Directional magnetic sub and method for determining downhole bit location

Abstract

The application provides a directional magnetic short section and a method for determining the position of a downhole drill bit. The directional magnetic short section is used to generate a rotating magnetic field and limit the position of an inclinometer, and comprises an upper centralizer with at least two through holes and a circular through hole with a diameter larger than the outer diameter of the inclinometer; a lower centralizer with at least two through holes and a circular through hole with a diameter smaller than the outer diameter of the inclinometer; a directional key sleeve which is a circular tube with an inner diameter larger than the outer diameter of the inclinometer; the directional key sleeve can be screwed with the upper centralizer and the lower centralizer; the upper centralizer, the directional key sleeve, the directional key and the lower centralizer are placed inside the axial hole cavity of a non-magnetic body; a directional screw is used to fix the relative position of the non-magnetic body and the directional key; the directional key is used to cooperate with the key groove of the inclinometer bevel shoe to limit the rotation of the inclinometer relative to the directional magnetic short section. In the technical scheme of the application, the directional magnetic short section can be used to generate a rotating magnetic field near the drill bit to effectively simulate the strength of the rotating magnetic field near the drill bit under actual working conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas engineering, in particular to a directional magnetic sub and a method for determining the position of a downhole drill bit. BACKGROUND

[0002] The complex structure well with horizontal well as a basic feature is an important well type for developing difficult-to-produce oil and gas resources such as low-permeability, shale oil and gas, and tight oil and gas. The conventional wellbore position measurement method is to measure the well depth, inclination angle and azimuth angle of multiple measurement points at different well depths, and to obtain the position of each measurement point in the well by a specific calculation method. The position of each measurement point in the well obtained by the method is based on the position of the previous measurement point, so the measurement error of the position of a certain measurement point is the cumulative error of the position measurement errors of all measurement points in the upper well section. This cumulative error cannot be ignored, which leads to the fact that the conventional wellbore position measurement method is not suitable for the complex structure well drilling engineering in which the relative positions of adjacent wells need to be precisely controlled.

[0003] The magnetic guidance drilling technology developed in recent years can directly measure the distance and direction from the drill bit to the adjacent drilled well, thereby avoiding the generation of the cumulative error of the conventional wellbore position measurement. Since the magnetic guidance drilling technology was introduced into the coalbed methane multi-lateral horizontal well drilling engineering, the technology is now being applied to the directional drilling engineering of other complex structure wells.

[0004] With the increasing scale of commercial shale gas exploitation, the well spacing of horizontal well sections is continuously reduced, the fracturing stages and liquid volume are continuously increased, and the interwell fracture channeling problem is increasingly prominent, which to some extent limits the production effect. However, the magnetic field strength of the magnetic beacon of the existing magnetic guidance drilling technology and the ranging algorithm cannot meet the needs of the relative position control of the cluster horizontal wells of shale gas. Therefore, a new device for identifying the position of a drill bit and a method for determining the position of a downhole drill bit are needed. SUMMARY

[0005] The main purpose of the present application is to provide a directional magnetic sub and a method for determining the position of a downhole drill bit, which can be used to simulate the rotating magnetic field near the drill bit, effectively simulate the strength of the rotating magnetic field near the drill bit under actual working conditions, and can be used for magnetic guidance drilling process simulation experiments to identify the position of the drill bit and provide important technical support for further field tests.

[0006] In order to achieve the above object, according to one aspect of the present application, a directional magnetic sub for determining the position of a downhole drill bit is provided, the directional magnetic sub being used for generating a rotating magnetic field and defining the position of an inclinometer, the directional magnetic sub comprising a non-magnetic body, an upper centralizer, a directional key sleeve, a directional key, a directional screw, a lower centralizer, a permanent magnet and a hole elastic retainer; wherein the upper centralizer has at least two through holes uniformly distributed in the circumferential direction and a circular through hole with a diameter larger than the outer diameter of the inclinometer, the circular through hole having an upper centralizer internal thread; the lower centralizer has at least two through holes uniformly distributed in the circumferential direction and a circular through hole with a diameter smaller than the outer diameter of the inclinometer, and has a lower centralizer external thread; the directional key sleeve is a circular tube with an inner diameter larger than the outer diameter of the inclinometer, one end of the directional key sleeve is machined with a key sleeve external thread, the other end of the directional key sleeve is machined with a key sleeve internal thread, and a stepped hole capable of installing the directional key is machined in the middle of the directional key sleeve; the key sleeve external thread of the directional key sleeve can be screwed with the upper centralizer internal thread of the upper centralizer, and the key sleeve internal thread of the directional key sleeve can be screwed with the lower centralizer external thread of the lower centralizer; the upper centralizer, the directional key sleeve, the directional key and the lower centralizer installed together are placed inside the axial cavity of the non-magnetic body; the directional screw is screwed into the stepped hole on the non-magnetic body and the blind hole on the arc-shaped end surface of the directional key, fixing the relative position of the non-magnetic body and the directional key; the other end of the directional key protrudes from the inner surface of the directional key sleeve, used for cooperating with the key groove of the inclinometer beveled shoe to limit the rotation of the inclinometer relative to the directional magnetic sub.

[0007] Further, the non-magnetic body is machined with a first internal thread and a first external thread at both ends respectively, a coaxial cavity is machined on the central axis of the non-magnetic body, the inner diameter and length of the cavity near the first internal thread end are suitable for installing the upper centralizer, the directional key sleeve, the directional key and the lower centralizer assembled together, a section of the non-magnetic body near the first external thread is provided with a plurality of holes perpendicular to the axis of the non-magnetic body, arranged in parallel along the non-magnetic body and distributed on both sides of the non-magnetic body, a permanent magnet is installed in each hole, the magnetic pole direction of the permanent magnet is perpendicular to the central axis of the non-magnetic body, and the hole elastic retainer fixes the permanent magnet in the hole.

[0008] Further, the non-magnetic body, the upper centralizer, the directional key sleeve, the directional key, the directional screw and the lower centralizer are all machined from non-magnetic materials.

[0009] Further, the directional magnetic sub for determining the position of the downhole drill bit comprises: a magnetic sub assembly for generating a rotating magnetic field, the magnetic sub assembly comprising a non-magnetic body having a mounting cavity and a permanent magnet arranged on the non-magnetic body; a directional key sleeve located in the mounting cavity, the directional key sleeve having a receiving cavity for accommodating the inclinometer; and a positioning assembly located in the mounting cavity, the positioning assembly comprising: a radial positioning structure connected or matched with the directional key sleeve, the radial positioning structure being used for radially positioning the directional key sleeve to prevent the directional key sleeve from moving in the radial direction of the mounting cavity; and an axial positioning structure matched or connected with the directional key sleeve, the axial positioning structure being used for axially positioning the directional key sleeve to prevent the directional key sleeve from moving in the axial direction of the mounting cavity.

[0010] Further, the axial positioning structure comprises a directional screw detachably connected with the non-magnetic body, the directional key sleeve is provided with a key groove, and one end of the directional screw is arranged in the key groove to axially position the directional key sleeve.

[0011] Further, the key groove is in communication with the receiving cavity, the directional magnetic sub further comprises a directional key, a part of the directional key is arranged in the key groove, another part of the directional key is located in the receiving cavity and used for abutting against the inclinometer, and the directional screw abuts the directional key against the inner wall surface of the key groove.

[0012] Further, the cross-sectional area of the key groove gradually decreases or sequentially decreases from the outside of the receiving cavity to the inside of the receiving cavity; and / or, one end of the directional screw is provided with a positioning protrusion, and the side of the directional key away from the receiving cavity is provided with a positioning groove, the positioning protrusion abuts against the positioning groove.

[0013] Further, the radial positioning structure comprises an upper centralizer, the upper centralizer is connected with the directional key sleeve, and at least part of the outer wall surface of the upper centralizer abuts against the inner wall surface of the mounting cavity to prevent the directional key sleeve from moving in the radial direction of the mounting cavity.

[0014] Further, the upper centralizer is provided with a first cavity, the receiving cavity is in communication with the mounting cavity through the first cavity; or the upper centralizer is provided with a first cavity, at least part of the inner wall surface of the first cavity is provided with an upper centralizer inner thread, at least part of the outer wall surface of the directional key sleeve is provided with a key sleeve outer thread matched with the upper centralizer inner thread, and the upper centralizer is threadedly connected with the directional key sleeve; or there is a gap between the outer wall surface of the directional key sleeve and the inner wall surface of the mounting cavity; the upper centralizer is provided with a first flow cavity, one end of the first flow cavity is in communication with the mounting cavity, and the other end of the first flow cavity is in communication with the gap.

[0015] Further, the radial positioning structure further comprises a lower centralizer, the lower centralizer is connected with the directional key sleeve, at least part of the outer wall surface of the lower centralizer abuts against the inner wall surface of the mounting cavity, so as to prevent the directional key sleeve from moving along the radial direction of the mounting cavity; along the axial direction of the containing cavity, the directional key sleeve has oppositely arranged first and second ends, the upper centralizer is located at the first end of the directional key sleeve, and the lower centralizer is located at the second end of the directional key sleeve.

[0016] Further, the lower centralizer is provided with a second cavity, the containing cavity is communicated with the mounting cavity through the second cavity; or, at least part of the outer wall surface of the lower centralizer is provided with a lower centralizer external thread, at least part of the inner wall surface of the containing cavity is provided with a key sleeve internal thread matched with the lower centralizer external thread, and the lower centralizer is threadedly connected with the directional key sleeve; or, the outer wall surface of the directional key sleeve and the inner wall surface of the mounting cavity have a gap; the lower centralizer is provided with a second flow cavity, one end of the second flow cavity is communicated with the gap, and the other end of the second flow cavity is communicated with the mounting cavity.

[0017] According to another aspect of the present application, a magnetic ranging-while-drilling device is provided, comprising: a directional magnetic sub used for generating a rotating magnetic field; a probe pipe used for receiving a magnetic field signal of the rotating magnetic field; wherein the directional magnetic sub is the directional magnetic sub used for determining the position of the downhole drill bit.

[0018] Further, the magnetic ranging-while-drilling device further comprises: a driving structure and a drill bit, the driving structure is drivingly connected with the drill bit, so as to rotate the drill bit; the directional magnetic sub, the driving structure and the drill bit are sequentially arranged; and / or a drilling tower and a computing device, the drilling tower is connected with the directional magnetic sub, and the computing device is connected with the probe pipe.

[0019] According to another aspect of the present application, a method for determining the position of a downhole drill bit is provided, the position of the downhole drill bit is determined by using the directional magnetic sub used for determining the position of the downhole drill bit; the method for determining the position of the downhole drill bit comprises: the upper end of the directional magnetic sub is connected with the non-magnetic drill collar, the lower end of the directional magnetic sub is connected with the drill bit, and the directional magnetic sub is lowered into a horizontal well section of a drilled well, so as to generate an alternating magnetic field in the downhole along with the rotation of the drill bit; a downhole alternating magnetic field measurement probe is lowered into the horizontal well section of the drilled well through a single-core armored bearing cable, detects an alternating magnetic field signal generated by the rotation of the directional magnetic sub in the drilled well by a distance, and transmits the alternating magnetic field signal to a ground interface box through the single-core armored bearing cable, and then transmits the alternating magnetic field signal to a computing device through the ground interface box, so as to determine the position of the downhole drill bit relative to the downhole alternating magnetic field measurement probe in the drilled well according to the alternating magnetic field signal; wherein the determination of the position of the downhole drill bit relative to the downhole alternating magnetic field measurement probe in the drilled well according to the alternating magnetic field signal comprises: determining the distance between the directional magnetic sub and the downhole alternating magnetic field measurement probe by the following formula:

[0020]

[0021] Wherein, R is the radial distance between the directional magnetic short section and the downhole alternating magnetic field measuring probe; H2 and H3 are the well depths when the directional magnetic short section drills to points P2 and P3 respectively, wherein the distance between the directional magnetic short section and the downhole alternating magnetic field measuring probe is the shortest when the directional magnetic short section is at point P2; B r3 and B q3 are the r-axis and q-axis magnetic induction intensity components respectively detected by the downhole alternating magnetic field measuring probe when the directional magnetic short section is at point P3; the r-axis points to the radial direction of the directional magnetic short section to the downhole alternating magnetic field measuring probe; the q-axis is orthogonal to the r-axis and the advancing direction of the directional magnetic short section.

[0022] Further, the method for determining the downhole drill bit position adopts the above-mentioned magnetic ranging while drilling device to determine the downhole drill bit position, and the method for determining the downhole drill bit position comprises the following steps:

[0023] Step S10: generating a rotating magnetic field by using the directional magnetic short section lowered in the drilling horizontal well section;

[0024] Step S20: receiving the magnetic field signal of the rotating magnetic field by using the probe lowered in the drilled horizontal well section;

[0025] Step S30: determining the relative position of the drilling horizontal well section and the drilled horizontal well section according to the magnetic field signal;

[0026] In step S30, the radial distance R of the drilling horizontal well section and the drilled horizontal well section satisfies the above-mentioned formula 1.

[0027] By applying the technical scheme of the present application, the magnetic short section assembly is used to generate a rotating magnetic field, the accommodating cavity is used to accommodate the inclinometer, the directional key sleeve can install the inclinometer in the installation cavity, the magnetic short section assembly rotates to generate a rotating magnetic field, and then the directional magnetic short section can be used to simulate the rotating magnetic field near the drill bit to effectively simulate the strength of the rotating magnetic field near the drill bit in the actual working condition. The device can be used for magnetic steering drilling process simulation experiment, and the drill bit position is marked to provide important technical support for further field test. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of the present application and its description are used to explain the present application and are not used to limit the present application. In the drawings:

[0029] Figure 1 A longitudinal sectional view of an embodiment of the directional magnetic short section for determining the downhole drill bit position according to the present application is shown;

[0030] Figure 2 A partial structure enlarged view of the directional magnetic short section of Figure 1 is shown;

[0031] Figure 3 shows Figure 1 a cross-sectional view of the directional magnetic short section (wherein the non-magnetic body, permanent magnet and hole elastic baffle ring are shown);

[0032] Figure 4 shows Figure 1 a cross-sectional view of the magnetic short section assembly of the directional magnetic short section of

[0033] Figure 5 shows Figure 1 a cross-sectional view of the magnetic short section assembly of the directional magnetic short section of

[0034] Figure 6 shows Figure 1 a structural schematic view of the directional key sleeve of the directional magnetic short section of

[0035] Figure 7 shows Figure 6 a cross-sectional view of the directional key sleeve of in the A-A direction of

[0036] Figure 8 shows Figure 6 a cross-sectional view of the directional key sleeve of in the B-B direction of

[0037] Figure 9 shows Figure 1 a structural schematic view of the directional key of the directional magnetic short section of

[0038] Figure 10 shows Figure 9 a top view of the directional key of

[0039] Figure 11 shows Figure 9 a cross-sectional view of the directional key of

[0040] Figure 12 shows Figure 1 a cross-sectional view of the directional screw of the positioning assembly of the directional magnetic short section of

[0041] Figure 13 shows Figure 1 a structural schematic view of one angle of the upper centralizer of the positioning assembly of the directional magnetic short section of

[0042] Figure 14 shows Figure 13 a cross-sectional view of the upper centralizer of

[0043] Figure 15 shows Figure 1 a structural schematic view of one angle of the lower centralizer of the positioning assembly of the directional magnetic short section of

[0044] Figure 16 shows Figure 15 a cross-sectional view of the lower centralizer of

[0045] Figure 17 a structure diagram of a hole elastic baffle ring of a directional magnetic sub; Figure 1

[0046] Figure 18 a structure diagram of an embodiment of a magnetic ranging-while-drilling device according to the present application is shown;

[0047] Figure 19 a relative position diagram of a directional magnetic sub and a downhole alternating magnetic field measuring probe according to the method of determining a downhole drill bit position of the present application is shown; and

[0048] Figure 20 a structure diagram of a hole elastic baffle ring of a directional magnetic sub; Figure 19 a structure diagram of a hole elastic baffle ring of a directional magnetic sub;

[0049] Wherein, the above drawings include the following reference signs:

[0050] 1, a well being drilled; 2, a well drilled; 3, a drilling tower; 4, a drill bit; 5, a directional magnetic sub; 6, a inclinometer; 7, a non-magnetic drill collar; 8, a downhole alternating magnetic field measuring probe; 9, a single core armored carrier cable; 50, a ground interface box; 10, a magnetic sub assembly; 11, a non-magnetic body; 12, a mounting cavity; 13, a first mounting hole; 14, a first cavity section; 15, a transition cavity section; 16, a second cavity section; 17, a permanent magnet; 18, a second mounting hole; 19, a computing device; 20, a directional key sleeve; 211, a key sleeve outer thread; 212, a key sleeve inner thread; 22, a containing cavity; 23, a directional key; 24, a key groove; 25, a positioning groove; 30, a positioning assembly; 31, a directional screw; 311, a positioning protrusion; 312, a screw; 32, an upper centralizing body; 33, a first cavity; 331, an upper centralizing inner thread; 34, a lower centralizing body; 341, a lower centralizing outer thread; 35, a second cavity; 36, a first flow cavity; 37, a second flow cavity; 40, a hole elastic baffle ring. DETAILED DESCRIPTION

[0051] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0052] It should be noted that, unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0053] ​In the present application, the orientation words such as "upper, lower, top, bottom" used without contrary description are generally directed to the directions shown in the drawings, or are directed to the vertical, perpendicular or gravity directions of the components themselves; similarly, for the convenience of understanding and description, "inner, outer" refers to the inner and outer relative to the contour of the components themselves, but the above orientation words are not used to limit the present application.

[0054] Natural gas as a low-carbon clean energy has become one of the future main energy sources in the world. According to the data, unconventional natural gas resources including shale gas have very rich reserves in the world, which is more than 8 times of the conventional natural gas reserves. With the increasing scale of commercial exploitation of shale gas, the well spacing of horizontal well section is continuously reduced, the fracturing stages and liquid volume are continuously increased, and the interwell fracture interference problem is increasingly prominent, which limits the production effect to a certain extent. Research shows that using magnetic ranging technology to accurately control the well spacing of horizontal well section can avoid the interaction of interwell fractures.

[0055] The development of magnetic ranging technology is initially to guide the efficient connection between the relief well and the accident well. At present, magnetic ranging technology has developed into one of the key technologies for many complex structure well drilling engineering. The relative position requirement of cluster horizontal well engineering for horizontal well section is similar to that of SAGD (Steam-Assisted Gravity Drainage) double horizontal well, but it also puts forward new technical challenges to magnetic ranging technology. According to the existing SAGD double horizontal well magnetic ranging algorithm, the magnetic sub needs to rotate and move more than one time of the design spacing of horizontal well section in the vertical drilling, in order to realize the ranging once. For example, in the SAGD double horizontal well drilling engineering, the spacing of horizontal well section is about 5m, and the magnetic sub usually rotates and moves the length of one drill pipe to range once. Compared with SAGD double horizontal well, cluster horizontal well has the significant characteristics of long horizontal well section length and large spacing. Since the design spacing of cluster horizontal well horizontal well section is mainly concentrated in 180m-420m, if the SAGD double horizontal well magnetic ranging method is applied, the magnetic sub needs to rotate and move 180m-420m in the vertical drilling to range once. Obviously, it cannot meet the requirement of the interval of measuring points in the drilling site. Moreover, the magnetic moment of the magnetic sub currently suitable for SAGD double horizontal well engineering is limited, and it is not suitable for cluster horizontal well engineering with 180m-420m spacing.

[0056] In order to simulate the rotating magnetic field near the drill bit, to effectively simulate the strength of the rotating magnetic field near the drill bit under actual working conditions, the magnetic directional drilling process simulation experiment can provide important technical support for further field test, and in order to realize the accurate measurement of the horizontal well section 180m-420m interval in the cluster horizontal well project for every drilling 1-3 drill pipe length, thereby accurately controlling the well spacing of the horizontal well section of the horizontal well, and avoiding the interaction of the interwell cracks, the application and the embodiment of the application provide a directional magnetic sub for determining the position of the downhole drill bit and a method for determining the position of the downhole drill bit.

[0057] As shown in Figures 1 to 3 In the embodiment of the application, the directional magnetic sub for determining the position of the downhole drill bit comprises a magnetic sub assembly 10, a directional key sleeve 20 and a positioning assembly 30, the magnetic sub assembly 10 is used for generating a rotating magnetic field, the magnetic sub assembly 10 comprises a non-magnetic body 11 and a permanent magnet 17 arranged on the non-magnetic body 11, the non-magnetic body 11 has a mounting cavity 12; the directional key sleeve 20 is located in the mounting cavity 12, the directional key sleeve 20 has a containing cavity 22 for containing the inclinometer 6; and the positioning assembly 30 is located in the mounting cavity 12, the positioning assembly 30 comprises: a radial positioning structure connected or matched with the directional key sleeve 20, the radial positioning structure is used for radially positioning the directional key sleeve 20 to prevent the directional key sleeve 20 from moving along the radial direction of the mounting cavity 12; and an axial positioning structure matched or connected with the directional key sleeve 20, the axial positioning structure is used for axially positioning the directional key sleeve 20 to prevent the directional key sleeve 20 from moving along the axial direction of the mounting cavity 12.

[0058] In the above arrangement, the magnetic sub assembly 10 is used for generating a rotating magnetic field, the containing cavity 22 is used for containing the inclinometer 6, the directional key sleeve 20 can install the inclinometer 6 in the mounting cavity 12, the magnetic sub assembly 10 rotates to generate a rotating magnetic field, and then the directional magnetic sub can be used for simulating the rotating magnetic field near the drill bit, so as to effectively simulate the strength of the rotating magnetic field near the drill bit under actual working conditions, and the device can be used for magnetic directional drilling process simulation experiment, and the drill bit position is marked, which provides important technical support for further field test.

[0059] In addition, the non-magnetic body 11 has the mounting cavity 12, and the directional key sleeve 20 and the positioning assembly 30 are located in the mounting cavity 12, and the non-magnetic body 11 has the mounting and supporting effects on the directional key sleeve 20 and the positioning assembly 30.

[0060] In the embodiment of the application, the positioning assembly 30 is used for positioning the directional key sleeve 20, preventing the directional key sleeve 20 from moving in the mounting cavity 12, so that the directional key sleeve 20 and the inclinometer 6 can be fixedly installed in the mounting cavity 12, and the inclinometer 6 can rotate together with the magnetic sub assembly 10.

[0061] Specifically, the positioning assembly 30 comprises a radial positioning structure and an axial positioning structure, the radial positioning structure is used for radially positioning the directional key sleeve 20 to prevent the directional key sleeve 20 from moving along the radial direction of the mounting cavity 12, and the axial positioning structure is used for axially positioning the directional key sleeve 20 to prevent the directional key sleeve 20 from moving along the axial direction of the mounting cavity 12. The radial positioning structure is connected with the directional key sleeve 20 to achieve the positioning effect on the directional key sleeve 20, and the axial positioning structure is matched or connected with the directional key sleeve 20 to achieve the positioning effect on the directional key sleeve 20.

[0062] In the embodiment of the present application, the directional magnetic short section can be used to simulate the rotating magnetic field near the drill bit to effectively simulate the strength of the rotating magnetic field near the drill bit under actual working conditions. The device can be used for magnetic directional drilling process simulation experiment to provide important technical support for further field test.

[0063] As shown in Figure 1 , Figure 2 , Figures 6 to 8 and Figure 12 , in the embodiment of the present application, the axial positioning structure comprises a directional screw 31, the directional screw 31 is detachably connected with the non-magnetic body 11, the directional key sleeve 20 is provided with a key groove 24, and one end of the directional screw 31 is arranged in the key groove 24 to axially position the directional key sleeve 20.

[0064] In the above arrangement, the directional screw 31 is used for axially positioning the directional key sleeve 20 to prevent the directional key sleeve 20 from moving along the axial direction of the mounting cavity 12. One end of the directional screw 31 is arranged in the key groove 24 arranged on the directional key sleeve 20, which can prevent the directional key sleeve 20 from moving and achieve the axial positioning effect on the directional key sleeve 20.

[0065] The directional screw 31 is detachably connected with the non-magnetic body 11, which is convenient to operate and easy to assemble on the one hand, and can facilitate the installation of the directional key sleeve 20 and the cooperation of the directional screw 31 and the key groove 24 on the other hand. For example, in actual operation, the directional key sleeve 20 can be arranged in the mounting cavity 12 first, and then the directional screw 31 is connected with the non-magnetic body 11, so that one end of the directional screw 31 is arranged in the key groove 24 to achieve the positioning purpose.

[0066] As shown in Figure 1 , Figure 2 , Figure 7 and Figure 8 , in the embodiment of the present application, the key groove 24 is in communication with the accommodating cavity 22, the directional magnetic short section further comprises a directional key 23, a part of the directional key 23 is arranged in the key groove 24, and the other part of the directional key 23 is located in the accommodating cavity 22, and the directional screw 31 abuts the directional key 23 against the directional key sleeve 20.

[0067] In the above arrangement, the key groove 24 is in communication with the accommodating cavity 22, when the orientation key 23 is inserted into the key groove 24, a part of the orientation key 23 is located in the key groove 24, and another part of the orientation key 23 is located in the accommodating cavity 22; the orientation screw 31 abuts the orientation key 23 against the orientation key sleeve 20, which can realize the axial positioning of the orientation screw 31 to the orientation key sleeve 20, and can fix the relative position of the orientation key 23 and the orientation key sleeve 20.

[0068] As shown in Figure 7 and Figure 8 , in the embodiment of the present application, the cross-sectional area of the key groove 24 decreases from the outside of the accommodating cavity 22 to the inside of the accommodating cavity 22, and the orientation key 23 abuts the inner wall surface of the key groove 24.

[0069] In the above arrangement, due to the decreasing cross-sectional area of the key groove 24 from the outside to the inside of the accommodating cavity 22, under the abutting action of the orientation screw 31, the orientation key 23 can abut the inner wall surface of the key groove 24, thereby realizing the purpose of abutting the orientation key 23 against the orientation key sleeve 20 by the orientation screw 31.

[0070] Specifically, as shown in Figures 7 to 9 and Figure 11 , in the embodiment of the present application, the key groove 24 is a T-shaped groove, and the orientation key 23 is a T-shaped key matched with the T-shaped groove, and the T-shaped key is abutted against the T-shaped groove by the orientation screw 31.

[0071] Of course, in alternative embodiments not shown in the drawings of the present application, the cross-sectional area of the key groove 24 can also be gradually reduced from the outside of the accommodating cavity 22 to the inside of the accommodating cavity 22 according to actual needs. This arrangement can also achieve the purpose of abutting the orientation key 23 against the orientation key sleeve 20 by the orientation screw 31.

[0072] As shown in Figures 10 to 12 , in the embodiment of the present application, one end of the orientation screw 31 is provided with a positioning protrusion 311, and the side of the orientation key 23 away from the accommodating cavity 22 is provided with a positioning groove 25, and the positioning protrusion 311 abuts the positioning groove 25.

[0073] In the above arrangement, through the abutting of the positioning protrusion 311 and the positioning groove 25, on the one hand, the purpose of abutting the orientation key 23 against the orientation key sleeve 20 by the orientation screw 31 can be achieved, and on the other hand, the purpose of axially positioning the orientation key sleeve 20 by the orientation screw 31 can be achieved, thereby preventing the orientation key sleeve 20 from moving along the axial direction of the mounting cavity 12.

[0074] In addition, through the cooperation between the protrusion and the groove, the orientation screw 31 and the orientation key 23 can be accurately matched to realize accurate positioning. Moreover, the protrusion and the groove are easy to process and facilitate assembly.

[0075] Specifically, as shown in Figures 10 to 12 the embodiment of the present application, the positioning protrusion 311 is a conical protrusion, and the positioning groove 25 is a conical groove, which can increase the contact area between the positioning protrusion 311 and the positioning groove 25, and improve the positioning effect on the directional key sleeve 20.

[0076] As shown in Figure 1 and Figure 2 the embodiment of the present application, the first end of the inclinometer 6 is arranged in the accommodating cavity 22, and the first end of the inclinometer 6 is provided with a fixing groove, and part of the structure of the directional key 23 located in the accommodating cavity 22 is clamped in the fixing groove, so as to fix the inclinometer 6 in the accommodating cavity 22.

[0077] In the above arrangement, the first end of the inclinometer 6 is arranged in the accommodating cavity 22, and the first end of the inclinometer 6 is provided with a fixing groove, and part of the structure of the directional key 23 located in the accommodating cavity 22 is clamped in the fixing groove, so as to fix the inclinometer 6 in the accommodating cavity 22.

[0078] As shown in Figure 1 , Figure 2 , Figure 4 and Figure 12 the embodiment of the present application, the directional screw 31 comprises a screw 312, the side wall of the non-magnetic body 11 is provided with a first mounting hole 13, at least part of the inner wall surface of the first mounting hole 13 is provided with a second internal thread, and the screw 312 is threadedly connected with the first mounting hole 13.

[0079] Through the threaded connection between the screw 312 and the first mounting hole 13, detachable connection between the directional screw 31 and the non-magnetic body 11 is realized.

[0080] As shown in Figure 12 the embodiment of the present application, the positioning protrusion 311 is connected with the screw 312, and the positioning protrusion 311 is located at one end of the screw 312, the screw 312 drives the positioning protrusion 311 to move, and the position of the positioning protrusion 311 can be adjusted and fixed through the screw 312, so that the positioning protrusion 311 cooperates with the positioning groove 25 to realize positioning.

[0081] Preferably, the positioning protrusion 311 is integrally formed with the screw 312.

[0082] As shown in Figure 4As shown in the embodiments of the present application, the first mounting hole 13 is in communication with the mounting cavity 12, so that the directional screw 31 can be matched with the directional key 23 after passing through the first mounting hole 13.

[0083] Specifically, as Figure 2 shown in the embodiments of the present application, the directional key sleeve 20 can fix the inclinometer 6 at a corresponding position, the directional key 23 is a fixed part between the directional screw 31 and the directional key sleeve 20, the screw 312 is fixed on the non-magnetic body 11 by threads, and the directional key 23 is fixed by the tapered positioning protrusion 311 to achieve the purpose of fixing the directional key sleeve 20.

[0084] As Figure 1 and Figure 2 shown in the embodiments of the present application, the radial positioning structure includes the positioning assembly 30, which includes the upper centralizing body 32 connected with the directional key sleeve 20, and at least part of the outer wall surface of the upper centralizing body 32 abuts against the inner wall surface of the mounting cavity 12 to prevent the directional key sleeve 20 from moving in a direction perpendicular to the axis of the mounting cavity 12.

[0085] In the above arrangement, the upper centralizing body 32 is used to radially position the directional key sleeve 20, which can prevent the directional key sleeve 20 from moving in a direction perpendicular to the axis of the mounting cavity 12. The upper centralizing body 32 is connected with the directional key sleeve 20, and the directional key sleeve 20 has a mounting and supporting effect on the upper centralizing body 32. Since at least part of the outer wall surface of the upper centralizing body 32 abuts against the inner wall surface of the mounting cavity 12, the upper centralizing body 32 cannot move in a direction perpendicular to the axis of the mounting cavity 12, so that the directional key sleeve 20 cannot move in a direction perpendicular to the axis of the mounting cavity 12, thereby realizing the radial positioning effect of the upper centralizing body 32 on the directional key sleeve 20.

[0086] As Figure 2 , Figure 13 and Figure 14 shown in the embodiments of the present application, along the axis direction of the containing cavity 22, the directional key sleeve 20 has oppositely arranged first and second ends, the upper centralizing body 32 is located at the first end of the directional key sleeve 20, the upper centralizing body 32 is provided with a first cavity 33, and the containing cavity 22 is in communication with the mounting cavity 12 through the first cavity 33.

[0087] In the above arrangement, the upper centralizing body 32 is located at the first end of the directional key sleeve 20, and the upper centralizing body 32 can radially position the directional key sleeve 20. The containing cavity 22 is in communication with the mounting cavity 12 through the first cavity 33, so that the first end of the inclinometer 6 sequentially passes through the mounting cavity 12 and the first cavity 33 and then extends into the containing cavity 22, and the first cavity 33 can achieve the purpose of installing the inclinometer 6 in the containing cavity 22.

[0088] As Figure 13 andFigure 14 As shown in the drawings, in the embodiment of the present application, the upper centralizing body 32 is provided with a first cavity 33, at least part of the inner wall surface of the first cavity 33 is provided with an upper centralizing internal thread 331, at least part of the outer wall surface of the directional key sleeve 20 is provided with a key sleeve external thread 211 matched with the upper centralizing internal thread 331, and the upper centralizing body 32 is threadedly connected with the directional key sleeve 20.

[0089] In the above arrangement, the upper centralizing internal thread 331 and the key sleeve external thread 211 are threadedly connected, so that the upper centralizing body 32 is threadedly connected with the directional key sleeve 20. This arrangement is simple in operation and convenient for assembly.

[0090] As shown in the drawings, Figure 1 and Figure 2 In the embodiment of the present application, the positioning assembly 30 further comprises a lower centralizing body 34, the lower centralizing body 34 is connected with the directional key sleeve 20, and at least part of the outer wall surface of the lower centralizing body 34 abuts against the inner wall surface of the mounting cavity 12 to prevent the directional key sleeve 20 from moving in the direction perpendicular to the axis of the mounting cavity 12.

[0091] In the above arrangement, the lower centralizing body 34 is used for radially positioning the directional key sleeve 20, and can prevent the directional key sleeve 20 from moving in the direction perpendicular to the axis of the mounting cavity 12. The lower centralizing body 34 is connected with the directional key sleeve 20, and the directional key sleeve 20 has the functions of mounting and supporting the lower centralizing body 34. Since at least part of the outer wall surface of the lower centralizing body 34 abuts against the inner wall surface of the mounting cavity 12, the lower centralizing body 34 cannot move in the direction perpendicular to the axis of the mounting cavity 12, so that the directional key sleeve 20 cannot move in the direction perpendicular to the axis of the mounting cavity 12, thereby realizing the radial positioning of the directional key sleeve 20 by the lower centralizing body 34.

[0092] As shown in the drawings, Figure 2 , Figure 15 and Figure 16 In the embodiment of the present application, along the axis direction of the containing cavity 22, the directional key sleeve 20 has oppositely arranged first and second ends, the lower centralizing body 34 is located at the second end of the directional key sleeve 20, the lower centralizing body 34 is provided with a second cavity 35, and the containing cavity 22 is communicated with the mounting cavity 12 through the second cavity 35.

[0093] In the above arrangement, the lower centralizing body 34 is located at the second end of the directional key sleeve 20, and the lower centralizing body 34 can radially position the directional key sleeve 20.

[0094] The containing cavity 22 is communicated with the mounting cavity 12 through the second cavity 35, so that the mounting cavity 12, the first cavity 33, the containing cavity 22, the second cavity 35 and the mounting cavity 12 are sequentially communicated to form a first channel, which can avoid the formation of a semi-closed cavity in the containing cavity 22, and the problems of easy accumulation of impurities and the like, and keep the containing cavity 22 clean.

[0095] In the drilling process, the drilling position needs to be cleaned, and in the embodiment of the present application, since the installation cavity 12, the first cavity 33, the accommodating cavity 22, the second cavity 35 and the installation cavity 12 are sequentially communicated to form a first channel, the drilling fluid can flow to the drilling position through the first channel to clean the drilling position, that is, the above-mentioned first channel can be used as a flow channel of the drilling fluid to deliver the drilling fluid to clean the drilling position.

[0096] The upper centralizing body 32 is located at the first end of the directional key sleeve 20, and the lower centralizing body 34 is located at the second end of the directional key sleeve 20, and the upper centralizing body 32 and the lower centralizing body 34 are both used for radially positioning the directional key sleeve 20, and by arranging the positioning structures (the upper centralizing body 32 and the lower centralizing body 34) at the opposite ends of the directional key sleeve 20, the positioning effect of the radial positioning structure on the directional key sleeve 20 can be improved.

[0097] As shown in Figure 16 , in the embodiment of the present application, at least part of the outer wall surface of the lower centralizing body 34 is provided with a lower centralizing outer thread 341, and at least part of the inner wall surface of the accommodating cavity 22 is provided with a key sleeve inner thread 212 matched with the lower centralizing outer thread 341, and the lower centralizing body 34 is threadedly connected with the directional key sleeve 20.

[0098] In the above arrangement, the lower centralizing outer thread 341 is threadedly connected with the key sleeve inner thread 212, so that the lower centralizing body 34 is threadedly connected with the directional key sleeve 20, and such an arrangement is simple to operate and convenient to assemble.

[0099] As shown in Figure 13 and Figure 14 , in the embodiment of the present application, the outer wall surface of the directional key sleeve 20 and the inner wall surface of the installation cavity 12 have a gap therebetween; the upper centralizing body 32 is provided with a first flow cavity 36, one end of the first flow cavity 36 is communicated with the installation cavity 12, and the other end of the first flow cavity 36 is communicated with the gap.

[0100] In the above arrangement, the installation cavity 12, the first flow cavity 36 and the above-mentioned gap are sequentially communicated, which can be used for delivering the drilling fluid to facilitate the cleaning of the drilling position by the drilling fluid.

[0101] As shown in Figure 13 and Figure 14 , in the embodiment of the present application, the upper centralizing body 32 is provided with a plurality of first flow cavities 36, and the plurality of first flow cavities 36 are arranged at intervals along the circumference of the upper centralizing body 32.

[0102] In the above arrangement, by arranging a plurality of first flow cavities 36, the flow area can be increased, so that the flow amount of the drilling fluid can be increased to ensure the cleaning effect.

[0103] As shown in Figure 15 andFigure 16 As shown in the drawings, in the embodiment of the present application, the outer wall surface of the directional key sleeve 20 and the inner wall surface of the mounting cavity 12 have a gap; the lower centralizing body 34 is provided with a second flow cavity 37, one end of the second flow cavity 37 is communicated with the gap, and the other end of the second flow cavity 37 is communicated with the mounting cavity 12.

[0104] In the above arrangement, the gap, the second flow cavity 37 and the mounting cavity 12 are communicated in sequence, which can be used for conveying drilling fluid, and facilitates the cleaning of the drilling position by the drilling fluid.

[0105] As shown in the drawings, Figure 15 and Figure 16 In the embodiment of the present application, the lower centralizing body 34 is provided with a plurality of second flow cavities 37, and the plurality of second flow cavities 37 are arranged in a circumferential direction of the lower centralizing body 34.

[0106] In the above arrangement, by arranging a plurality of second flow cavities 37, the flow area can be increased, so that the flow amount of the drilling fluid is increased, and the cleaning effect is ensured.

[0107] In the embodiment of the present application, the mounting cavity 12, the first flow cavity 36, the above-mentioned gap, the second flow cavity 37 and the mounting cavity 12 are communicated in sequence to form a second channel, and the drilling fluid can flow to the drilling position through the second channel to clean the drilling position, that is, the above-mentioned second channel can be used as a flow channel of the drilling fluid to convey the drilling fluid to clean the drilling position.

[0108] Specifically, as shown in the drawings, Figure 2 In the embodiment of the present application, the upper centralizing body 32 is threadedly connected with the directional key sleeve 20, which is used for radially positioning the directional key sleeve 20 to prevent the directional key sleeve 20 from falling off, and can realize the circulation of the drilling fluid. The lower centralizing body 34 is threadedly connected with the directional key sleeve 20, which is used for radially positioning the directional key sleeve 20 to prevent the directional key sleeve 20 from falling off, and can realize the circulation of the drilling fluid.

[0109] As shown in the drawings, Figure 4 , Figure 5 and Figure 17 In the embodiment of the present application, the magnetic short section assembly 10 comprises a non-magnetic body 11 and a permanent magnet 17, the non-magnetic body 11 is provided with a second mounting hole 18, the second mounting hole 18 is used for mounting the permanent magnet 17, the directional magnetic short section further comprises a hole elastic retainer 40, the hole elastic retainer 40 is mounted in the second mounting hole 18, after the permanent magnet 17 is mounted in the second mounting hole 18, the hole elastic retainer 40 is mounted in the second mounting hole 18, and the permanent magnet 17 is fixed in the second mounting hole 18 through the hole elastic retainer 40. When the non-magnetic body 11 rotates, the permanent magnet 17 can rotate together, so that the rotating magnetic field detection can be realized. When the inclinometer 6 is connected, the corresponding tool face angle and other data can be obtained through a certain device.

[0110] like Figure 4 As shown, in the embodiment of the present invention, the non-magnetic body 11 is a circular tube column, and the second mounting hole 18 is a circular hole for placing the permanent magnet 17. The permanent magnet 17 is fixed in the circular hole by an elastic retaining ring 40 through the hole.

[0111] Preferably, the permanent magnet 17 is a cylindrical structure.

[0112] like Figure 4 As shown, in an embodiment of the present invention, the non-magnetic body 11 has a mounting cavity 12, and the directional key sleeve 20 and the positioning assembly 30 are both mounted in the mounting cavity 12. The mounting cavity 12 includes a first cavity section 14, a transition cavity section 15, and a second cavity section 16, which are sequentially connected. In a cross section perpendicular to the axis of the mounting cavity 12, the cross-sectional area of ​​the first cavity section 14 is larger than that of the second cavity section 16. The cross-sectional area of ​​the transition cavity section 15 gradually decreases from the first cavity section 14 to the second cavity section 16. The lower centralizing body 34 and the directional key sleeve 20 are both located in the first cavity section 14, and the lower centralizing body 34 is located between the directional key sleeve 20 and the transition cavity section 15. The inner wall surface of the transition cavity section 15 abuts against the lower centralizing body 34 to prevent the lower centralizing body 34 from moving along the axis of the mounting cavity 12 toward the second cavity section 16.

[0113] In the above setting, the lower stabilizing body 34 and the directional key sleeve 20 are both located in the first cavity section 14. The cross-sectional area of ​​the first cavity section 14 is larger than the cross-sectional area of ​​the second cavity section 16. The larger cross-sectional area of ​​the first cavity section 14 can conveniently install the lower stabilizing body 34 and the directional key sleeve 20.

[0114] The first cavity section 14, the first flow cavity 36, the gap between the outer wall surface of the directional key sleeve 20 and the inner wall surface of the installation cavity 12, the second flow cavity 37, the transition cavity section 15 and the second cavity section 16 are connected in sequence to form a second channel for transporting drilling fluid to clean the drilling position.

[0115] The first cavity section 14, the first cavity 33, the accommodating cavity 22 (specifically, the gap between the inner wall surface of the accommodating cavity 22 and the outer wall surface of the inclinometer 6), the second cavity 35, the transition cavity section 15 and the second cavity section 16 are connected in sequence to form a first channel for transporting drilling fluid to clean the drilling position.

[0116] When the lower stabilizing body 34 is installed in the first cavity section 14, the lower stabilizing body 34 abuts against the inner wall surface of the transition cavity section 15. The transition cavity section 15 has a stopping effect on the lower stabilizing body 34, which can prevent the lower stabilizing body 34 from moving along the axis of the installation cavity 12 toward the second cavity section 16, thereby improving the axial positioning effect of the directional key sleeve 20.

[0117] In the embodiment of the present invention, except for the permanent magnet 17 , other structures of the oriented magnetic sub are made of non-magnetic materials.

[0118] As shown in Figure 1 and Figure 2 shown, in the embodiment of the present application, the magnetic short section assembly 10 generates a magnetic field, the directional key sleeve 20 and the directional key 23 are fixedly connected with the inclinometer 6, the directional key sleeve 20 is fixed in the mounting cavity 12 of the non-magnetic body 11 in the direction perpendicular to the axis of the mounting cavity 12 by the upper centralizer 32 and the lower centralizer 34, and the circulation of the drilling fluid is ensured, the directional key sleeve 20 is fixed in the mounting cavity 12 of the non-magnetic body 11 in the direction of the axis of the mounting cavity 12 by the directional screw 31 and the directional key 23, the permanent magnet 17 is filled in the second mounting hole 18 on the non-magnetic body 11, and the permanent magnet 17 is fixed by the hole elastic stop ring 40 to prevent the permanent magnet 17 from falling off. The directional magnetic short section can rotate to generate a rotating magnetic field to effectively simulate the strength of the rotating magnetic field near the drill bit under actual working conditions.

[0119] As shown in Figures 1 to 3 shown, in the embodiment of the present application, the directional magnetic short section 5 for determining the position of the downhole drill bit is used to generate a rotating magnetic field and limit the position of the inclinometer 6, and the directional magnetic short section 5 comprises a non-magnetic body 11, an upper centralizer 32, a directional key sleeve 20, a directional key 23, a directional screw 31, a lower centralizer 34, a permanent magnet 17 and a hole elastic stop ring 40; wherein the upper centralizer 32 has four through holes uniformly distributed in the circumference and a circular through hole with a diameter larger than the outer diameter of the inclinometer 6, and the circular through hole has an upper centralizer internal thread 331; the lower centralizer 34 has four through holes uniformly distributed in the circumference and a circular through hole with a diameter smaller than the outer diameter of the inclinometer 6, and has a lower centralizer external thread 341; the directional key sleeve 20 is a circular tube with an inner diameter larger than the outer diameter of the inclinometer 6, one end of the directional key sleeve 20 is processed with a key sleeve external thread 211, the other end of the directional key sleeve 20 is processed with a key sleeve internal thread 212, and a stepped hole capable of installing the directional key 23 is processed in the middle of the directional key sleeve 20; the key sleeve external thread 211 of the directional key sleeve 20 can be screwed with the upper centralizer internal thread 331 of the upper centralizer 32, and the key sleeve internal thread 212 of the directional key sleeve 20 can be screwed with the lower centralizer external thread 341 of the lower centralizer 34; the upper centralizer 32, the directional key sleeve 20, the directional key 23 and the lower centralizer 34 are installed together and placed inside the axial hole cavity of the non-magnetic body 11; the directional screw 31 is screwed into the stepped hole on the non-magnetic body 11 and the blind hole on the arc-shaped end surface of the directional key 23 to fix the relative position of the non-magnetic body 11 and the directional key 23; the other end of the directional key 23 protrudes from the inner surface of the directional key sleeve 20 and is used to cooperate with the key groove of the inclinometer wedge shoe to limit the rotation of the inclinometer 6 relative to the directional magnetic short section 5.

[0120] As shown in Figures 1 to 3As shown in the figure, in the embodiment of the present application, the non-magnetic body 11 is machined with a first inner thread and a first outer thread at both ends, respectively, and a coaxial hole cavity is machined on the central axis of the non-magnetic body 11, the hole cavity near the first inner thread end is suitable for installing the upper centralizing body 32, the directional key sleeve 20, the directional key 23 and the lower centralizing body 34 assembled together, and a plurality of holes are arranged on the non-magnetic body 11 in parallel with the axis of the non-magnetic body 11 and distributed on both sides of the non-magnetic body 11, and a permanent magnet 17 is installed in each hole, and the magnetic pole direction of the permanent magnet 17 is perpendicular to the central axis of the non-magnetic body 11, and the permanent magnet 17 is fixed in the hole by the elastic retainer ring 40.

[0121] In the embodiment of the present application, the non-magnetic body 11, the upper centralizing body 32, the directional key sleeve 20, the directional key 23, the directional screw 31 and the lower centralizing body 34 are all machined from non-magnetic materials.

[0122] As shown in the figure, Figure 18 In the embodiment of the present application, the while-drilling magnetic ranging device comprises a directional magnetic short section 5 and a downhole alternating magnetic field measuring probe 8, the directional magnetic short section 5 is used for generating a rotating magnetic field, and the downhole alternating magnetic field measuring probe 8 is used for receiving a magnetic field signal of the rotating magnetic field.

[0123] As shown in the figure, Figure 18 In the embodiment of the present application, the while-drilling magnetic ranging device further comprises a driving structure, a drill bit 4, a drilling tower 3 and a computing device 19, the driving structure is drivingly connected with the drill bit 4 to make the drill bit 4 rotate, the directional magnetic short section 5, the driving structure and the drill bit 4 are sequentially arranged, the drilling tower 3 is connected with the directional magnetic short section 5, and the computing device 19 is connected with the downhole alternating magnetic field measuring probe 8.

[0124] It should be noted that, since the while-drilling magnetic ranging device of the present application comprises the directional magnetic short section for determining the position of the downhole drill bit of the present application, the while-drilling magnetic ranging device of the present application also has the above advantages of the directional magnetic short section for determining the position of the downhole drill bit of the present application, which will not be repeated here.

[0125] As shown in the figure, Figure 18 In the embodiment of the present application, the while-drilling magnetic ranging device comprises a directional magnetic short section 5, a downhole alternating magnetic field measuring probe 8, a single-core armored bearing cable 9, a ground interface box 50 and a computing device 19.

[0126] The upper end of the directional magnetic short section 5 is connected with the non-magnetic drill collar 7, and the lower end is connected with other drilling tools such as the drill bit 4, and is placed in the horizontal well section of the drilling well 1, and an alternating magnetic field is generated in the well under the rotation of the drilling string; the downhole alternating magnetic field measuring probe 8 is placed in the horizontal well section of the drilled well 2 through the single-core armored bearing cable 9, is used for detecting the alternating magnetic field signal generated around the directional magnetic short section 5 in the drilling well 1, and is transmitted to the ground interface box 50 through the single-core armored bearing cable 9, and is transmitted to the computing device 19 by the ground interface box 50, and the computing device 19 is used for determining the relative position of the horizontal well section of the drilling well 1 and the horizontal well section of the drilled well 2 according to the alternating magnetic field signal.

[0127] The directional magnetic short section 5 includes a non-magnetic body 11, a cylindrical permanent magnet 17, an elastic retaining ring 40 for the hole, a directional key 23, a directional key sleeve 20, a directional screw 31, an upper centralizing body 32 and a lower centralizing body 34. The number of the cylindrical permanent magnets 17 is determined by the size of the required magnetic moment, the axis of the cylindrical permanent magnet 17 is orthogonal to the central axis of the magnetic short section, and the placement direction of the permanent magnet poles is consistent. In the measurement process, the internal thread of the directional magnetic short section 5 is screwed with the external thread of the non-magnetic drill collar 7, the inclinometer 6 is seated in the directional key sleeve 20, and the relative rotation between the inclinometer 6 and the directional magnetic short section 5 is prevented by the directional key 23.

[0128] As shown in Figures 18 to 20 , in the embodiment of the present application, the probe remains stationary in the well during each ranging process, and the directional magnetic short section rotates from point P1 to point P3, and the directional magnetic short section is closest to the probe when moving to point P2. Assuming that the well section between point P1 and point P3 is a straight line, taking the center of the magnetic magnet section directional magnetic short section as the origin, and taking the wellbore high side direction as the h axis, the wellbore extension direction as the w axis, and the l axis being orthogonal to the h axis and the w axis at the same time.

[0129] Taking the center of the magnetic magnet section directional magnetic short section as the origin, taking the radial direction of the directional magnetic short section to the probe as the r axis, and taking the wellbore extension direction as the w axis, a rqw rectangular coordinate system is established, and the q axis is orthogonal to the r axis and the w axis at the same time. Then, in the rqw coordinate system, the coordinates of point P1, point P2 and point P3 can be represented as (R, 0, W1), (R, 0, 0) and (R, 0, W2) respectively, wherein W1 is the distance between point P1 and point P2 along the w axis, and W2 is the distance between point P3 and point P2 along the w axis.

[0130] As shown in Figure 20 , in the embodiment of the present application, m is the direction of the magnetic steel section in the magnetic short section, A mr is the included angle between m and the r axis.

[0131] As shown in Figures 18 to 20As shown, in an embodiment of the present invention, a method for determining the position of a downhole drill bit uses the above-mentioned directional magnetic sub for determining the position of a downhole drill bit to determine the position of the downhole drill bit; the method for determining the position of a downhole drill bit includes:

[0132] The upper end of the directional magnetic sub 5 is connected to the non-magnetic drill collar 7, and the lower end of the directional magnetic sub 5 is connected to the drill bit 4. It is lowered into the horizontal well section of the well being drilled 1, and an alternating magnetic field is generated in the well as the drill bit rotates.

[0133] A downhole alternating magnetic field measuring probe 8 is lowered into a horizontal section of the drilled well 2 via a single-core armored carrier cable 9. The probe detects the alternating magnetic field signal generated by the rotation and movement of the directional magnetic sub 5 in the well being drilled 1. The signal is then transmitted to a surface interface box 50 via the single-core armored carrier cable 9. The surface interface box 50 then transmits the signal to a computing device 19. The computing device 19 determines the position of the downhole drill bit relative to the downhole alternating magnetic field measuring probe in the drilled well 2 based on the alternating magnetic field signal.

[0134] Determining the position of the downhole drill bit relative to the downhole alternating magnetic field measurement probe in the drilled well based on the alternating magnetic field signal includes determining the distance of the directional magnetic sub relative to the downhole alternating magnetic field measurement probe using the following formula:

[0135]

[0136] Wherein, R is the radial distance between the directional magnetic sub and the downhole alternating magnetic field measuring probe; H2 and H3 are the well depths when the directional magnetic sub 5 is drilled to points P2 and P3, respectively. The distance between the directional magnetic sub 5 and the downhole alternating magnetic field measuring probe 8 is the shortest at point P2; B r3 and B q3 They are respectively the r-axis and q-axis magnetic induction intensity components detected by the downhole alternating magnetic field measuring probe 8 when the oriented magnetic sub 5 is at point P3; the r-axis points to the radial direction from the oriented magnetic sub to the downhole alternating magnetic field measuring probe; the q-axis is orthogonal to the r-axis and the forward direction of the oriented magnetic sub.

[0137] like Figures 18 to 20 As shown, in an embodiment of the present invention, the method for determining the position of the downhole drill bit adopts a while-drilling magnetic ranging method, and the distance is measured using the above-mentioned while-drilling magnetic ranging device. The while-drilling magnetic ranging method includes:

[0138] Step S10: generating a rotating magnetic field using the directional magnetic sub 5 lowered into the horizontal well section of the well being drilled 1;

[0139] Step S20: using the downhole alternating magnetic field measurement probe 8 placed in the horizontal well section of the drilled well 2 to receive the magnetic field signal of the rotating magnetic field;

[0140] Step S30: determining the relative position of the horizontal well section being drilled 1 and the horizontal well section already drilled 2 according to the magnetic field signal;

[0141] In step S30, the radial distance R between the horizontal well section of the drilling well 1 and the horizontal well section of the drilled well 2 satisfies formula 1.

[0142] In the embodiment of the present application, the method for measuring the distance while drilling is applied to the above-mentioned magnetic distance measuring device while drilling, which is used to solve the technical problem of the prior art that the relative position between the horizontal well section of the drilling well and the horizontal well section of the drilled well is determined according to the alternating magnetic field signal underground, and the interval between the measuring points is too large because the alternating magnetic field signal needs to be drilled for more than one well spacing length.

[0143] As shown in Figure 19 and Figure 20 In the embodiment of the present application, the method for measuring the distance while drilling includes: controlling the rotary table or the top drive device to rotate the directional magnetic short section with the drill string, so that the alternating magnetic field is generated around the directional magnetic short section; in each distance measuring process, the downhole alternating magnetic field measuring probe remains stationary underground, and the directional magnetic short section is rotated from point P1 to point P3, and the directional magnetic short section is closest to the probe when it moves to point P2; receiving the alternating magnetic field signal detected by the downhole alternating magnetic field measuring probe in the drilling well 1; wherein the alternating magnetic field signal is the alternating magnetic field signal generated by the directional magnetic short section in the drilling well 1; and determining the relative position between the horizontal well section of the drilling well 1 and the horizontal well section of the drilled well 2 according to the alternating magnetic field signal.

[0144] Wherein, the relative position between the horizontal well section of the drilling well and the horizontal well section of the drilled well is determined according to the alternating magnetic field signal, including: determining the radial distance between the horizontal well section of the drilling well and the horizontal well section of the drilled well, and the included angle between the high side direction of the drilling well and the radial direction by the following equation group:

[0145]

[0146] Wherein, B r3 , B q3 , B h and B l satisfy the following formula:

[0147]

[0148] Wherein, R is the radial distance between the horizontal well section of the drilling well and the horizontal well section of the drilled well; A hr is the included angle between the high side direction of the drilling well and the radial direction; H2 and H3 are the depths of the directional magnetic short section when it is drilled to points P2 and P3, respectively; B x , B y and B z are the three-axis magnetic induction intensity components of the magnetic field generated by the directional magnetic short section detected by the three-axis through-hole sensor inside the downhole alternating magnetic field measuring probe when the directional magnetic short section is at point P2; B x3 , B y3 and Bz3 B, B and B are respectively three-axis magnetic induction intensity components of the magnetic field generated by the directional magnetic short section detected by the three-axis through-hole sensor inside the downhole alternating magnetic field measurement probe at point P3; M is a conversion matrix of the sensor coordinates and the wellbore coordinates; B q3 , B r3 and B w3 are respectively the magnetic induction intensity q, r, w axis components when the magnetic short section moves to point P3 during the ranging process; B h , B l and B w are respectively the h, l, w axis components of the magnetic induction intensity obtained at the probe.

[0149] The present application and the embodiments of the present application also provide a computer device to solve the prior art scheme of determining the relative position of the drilled horizontal well section and the horizontal well section being drilled according to the downhole alternating magnetic field signal, which causes the technical problem of too large measurement point interval due to the need of drilling the alternating magnetic field signal of more than one length of adjacent well spacing. The computer device comprises a memory, a processor and a computer program stored on the memory and executable on the processor, and the processor implements the above-mentioned while-drilling magnetic ranging method when executing the computer program.

[0150] Through the embodiments of the present application, the relative position of the drilled horizontal well section and the horizontal well section being drilled is determined based on the magnetic field distribution around the directional magnetic short section, which can realize one ranging without moving the directional magnetic short section by more than one length of adjacent well spacing, not only can meet the requirement of the measurement point interval of the cluster horizontal well drilling site, but also can reduce the measurement time and improve the ranging accuracy.

[0151] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects: the magnetic short section assembly is used to generate a rotating magnetic field, the accommodating cavity is used to accommodate the inclinometer, the directional key sleeve can install the inclinometer in the installation cavity, the magnetic short section assembly rotates to generate a rotating magnetic field, and then the directional magnetic short section can be used to simulate the rotating magnetic field near the drill bit to effectively simulate the strength of the rotating magnetic field near the drill bit in the actual working condition. The device can be used for magnetic steering drilling process simulation experiment, and the drill bit position is marked to provide important technical support for further field test.

[0152] Obviously, the above-mentioned embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the present application.

[0153] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, as the scope of the exemplary embodiments of this application is limited only by the appended claims. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Also, unless otherwise indicated herein, the materials described herein can be used in a variety of applications.

[0154] It should be noted that the terms "first", "second", and the like, herein do not necessarily have an ordinal meaning. Rather, such terms are used to distinguish between similar objects or actions. It should also be noted that the terms "coupled" and / or "connected", as can be used herein, can include an electrical and / or physical connection, wireless connection, and / or any combination thereof, unless otherwise indicated herein.

[0155] The preferred embodiments of the application are described herein with reference to the accompanying drawings, in which the same reference numbers in different drawings indicate similar components. The application is not limited to the preferred embodiments described herein, but can be practiced with modifications and alterations within the scope of the appended claims. Accordingly, the specification and drawings are to be regarded as illustrative only and are not restrictive of the scope of the application.

Claims

1. A directional magnetic sub for determining the position of a downhole drill bit, characterized in that, the directional magnetic sub (5) is used to generate a rotating magnetic field and define the position of the inclinometer (6), and the directional magnetic sub (5) comprises a non-magnetic body (11), an upper centralizer (32), a directional key sleeve (20), a directional key (23), a directional screw (31), a lower centralizer (34), permanent magnets (57), and a hole elastic retainer ring (40); wherein the upper centralizer (32) has at least two through holes uniformly distributed in the circumference and a circular through hole with a diameter larger than the outer diameter of the inclinometer (6), and the circular through hole has an upper centralizer internal thread (331); the lower centralizer (34) has at least two through holes uniformly distributed in the circumference and a circular through hole with a diameter smaller than the outer diameter of the inclinometer (6), and has a lower centralizer external thread (341); the directional key sleeve (20) is a circular tube with an inner diameter larger than the outer diameter of the inclinometer (6), one end of the directional key sleeve (20) is machined with a key sleeve external thread (211), the other end of the directional key sleeve (20) is machined with a key sleeve internal thread (212), and the middle part of the directional key sleeve (20) is machined with a stepped hole capable of installing the directional key (23); the key sleeve external thread (211) of the directional key sleeve (20) can be screwed with the upper centralizer internal thread (331) of the upper centralizer (32), and the key sleeve internal thread (212) of the directional key sleeve (20) can be screwed with the lower centralizer external thread (341) of the lower centralizer (34); the upper centralizer (32), the directional key sleeve (20), the directional key (23), and the lower centralizer (34) installed together are placed inside the axial hole cavity of the non-magnetic body (11); the directional screw (31) is screwed into the stepped hole on the non-magnetic body (11) and the blind hole on the arc-shaped end surface of the directional key (23), fixing the relative position of the non-magnetic body (11) and the directional key (23); the other end of the directional key (23) protrudes from the inner surface of the directional key sleeve (20) and is used to cooperate with the key groove of the inclinometer beveled leading shoe to limit the rotation of the inclinometer (6) relative to the directional magnetic sub (5).

2. The directional magnetic stub of claim 1, wherein, the non-magnetic body (11) is machined with a first internal thread and a first external thread at both ends, respectively, and a coaxial hole cavity is machined on the central axis of the non-magnetic body (11), the hole cavity near the first internal thread end has an inner diameter and a length suitable for installing the upper centralizer (32), the directional key sleeve (20), the directional key (23), and the lower centralizer (34) assembled together, and a section of the non-magnetic body (11) near the first external thread is provided with a plurality of holes perpendicular to the axis of the non-magnetic body (11), arranged in parallel along the non-magnetic body (11), and distributed on both sides of the non-magnetic body (11), and a permanent magnet (57) is installed in each hole, the magnetic pole direction of the permanent magnet (57) is perpendicular to the central axis of the non-magnetic body (11), and a hole elastic retainer ring (40) fixes the permanent magnet (57) in the hole.

3. The oriented magnetic stub of claim 1, wherein, The non-magnetic body (11), the upper centralizer (32), the directional key sleeve (20), the directional key (23), the directional screw (31) and the lower centralizer (34) are all made of non-magnetic material.

4. A method of determining the position of a downhole drill bit, characterized by, Determining the position of a downhole drill bit using a directional magnetic sub for determining the position of a downhole drill bit according to any one of claims 1 to 3; The method for determining the position of a downhole drill bit comprises: The upper end of the directional magnetic sub (5) is connected with a non-magnetic drill collar (7), and the lower end of the directional magnetic sub (5) is connected with a drill bit (4), which is lowered into a horizontal well section of a drilled well and generates an alternating magnetic field in the downhole with the rotation of the drill bit; A downhole alternating magnetic field measuring probe (8) is lowered into the horizontal well section of the drilled well through a single-core armored bearing cable (9), detects an alternating magnetic field signal generated by the rotation of the directional magnetic sub (5) in the drilled well by a distance, and transmits the signal to a ground interface box (50) through the single-core armored bearing cable (9), and then to a computing device (19) through the ground interface box (50), which determines the position of the downhole drill bit relative to the downhole alternating magnetic field measuring probe in the drilled well according to the alternating magnetic field signal; wherein determining the position of the downhole drill bit relative to the downhole alternating magnetic field measuring probe in the drilled well according to the alternating magnetic field signal comprises determining the distance of the directional magnetic sub relative to the downhole alternating magnetic field measuring probe by the following formula: wherein R is the radial distance of the oriented magnetic short section to the downhole alternating magnetic field measuring probe; H2 and H3 are the depths of the oriented magnetic short section (5) drilled to points P2 and P3, respectively, wherein the oriented magnetic short section (5) is closest to the downhole alternating magnetic field measuring probe (8) at point P2; B r3 and B q3 are the r-axis and q-axis magnetic induction intensity components detected by the downhole alternating magnetic field measuring probe (8) at point P3, respectively; the r-axis points to the radial direction of the oriented magnetic short section to the downhole alternating magnetic field measuring probe; the q-axis is orthogonal to the r-axis and the forward direction of the oriented magnetic short section.

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