This diagram shows the overall structural state of the self-locking drilling reamer of the present invention after the telescopic reamer blades are extended; Figure 3 A structural diagram of the cam body in the self-locking drilling reamer of exemplary embodiment 1 of the present invention is shown; Figure 4 A control principle diagram of the cam mechanism in the self-locking drilling reamer of exemplary embodiment 1 of the present invention is shown; Figure 5 A schematic diagram showing the fracture location of the sliding mandrel in the self-locking drilling reamer of Exemplary Embodiment 1 of the present invention is shown.

[0038] like Figures 1 to 5 As shown in the exemplary embodiment, the self-locking drilling reaming device may include a cylinder 1, a core tube 2, a cutter wing assembly 3, an extension assembly 4, and a retraction self-locking assembly 5. The core tube 2 is inserted into the cylinder 1, and its outer wall is not fitted against the inner wall of the cylinder 1; that is, a gap exists between the core tube 2 and the cylinder 1. A groove penetrating both the inner and outer walls may be formed on the side wall of the cylinder 1. The cutter wing assembly 3 can be installed in the groove. The extension assembly 4 can be installed in the gap between the core tube 2 and the cylinder 1, and can be installed at one end of the cutter wing assembly 3. The retraction self-locking assembly 5 can be installed inside the cylinder 1 and fixedly connected to the cutter wing assembly 5. The other end of the wing assembly 3; the wing assembly 3 may include an upper fork 32, a telescopic reaming wing 31 and a lower fork 33, which are fixedly connected in sequence along the axial direction; the extension assembly 4 can push the wing assembly 3 to move upward along the axial direction of the cylinder 1 under the pressure of the drilling fluid, thereby extending the telescopic reaming wing 31 from the groove to perform reaming operations on the wellbore; the retraction self-locking assembly 5 can lock the telescopic reaming wing 31 after it has extended from the groove to avoid irregular wellbore diameter in the reaming section caused by drilling fluid pressure fluctuations during reaming operations; the retraction self-locking assembly 5 can also retract the telescopic reaming wing 31 back into the groove after the reaming operation is completed.

[0039] Optionally, the number of grooves opened on the cylinder 1 can be three, and four guide grooves (not shown in the figure) can be evenly arranged on the two sides of each groove. Four guide rails (not shown in the figure) can be evenly arranged on the two sides of the telescopic reamer 31. The guide rails can be embedded in the guide grooves, so that the telescopic reamer 31 can slide freely up and down in the grooves along the guide grooves. However, the present invention is not limited to this. The number of grooves can also be other, and the connection structure between the telescopic reamer 31 and the grooves of the cylinder 1 can also be other structures besides the guide grooves and guide rails. This embodiment does not impose specific limitations.

[0040] In the embodiment, the self-locking while-drilling reaming device further comprises a limiting seat 6, which is installed in the gap between the core pipe 2 and the barrel 1, and the upper end of the limiting seat 6 is fixedly connected with the lower end of the extending assembly 4, and an annular space is formed between the limiting seat 6, the extending assembly 4 and the core pipe 2, four first liquid passing holes 21 are formed in the side wall of the core pipe 2, the four first liquid passing holes 21 are distributed in the circumferential direction of the side wall of the core pipe 2, and the four first liquid passing holes 21 are in communication with the inner cavity of the core pipe 2 and the annular space, so that the drilling fluid in the core pipe 2 enters the annular space through the four first liquid passing holes 21, and when the drilling fluid in the annular space reaches a certain pressure, the extending assembly 4 and the blade assembly 3 are pushed to move upward, so that the telescopic reaming blade 31 is extended; however, the present application is not limited thereto, and the first liquid passing holes 21 formed in the core pipe 2 can also be of other numbers, which are not limited by the embodiment.

[0041] In the embodiment, the extending assembly 4 comprises a pressure-bearing piston 41, a pressure-bearing cap 42 and a first elastic member 43, the upper end of the pressure-bearing piston 41 is fixedly connected with the lower shifting fork 33, and the lower end of the pressure-bearing piston 41 abuts against the upper end of the limiting seat 6, the pressure-bearing cap 42 and the first elastic member 43 are both arranged in the pressure-bearing piston 41, that is, the outer wall of the pressure-bearing cap 42 is attached to the inner wall of the pressure-bearing piston 41, the inner wall of the pressure-bearing piston 41 is formed with a step, and the upper and lower ends of the first elastic member 43 abut against the step of the inner wall of the pressure-bearing piston 41 and the upper end of the pressure-bearing cap 42, respectively, when the pressure of the drilling fluid in the annular space is below the critical value that can push the pressure-bearing piston 41 to move upward, only the pressure-bearing piston 41 can be pushed to move upward, and when the pressure of the drilling fluid continues to rise to above the critical value, the pressure-bearing cap 42 can be pushed to compress the first elastic member 43 to continue to move upward.

[0042] Optionally, the side wall of the pressure-bearing piston 41 can be provided with four second liquid passing holes 411, the four second liquid passing holes 411 can pass through the inner and outer walls of the pressure-bearing piston 41, that is, the four second liquid passing holes 411 can be in communication with the annular space formed among the pressure-bearing piston 41, the heart pipe 2 and the limiting seat 6, the side wall of the barrel 1 is provided with four third liquid passing holes 11, the four third liquid passing holes 11 can pass through the inner and outer walls of the barrel 1, one nozzle 12 is installed in each of the four third liquid passing holes 11, when the telescopic reamer wing 31 is not extended out of the groove, the pressure-bearing piston 41 is located at the lowermost end of the stroke, at this time, the second liquid passing hole 411 is not in communication with the third liquid passing hole 11; when the pressure-bearing piston 41 is pushed upward to the uppermost end of the stroke under the pressure of the drilling fluid, that is, when the telescopic reamer wing 31 is opened to the maximum reaming diameter, the second liquid passing hole 411 can be in communication with the third liquid passing hole 11, part of the high-pressure drilling fluid in the annular space can enter the third liquid passing hole 11 of the barrel 1 from the second liquid passing hole 411, and finally be sprayed out through the nozzle 12 in the third liquid passing hole 11, so as to clean and cool the telescopic reamer wing 31; but the present application is not limited to this, the second liquid passing hole 411, the third liquid passing hole 11 and the nozzle 12 can also be other numbers, which are not specifically limited in the embodiment.

[0043] In the embodiment, the retraction self-locking assembly 5 can include a cam mechanism 51, a flow guide ring 52 and a second elastic member 53, the flow guide ring 52, the second elastic member 53 and the cam mechanism 51 are sequentially arranged along the axial direction of the barrel 1, wherein the cam mechanism 51 includes a cam body 511 and two cam control rods 512, the cam body 511 is provided with a sliding groove 5111 passing through the side wall thereof, one end of each of the two cam control rods 512 is fixedly installed in the side wall of the barrel 1, and the other end is embedded into the sliding groove 5111, the two cam control rods 512 can slide in the sliding groove 5111 and relatively move with the cam body 511; but the present application is not limited to this, the cam control rod 512 can also be other numbers, which are not specifically limited in the embodiment.

[0044] Specifically, the cam body 511 can be pushed up by the pressure piston 41, and can also be lowered by the elastic action of the second elastic member 53. Due to the opening direction of the sliding groove 5111 and the cooperation of the cam control rod 512 and the sliding groove 5111, the cam body 511 can rotate in one direction relative to the cylinder body 1 while moving axially. When the cam control rod 512 is at point a in the sliding groove 5111, the cam body 511 is in an unlocked state. When the cam control rod 512 moves along the sliding groove from point b to point c, the cam body 511 is triggered to lock. When the cam body 511 continues to rotate, the cam control rod 512 moves along the sliding groove to point d, and the cam body 511 completes axial locking. When the cam body 511 continues to rotate, the cam control rod 512 moves along the sliding groove to point e, and the cam body 511 is triggered to unlock. When the cam body 511 continues to rotate, the cam control rod 512 moves along the sliding groove to point f, and the cam body 511 completes unlocking and returns to the initial position.

[0045] Alternatively, the retraction self-locking assembly 5 can further include a spring protection sleeve 54, two sets of axial thrust bearings 55, and a moving sleeve 56. The spring protection sleeve 54 abuts the lower end of the second elastic member 53, the upper end of the second elastic member 53 abuts the flow guide ring 52, one set of the two sets of axial thrust bearings 55 is arranged between the cam body 511 and the spring protection sleeve 54, and the other set is arranged between the cam body 511 and the moving sleeve 56. The upper end of the moving sleeve 56 is fixedly connected with the axial thrust bearing 55, and the lower end is fixedly connected with the blade assembly 3. However, the number of axial thrust bearings 55 can be more than two, as long as they are arranged at the upper and lower ends of the cam body 511.

[0046] In this embodiment, the blade assembly 3 can further include an upper shift fork limiting block 34 and a lower shift fork limiting block 35. The upper shift fork limiting block 34 is installed on the upper end of the upper shift fork 32 by a fastening screw, and the lower shift fork limiting block 35 is installed on the lower end of the lower shift fork 33 by a fastening screw. When the blade assembly 3 is pushed up by the pressure piston 41 to the uppermost end of the stroke, the upper shift fork limiting block 34 abuts the upper step surface of the groove of the cylinder body 1 at this time, and the telescopic reaming blade 3 is opened to the maximum reaming diameter (i.e. the reaming working diameter). When the blade assembly 3 returns to the lowermost end of the stroke, the lower shift fork limiting block 35 abuts the lower step surface of the groove of the cylinder body 1 at this time, and the telescopic reaming blade 31 is retracted into the groove. However, the connection mode between the upper shift fork limiting block 34 and the upper shift fork 32, and the connection mode between the lower shift fork limiting block 35 and the lower shift fork 33 can also be welding, bolt connection or other modes, not limited to fastening screw connection.

[0047] In the embodiment, the self-locking while-drilling reaming device further comprises a sliding mandrel 7 sleeved on the core pipe 2, and the spring protection sleeve 54, the axial thrust bearing 55, the cam body 511, the moving sleeve 56, the blade wing assembly 3 and the extension assembly 4 are all sleeved on the sliding mandrel 7, and all the components sleeved on the sliding mandrel 7 can move axially together with the sliding mandrel 7.

[0048] Alternatively, a shear cut 71 can be formed on the sliding mandrel 7, and when the telescopic reaming blade wing 31 in the blade wing assembly 3 cannot be retracted by the retraction self-locking assembly 5, the barrel 1 can be lifted up, the blade wing assembly 3 and the extension assembly 4 can be pushed down by the axial downward friction force generated between the telescopic reaming blade wing 31 and the well wall, and finally the sliding mandrel 7 can be sheared off at the shear cut 71, so that the blade wing assembly 3 and the extension assembly 4 return to the lowermost end of the stroke, and the telescopic reaming blade wing 31 is forced to be retracted.

[0049] The specific working process of the self-locking while-drilling reaming device is described in detail as follows:

[0050] As shown in FIG. Figures 1 to 5 When the self-locking while-drilling reaming device performs reaming operation, the drilling fluid is first injected into the device from the upper end of the barrel 1, and when the drilling fluid discharge reaches 20-23 L / s, the drilling fluid in the annular space between the limiting seat 6, the pressure-bearing piston 41 and the core pipe 2 starts to push the pressure-bearing piston 41 upward, at this time the cam control rod 512 is located at position a of the sliding groove 5111 of the cam body 511; when the drilling fluid increases to the normal working discharge of 30-33 L / s, the upper end surface of the upper shift fork limiting block 34 moves to abut against the upper step surface of the groove of the barrel 1, at this time the cam control rod 512 is located at position b of the sliding groove 5111 of the cam body 511; continue to increase the drilling fluid discharge, and due to the limiting effect of the upper shift fork limiting block 34, the upper shift fork 32 cannot continue to move upward, which causes the pressure-bearing piston 41 also unable to continue to move, at this time the high-pressure drilling fluid pushes the pressure-bearing cap 42 to compress the first elastic member 43 to continue to move upward, and further makes the upper step surface 72 of the sliding mandrel 7 push the axial thrust bearing 55 and the cam body 511 to continue to move upward, when the drilling fluid discharge reaches 40-43 L / s, at this time the cam control rod 512 reaches position c of the sliding groove 5111 of the cam body 511, triggering the cam mechanism to be self-locked, at this time the drilling discharge is reduced to the normal working discharge of 30-33 L / s, and under the elastic force of the second elastic member 53, the cam body 511 moves downward, due to the one-way rotation characteristic of the cam body 511, the cam control rod 512 will run to position d of the sliding groove 5111 of the cam body 511, at this time due to the blocking effect of the cam control rod 512, even if the drilling fluid discharge is reduced to 0 L / s, the cam body 511 cannot move downward, which causes the telescopic reaming blade wing 31 also unable to be retracted into the groove of the barrel 1, and thus the telescopic reaming blade wing 31 is locked at the maximum reaming diameter (i.e. the reaming working position), thereby achieving the purpose.

[0051] When the retractable reamer wing 31 needs to be retrieved, the drilling fluid flow rate is increased to 40-43 L / s, at which point the cam control rod 512 runs to the e position of the sliding slot 5111 of the cam body 511, triggering the cam mechanism to unlock. At this point, the drilling fluid flow rate is reduced to less than 20-23 L / s, and the cam control rod 512 runs to the f position of the sliding slot 5111 of the cam body 511, thereby retracting the retractable reamer wing 31 into the recess of the barrel 1.

[0052] If the cam mechanism cannot be unlocked by increasing the drilling fluid flow rate to the wing unlocking flow rate, causing the retractable reamer wing 31 to fail to be normally retracted, the barrel 1 can be pulled up, relying on the friction between the retractable reamer wing 31 and the well wall to push the retractable reamer wing 31 and the pressure-bearing piston 41 downward, thereby driving the pressure-bearing cap 42 downward, finally cutting the sliding mandrel 7 at the shear cut 71, and returning the retractable reamer wing 31, the downshift fork 33, the pressure-bearing piston 41, and other components to the initial position at the lowermost end of the stroke, achieving the function of forced retrieval of the retractable reamer wing 31.

[0053] Example Embodiment 2

[0054] The present example embodiment provides the application of the self-locking while-drilling reaming device as described in Example Embodiment 1 in wellhead reaming operations.

[0055] As Figures 1 to 5As shown in the figure, when the self-locking reaming-while-drilling device is working, first, drilling fluid is injected into the device from the upper end of the barrel 1. At this time, the telescopic reamer wing 31 is still in the state of not being extended, and the cam control rod 512 is located at position a of the sliding groove 5111 of the cam body 511. When the drilling fluid flow rate reaches 20-23 L / s, the drilling fluid in the annular space formed between the limiting seat 6, the pressure-bearing piston 41 and the core pipe 2 begins to push the pressure-bearing piston 41 to move upward, and the telescopic reamer wing 31 can be extended out of the groove of the barrel 1. When the drilling fluid flow rate increases to the normal working flow rate of 30-33 L / s, the upper end surface of the upper yoke limiting block 34 moves to abut against the upper step surface of the groove of the barrel 1, at which time the cam control rod 512 is located at position b of the sliding groove 5111 of the cam body 511, and the telescopic reamer wing 31 can reach the maximum reaming diameter. When the drilling fluid flow rate continues to increase, due to the limiting effect of the upper yoke limiting block 34, the upper yoke 32 cannot continue to move upward, which causes the pressure-bearing piston 41 to also fail to continue to move. At this time, the high-pressure drilling fluid pushes the pressure-bearing cap 42 to compress the first elastic member 43 to continue to move upward, and further pushes the upper step surface 72 of the sliding arbor 7 to push the axial thrust bearing 55 and the cam body 511 to continue to move upward. When the drilling fluid flow rate reaches 40-43 L / s, at this time, the cam control rod 512 reaches position c of the sliding groove 5111 of the cam body 511, triggering the self-locking of the retracting self-locking assembly 5. At this time, the drilling fluid flow rate is reduced to the normal working flow rate of 30-33 L / s, and under the elastic force of the second elastic member 53, the cam body 511 moves downward. Due to the one-way rotation characteristic of the cam body 511, the cam control rod 512 will run to position d of the sliding groove 5111 of the cam body 511. At this time, due to the blocking effect of the cam control rod 512, even if the drilling fluid flow rate is reduced to 0 L / s, the cam body 511 cannot move downward, which causes the telescopic reamer wing 31 to also fail to be retracted into the groove of the barrel 1. Therefore, the telescopic reamer wing 31 is locked at the maximum reaming diameter (i.e., the reaming working position).

[0056] When the telescopic reamer wing 31 needs to be retracted when the retracting self-locking assembly 5 is in the locked state, the drilling fluid flow rate is only increased to 40-43 L / s, at which time the cam control rod 512 runs to position e of the sliding groove 5111 of the cam body 511, triggering the unlocking of the cam mechanism. Then, the drilling fluid flow rate is reduced to less than 20-23 L / s, and the cam control rod 512 runs to position f of the sliding groove 5111 of the cam body 511, and then the telescopic reamer wing 31 is retracted into the groove of the barrel 1.

[0057] If the cam mechanism cannot be unlocked when the drilling fluid discharge is increased to the unlocking discharge of the blade wing, causing the retractable reaming blade wing 31 to fail to be normally retrieved, the cylinder 1 can be lifted, the friction between the retractable reaming blade wing 31 and the well wall is relied on to push the retractable reaming blade wing 31 and the pressure-bearing piston 41 to run downward, thereby driving the pressure-bearing cap 42 to move downward, finally the sliding mandrel 7 is cut off from the shear cut 71, the retractable reaming blade wing 31, the lower yoke 33, the pressure-bearing piston 41 and other components return to the initial position at the lowermost end of the stroke, and the function of forced retrieval of the retractable reaming blade wing 31 is realized.

[0058] In summary, the present application can effectively expand the wellbore, is beneficial to downhole testing and casing operation, can optimize the casing program, reduce the amount of casing steel and cement used for well cementing, and reduce operation cost, can solve the exploration and drilling problems caused by creep and extrusion of salt-gypsum layer; the drilling fluid is used as driving force, has the advantages of simple operation and obvious state indication of the reaming device; the cam mechanism is used to lock the retractable reaming blade wing, effectively avoiding the problem of irregular wellbore diameter of the reaming section caused by pressure fluctuation of the drilling fluid; the sliding mandrel is used to break the retractable reaming blade wing for forced retrieval, effectively avoiding the sticking accident caused by failure of the retractable reaming blade wing to be retrieved; the integral retractable reaming blade wing has the advantages of high strength and long service life.

[0059] Although the present application has been described above with reference to the example embodiments and the accompanying drawings, it should be clear for those skilled in the art that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A self-locking drilling reaming device, characterized in that, The eye-expanding device includes a cylindrical body, a core tube, a blade assembly, an extension assembly, and a retraction self-locking assembly, wherein... The core tube is inserted into the cylinder, and a groove is opened on the cylinder that runs through the inner and outer walls of the cylinder. The blade assembly is located in the groove and includes a telescopic eye-expanding blade and upper and lower forks. The upper and lower forks are respectively located at both ends of the telescopic eye-expanding blade. One end of the extension component is fixedly connected to the blade assembly and is located between the core tube and the cylinder. The extension component can move axially under drilling fluid pressure to push the telescopic reaming blade out of the groove. The retraction self-locking component is fixedly connected to the other end of the blade wing assembly. It can lock after the telescopic expanding blade wing is extended, and it can also push the telescopic expanding blade wing in the opposite direction to retract it. The retraction self-locking assembly includes a guide ring, a second elastic element, and a cam mechanism arranged sequentially along the axial direction. The cam mechanism includes a cam control rod and a cam body. A sliding groove is provided on the side wall of the cam body. One end of the cam control rod is fixedly connected to the cylinder body, and the other end is embedded in the sliding groove. The cam body can move along the axial direction and rotate unidirectionally in the cylinder body under the cooperation of the cam control rod and the sliding groove, so as to realize the two states of axial locking and unlocking. The retraction self-locking assembly also includes a spring protective sleeve, at least two sets of axial thrust bearings and a movable sleeve. The two ends of the second elastic element abut against the guide ring and the spring protective sleeve respectively. The movable sleeve is fixedly connected to the upper end of the blade assembly. One set of the two sets of axial thrust bearings is located between the movable sleeve and the cam body, and the other set is located between the cam body and the spring protective sleeve.

2. The self-locking drilling reaming device according to claim 1, characterized in that, The drilling device also includes a limiting seat, which is located between the core tube and the cylinder and connected to one end of the extension component. An annular space is formed between the limiting seat, the extension component and the core tube. Several first fluid passage holes are provided on the side wall of the core tube. The first fluid passage holes can connect the inner cavity of the core tube with the annular space, so that drilling fluid enters the annular space from the inner cavity of the core tube along the first fluid passage holes.

3. The self-locking drilling reaming device according to claim 2, characterized in that, The extension assembly includes a pressure cap, a pressure piston, and a first elastic element. One end of the pressure piston is fixedly connected to the lower fork, and the other end is connected to the limiting seat. The pressure cap and the first elastic element are both inserted into the pressure piston. The two ends of the first elastic element abut against the step on the inner wall of the pressure piston and the end face of the pressure cap, respectively.

4. The self-locking drilling reaming device according to claim 3, characterized in that, The pressure-bearing piston has several second fluid passage holes on its side wall, and the cylinder has several third fluid passage holes on its side wall. Each third fluid passage hole is equipped with a nozzle. The second fluid passage holes can connect the annular space with the third fluid passage holes, so that the drilling fluid in the annular space enters the third fluid passage hole along the second fluid passage hole and is discharged from the nozzle.

5. The self-locking drilling reaming device according to claim 1, characterized in that, The blade assembly also includes an upper fork limiting block and a lower fork limiting block. The upper fork limiting block is fixedly installed on the upper end of the upper fork, and the lower fork limiting block is fixedly installed on the lower end of the lower fork.

6. The self-locking drilling reaming device according to claim 1, characterized in that, The eye-expanding device also includes a sliding mandrel, which is sleeved on the core tube. The spring protective sleeve, axial thrust bearing, cam body, moving sleeve, blade assembly and extension assembly are all sleeved on the sliding mandrel and can move axially together with the sliding mandrel.

7. The self-locking drilling reaming device according to claim 6, characterized in that, The sliding mandrel has a shearing opening, and the blade assembly and the extension assembly can move axially to cut the sliding mandrel at the shearing opening, so that the telescopic expanding blade can be retracted.

8. The application of the self-locking drilling reaming device according to any one of claims 1 to 7 in wellhead reaming operations, the application comprising: When the telescopic reamer blade is in the retracted state, increasing the drilling fluid discharge rate to 20-23 L / s allows the telescopic reamer blade to extend out of the groove. When the drilling fluid flow rate is increased to 30-33 L / s, the telescopic reamer blade can be extended to the maximum reamer diameter. When the retraction self-locking component increases the drilling fluid discharge rate to 40-43 L / s in the unlocked state, it can trigger the self-locking of the retraction self-locking component. When the retraction self-locking component increases the drilling fluid discharge rate to 40-43 L / s while in the locked state, it can trigger the retraction self-locking component to unlock. When the retraction self-locking component reduces the drilling fluid flow rate to less than 20-23 L / s after triggering unlocking, it can retract the telescopic reamer's wing.

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