WO2024016567A1 - Strong magnetic salvaging tool and strong magnetic performance testing method - Google Patents

Abstract

The present invention relates to a strong magnetic salvaging tool and a strong magnetic performance testing method. The strong magnetic salvaging tool comprises a mandrel (1); a plurality of ribs (11) are arranged on the outer wall of the mandrel (1) at intervals in the circumferential direction; each rib (11) extends from a first end of the mandrel (1) to a second end of the mandrel (1) in the axial direction of the mandrel (1); the gap between two adjacent ribs (11) forms an impurity storage cavity. Mounting recesses (12) penetrating through two ends of each rib (11) are formed in two side surfaces of each rib (11), and a magnetic strip structure (2) is embedded in each mounting recess (12). Two end blocking caps (3) capable of limiting both ends of each magnetic strip structure (2) are arranged at both ends of the mandrel (1); the two end blocking caps (3) are locked and fixed by means of a locking assembly located in the mandrel (1). In the present invention, magnets are simple and reliable to install and convenient to replace, and there is no risk of falling into a well; according to the present invention, the performance of the magnets in the strong magnetic salvaging tool can also be tested, and the operation is simple.

Description

Strong magnetic salvage tools and strong magnetic performance testing methods

Related applications

This application requires the priority of the Chinese invention patent with the patent application number 202210856985.2, the filing date being July 20, 2022, and the invention title being “A strong magnetic salvage tool and a strong magnetic performance testing method”.

Technical field

The invention relates to the technical field of strong magnetic fishing, and in particular to a strong magnetic fishing tool and a strong magnetic performance testing method.

Background technique

Wellbore cleaning is a very important step in drilling, completion and other operations. Uncleaned wellbore impurities can lead to many unexpected problems and costs, especially in some highly deviated wells, extended reach wells and ultra-deep wells. These problems are particularly prominent. The composition of downhole impurities is very complex. It may be rock debris produced during drilling, mud cake produced by mud, metal debris produced by grinding, and cement sheath or cement sheath produced during the cementing process. Cement blocks may also be flash and burrs produced during perforation, oil casing rust, etc. Remaining debris in wells can result in tens of millions of dollars in accident risk and make the well less efficient. In deep well oil and gas reservoirs, it is often necessary to maximize the annular circulation rate so that contaminants in the well do not settle to the bottom of the well during operation. Historical data shows that 30% of production shutdown time is caused by debris in the well.

Downhole strong magnetic fishing tools are mainly used to remove iron-containing metal debris downhole, such as metal debris generated by casing windows and milling packers. The tool contains special magnets that collect and recover metal debris from well fluids. New deep-well magnetic fishing tools include non-rotating centralizers to prevent collected debris from falling when the tool is removed from the casing. The key properties of strong magnetic fishing tools include the temperature resistance of the magnet and the strength of the magnetic field, as well as whether the magnet will fall off easily after being attached to the tool.

However, the current installation method of magnets, key components of strong magnetic fishing tools, requires external bolts, rings, etc. These bolts and rings may fall into the well, posing a risk of falling into the well. At the same time, it is also very important that the magnetic strip is easy to replace, because the entire mandrel will be inspected before going down the well. Since temperature and vibration will weaken the magnet, the magnetic strip sometimes needs to be replaced. However, the magnetic strip of existing tools is in use. Not easy to replace. In addition, there are currently no special testing devices and methods that can test the performance of magnets in strong magnetic salvage tools, and it is impossible to effectively optimize their performance and ensure their effectiveness.

Therefore, the inventor relied on many years of experience and practice in related industries to propose a strong magnetic salvage tool and a strong magnetic performance testing method to overcome the shortcomings of the existing technology.

Contents of the invention

The purpose of the present invention is to provide a strong magnetic fishing tool, the installation of the magnet is simple and reliable, easy to replace, and there is no risk of falling into a well.

Another object of the present invention is to provide a strong magnetic performance testing method that can test the performance of magnets in strong magnetic salvage tools and is simple to operate.

The above objects of the present invention can be achieved by adopting the following technical solutions:

The invention provides a strong magnetic fishing tool, which includes a mandrel. The outer wall of the mandrel is provided with a plurality of convex ribs at circumferential intervals. Each convex rib extends from the first end of the mandrel to the second end along the axial direction of the mandrel. end, the gap between two adjacent convex ribs constitutes an impurity storage cavity; there are installation grooves running through both ends of the convex rib on both sides of the convex rib, and a magnetic strip structure is embedded in each installation groove; on the core shaft The two ends of the magnetic strip structure are provided with two end blocking caps that can limit the two ends of the magnetic strip structure. The two end blocking caps are locked and fixed by the locking assembly located in the mandrel.

The present invention also provides a strong magnetic performance testing method for testing the performance of the magnetic strip structure in the above-mentioned strong magnetic salvage tool. The strong magnetic performance testing method includes the following steps:

S1. Complete the assembly of the core shaft, each magnetic strip structure, two end caps and locking components to form the main body of the magnetic test;

S2. Put metal scraps into the temperature control box and put the magnetic test body into the temperature control box;

S3. Adjust the temperature of the temperature control box to the set temperature;

S4. After the magnetic test body is placed in the temperature control box for a preset time, the magnetic test body is taken out and the weight of the adsorbed metal debris in each impurity storage cavity is detected.

From the above, in the strong magnetic fishing tool of the present invention, the outer wall of the mandrel has a plurality of convex ribs arranged at intervals, and the impurity storage cavity formed by the gap between two adjacent convex ribs can store impurities more safely. ; And using the impurity storage cavity, the circulation area of the annulus can be increased and the impact on the fluid flow can be reduced when the tool is actually used. The magnetic strip structure is installed by slotting on the convex edge, and the magnet is installed on the mandrel by using the end cap and the locking component to limit the locking. The structure is simple, the fixing method is reliable, and the magnetic strip is in use during use. The structure is also easy to replace; in addition, this installation method does not require any external bolts, rings, etc., and there is no risk of falling into the well.

The strong magnetic performance testing method in the present invention can perform ground testing and simulation on the strong magnet, a key component of the integrated drilling, scraping and milling wellbore cleaning string. The operation is simple and is of great significance for improving the performance of strong magnetic fishing tools.

Description of drawings

The following drawings are only intended to schematically illustrate and explain the present invention and do not limit the scope of the present invention. in:

Figure 1: Structural diagram of the mandrel, magnetic strip structure and end stop cap provided by the present invention after assembly.

Figure 2: A cross-sectional view along B-B in Figure 1.

Figure 3: is a cross-sectional view along C-C in Figure 1.

Figure 4: Cross-sectional view of a mandrel provided for the present invention.

Figure 5: Cross-sectional view of an end cap provided for the present invention.

Figure 6: A structural diagram of the first structure of the magnet structure when the mounting slot provided by the present invention is a rectangular mounting slot.

Figure 7: is a cross-sectional view along D-D in Figure 6.

Figure 8: A cross-sectional view of the second structure of the magnet structure when the mounting slot provided by the present invention is a rectangular mounting slot.

Figure 9: Structural diagram of the third structure of the magnet structure when the mounting slot provided by the present invention is a rectangular mounting slot.

Figure 10: is a cross-sectional view along E-E in Figure 9.

Figure 11: Cross-sectional view of a trapezoidal magnetic strip provided for the present invention.

Figure 12 is a side view of Figure 11.

Figure 13: Another cross-sectional view of a trapezoidal magnetic strip provided for the present invention.

Figure 14: Another cross-sectional view of the trapezoidal magnetic strip provided for the present invention.

Figure 15: A cross-sectional view along A-A when the magnetic test body constructed in Figure 1 adopts the first magnetic pole arrangement.

Figure 16: A cross-sectional view along A-A when the magnetic test body constructed in Figure 1 adopts the second magnetic pole arrangement.

Figure 17: A cross-sectional view along A-A when the magnetic test body constructed in Figure 1 adopts the third magnetic pole arrangement.

Figure 18: A cross-sectional view along A-A when the magnetic test body constructed in Figure 1 adopts the fourth magnetic pole arrangement.

Among them, N in the attached figure represents the N pole, and S represents the S pole.

Explanation of reference numbers:

1. Mandrel; 11. Raised rib; 12. Mounting slot; 121. Rectangular mounting slot; 122. Isosceles trapezoidal mounting slot;

2. Magnetic stripe structure; 21. Rectangular protective sleeve; 211. Mounting hole; 212. Through hole; 22. Rectangular magnetic stripe; 23. Baffle; 24. Stopper pin; 25. Isosceles trapezoidal magnetic stripe;

3. End blocking cap; 31. Plug-in slot; 32. Center hole;

41. Screw; 42. Nut.

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention will now be described with reference to the accompanying drawings.

Embodiment 1

Referring to Figures 1 to 18, this embodiment provides a strong magnetic fishing tool, which includes a mandrel 1. The outer wall of the mandrel 1 is provided with a plurality of convex ribs 11 at circumferential intervals. Each convex rib 11 is along the center of the mandrel 1. The axial direction extends from the first end to the second end of the mandrel 1, and the gap between two adjacent protrusions 11 constitutes an impurity storage cavity. Mounting slots 12 are provided on both sides of the rib 11 and run through both ends of the rib 11. A magnetic strip structure 2 is embedded in each mounting slot 12; There are two end blocking caps 3 for limiting positions at both ends. The two end blocking caps 3 are locked and fixed by a locking assembly located in the mandrel 1 .

Among them, the mandrel 1 is a cylindrical structure with both ends open and hollow. The convex ribs 11 are evenly arranged along the circumferential direction. The length of each convex rib 11 is the same as the length of the mandrel 1. Each convex rib 11 can be the same as the length of the mandrel 1. 1 Integrated molding. The specific number of convex ribs 11 can be determined according to the outer diameter of the mandrel 1 and actual needs. The gap between two adjacent convex ribs 11 provides an impurity storage cavity, which can safely store impurities even when the tool rotates at high speed. The shapes of the two mounting grooves 12 on the same ridge 11 can be the same or different; the specific structures of the two magnetic strip structures 2 installed in the two mounting grooves 12 on the same ridge 11 can be the same or different. Different; the shapes of the mounting slots 12 on different ribs 11 can be the same or different; the specific structures of the magnetic strip structures 2 installed in the mounting slots 12 on different ribs 11 can be the same or different; the magnetic strips The magnetic pole placement orientation of structure 2 can be the same or different; it depends on the installation and performance requirements. During assembly, first install each magnetic strip structure 2 in each installation slot 12, then fix each magnetic strip structure 2 at both ends of the core shaft 1 through two end stoppers 3, and then use the locking assembly to secure the two ends. Once the blocking cap 3 is locked, the assembly of the core shaft 1 and each magnetic strip structure 2 can be completed.

Therefore, in the strong magnetic fishing tool in this embodiment, the outer wall of the mandrel 1 has a plurality of spaced convex ribs 11, and the impurity storage cavity formed by the gap between two adjacent convex ribs 11 can be used more safely. Impurities are stored; and the impurity storage cavity can be used to increase the circulation area of the annulus and reduce the impact on fluid flow when the tool is actually used. The magnetic strip structure 2 is installed by slotting on the ridge 11, and the magnet is installed on the core shaft 1 by using the end cap 3 and the locking component to limit and lock. The structure is simple, the fixing method is reliable, and it is in use The magnetic strip structure 2 is also easy to replace during the process; in addition, this installation method does not require any external bolts, rings, etc., and there is no risk of falling into the well.

In a specific implementation, referring to Figures 1 and 5, the inner end of the end stop cap 3 is provided with a plug-in slot 31, and the ends of the mandrel 1 and each rib 11 can be inserted into the plug-in slot 31 to form a Limit. The locking assembly includes a screw rod 41 and two nuts 42. The screw rod 41 is inserted into the mandrel 1 and its two ends are penetrated by the two end blocks 3. The two nuts 42 are connected to both ends of the screw rod 41 and can abut against each other. On the outer end surfaces of the two end blocking caps 3.

The shape of the plug-in slot 31 should match the shape of the end portions of the mandrel 1 and each protruding rib 11, and they should be limited and fixed by plug-in engagement with each other, which is simpler and more reliable. The end blocking cap 3 can adopt a circular block structure and has a central hole 32 through which the screw 41 can pass. The diameter of the screw 41 is smaller than the inner diameter of the mandrel 1 and the aperture of the central hole 32. The specific inner hole diameter of the mandrel 1 is determined according to the design size of the actual strong magnetic fishing tool in order to connect and cooperate with other components in the tool. After each magnetic strip structure 2 is installed, the two ends of the magnetic strip structure 2 are fixed through the end caps 3, and then locked through the screw rod 41 and the nut 42, making disassembly and assembly more convenient.

Preferably, referring to Figure 4, the width of the ridge 11 along the circumferential direction of the mandrel 1 gradually decreases from the inner radial direction of the mandrel 1 to the outside, which can increase the volume of the impurity storage cavity, which is more conducive to accommodating impurities and increasing the throughput. flow area.

Furthermore, the shape of the installation groove 12 matches the shape of the magnetic strip structure 2 . The shape of the installation groove 12 can be selected according to needs. Considering the convenience of installation, in this embodiment, it is more preferred that the installation groove 12 is along the core axis 1 The axial cross-sectional shape adopts rectangle or isosceles trapezoid.

Specifically, in some embodiments, when the installation groove 12 is a rectangular installation groove 121, with reference to Figures 1, 2 and 6 to 10, the magnetic stripe structure 2 installed in the rectangular installation groove 121 includes a rectangular shape with openings at both ends. The protective cover 21 and the plurality of rectangular magnetic strips 22 inserted in the rectangular protective cover 21 are provided with a baffle 23 between two adjacent rectangular magnetic strips 22, and two rectangular magnetic strips 23 are inserted at both ends of the rectangular protective cover 21. 24 stop pins.

The shape of the blocking piece 23 can be, for example, the cylindrical shape shown in FIG. 7 or other shapes. The blocking piece 23 is a non-magnetic structure to separate two adjacent rectangular magnetic strips 22 . In actual use, each rectangular magnetic strip 22 in the magnetic strip structure 2 has the same specifications, and preferably adopts standard specifications. Then, the size and quantity of the baffles 23 are determined according to the design length of the core shaft 1 and the length of the rectangular magnetic strips 22 . Corresponding mounting holes 211 are provided at both ends of the rectangular protective sleeve 21 for the stopper pins 24 to be inserted. After installing each rectangular magnetic strip 22 and each blocking piece 23, each rectangular magnetic strip 22 and each blocking piece 23 are staggered and closely arranged along the axial direction of the rectangular protective sleeve 21, and are fixed at both ends by inserting stop pins 24. Installation easy and convenient.

When the installation groove 12 is a rectangular installation groove 121 and the magnetic stripe structure 2 is composed of a rectangular protective sleeve 21, a rectangular magnetic stripe 22, a blocking piece 23 and a stop pin 24, the magnetic stripe structure 2 has the following three structural forms:

The first type: Referring to Figures 6 and 7, a plurality of through holes 212 are opened on the side of the rectangular protective cover 21 facing the impurity storage cavity. The through holes 212 are arranged facing the side of the corresponding rectangular magnetic strip 22, and each rectangular magnetic strip The side faces of the strips 22 facing the through holes 212 are respective S poles. That is to say, in addition to the holes on the side walls of the rectangular protective cover 21 where the stop pins 24 are installed, there are also holes on the side walls close to the S poles of the rectangular magnetic strips 22 corresponding to the positions of each rectangular magnetic strip 22 . . According to the orientation in FIG. 7 , the mounting hole 211 and the through hole 212 are facing upward, and the N pole of the rectangular magnetic strip 22 is facing downward.

Second type: Referring to Figure 8, a plurality of through holes 212 are opened on the side of the rectangular protective cover 21 facing the impurity storage cavity. The through holes 212 are arranged facing the side of the corresponding rectangular magnetic strip 22, and the center of each rectangular magnetic strip 22 is The side surfaces of the through hole 212 are respectively N poles. That is to say, in addition to the holes on the side walls of the rectangular protective sleeve 21 where the stop pins 24 are installed, there are also holes on the side walls close to the N poles of the rectangular magnetic strips 22 corresponding to the positions of each rectangular magnetic strip 22 . According to the orientation in FIG. 8 , the mounting holes 211 , the through holes 212 and the N poles of the rectangular magnetic strip 22 are all facing upward.

In the first and second structures, the number of through holes 212 should be the same as the number of rectangular magnetic strips 22. The shape of the through holes 212 can be the circular holes in Figure 6, or other shapes.

Third type: Referring to Figures 9 and 10, the circumferential wall surface of the rectangular protective sleeve 21 corresponding to the rectangular magnetic strip 22 is a closed surface. That is, except for the hole at the position where the stop pin 24 is installed, there are no holes in other positions on the side wall of the rectangular protective sleeve 21 . In this mode, the side of the rectangular protective sleeve 21 with the mounting hole 211 is the side facing the N pole of the rectangular magnetic strip 22 . According to the orientation in Figure 10, the mounting hole 211 and the N pole of the rectangular magnetic strip 22 both face upward. This method makes it easier to clean the adsorbed metal debris.

In other embodiments, when the installation groove 12 is a rectangular installation groove 121, the magnetic stripe structure 2 can also adopt the following structure: the magnetic stripe structure 2 installed in the rectangular installation groove 121 includes a rectangular installation block, with an upper edge on the rectangular installation block. A plurality of slots with slots facing toward the impurity storage cavity are provided in the length direction, and block-shaped magnetic strips are inserted and fixed in each slot. There are two specific structures in this method:

The fourth type: The sides of each block magnetic strip facing the notch are their respective N poles.

The fifth type: The sides of each block magnetic strip facing the notch are their respective S poles.

Among them, the shape of the block magnetic strip should match the shape of the slot. For example, when the slot adopts a cylindrical slot, the block magnetic strip will be a cylindrical magnetic strip. The block magnetic strip can be fixed by interference fit with the slot, or it can be fixed by connecting with fasteners, depending on the needs.

When the installation groove 12 is an isosceles trapezoidal installation groove 122, with reference to Figures 1, 3 and 11 to 14, the installation groove 12 is an isosceles trapezoidal installation groove 122, and the isosceles trapezoidal cross-section of the isosceles trapezoidal installation groove 122 is The upper bottom is arranged toward the impurity storage cavity; the magnetic strip structure 2 installed in the isosceles trapezoidal installation slot 122 includes a plurality of isosceles trapezoidal magnetic strips 25, and a blocking piece 23 is provided between two adjacent isosceles trapezoidal magnetic strips 25. .

The shape of the blocking piece 23 can be, for example, an isosceles trapezoidal block or other shapes. The blocking piece 23 is a non-magnetic structure to separate two adjacent isosceles trapezoidal magnetic strips 25 . In actual use, the specifications of each isosceles trapezoidal magnetic strip 25 in the magnetic stripe structure 2 are the same, and standard specifications are preferably used. Then, the length of the baffle 23 is determined according to the design length of the core shaft 1 and the length of the isosceles trapezoidal magnetic strip 25. Size and quantity; as needed, a baffle 23 can be added outside the outermost isosceles trapezoid magnetic strip 25. After installing the isosceles trapezoidal magnetic strips 25 and the baffles 23, the rectangular magnetic strips 22 and the baffles 23 are staggered and closely arranged along the axial direction of the rectangular protective sleeve 21. Since the notches of the isosceles trapezoidal installation grooves 122 correspond to The upper bottom of the isosceles trapezoidal section is a narrow end, which can limit the internally installed isosceles trapezoidal magnetic strip 25 and the baffle 23. In this way, there is no need to set a protective cover, and finally the ends are used at both ends. The blocking cap 3 can be fixed at the limit position, and the installation is simple and convenient.

When the mounting slot 12 is an isosceles trapezoidal mounting slot 122, the magnet structure has the following three structural forms:

Type 1: Referring to Figures 11 and 12, the trapezoidal upper bottom surfaces of each isosceles trapezoidal magnetic stripe 25 in the magnetic stripe structure 2 are their respective N poles, and the trapezoidal bottom surfaces are their respective S poles. That is, according to the orientation in Figure 11, the magnetizing direction of the isosceles trapezoidal magnetic strip 25 is up and down magnetization, and the N pole is located at one end close to the narrow surface of the isosceles trapezoid, and the S pole is located at one end close to the wide surface of the isosceles trapezoid. .

Second type: Referring to Figure 13, the trapezoidal upper bottom surfaces of each isosceles trapezoidal magnetic stripe in the magnetic stripe structure 2 are their respective S poles, and the trapezoidal bottom surfaces are their respective N poles. That is, according to the orientation in Figure 13, the magnetizing direction of the isosceles trapezoidal magnetic strip 25 is up and down magnetization, and the S pole is located at one end close to the narrow surface of the isosceles trapezoid, and the N pole is located at one end close to the wide surface of the isosceles trapezoid. .

Third type: Referring to Figure 14, the two trapezoidal waist sides of each isosceles trapezoidal magnetic strip in the magnetic stripe structure 2 are respective N poles and S poles. That is, according to the orientation in Figure 14, the magnetizing direction of the isosceles trapezoidal magnetic strip 25 is left and right magnetization, and the N pole is located at the end close to the left side of the isosceles trapezoid, and the S pole is located at the end close to the right side of the isosceles trapezoid. .

In actual application, the multiple mounting grooves 12 on the multiple ridges 11 of the entire core shaft 1 can all adopt rectangular mounting grooves 121, or they can all adopt isosceles trapezoidal mounting grooves 122, or some of them can adopt rectangular mounting grooves 121. The magnetic stripe structure 2 installed in the trapezoidal installation slot 12 and the rectangular installation slot 121 can be installed in any of the above five ways. The magnetic stripe structure 2 installed in the isosceles trapezoidal installation slot 122 can be installed in the above three ways. Any of; the specific shape of each installation slot 12 and the specific structural form of the magnetic stripe structure 2 can be determined according to the installation needs and the performance needs that can be achieved, and various combinations can be tested through relevant performance tests. , to determine the optimal way.

Embodiment 2

This embodiment provides a strong magnetic performance testing method for testing the performance of the magnetic strip structure 2 in the strong magnetic salvage tool of the first embodiment. The strong magnetic performance testing method includes the following steps:

S1. Complete the assembly of the core shaft 1, each magnetic strip structure 2, the two end caps 3 and the locking assembly to form the main body of the magnetic test;

S2. Put metal scraps into the temperature control box and put the magnetic test body into the temperature control box;

S3. Adjust the temperature of the temperature control box to the set temperature;

S4. After the magnetic test body is placed in the temperature control box for a preset time, the magnetic test body is taken out and the weight of the adsorbed metal debris in each impurity storage cavity is detected.

When performing the above test, the size of the mandrel 1 in the magnetic test body can be based on the actual tool size. The heating of the temperature control box can be achieved by using resistance wires, for example, or other methods can be used. In step S4, the method of detecting the weight of the adsorbed metal debris can be to peel off the adsorbed metal debris in the impurity storage chamber and then weigh it, or other methods can be used; after detecting each weight, a comparative analysis can be performed. According to the detected weight of metal debris adsorbed in each impurity storage cavity, the adsorption capacity of the two magnetic strip structures 2 on both sides of the impurity storage cavity to metal debris can be judged, and the adsorption capacity of the metal debris at the set temperature can also be judged. The temperature resistance of the magnetic strip can also be used to judge the magnetic field strength under this condition.

In some embodiments, due to different temperatures, different magnetic stripe materials, different magnetic stripe shapes, and different magnetic pole arrangements of each magnetic stripe structure 2, the performance of the magnetic stripe will be affected, and ultimately the performance of each magnetic stripe will be affected. The adsorption performance of metal iron filings in the impurity storage cavity. In order to facilitate testing of the optimal combination of magnetic stripe structure 2, the following steps are included after step S4:

S5. Adjust the shape, and/or material, and/or magnetic pole arrangement of each magnetic strip structure 2, and/or change the set temperature of the temperature control box; then repeat steps S1-S4 to complete multiple sets of performance tests.

In this way, after conducting multiple sets of performance tests, and by comparing and analyzing the weight of metal debris adsorbed in each impurity storage cavity in the multiple sets of performance tests, the optimal shape, material, and magnetic pole arrangement of each magnetic stripe structure 2 can be obtained. The optimal combination method; the use limits and characteristics of magnetic strips of different materials under different temperature environments can also be determined based on the analysis results; the impact of different conditions on the magnetic field strength can also be determined based on the analysis results, and the impact at different temperatures can also be determined based on the analysis results. Magnetic failure of magnetic strips in the environment.

Among them, when conducting multiple sets of performance tests, the shape, and/or material, and/or magnetic pole arrangement of each magnetic strip structure 2 is adjusted, and/or the set temperature of the temperature control box is changed. These adjustable parameters can be adjusted as needed. Any combination can be used to conduct more sets of comparative tests and more accurately compare better combinations.

It should be noted that the optimal combination method mentioned here does not refer to the method that absorbs the most metal debris in the impurity storage cavity, but requires a comprehensive consideration of the amount of metal debris adsorbed in the impurity storage cavity, the amount of the impurities The size of the flow area after adsorbing metal debris in the storage cavity and the assembly and installation method are used to comprehensively determine the optimal method. In practice, one or two optimal methods are generally selected based on multiple sets of performance tests for use in actual salvage tools.

In other embodiments, since the fishing tool rotates under actual working conditions, there will be a collision with the casing wall. Since the magnetic strip itself is fragile, the magnetic properties of the magnetic strip will also be reduced after the collision. . In order to facilitate testing of the magnetic conditions under different conditions when there is a possibility of collision and breakage of the magnetic strip, in step S3, after adjusting the temperature of the temperature control box, the rotating structure in the temperature control box is turned on, and the rotating structure is used to drive the magnetic test body to rotate. So that the magnetic test body collides with the inner wall of the temperature control box.

After step S4, the following steps are also included:

S5. Adjust the shape, and/or material, and/or magnetic pole arrangement of each magnetic strip structure 2, and/or change the set temperature of the temperature control box; then repeat steps S1-S4 to complete multiple sets of performance tests.

In this way, after conducting multiple sets of performance tests, and by comparing and analyzing the weight of adsorbed metal debris in each impurity storage cavity in the multiple sets of performance tests, the magnetic failure of the magnetic strip under different conditions can be obtained.

Among them, when conducting multiple sets of performance tests, the shape, and/or material, and/or magnetic pole arrangement of each magnetic strip structure 2 is adjusted, and/or the set temperature of the temperature control box is changed. These adjustable parameters can be adjusted as needed. random combination. The temperature control box has a cylindrical structure, and its material can be the same as the actual casing to better simulate the real situation of the fishing tool colliding with the casing while rotating downhole. The specific rotation structure can adopt any existing method, as long as it can easily drive the magnetic test body to rotate. During the test, the magnetic test body can be axially oriented horizontally or vertically, depending on the actual device layout, which is not limited by the present invention.

Further, a specific example will be used to illustrate the above-mentioned testing method below.

Referring to Figures 1 to 18, in this example, a total of four ridges 11 are provided on the outer circumference of the mandrel 1 according to the size of the mandrel 1 used. Taking into account the convenience of installation and testing, a total of four mounting grooves 12 on the two adjacent convex ribs 11 of the four convex ribs 11 adopt rectangular mounting grooves 121. The other two adjacent convex ribs 11 There are four mounting slots 12 in total, all of which adopt isosceles trapezoidal mounting slots 122 . In this way, among the four impurity storage cavities formed, the two sides of one of the impurity storage cavities correspond to the rectangular installation groove 121 and the rectangular installation slot 121, and the two sides of the other impurity storage cavity correspond to the isosceles trapezoidal installation groove 122 and the isosceles trapezoidal installation slot 122. The trapezoidal installation groove 122, and the other two impurity storage chambers correspond to the rectangular installation groove 121 and the isosceles trapezoidal installation groove 122 on both sides. By installing any one of the five structures mentioned in the first embodiment in the rectangular installation groove 121 and installing any one of the three structures mentioned in the first embodiment in the isosceles trapezoidal installation groove 122 , using the same mandrel 1, more combinations of magnetic strips can be installed, and more sets of test tests can be performed, and each set of tests can test multiple conditions.

Specifically, in this example, after the entire magnetic test body is installed, there can be the following four magnetic pole arrangements:

The first method: Referring to Figure 15, this method is to install the above-mentioned second structure in each rectangular installation slot 121, and install the above-mentioned first structure in each isosceles trapezoidal installation slot 122; after the installation is completed, two adjacent magnetic strips The magnetism of structure 2 is all in the repulsive state.

Second type: Referring to Figure 16, this method is to install the above-mentioned first structure and the second structure respectively in two rectangular mounting grooves 121 on the same ridge 11, and the two isosceles on the same ridge 11 The above-mentioned first structure and second structure are respectively installed in the trapezoidal installation groove 122, and the specific distribution is shown in Figure 16, so that after the installation is completed, the magnetism of the two adjacent magnetic strip structures 2 is in an attractive state.

The third method: Referring to Figure 17, this method is to install the above-mentioned third structure in each rectangular installation slot 121, and install the above-mentioned third structure in each isosceles trapezoidal installation slot 122, and after the installation is completed, the adjacent The magnetism of the two rectangular magnetic strip structures 2 is in a repulsive state, and the N pole of each trapezoidal magnetic strip structure 2 faces the center of the core shaft 1 .

The fourth method: Referring to Figure 18, this method is to install the above-mentioned third structure in each rectangular installation slot 121, and install the above-mentioned third structure in each isosceles trapezoidal installation slot 122, and after the installation is completed, the adjacent The magnetism of the two rectangular magnetic strip structures 2 is in an attractive state, and the N pole of each trapezoidal magnetic strip structure 2 faces the center of the core shaft 1 .

When conducting the test, first use the first method of magnetic test body, select a magnetic strip of a material, and complete a set of performance tests according to the above steps S1-S4; before entering step S5, use the second method of magnetic test body. From the first method to the fourth method, adjust the set temperature of the temperature control box, adjust the material of the magnetic strip, and conduct other sets of performance tests; finally, based on these sets of performance tests, the optimal magnetic strip structure can be selected 2 And the arrangement of magnetic poles can also determine the adsorption and failure conditions of magnets of different materials at different temperatures.

Of course, these examples are only illustrations. The specific combination during actual testing depends on the needs. You can also add a rotation function to the magnetic test body to conduct more tests.

Using the above-mentioned strong magnetic performance testing method, the key component of the drilling, scraping and milling integrated wellbore cleaning string can be tested and simulated on the ground - the strong magnet. The operation is simple and is of great significance for improving the performance of strong magnetic fishing tools.

The above are only illustrative embodiments of the present invention and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention shall fall within the scope of protection of the present invention.

Claims (11)

1. A strong magnetic fishing tool, which includes a mandrel. The outer wall of the mandrel is provided with a plurality of convex ribs at circumferential intervals. Each of the convex ribs is formed along the axial direction of the mandrel. The first end extends to the second end, and the gap between two adjacent convex ribs constitutes an impurity storage cavity;

   Installation slots are provided on both sides of the convex rib and run through both ends of the rib, and a magnetic strip structure is embedded in each of the installation slots; at both ends of the mandrel, there are installation slots capable of attaching to the magnetic strip. There are two end blocking caps for limiting positions at both ends of the structure, and the two end blocking caps are locked and fixed by a locking assembly located in the mandrel.
2. The strong magnetic fishing tool according to claim 1, wherein,

   A plug-in slot is provided at the inner end of the end stop cap, and the ends of the mandrel and each of the ribs can be inserted into the plug-in slot to form a limit;

   The locking assembly includes a screw rod and two nuts. The screw rod is installed in the mandrel and its two ends are penetrated by the two end blocks. The two nuts are connected to both sides of the screw rod. The end can abut against the outer end surfaces of the two end blocking caps.
3. The strong magnetic fishing tool according to claim 1, wherein,

   The width of the protruding rib along the circumferential direction of the mandrel gradually decreases from the inner radial direction of the mandrel outward.
4. The strong magnetic fishing tool according to claim 1, wherein,

   The installation slot is a rectangular installation slot, and the magnetic strip structure installed in the rectangular installation slot includes a rectangular protective sleeve with openings at both ends and a plurality of rectangular magnetic strips running through the rectangular protective sleeve. There is a blocking piece between the rectangular magnetic strips, and two stop pins are inserted at both ends of the rectangular protective sleeve.
5. The strong magnetic fishing tool as claimed in claim 4, wherein,

   A plurality of through holes are provided on the side of the rectangular protective sleeve facing the impurity storage cavity, and the through holes are arranged facing the side of the corresponding rectangular magnetic strip;

   The side surfaces of each rectangular magnetic strip facing the through hole are respective N poles; or, the side surfaces of each rectangular magnetic strip facing the through hole are respective S poles.
6. The strong magnetic fishing tool according to claim 1, wherein,

   The mounting slot is a rectangular mounting slot. The magnetic strip structure installed in the rectangular mounting slot includes a rectangular mounting block. The rectangular mounting block is provided with slots along its length direction toward a plurality of insertion holes in the impurity storage cavity. Slots, each of which is inserted and fixed with a block-shaped magnetic strip;

   The side surfaces of each block magnetic strip facing the notch are respective N poles; or, the side surfaces of each block magnetic strip facing the notch are respective S poles.
7. The strong magnetic fishing tool according to claim 1, wherein,

   The installation groove is an isosceles trapezoidal installation groove, and the upper bottom of the isosceles trapezoidal section of the isosceles trapezoidal installation groove is set toward the impurity storage cavity; the magnetic strip structure installed in the isosceles trapezoidal installation groove includes a plurality of Each isosceles trapezoid magnetic strip is provided with a blocking piece between two adjacent isosceles trapezoid magnetic strips.
8. The strong magnetic fishing tool as claimed in claim 7, wherein,

   The trapezoidal upper bottom surfaces of each isosceles trapezoidal magnetic stripe in the magnetic stripe structure are all N poles, and the trapezoidal bottom surfaces are all S poles; or

   The trapezoidal upper bottom surfaces of each isosceles trapezoidal magnetic stripe in the magnetic stripe structure are all respective S poles, and the trapezoidal bottom surfaces are all respective N poles; or

   The two trapezoidal waist sides of each isosceles trapezoidal magnetic strip in the magnetic stripe structure are respective N poles and S poles.
9. A strong magnetic performance testing method, which is used to test the performance of the magnetic strip structure in the strong magnetic salvage tool as claimed in any one of claims 1 to 8, and the strong magnetic performance testing method includes the following steps:

   S1. Complete the assembly of the mandrel, each of the magnetic strip structures, the two end caps and the locking assembly to form a magnetic test body;

   S2. Put metal scraps into the temperature control box, and put the magnetic test body into the temperature control box;

   S3. Adjust the temperature of the temperature control box to the set temperature;

   S4. After the magnetic test body is placed in the temperature control box for a preset time, the magnetic test body is taken out and the weight of the adsorbed metal debris in each impurity storage cavity is detected.
10. The ferromagnetic performance testing method as claimed in claim 9, wherein,

    In step S3, after adjusting the temperature of the temperature control box, the rotating structure in the temperature control box is turned on, and the rotating structure is used to drive the magnetic test body to rotate, so that the magnetic test body is in contact with the temperature control box. The inner wall of the control box collides.
11. The ferromagnetic performance testing method as claimed in claim 9 or 10, wherein,

    After step S4, the following steps are also included:

    S5. Adjust the shape, and/or material, and/or magnetic pole arrangement of each magnetic stripe structure, and/or change the set temperature of the temperature control box; then repeat steps S1-S4 to complete multiple sets of performance test.

Images