Efficient easy-to-withdraw milling shoe and milling process

Abstract

The invention provides an efficient easy-to-withdraw milling shoe and a milling process, the milling shoe comprises an upper joint, a milling shoe body and milling teeth which can be connected in sequence, the upper joint comprises a joint part and a lower connecting part which are connected, the joint part can be connected with a milling drilling tool, and the lower connecting part is provided with an external thread section; the milling shoe body comprises an upper connecting part and a milling shoe body which are connected with each other, an internal thread section is arranged in the upper connecting part, and the internal thread section is matched with the external thread section so that the upper connecting part and the lower connecting part can be connected together; the milling teeth are arranged at one end, deviating from the upper connecting part, of the milling shoe body. A tool used in the milling process comprises the high-efficiency easy-to-withdraw milling shoe. According to the efficient easy-to-withdraw milling shoe, the treatment period is shortened after the milling shoe gets stuck, the treatment mode is simpler and more convenient, and fault loss is reduced to the maximum extent.

Description

Technical Field

[0001] The invention relates to the field of milling well fallen objects operation in oil drilling and oil testing engineering, and in particular to a high-efficiency and easily retractable milling shoe and a milling process. Background Art

[0002] In drilling or oil testing and well repair operations, grinding shoes are often used to clean the bottom of the well or trim the fish top or even grind the fish in the well. The bottom of the grinding shoe is inlaid or welded with carbide columns, alloy teeth or blades for grinding metal objects in the well. The outer diameter of the grinding shoe is 10-20mm smaller than the wellbore and 5-10mm smaller than the inner diameter of the casing. A circulation channel is arranged on the outer circumference of the grinding shoe. The top joint of the grinding shoe is a conventional drill string connection buckle. The grinding shoe is connected to the drill collar or weighted drill pipe at the bottom of the grinding drill string through the drill tool buckle. During operation, large pieces of iron filings often return to the annular gap between the mill shoe, casing, and well wall, and if not handled properly, the drill will get stuck. Especially when milling long-length fish in small boreholes, if the iron filings generated by the milling operation are not cleaned in time or the content in the working fluid reaches a certain level, the probability of drill getting stuck increases rapidly. Once drill getting stuck, it is necessary to reverse or explosively loosen the drill string above the mill shoe, use sleeve milling to clean the annular space around the mill shoe, and then reverse the jamming to remove the jamming, which will cause great economic losses and negative impacts on normal production operations. Therefore, it is of great significance to provide an efficient and easy-to-retract mill shoe and milling process that can reduce the workload of explosive loosening, reverse drilling tool reverse, and reduce the economic losses and negative impacts caused by drill getting stuck in milling.

[0003] A Chinese patent with application number "CN202020617071.7" and name "Reducible Anti-Stuck Mill Shoe" discloses a reducible anti-stuck mill shoe, which includes a stop sleeve joint, a mill shoe body and a milling part; one end of the stop sleeve joint is detachably connected to the pipe column; one end of the mill shoe body is detachably connected to the other end of the stop sleeve joint, and the axial side of the mill shoe body is evenly distributed with a plurality of slide grooves along the axial direction of the mill shoe body, and the slide groove has an inclination angle from one end of the mill shoe body to the other end of the mill shoe body, and the end of the slide groove close to the stop sleeve joint is the first end; the milling part includes a plurality of mill shoe blocks and a plurality of fixed shear nails, each of which is slidably connected to one of the slide grooves, and one end of each fixed shear nail is connected to one of the mill shoe blocks, and the other end is connected to the bottom of one of the slide grooves, which is used to fix the mill shoe block to the first end. However, the present application is different from its structure. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention aims to solve one or more problems in the prior art. For example, one of the purposes of the present invention is to provide a high-efficiency and easy-to-retract milling shoe and milling process that can reduce the workload of explosive loosening and reverse drilling, and reduce the economic losses and negative effects caused by milling and drilling jams.

[0005] In order to achieve the above-mentioned purpose, the present invention provides, on the one hand, a high-efficiency and easy-to-retract grinding shoe, which may include: an upper joint, a grinding shoe grinding body and grinding teeth that can be connected in sequence, wherein the upper joint includes a joint part and a lower connecting part that are connected, the joint part can be connected to the grinding and milling drill, and the lower connecting part has an external thread section; the grinding shoe grinding body includes an upper connecting part and a grinding shoe body that are connected, the interior of the upper connecting part has an internal thread section, and the internal thread section and the external thread section are adapted to enable the upper and lower connecting parts to be connected together; the grinding teeth are arranged at one end of the grinding shoe body away from the upper connecting part.

[0006] According to one or more exemplary embodiments of one aspect of the present invention, the exterior of the lower connecting portion may also have an upper packing groove and a lower packing groove opened at both ends of the external thread segment, and an upper double bevel located above the upper packing groove; the interior of the upper connecting portion may also have an upper sealing surface and a lower sealing surface opened at both ends of the internal thread segment, and a lower double bevel located above the upper sealing surface; when the upper and lower connecting portions are connected together, the upper and lower packing grooves can respectively face the upper and lower sealing surfaces, and the upper double bevel and the lower double bevel can contact each other.

[0007] According to one or more exemplary embodiments of an aspect of the present invention, the threads in the external thread section and the internal thread section may include rectangular rough threads.

[0008] According to one or more exemplary embodiments of an aspect of the present invention, the outer portion of the lower connecting portion may further include a marking groove located above the upper double slope, and the central axis of the lower connecting portion may include a flow channel.

[0009] According to one or more exemplary embodiments of an aspect of the present invention, the mill shoe grinding body may further include a shell, which is circumferentially distributed on the outside of the mill shoe grinding body; the mill shoe body may include an inner flow channel and an outer flow channel, the inner flow channel is located at the central axis of the mill shoe body, and the outer flow channel is located outside the shell.

[0010] According to one or more exemplary embodiments of an aspect of the present invention, the grinding tooth may include a grinding body, a bottom flow channel and a flow channel hole, wherein the grinding body is composed of an alloy blade, an alloy column and an alloy tooth.

[0011] According to one or more exemplary embodiments of an aspect of the present invention, the grinding body may be in the form of a blade, and the blade may be a positive-rotation blade.

[0012] According to one or more exemplary embodiments of an aspect of the present invention, the number of the blades may include 3, 4, 6 or 8.

[0013] Another aspect of the present invention provides a high-efficiency easy-retracting milling process, wherein the tool used in the milling process may include the high-efficiency easy-retracting mill shoe as described above.

[0014] According to one or more exemplary embodiments of another aspect of the present invention, the tools used in the milling process may further include a drill string scoop, a return pipe, a drill collar, a while drilling jar, a drill rod, and a weighted drill rod.

[0015] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0016] (1) The high-efficiency and easy-to-retract mill shoe provided by the present invention adopts a rectangular thread, thereby realizing easy-to-retract and quick-connection, avoiding the need for explosive loosening after the drill is stuck or the original drill being reversed from other parts when reversed, forcing the use of reverse drills for reverse operations, thereby minimizing the economic losses and negative effects caused by drill stuck in the milling machine;

[0017] (2) The high-efficiency and easy-to-retract grinding shoe provided by the present invention shortens the processing cycle after the grinding shoe is stuck, simplifies the processing method, and minimizes the loss caused by failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other objects and / or features of the present invention will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0019] Figure 1 A schematic longitudinal section view of an upper joint in an exemplary embodiment of the present invention is shown;

[0020] Figure 2 A schematic longitudinal section diagram of a grinding body and grinding teeth of a grinding shoe in an exemplary embodiment of the present invention is shown;

[0021] Figure 3 Shows Figure 2 Schematic diagram of the transverse section of the grinding tooth.

[0022] Description of reference numerals:

[0023] 1-upper joint, 11-joint part, 12-lower connecting part, 121-external thread section, 122-upper plate root groove, 123-lower plate root groove, 124-upper double bevel, 125-marking groove, 126-flow channel;

[0024] 21-upper connecting portion, 211-internal thread section, 212-upper sealing surface, 213-lower sealing surface, 214-lower double inclined surface, 221-inner flow channel, 222-outer flow channel, 23-housing;

[0025] 3-grinding teeth, 31-grinding body, 311-alloy blade, 312-alloy column, 313-alloy teeth, 32-bottom flow channel, 33-flow channel hole. DETAILED DESCRIPTION

[0026] Hereinafter, a high-efficiency and easy-to-retract grinding shoe and a grinding and milling process of the present invention will be described in detail in conjunction with the accompanying drawings and exemplary embodiments.

[0027] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0029] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] Exemplary Embodiment 1

[0031] Figure 1 A schematic longitudinal section view of an upper joint in an exemplary embodiment of the present invention is shown; Figure 2 A schematic longitudinal section diagram of a grinding body and grinding teeth of a grinding shoe in an exemplary embodiment of the present invention is shown; Figure 3 Shows Figure 2 Schematic diagram of the transverse section of the grinding tooth.

[0032] The present exemplary embodiment provides a high-efficiency, easy-to-retract grinding shoe.

[0033] like Figures 1 to 3 As shown in , the high-efficiency and easy-to-retract grinding shoe mainly includes: an upper joint 1, a grinding shoe grinding body and a grinding tooth 3 which can be connected in sequence.

[0034] The upper joint 1 includes a joint part 11 and a lower joint part 12 connected to each other. The joint part 11 can be connected to a milling drill. The buckle shape matches the drill connected to it and can meet the connection strength requirements. The lower joint part 12 has an external thread section 121. The grinding shoe body includes an upper connection part 21 and a grinding shoe body connected to each other. The upper connection part 21 has an internal thread section 211 inside. The internal thread section 211 and the external thread section 121 are adapted to enable the upper and lower connection parts to be connected together. The grinding teeth 3 are arranged at one end of the grinding shoe body away from the upper connection part 21.

[0035] In this exemplary embodiment, the outer part of the lower connecting part 12 may also have an upper packing groove 122 and a lower packing groove 123 opened at both ends of the external thread section 121, and an upper double bevel 124 located above the upper packing groove 122. The inner part of the upper connecting part 21 may also have an upper sealing surface 212 and a lower sealing surface 213 opened at both ends of the internal thread section 211, and a lower double bevel 214 located above the upper sealing surface 212. When the upper and lower connecting parts are connected together, the upper and lower packing grooves can face the upper and lower sealing surfaces respectively, and the upper double bevel and the lower double bevel can contact each other. The threads in the external thread section and the internal thread section may include rectangular rough threads, and the upper and lower connecting parts are connected by rectangular rough threads. Preferably, in order to meet the sealing requirements between the upper and lower parts and the central flow channel and the outside, three "0" sealing packings of different diameters may be provided at both ends of the thread, with 1 upper packing and 2 lower packings, which are respectively arranged in the upper and lower packing grooves. The sealing body formed by the upper and lower packing grooves, the "0"-shaped sealing ring (sealing packing) and the upper and lower sealing surfaces can achieve the isolation of the working fluid inside and outside the pipe. When the upper and lower connecting parts are connected together, the lower end face of the lower connecting part 12 and the step (not shown in the figure) inside the grinding shoe body are weakly matched. When the upper and lower double inclined surfaces are in contact and the torque increases, the grinding shoe body and the grinding teeth remain stationary, and the upper joint is slightly deflected to the right to buckle, and the lower end face of the upper joint is in contact with the upper end face of the grinding shoe body, and high torque transmission is achieved together with the upper and lower double inclined surfaces. The inclined surface design can prevent internal stress concentration caused by torsion.

[0036] In this exemplary embodiment, the outer portion of the lower connecting portion 12 may also have a marking groove 125 located on the upper double inclined surface 124, and the central axis of the lower connecting portion 12 may have a flow channel 126. The grinding shoe body may also include a shell 23, which is circumferentially distributed on the outer portion of the grinding shoe body. The grinding shoe body may include an inner flow channel 221 and an outer flow channel 222, wherein the inner flow channel 221 is located at the central axis of the grinding shoe body, and the outer flow channel 222 is located outside the shell 23 and communicates with the bottom flow channel 32. Here, the marking groove may be marked with information such as the manufacturer, model, and number of the product.

[0037] In this exemplary embodiment, the grinding tooth 3 may include a grinding body 31, a bottom flow channel 32 and a flow channel hole 33, wherein the grinding body 31 is composed of an alloy blade 311, an alloy column 312 and an alloy tooth 313. The grinding body may include blades, which may include positively rotating blades. According to the outer diameter of the grinding shoe, the number of blades may include 3, 4, 6 or 8. A 10 mm thick integral alloy blade is vertically installed at the front end of each blade, and the cutting edge of the blade faces the cutting direction. An octagonal alloy column is installed at the same height behind the blade. The alloy column can be tilted by 1 to 2 degrees and not more than 3 degrees. The alloy column is staggered in different blade radial directions to prevent the occurrence of a cutting blind area on the circumference. The alloy teeth are gradually lowered and welded along the cutting direction from the alloy column to the edge of the flow channel to support the alloy blade and the alloy column. The flow channel in the high-efficiency and easy-to-retract grinding shoe is to meet the circulation needs of the working fluid.

[0038] Exemplary Embodiment 2

[0039] This exemplary embodiment provides a high-efficiency, easy-to-retract milling process. The tool used in the milling process may include the high-efficiency, easy-to-retract milling shoe as described in Exemplary Embodiment 1.

[0040] In this exemplary embodiment, the tools used in the milling process may also include a drill column type bailing cup, a return fan, a drill collar, a drilling jar, a drill pipe, and a weighted drill pipe. Here, the drill tool assembly for milling may include two combinations, the first of which is a grinding shoe, a drill column type bailing cup, a return fan, 2 to 3 columns of drill collars, a drilling jar, 2 to 3 columns of weighted drill pipes, and a drill pipe, and the second of which is a grinding shoe, a drill column type bailing cup, a return fan, 5 to 6 columns of weighted drill pipes, a drilling jar, 2 to 3 columns of weighted drill pipes, and a drill pipe.

[0041] In order to better understand the above exemplary embodiment 2, it is further explained below with reference to specific examples.

[0042] Example 1

[0043] (1) Connect the upper joint of the high-efficiency and easy-to-retract grinding shoe to the drilling tool and tighten it according to regulations.

[0044] (2) Lift the drill tool so that the bottom surface of the grinding shoe is 0.4 to 0.5 m away from the turntable surface. Here, the turntable surface refers to the upper plane of the turntable.

[0045] (3) Place a palm mat or wooden board under the grinding shoe, and use chain pliers or pipe pliers to remove the upper and lower halves of the grinding shoe in reverse.

[0046] (4) Check whether the three "0"-shaped sealing rings are intact, apply lithium-based grease evenly on the rectangular threaded male buckle, and connect the upper and lower halves of the grinding shoe so that the first pair of bevels are in contact with the second pair of bevels.

[0047] (5) Lift the drill bit box to its storage location, steadily lower the drill string through the wellhead assembly, and mill the drill string to a distance of 0.5 to 1.0 m from the bottom of the well.

[0048] (6) Test the friction resistance values ​​by moving up and down and rotating.

[0049] (7) Turn on the pump, rotate the drill bit and adjust all parameters to the specified values.

[0050] Among them, the ranges of various parameters can be respectively: rotation speed: 40-60rpm, torque: idling torque: +5-8kN.m, drilling pressure: 0-50KN, displacement: 80-100% of drilling displacement, pump pressure: determined according to displacement.

[0051] In this example, every 30 minutes or 0.2-0.5m of milling, the drill tool is lifted 2-3m to correct the parameters and salvage once with large or variable displacement. The resistance encountered when lifting the drill tool should not exceed 100KN, otherwise the back-marking will pass. During the milling process, the pump must not be stopped or replaced before the drill tool leaves the bottom of the well. Once stuck, the pump should be immediately turned on to press down or cooperate with the jar to hit down to release and rotate the drill tool to back-mark. If the pressure is not released or the drill tool is at the bottom of the well, increase the torque under the original hanging weight state to try to rotate and release it. The rotation torque must not exceed the minimum torsional yield strength of the drill tool or tool. If the jarring or rotation to release the jam fails and the milling drill tool needs to be withdrawn, move the drill tool up and down 2-3 times to eliminate friction resistance. Adjust the hanging weight to the original hanging weight + 20-30kN, set the reverse torque to idle + 5-8kN.m, and the speed to 10-20rpm. Reverse the drill bit, when the torque is stable at the idle torque and the hanging weight drops rapidly, slowly lift the drill bit out of the upper part of the mill shoe, and stop rotating the drill bit when the upper and lower parts of the mill shoe are 0.5 to 1.0 m away. Pull out the drill bit, replace the milling bit or the lower part of the mill shoe. If the milling method is used to remove the objects between the mill shoe rings, the upper part of the mill shoe can be used to release them.

[0052] The interlocking drill tool used when releasing the interlocking of the upper part of the grinding shoe includes: the upper part of the grinding shoe, a return fan, 2 to 3 columns of weighted drill rods, a drilling jar, 2 to 3 columns of weighted drill rods and a drill rod. The specific steps include:

[0053] (1) Drill down to 0.5-1.0m above the fish top, flush the fish top with a large displacement for 10-20 minutes or circulate to remove the oil and gas aftereffects. Here, circulation means that the working fluid flows from the flow channel in the milling pipe string through the flow channel in the mill shoe, and flows from the flow channel hole at the bottom of the mill shoe and the bottom flow channel, the external flow channel of the shell, and the gap between the mill shoe body and the casing ring from the bottom to the ground and returns to complete a cycle. The circulation can bring mud, iron impurities, oil, gas, water and other working fluids out of the ground.

[0054] (2) Test the rotational and up and down friction resistance values ​​when the pump is turned on and off, as well as the pump pressure at different displacements.

[0055] (3) Set the screw parameters, which can be: speed: 10-20 rpm, torque: idling torque: +3-5 kN.m, drilling pressure: 10-20 KN, displacement: 5-10 L, pump pressure: depends on the displacement.

[0056] (4) Slowly rotate and lower the drill bit to lock it.

[0057] (5) When the torque increases from idling torque to grinding torque, slowly lift the drill bit 2 to 3 meters away from the bottom of the well.

[0058] (6) Turn on the pump to test the pump pressure values ​​of different displacements, and determine the locking condition based on the pump pressure, torque, and friction resistance.

[0059] (7) Once the interlocking is confirmed to be successful, remove the drill and replace the grinding shoe.

[0060] In summary, the advantages of the present invention include at least one of the following:

[0061] (1) The high-efficiency and easy-to-retract mill shoe provided by the present invention utilizes a combination of four processes, namely, split, rectangular buckle, double inclined steps, and weak gap, in conjunction with a grinding and milling technology to separate the mill shoe grinding body from the upper joint body. Once the grinding and milling operation fails to rotate or becomes stuck, the upper drill string needs to be withdrawn, and sleeve milling or grinding and milling are performed to clean the annular gap around the grinding body. The drill string can be reversed to complete the withdrawal, without the need for explosive loosening or reverse buckling of the drill tool, thereby meeting the need for quickly handling the stuck drill in the mill shoe.

[0062] (2) The high-efficiency and easy-to-retract grinding shoe provided by the present invention can reverse and withdraw the upper drill bit of the grinding body during the milling operation, especially when the drill bit is stuck in a small borehole or a small annular gap, leaving only the grinding body part in the well. After the short sleeve milling barrel is lowered to clean the annulus, the upper half is lowered for fastening operation, and the grinding body is pulled out for replacement. Alternatively, a grinding shoe can be directly replaced to grind off the grinding body in the well, thereby avoiding the need for explosive loosening after the drill bit is stuck or the original drill bit is reversed from other parts when it is reversed, and being forced to use reversed drill bits for reversed operations, reducing the workload of explosive loosening and reversed drill bits, reducing the difficulty of handling the drill bit stuck in the grinding shoe from the tool structure, and minimizing the economic losses and negative effects caused by drill bit stuck in milling. It has great economic value and social benefits and strong promotion value.

[0063] Although the above describes a high-efficiency and easily retractable grinding shoe and grinding and milling process of the present invention in combination with exemplary embodiments, those skilled in the art should be aware that various modifications and changes may be made to the exemplary embodiments of the present invention without departing from the spirit and scope defined by the claims.

Claims

1. A high-efficiency and easy-to-retract grinding shoe. It is characterized in that The grinding shoe comprises: an upper joint, a grinding shoe grinding body and grinding teeth which can be connected in sequence, wherein: The upper joint comprises a joint part and a lower joint part connected to each other, the joint part can be connected to the milling drill, and the lower joint part has an external thread section; The grinding shoe body comprises an upper connecting part and a grinding shoe body connected to each other, the interior of the upper connecting part is provided with an internal thread section, and the internal thread section and the external thread section are adapted to enable the upper and lower connecting parts to be connected together; The grinding teeth are arranged at one end of the grinding shoe body away from the upper connecting part.

2. The high-efficiency and easy-to-retract grinding shoe according to claim 1, It is characterized in that The outer portion of the lower connecting portion also has an upper packing groove and a lower packing groove opened at both ends of the external thread section, and an upper double inclined surface located above the upper packing groove; The interior of the upper connecting part also has an upper sealing surface and a lower sealing surface opened at both ends of the internal thread section, and a lower double inclined surface located above the upper sealing surface; when the upper and lower connecting parts are connected together, the upper and lower packing grooves can face the upper and lower sealing surfaces respectively, and the upper double inclined surface and the lower double inclined surface can contact each other.

3. The high-efficiency and easy-to-retract grinding shoe according to claim 1, It is characterized in that The threads in the external thread section and the internal thread section include rectangular rough threads.

4. The high-efficiency and easy-to-retract grinding shoe according to claim 2, It is characterized in that The outer portion of the lower connecting portion is also provided with a marking groove located above the upper double inclined surface, and the central axis of the lower connecting portion is provided with a flow channel.

5. The high-efficiency and easy-to-retract grinding shoe according to claim 1, It is characterized in that The mill shoe grinding body also includes a shell, which is circumferentially distributed outside the mill shoe grinding body; the mill shoe body includes an inner flow channel and an outer flow channel, the inner flow channel is located at the central axis of the mill shoe body, and the outer flow channel is located outside the shell.

6. The high-efficiency and easy-to-retract grinding shoe according to claim 1, It is characterized in that The grinding teeth include a grinding body, a bottom flow channel and a flow channel hole, wherein the grinding body is composed of an alloy blade, an alloy column and an alloy tooth.

7. The high-efficiency and easy-to-retract grinding shoe according to claim 6, It is characterized in that The grinding body comprises blades, and the blades comprise positive-rotation blades.

8. The high-efficiency and easy-to-retract grinding shoe according to claim 7, It is characterized in that The number of the blades includes 3, 4, 6 or 8.

9. An efficient and easy-to-retract milling process, It is characterized in that The tool used in the milling process includes the high-efficiency, easy-to-retract mill shoe as described in any one of claims 1 to 8.

10. The high-efficiency and easy-retracting grinding and milling process according to claim 9, It is characterized in that The tools used in the milling process also include drill column bailing cups, return pipes, drill collars, drilling jars, drill rods and weighted drill rods.

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