Horizontal reference well high-precision magnetic ranging directional drilling method and system

Abstract

This invention proposes a high-precision magnetic ranging directional drilling method and system for horizontal reference wells. The method includes: determining the deployment of the well system; sequentially drilling non-target formation sections of vertical / directional wells and horizontal wells according to the well system deployment; lowering a ranging system, which includes a dynamic magnetic field acquisition instrument located in the vertical / directional well and a magnetic field generator located behind the drill bit; and guiding the drill bit to complete the drilling of the target formation section of the horizontal well based on the mutual cyclic leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator. This invention's high-precision magnetic ranging directional drilling method and system for horizontal reference wells, by setting up the well system and the ranging system, can use the actual drilling data of previously drilled vertical or directional wells and the magnetic ranging system to guide the drilling direction of the horizontal section of the horizontal well, solving the problem of precise wellbore trajectory control for the first horizontal reference well in a horizontal well group with concentrated source rock oil and gas.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas drilling, and specifically relates to a high-precision magnetic ranging directional drilling method and system for horizontal reference wells. Background Technology

[0002] As oil and gas development enters new areas, the requirements for drilling technology are becoming increasingly stringent, particularly regarding the accuracy of wellbore trajectory positioning. For example, steam-assisted gravity drainage parallel well drilling technology requires drilling pairs of relatively parallel horizontal wells, and in-situ conversion and development of oil and gas resources necessitates drilling a series of relatively parallel horizontal well groups. Completing such specialized wells generally requires magnetic ranging to measure and adjust the spatial distance and orientation between wellbores to ensure the accuracy of the spatial position between well trajectories. Current magnetic ranging methods primarily involve placing a magnetic field detection device in one completed well and installing a magnetic field of known strength and pattern in another well under drilling. The relative distance between the two wells is calculated by measuring the magnetic field, thus guiding the drilling operation, as illustrated in US Patents 5485089 and 5589775. This method is widely used in steam-assisted gravity drainage parallel well drilling, achieving a vertical error control accuracy of ±0.5m and a lateral error control accuracy of ±1m under a 5m spacing between paired horizontal wells. However, this method requires drilling a horizontal reference well to guide the wellbore trajectory control of the second horizontal well. This method cannot guarantee the accuracy of the wellbore trajectory control of the first horizontal reference well. In source rock oil and gas exploration and development, conventional development methods cannot achieve commercial oil and gas development; special processes are needed to alter the state of the source rock's organic matter to achieve organic matter production. Generally, multiple dense horizontal well networks need to be drilled in relatively thin target layers. The well network spacing is small, and the spacing accuracy between wells is high. Furthermore, all trajectories must be within the target layer, placing extremely high demands on wellbore trajectory control. Drilling a high-precision first horizontal reference well is particularly crucial. Existing directional drilling methods, due to the influence of trajectory measurement elliptic errors, cannot guarantee the accuracy of actual downhole control. Summary of the Invention

[0003] To address the above problems, this invention proposes a high-precision magnetic ranging directional drilling method for horizontal reference wells, the method comprising:

[0004] Determine the deployment of the well system;

[0005] Based on the deployment of the well system, drilling of non-target formation sections of vertical / directional wells and horizontal wells will be completed sequentially;

[0006] A ranging system is lowered, which includes a dynamic magnetic field acquisition instrument located in the vertical / directional well and a magnetic field generator located behind the drill bit; the drill bit is guided to complete the drilling of the target formation section of the horizontal well based on the mutual cyclic leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator.

[0007] Furthermore, the deployment of the well system includes:

[0008] One horizontal well and N vertical / directional wells approximately perpendicular to the target formation section of the horizontal well, wherein N ≥ 1;

[0009] The horizontal well deployment includes the wellhead location, the build-up point, at least two target windows for the target formation horizontal well section, and the azimuth angle of the target formation horizontal well section determined based on the first target window point A and the last target window point B of the target formation horizontal well section.

[0010] Furthermore, determining the target formation target window point also includes drilling a pilot well to correct the position of the target window point.

[0011] Furthermore, the lateral distance between the target formation section of the vertical / directional well and the target formation horizontal well section of the horizontal well determined by the target window point is 1m to 20m.

[0012] The horizontal distance between target window point A and target window point B in the horizontal well section of the target formation is greater than 200m;

[0013] The horizontal distance between the wellhead location and the target window point A of the horizontal well section of the target formation is 100-800m.

[0014] The lateral distance between the target formation well section of the vertical / directional well and the target formation horizontal well section of the horizontal well section of the horizontal well is 1m to 20m;

[0015] The horizontal distance between target window point A and target window point B in the horizontal well section of the target formation is greater than 200m;

[0016] The horizontal distance between the wellhead location and the target window point A of the horizontal well section of the target formation is 100-800m.

[0017] Furthermore, the target formation section of the vertical / directional well includes a vertical section or an inclined section. If it is a directional well, the difference between the azimuth of the inclined section and the azimuth determined by the target window point of the horizontal well section of the target formation is less than 20°.

[0018] Furthermore, the number N of vertical / directional wells is determined by the horizontal distance between the target window point A and the target window point B of the horizontal well section of the target formation and the effective magnetic signal detection distance parameter of the ranging system.

[0019] Furthermore, N = |[L / (2L0) + 0.5]|

[0020] Where L represents the horizontal distance between target window point A and target window point B in the horizontal well section of the target formation, L0 represents the effective magnetic signal detection distance parameter of the ranging system, and |[…]| represents rounding the value calculated by the formula to the nearest integer.

[0021] Furthermore, the deployment of the N wells perpendicular to the target formation section of the horizontal well includes:

[0022] If no pilot well is drilled, the distances between the projection points of the N vertical or directional wells in the target formation on the horizontal well design trajectory and the target window point A of the horizontal well section of the target formation are arranged according to the sizes L0, 3L0, 5L0, ..., (2N-1)L0.

[0023] If pilot wells are drilled, the distances between the projection points of the N vertical or directional wells in the target formation on the horizontal well design trajectory and the target window point A of the horizontal well section of the target formation are arranged according to the magnitudes of L0+Ld, 3L0+Ld, 5L0+Ld, ..., (2N-1)+Ld.

[0024] Where L0 represents the effective magnetic signal detection distance parameter of the ranging system; Ld represents the stable non-ranging parameter.

[0025] Furthermore, the magnetic field generator includes a natural magnet, a magnet, and an energized solenoid coil;

[0026] The magnetic field strength of the magnetic field generator is greater than the geomagnetic strength and the residual magnetic field strength of the drill string.

[0027] Furthermore, the drilling of the target formation section of the horizontal well is guided by the mutually circulating leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator, including:

[0028] The dynamic magnetic field acquisition instrument leads the magnetic field generator, and guides the drill bit to perform directional drilling operations in a direction offset from the dynamic magnetic field acquisition instrument by a predetermined distance based on the relative positional relationship between the dynamic magnetic field acquisition instrument and the magnetic field generator.

[0029] The magnetic field generator is located to the side of the dynamic magnetic field acquisition instrument. It uses the stable directional drilling capability of the drill string assembly to quickly traverse the distance to the side of the dynamic magnetic field acquisition instrument.

[0030] The magnetic field generator leads the dynamic magnetic field acquisition instrument. Based on the relative positions of the dynamic magnetic field acquisition instrument and the magnetic field generator, the positional change of the magnetic field generator is determined, and the drilling direction of the drill bit is further guided.

[0031] Furthermore, the magnetic field generator leading the dynamic magnetic field acquisition instrument to guide the drill bit drilling also includes avoiding magnetic signal interference from the magnetic field generator and drill tool components.

[0032] Furthermore, the method of avoiding magnetic signal interference from the magnetic field generator and drill components includes:

[0033] Increase the magnetic field strength of the magnetic field generator, or;

[0034] The effective magnetic signal detection distance range at the bottom of the drill bit component assembly is achieved using a non-magnetic material drill bit, or;

[0035] Increase the distance between the horizontal section of the horizontal well and the wellbore track of the vertical or directional well to make it greater than 3m.

[0036] This invention also provides a high-precision magnetic ranging directional drilling system for horizontal reference wells. The system includes: a deployment unit, a first drilling unit, a lowering unit, and a second drilling unit.

[0037] Deployment unit, used to determine the deployment of the well system;

[0038] The first drilling unit is used to sequentially complete the drilling of non-target formation sections of vertical / directional wells and horizontal wells according to the deployment of the well system;

[0039] The lowering unit is used to lower the ranging system, which includes a dynamic magnetic field acquisition instrument located in the vertical / directional well and a magnetic field generator located behind the drill bit;

[0040] The second drilling unit is used to guide the drill bit to complete the drilling of the target formation section of the horizontal well based on the mutual cyclic leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator.

[0041] Furthermore, the deployment unit deployment well system includes:

[0042] One horizontal well and N vertical / directional wells approximately perpendicular to the target formation section of the horizontal well, wherein N ≥ 1;

[0043] The horizontal well deployment includes the wellhead location, the build-up point, at least two target windows for the target formation horizontal well section, and the azimuth angle of the target formation horizontal well section determined based on the first target window point A and the last target window point B of the target formation horizontal well section.

[0044] Furthermore, the lateral distance between the target formation section of the vertical / directional well and the target formation horizontal well section of the horizontal well determined by the target window point is 1m to 20m.

[0045] The horizontal distance between target window point A and target window point B in the horizontal well section of the target formation is greater than 200m;

[0046] The horizontal distance between the wellhead location and the target window point A of the horizontal well section of the target formation is 100-800m.

[0047] Furthermore, the number N of vertical / directional wells is determined by the horizontal distance between the target window point A and the target window point B of the horizontal well section of the target formation and the effective magnetic signal detection distance parameter of the ranging system.

[0048] Furthermore, N = |[L / (2L0) + 0.5]|

[0049] Where L represents the horizontal distance between target window point A and target window point B in the horizontal well section of the target formation, L0 represents the effective magnetic signal detection distance parameter of the ranging system, and |[…]| represents rounding the value calculated by the formula to the nearest integer.

[0050] Furthermore, the deployment of the N wells perpendicular to the target formation section of the horizontal well includes:

[0051] If no pilot well is drilled, the distances between the projection points of the N vertical or directional wells in the target formation on the horizontal well design trajectory and the target window point A of the horizontal well section of the target formation are arranged according to the sizes L0, 3L0, 5L0, ..., (2N-1)L0.

[0052] If pilot wells are drilled, the distances between the projection points of the N vertical or directional wells in the target formation on the horizontal well design trajectory and the target window point A of the horizontal well section of the target formation are arranged according to the magnitudes of L0+Ld, 3L0+Ld, 5L0+Ld, ..., (2N-1)+Ld.

[0053] Where L0 represents the effective magnetic signal detection distance parameter of the ranging system; Ld represents the stable non-ranging parameter.

[0054] Furthermore, the ranging system also includes an information transmission system, a ground information processing unit, and a guidance software system.

[0055] The information transmission system is used to transmit the magnetic field information collected by the dynamic magnetic field acquisition instrument to the ground information processing instrument. The magnetic field information includes the intensity, direction and changes of the dynamically rotating magnetic field generated by the magnetic field generator.

[0056] The ground information processing instrument is used to convert the collected magnetic field information into digital signals and send the digital signals to the guidance software system;

[0057] The guidance software system is used to determine the relative positional relationship between the dynamic magnetic field acquisition instrument and the magnetic field generator based on the digital signal, and to determine the position of the drill bit based on the relative positional relationship to guide drilling operations.

[0058] Furthermore, the second drilling unit, used to complete the drilling of the target formation section of the horizontal well based on the mutually cyclical leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator, includes:

[0059] The dynamic magnetic field acquisition instrument leads the magnetic field generator, and guides the drill bit to perform directional drilling operations in a direction offset from the dynamic magnetic field acquisition instrument by a predetermined distance based on the relative positional relationship between the dynamic magnetic field acquisition instrument and the magnetic field generator.

[0060] The magnetic field generator is located to the side of the dynamic magnetic field acquisition instrument. It uses the stable directional drilling capability of the drill string assembly to quickly traverse the distance to the side of the dynamic magnetic field acquisition instrument.

[0061] The magnetic field generator leads the dynamic magnetic field acquisition instrument. Based on the relative positions of the dynamic magnetic field acquisition instrument and the magnetic field generator, the positional change of the magnetic field generator is determined, and the drilling direction of the drill bit is further guided.

[0062] Furthermore, the magnetic field generator leading the dynamic magnetic field acquisition instrument to guide the drill bit drilling also includes avoiding magnetic signal interference from the magnetic field generator and drill tool components.

[0063] The present invention relates to a high-precision magnetic ranging directional drilling method and system for horizontal reference wells, which includes a well system and a ranging system. Based on the magnetic ranging method, the drilling direction of the horizontal section of the horizontal well can be guided by the magnetic ranging system using actual drilling data from previously drilled vertical or directional wells. This can solve the problem of precise control of the wellbore trajectory of the first horizontal reference well in a horizontal well group with concentrated source rock oil and gas.

[0064] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0065] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0066] Figure 1A schematic diagram of the process of a high-precision magnetic ranging directional drilling method for horizontal reference wells in an embodiment of the present invention is shown.

[0067] Figure 2 A schematic diagram of the well system configuration in an embodiment of the present invention is shown;

[0068] Figure 3 A schematic diagram of the multi-target trajectory of a horizontal well in an embodiment of the present invention is shown;

[0069] Figure 4 A schematic diagram of a pilot well in an embodiment of the present invention is shown;

[0070] Figure 5 This diagram illustrates the deployment of vertical or directional wells without a pilot hole in an embodiment of the present invention.

[0071] Figure 6 This diagram illustrates the deployment of vertical or directional wells during pilot hole drilling in an embodiment of the present invention.

[0072] Figure 7 A schematic diagram of the ranging system configuration in an embodiment of the present invention is shown;

[0073] Figure 8 A schematic diagram of the installation position of the magnetic field generator in an embodiment of the present invention is shown;

[0074] Figure 9 A schematic diagram of the non-magnetic sleeve insertion position in an embodiment of the present invention is shown;

[0075] Figure 10 A schematic diagram of the side well section of the dynamic magnetic field acquisition instrument in an embodiment of the present invention is shown;

[0076] Figure 11 A schematic diagram of the drilling method of the drill bit leading dynamic magnetic field acquisition instrument in an embodiment of the present invention is shown. Detailed Implementation

[0077] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0078] This invention provides a high-precision magnetic ranging directional drilling method and system for horizontal reference wells, which is used to solve or partially solve the problem of precise wellbore trajectory control of the first horizontal well in a horizontal well group with concentrated source rock oil and gas.

[0079] This invention provides a high-precision magnetic ranging directional drilling method for horizontal reference wells. Figure 1 This diagram illustrates the flow chart of a high-precision magnetic ranging directional drilling method for horizontal reference wells, as shown in an embodiment of the present invention. Figure 1 The method includes: determining the deployment of the well system; sequentially drilling non-target formation sections of vertical / directional wells and horizontal wells according to the deployment of the well system; lowering a ranging system, the ranging system including a dynamic magnetic field acquisition instrument located in the vertical / directional well and a magnetic field generator located behind the drill bit; and guiding the drill bit to complete the drilling of the target formation section of the horizontal well according to the mutual cyclic leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator.

[0080] Specifically, the deployment of the well system includes: one horizontal well and N vertical / directional wells perpendicular to the target formation well section of the horizontal well, wherein N≥1; the horizontal well deployment includes the wellhead location, the build-up point, at least two target window points of the target formation horizontal well section, and the azimuth angle of the target formation horizontal well section determined based on the first target window point A and the last target window point B of the target formation horizontal well section.

[0081] Specifically, determining the target formation target window point also includes drilling pilot wells to correct the position of the target window point.

[0082] Specifically, the lateral distance between the target formation section of the vertical / directional well and the target formation horizontal well section of the horizontal well determined by the target window point is 1m to 20m; the horizontal distance between the target formation horizontal well section target window point A and the target formation horizontal well section target window point B is greater than 200m; and the horizontal distance between the wellhead position and the target formation horizontal well section target window point A is 100 to 800m.

[0083] Specifically, the target formation section of the vertical / directional well includes a vertical section or an inclined section. If it is a directional well, the difference between the azimuth of the inclined section and the azimuth determined by the target window point of the horizontal well section of the target formation is less than 20°.

[0084] Specifically, the number N of vertical / directional wells is determined by the horizontal distance between target window point A and target window point B of the target formation horizontal well section and the effective magnetic signal detection distance parameter of the ranging system.

[0085] N = |[L / (2L0)+0.5]|

[0086] Where L represents the horizontal distance between target window point A and target window point B in the horizontal well section of the target formation, L0 represents the effective magnetic signal detection distance parameter of the ranging system, and |[…]| represents rounding the value calculated by the formula to the nearest integer.

[0087] Specifically, the deployment of the N vertical / directional wells perpendicular to the target formation section of the horizontal well includes:

[0088] If no pilot well is drilled, the distances between the projection points of the N vertical or directional wells in the target formation on the horizontal well design trajectory and the target window point A of the horizontal well section of the target formation are arranged according to the sizes L0, 3L0, 5L0, ..., (2N-1)L0.

[0089] If pilot wells are drilled, the distances between the projection points of the N vertical or directional wells in the target formation on the horizontal well design trajectory and the target window point A of the horizontal well section of the target formation are arranged according to the magnitudes of L0+Ld, 3L0+Ld, 5L0+Ld, ..., (2N-1)+Ld.

[0090] Where L0 represents the effective magnetic signal detection distance parameter of the ranging system; Ld represents the stable non-ranging parameter.

[0091] Specifically, the magnetic field generator includes a natural magnet, a magnet, and an energized solenoid coil;

[0092] The magnetic field strength of the magnetic field generator is greater than the geomagnetic strength and the residual magnetic field strength of the drill string.

[0093] Specifically, the drilling of the target formation section of the horizontal well, based on the mutually cyclical leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator, includes:

[0094] The dynamic magnetic field acquisition instrument leads the magnetic field generator, and guides the drill bit to perform directional drilling operations in a direction offset from the dynamic magnetic field acquisition instrument by a predetermined distance based on the relative positional relationship between the dynamic magnetic field acquisition instrument and the magnetic field generator.

[0095] The magnetic field generator is located to the side of the dynamic magnetic field acquisition instrument. It uses the stable directional drilling capability of the drill string assembly to quickly traverse the distance to the side of the dynamic magnetic field acquisition instrument.

[0096] The magnetic field generator leads the dynamic magnetic field acquisition instrument. Based on the relative positions of the dynamic magnetic field acquisition instrument and the magnetic field generator, the positional change of the magnetic field generator is determined, and the drilling direction of the drill bit is further guided.

[0097] Specifically, the magnetic field generator leading the dynamic magnetic field acquisition instrument to guide the drill bit drilling also includes avoiding magnetic signal interference from the magnetic field generator and drill tool components.

[0098] Specifically, avoiding magnetic signal interference from the magnetic field generator and drill components includes:

[0099] Increase the magnetic field strength of the magnetic field generator, typically greater than the geomagnetic strength (0.5-0.6 Gauss), or;

[0100] The drill bit assembly uses a non-magnetic material drill bit within the effective magnetic signal detection distance parameter range at the bottom, or;

[0101] Increase the distance between the horizontal section of the horizontal well and the wellbore track of the vertical or directional well to make it greater than 3m.

[0102] In this embodiment of the invention, the specific steps of the high-precision magnetic ranging directional drilling method for horizontal reference wells are also described in detail:

[0103] Figure 2 A schematic diagram of the well system configuration in an embodiment of the present invention is shown. Figure 2 In this system, the well system includes one horizontal well 1 to be drilled and one or more vertical or directional wells 2. The target layers of the vertical or directional wells 2 are located near the designed trajectory 11 of the horizontal section of the horizontal well. Because the horizontal section of the horizontal well 1 requires high control precision, conventional directional control techniques are insufficient to guarantee drilling accuracy. Therefore, one or more vertical or directional wells 2 are needed to guide the drilling operation along the wellbore trajectory of the horizontal section 11. The horizontal well has four key parameters: wellhead position 12, kick-off point (KOP), the first target window point A reached during drilling of the horizontal section, the last target window point B reached during drilling of the horizontal section, and the azimuth angle Φ determined by points A and B. These parameters are provided by geological reservoir personnel. The horizontal distance between the wellhead and point A is calculated as the target distance R; the horizontal distance between points A and B is calculated as the length L of the horizontal section. R is generally between 100 and 800 m, and L is generally over 200 m.

[0104] Figure 3 The diagram shows a horizontal well multi-target trajectory in an embodiment of the present invention. The horizontal well may not have other target points between target points A and B, that is, the designed trajectory is a straight segment before A and B. Alternatively, target points may be added to restrict the trajectory between A and B according to actual geological needs, such as the vertical undulation of the strata. Figure 3 In this embodiment, the added target points are A1, A2, A3, and B1. The number and location of the added target points are merely illustrative and there are no specific limitations on the number and location of the target points.

[0105] Figure 2 and Figure 3 In this well, either a vertical or directional well 2 includes a well section 23 above the geological target stratum and a well section 24 above the geological target stratum. If the well section above the geological target stratum is approximately vertical, then the well is a vertical well 21; if it is not approximately vertical, then the well is a directional well 22.

[0106] To avoid wellbore trajectory collisions between horizontal wells and vertical or directional wells, a certain lateral distance d exists between the geological target formation section of a vertical or directional well and the A and B points of a horizontal well. This lateral distance is generally greater than 1m and less than 20m. The lateral distance can be a uniform value d, or different values ​​(d1, d2, etc.) can be used for different vertical or directional wells. The geological target formation section of a vertical or directional well can be a vertical section or an inclined section. If it is an inclined section, its azimuth angle is approximately the same as the azimuth angle Φ determined by points A and B, with the difference generally less than 20°.

[0107] The wellhead 23 of the vertical or directional well 2 can be located on the same drilling platform as the wellhead 12 of the horizontal well (the wellhead distance is generally less than 100m), or it can be located on a different drilling platform, depending on the surface conditions. The wellhead 25 of the vertical or directional well 2 can be on the same drilling platform or on a different drilling platform. If the vertical or directional well 2 and the horizontal well 1 are on the same drilling platform, the distance between the wellheads of the vertical or directional well 2 and the horizontal well 1 should meet the minimum distance for drilling rig operation and ranging system operation, which can be determined by the drilling rig model and the ranging system operating machine model, and generally needs to be greater than 10m.

[0108] In this embodiment of the invention, if there is some uncertainty regarding the geological reservoir and target formation data during horizontal well drilling, a pilot well can be drilled. Figure 4 The diagram illustrates a pilot well in an embodiment of the present invention. After reaching the build-up point, instead of directly drilling towards target point A at a certain arc or angle, a near-vertical wellbore 131 or a straight-angled wellbore 132 is drilled through the target formation to understand the distribution or formation data of the target formation, verify whether the designed target point A is located within the target formation, and make corrections accordingly. After obtaining the target formation data, the drilled pilot well is backfilled with cement, and the drilling resumes from the build-up point KOP, directional drilling towards the adjusted target point A. If the geological reservoir has clear target formation data, drilling a pilot well may not be necessary.

[0109] In this embodiment of the invention, the number N of vertical or directional wells 2 needs to take into account the effective magnetic signal detection distance parameter L0 of the long-distance magnetic steerable drilling equipment and the length L of the horizontal section of the horizontal well. The specific method is as follows:

[0110] The effective magnetic signal detection distance parameter L0 of long-distance magnetic steerable drilling equipment is generally provided by the long-distance magnetic steerable drilling equipment supplier, and in some cases it can be obtained through ground tests.

[0111] Calculate the N value, which is the length L of the horizontal section of the horizontal well divided by the effective magnetic signal detection distance parameter L0, rounded to the nearest integer. See below for reference:

[0112] N = |[L / (2L0)+0.5]|

[0113] In this embodiment of the invention, the determination of the number N of vertical or directional wells 2 includes the following two methods:

[0114] No pilot well was drilled. Figure 5 This diagram illustrates the deployment of vertical or directional wells without a pilot hole in an embodiment of the present invention. Figure 5 In the design trajectory of the horizontal well, the distances from the projection points of the N vertical or directional wells in the target formation to A are approximately arranged according to the magnitudes of L0, 3L0, 5L0, ..., (2N-1)L0.

[0115] Such as drilling pilot wells Figure 6 This diagram illustrates the deployment of vertical or directional wells during pilot hole drilling in an embodiment of the present invention. Figure 6 In this context, the distance from the projection point of the N vertical or directional wells in the target formation onto the designed horizontal well trajectory to point A is approximately arranged according to the magnitudes of L0+Ld, 3L0+Ld, 5L0+Ld, ..., (2N-1)+Ld. Ld represents a stable non-distance parameter, which can be determined in three ways: first, it can be determined by the relatively stable spatial distance determined by the geological reservoir based on the formation distribution; second, it can be approximated as L0; third, based on the designed wellbore trajectory, the measurement accuracy of the directional drilling measuring instrument, the target geomagnetic environment, and the target trajectory control accuracy requirements, the existing directional drilling error ellipse calculation method is applied to analyze the safe drilling distance under the target trajectory control accuracy requirements, determining a value of 30–150 m. This analysis method is existing technology and will not be elaborated further.

[0116] The embodiments of the present invention also provide a detailed description of the composition of the ranging system. Figure 7 A schematic diagram of the ranging system configuration in an embodiment of the present invention is shown. Figure 7 In the system, the ranging system 3 consists of a magnetic field generator 31, a dynamic magnetic field acquisition instrument 32, an information transmission system 33, a ground information processing instrument 34, and a guidance software system 35.

[0117] The magnetic field generator 31 can generate a certain magnetic field strength under a certain magnetic field mode, and it can be detected by the magnetic field strength detector 32. More specifically, the magnetic field generator 32 can be a natural magnet, a magnet with a certain magnetic field strength, or a group of magnets or magnets arranged and installed according to certain rules to form a specific magnet device, or a solenoid magnetic field generator that generates a magnetic field of a certain strength after being energized; the magnetic field strength is greater than the geomagnetic intensity and the residual magnetic field strength of the drill string. Figure 8 A schematic diagram of the installation position of the magnetic field generator in an embodiment of the present invention is shown. Figure 8In the process of drilling horizontal wells, the magnetic field generator 31 is usually installed behind the drill bit 311 of the drill string assembly. It generates a dynamic rotating magnetic field as the drill string rotates. The magnetic field generator 31 can also be installed behind the downhole power drill string 312 according to special needs. It rotates with the drill string during operation and generates a dynamically changing magnetic field.

[0118] The dynamic magnetic field acquisition instrument 32 is an instrument for detecting the distribution intensity and direction of the nearby magnetic field, also called a probe, which can detect the intensity of the surrounding three-axis (three different directions) magnetic field. In this case, it mainly acquires the intensity, direction and changes of the dynamic rotating magnetic field generated by the magnetic field generator 31, and transmits the acquired information to the ground information processing instrument 34 through the information transmission system 33.

[0119] The dynamic magnetic field acquisition instrument 32 is mainly installed in the target formation section of drilled vertical or directional wells and connected to the surface wellhead via a connecting device. The connecting device includes tubing, coiled tubing, and wire rope.

[0120] The information transmission system 33 is responsible for transmitting the received information to the ground information processing unit 34 via wired cable or wireless signal.

[0121] The ground information processing unit 34 processes the received information from the dynamic magnetic field acquisition unit into digital information, which is then used by the guidance software system 35 for calculation and analysis to determine the relative positions of the magnetic field generator 31 and the dynamic magnetic field acquisition unit 32 underground, including distance and orientation. Furthermore, based on geomagnetic data and directional drilling measurement data from directional wells or vertical wells and horizontal sections, the specific underground location of the magnetic field generator is determined.

[0122] The location of the drill bit can be determined by the specific location of the magnetic field generator underground obtained by the ranging system, thereby guiding subsequent drilling operations.

[0123] The steps of the three-dimensional wellbore magnetic ranging method are described in detail in this embodiment of the invention:

[0124] Step (1): Complete the deployment and drilling of vertical or directional well 2 according to the well system.

[0125] There are no fixed requirements for the drilling sequence of vertical wells; it can be determined according to specific factors such as the surface drilling platform, wellhead location, and surface conditions.

[0126] For vertical or directional well drilling operations, high-precision measurement-while-drilling (MWD) instruments and calculation methods should be used to reduce the elliptic error of the wellbore trajectory. The deviation measurement error of the MWD instrument should be less than 0.1°, and the azimuth measurement error should be less than 1°.

[0127] Vertical or directional wells can be cored in all or part of the target formation to obtain geological data of the target formation within the horizontal well section, and to determine the strike and variation of the formation.

[0128] The completion methods for vertical or directional wells can be open-hole completion, screen completion, or casing completion. The specific completion method is determined based on the oil and gas production needs, drilling safety requirements, and geological formation and wellbore stability. If screen completion or casing completion is used, a non-magnetic casing 25mm needs to be installed and run in the well section of the target formation. Figure 9 This diagram illustrates the insertion position of the non-magnetic sleeve in an embodiment of the present invention. The non-magnetic sleeve includes fiberglass sleeves, non-magnetic alloy steel sleeves, aluminum alloy sleeves, etc. The length of the non-magnetic sleeve is between 5 and 20 meters, at least greater than 5 meters, and generally between 10 and 15 meters.

[0129] Step (2): Complete drilling of the non-target formation section of the horizontal well.

[0130] High-precision drilling directional measurement instruments and calculation methods are adopted to reduce the wellbore trajectory elliptic error. The well inclination measurement error of the drilling measurement instrument is less than 0.1°, and the azimuth measurement error is less than 1°.

[0131] Step (3): Deploy the ranging system

[0132] When entering the target formation, a magnetic field generator 31 is pre-installed in the drill string assembly. The magnetic field generator is usually installed behind the drill bit 311, but it can also be installed behind the downhole power drill string 312 according to special needs. During operation, it rotates with the drill string to generate a dynamically changing magnetic field.

[0133] The dynamic magnetic field acquisition instrument is lowered into the vertical or directional well closest to the drill bit via a connecting device, positioning it in the middle of the target formation section of the well. If the well is a screen-completed or casing-completed well, the dynamic magnetic field acquisition instrument is inside the non-magnetic casing 25. If the well is an open-hole complete well, the instrument is inside the open-hole. During operation, the dynamic magnetic field acquisition is static, and its relative position is fixed.

[0134] Step (4): Start drilling by leading the drill bit with the dynamic magnetic field acquisition instrument.

[0135] At this time, the dynamic magnetic field acquisition instrument or probe is located in front of the drill bit, such as... Figure 7 As shown, there is no magnetic interference between the two. The distance and azimuth of the dynamic magnetic field acquisition instrument and the magnetic field generator are measured in real time using a ranging system. Since the actual dynamic magnetic field acquisition instrument is stationary and has a fixed position, changes in the measured distance and azimuth can determine the positional changes of the magnetic field generator, thereby inferring the positional changes of the drill bit. This, in turn, guides the drilling direction of the drill bit.

[0136] Since horizontal wells, vertical wells, and directional wells are spaced apart in the well system, after the distance measurement system measures the actual distance and azimuth changes of the dynamic magnetic field acquisition instrument and the magnetic field generator in real time, it is necessary to guide the drill bit to perform directional drilling operations in a direction offset from the predetermined distance of the dynamic magnetic field acquisition instrument.

[0137] Drilling begins with the dynamic magnetic field acquisition instrument leading the drill bit. The dynamic magnetic field acquisition instrument or probe is located in front of the drill bit. The distance and orientation of the dynamic magnetic field acquisition instrument and the magnetic field generator are measured in real time using a ranging system. After measuring the actual distance and orientation changes of the dynamic magnetic field acquisition instrument and the magnetic field generator in real time using the ranging system, the drill bit needs to be guided to perform directional drilling operations in a direction offset from the predetermined distance of the dynamic magnetic field acquisition instrument.

[0138] Step (5): Quickly pass through the side section of the dynamic magnetic field acquisition instrument

[0139] As the magnetic ranging system guides the drill bit to continue drilling, the actual distance between the dynamic magnetic field acquisition instrument and the magnetic field generator continuously decreases. When the magnetic field generator is located to the side of the dynamic magnetic field acquisition instrument... Figure 10 This diagram illustrates a rapid passage through the side well section of the dynamic magnetic field acquisition instrument in an embodiment of the present invention. Figure 10 In the process, the measurement accuracy of the dynamic magnetic field acquisition instrument in measuring the magnetic field changes of the magnetic field generator decreases, leading to situations where the measurement accuracy is unreliable. At this point, since the LL section is relatively short, magnetic ranging and orientation operations can be discontinued. The stable directional capability of the drill string assembly can be utilized to quickly drill through the lateral distance LL of the dynamic magnetic field acquisition instrument.

[0140] Step (6): Drill according to the method of drill bit leading dynamic magnetic field acquisition instrument.

[0141] After passing the side section of the well where the dynamic magnetic field acquisition instrument is located, the drill bit now leads the dynamic magnetic field acquisition instrument. Figure 11 This diagram illustrates the drilling method of the drill bit-led dynamic magnetic field acquisition instrument in an embodiment of the present invention. Figure 11 In horizontal well drilling, the drill string components behind the drill bit possess a certain degree of magnetism, generating a rotating dynamic magnetic field together with the magnetic field generator, which is detected by the dynamic magnetic field acquisition instrument. To avoid magnetic signal interference between the two, the following methods should be used: first, increase the magnetic field strength of the magnetic field generator to significantly distinguish it from the drill string's magnetic field strength; second, use non-magnetic materials for the bottom L0 range of the horizontal well drill string assembly; and third, increase the distance between the horizontal section of the horizontal well and the wellbore trajectory of the vertical or directional well to greater than 3 meters.

[0142] The distance and azimuth of the dynamic magnetic field acquisition instrument and the magnetic field generator are measured in real time using a ranging system. Since the actual dynamic magnetic field acquisition instrument is stationary and has a fixed position, changes in the measured distance and azimuth can determine the positional changes of the magnetic field generator, thereby inferring the positional changes of the drill bit. This then guides the drilling direction of the drill bit.

[0143] As the distance between the drill bit and the dynamic magnetic field acquisition instrument and the magnetic field generator increases, the signal detected by the dynamic magnetic field acquisition instrument from the magnetic field generator becomes weaker and weaker until it can no longer detect the signal, thus making it impossible to continue guiding the drill bit's drilling direction.

[0144] Step (7): Change the position of the dynamic magnetic field acquisition instrument

[0145] As the distance between the drilling bit and the dynamic magnetic field acquisition instrument and the magnetic field generator increases, the signal detected by the dynamic magnetic field acquisition instrument from the magnetic field generator becomes weaker and weaker until it can no longer be detected. At this point, the dynamic magnetic field acquisition instrument needs to be moved to a nearby vertical or directional well in the same way as described above, and the drilling bit is guided to continue to advance by the dynamic magnetic field acquisition instrument leading the drilling bit.

[0146] Step (8): Continue to cycle through steps (4)(5)(6)(7) to guide the drill bit to drill until the horizontal well operation is completed.

[0147] By using the above methods and the actual drilling data from previously drilled vertical or directional wells, and by utilizing a magnetic ranging system to guide the drilling direction of the horizontal section of the horizontal well, the problem of accurately controlling the wellbore trajectory of the first horizontal reference well in a horizontal well group with concentrated source rock oil and gas can be solved.

[0148] This invention also provides a high-precision magnetic ranging directional drilling system for horizontal reference wells. The system includes: a deployment unit, a first drilling unit, a lowering unit, and a second drilling unit.

[0149] Deployment unit, used to determine the deployment of the well system;

[0150] The first drilling unit is used to sequentially complete the drilling of non-target formation sections of vertical / directional wells and horizontal wells according to the deployment of the well system;

[0151] The lowering unit is used to lower the ranging system, which includes a dynamic magnetic field acquisition instrument located in the vertical / directional well and a magnetic field generator located behind the drill bit;

[0152] The second drilling unit is used to guide the drill bit to complete the drilling of the target formation section of the horizontal well based on the mutual cyclic leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator.

[0153] Specifically, the deployment unit deployment well system includes:

[0154] One horizontal well and N vertical / directional wells approximately perpendicular to the target formation section of the horizontal well, wherein N ≥ 1;

[0155] The horizontal well deployment includes the wellhead location, the build-up point, at least two target windows for the target formation horizontal well section, and the azimuth angle of the target formation horizontal well section determined based on the first target window point A and the last target window point B of the target formation horizontal well section.

[0156] Specifically, the lateral distance between the target formation section of the vertical / directional well and the target formation horizontal well section of the horizontal well determined by the target window point is 1m to 20m.

[0157] The horizontal distance between target window point A and target window point B in the horizontal well section of the target formation is greater than 200m;

[0158] The horizontal distance between the wellhead location and the target window point A of the horizontal well section of the target formation is 100-800m.

[0159] Specifically, the number N of vertical / directional wells is determined by the horizontal distance between target window point A and target window point B of the target formation horizontal well section and the effective magnetic signal detection distance parameter of the ranging system.

[0160] N = |[L / (2L0)+0.5]|

[0161] Where L represents the horizontal distance between target window point A and target window point B in the horizontal well section of the target formation, L0 represents the effective magnetic signal detection distance parameter of the ranging system, and |[…]| represents rounding the value calculated by the formula to the nearest integer.

[0162] Specifically, the deployment of the N vertical / directional wells perpendicular to the target formation section of the horizontal well includes:

[0163] If no pilot well is drilled, the distances between the projection points of the N vertical or directional wells in the target formation on the horizontal well design trajectory and the target window point A of the horizontal well section of the target formation are arranged according to the sizes L0, 3L0, 5L0, ..., (2N-1)L0.

[0164] If pilot wells are drilled, the distances between the projection points of the N vertical or directional wells in the target formation on the horizontal well design trajectory and the target window point A of the horizontal well section of the target formation are arranged according to the magnitudes of L0+Ld, 3L0+Ld, 5L0+Ld, ..., (2N-1)+Ld.

[0165] Where L0 represents the effective magnetic signal detection distance parameter of the ranging system; Ld represents the stable non-ranging parameter.

[0166] Specifically, the ranging system also includes an information transmission system, a ground information processing unit, and a guidance software system.

[0167] The information transmission system is used to transmit the magnetic field information collected by the dynamic magnetic field acquisition instrument to the ground information processing instrument. The magnetic field information includes the intensity, direction and changes of the dynamically rotating magnetic field generated by the magnetic field generator.

[0168] The ground information processing instrument is used to convert the collected magnetic field information into digital signals and send the digital signals to the guidance software system;

[0169] The guidance software system is used to determine the relative positional relationship between the dynamic magnetic field acquisition instrument and the magnetic field generator based on the digital signal, and to determine the position of the drill bit based on the relative positional relationship to guide drilling operations.

[0170] Specifically, the second drilling unit is used to complete the drilling of the target formation section of the horizontal well based on the mutual cyclic leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator, including:

[0171] The dynamic magnetic field acquisition instrument leads the magnetic field generator, and guides the drill bit to perform directional drilling operations in a direction offset from the dynamic magnetic field acquisition instrument by a predetermined distance based on the relative positional relationship between the dynamic magnetic field acquisition instrument and the magnetic field generator.

[0172] The magnetic field generator is located to the side of the dynamic magnetic field acquisition instrument. It uses the stable directional drilling capability of the drill string assembly to quickly traverse the distance to the side of the dynamic magnetic field acquisition instrument.

[0173] The magnetic field generator leads the dynamic magnetic field acquisition instrument. Based on the relative positions of the dynamic magnetic field acquisition instrument and the magnetic field generator, the positional change of the magnetic field generator is determined, and the drilling direction of the drill bit is further guided.

[0174] Specifically, the magnetic field generator leading the dynamic magnetic field acquisition instrument to guide the drill bit drilling also includes avoiding magnetic signal interference from the magnetic field generator and drill tool components.

[0175] The present invention relates to a high-precision magnetic ranging directional drilling method and system for horizontal reference wells, which sets up a well system and a ranging system. Based on the three-dimensional wellbore magnetic ranging method, the drilling direction of the horizontal section of the horizontal well can be guided by the magnetic ranging system using the actual drilling data of the previously drilled vertical or directional wells. This can solve the problem of precise control of the wellbore trajectory of the first horizontal reference well in a horizontal well group with concentrated source rock oil and gas.

[0176] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-precision magnetic ranging directional drilling method for horizontal reference wells, characterized in that, The method includes: Determine the deployment of the well system; Based on the deployment of the well system, drilling of non-target formation sections of vertical / directional wells and horizontal wells will be completed sequentially; A ranging system is lowered, which includes a dynamic magnetic field acquisition instrument located in the vertical / directional well and a magnetic field generator located behind the drill bit; the drill bit is guided to complete the drilling of the target formation section of the horizontal well based on the mutual cyclic leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator. The deployment of the well system includes: One horizontal well and N vertical / directional wells approximately perpendicular to the target formation section of the horizontal well, wherein N ≥ 1; The horizontal well deployment includes the wellhead location, the build-up point, at least two target windows for the target formation horizontal well section, and the azimuth angle of the target formation horizontal well section determined based on the first target window point A and the last target window point B of the target formation horizontal well section; The drilling of the target formation section of a horizontal well is guided by the mutual cyclic leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator, including: The dynamic magnetic field acquisition instrument leads the magnetic field generator, and guides the drill bit to perform directional drilling operations in a direction offset from the dynamic magnetic field acquisition instrument by a predetermined distance based on the relative positional relationship between the dynamic magnetic field acquisition instrument and the magnetic field generator. The magnetic field generator is located to the side of the dynamic magnetic field acquisition instrument. It uses the stable directional drilling capability of the drill string assembly to quickly traverse the distance to the side of the dynamic magnetic field acquisition instrument. The magnetic field generator leads the dynamic magnetic field acquisition instrument. Based on the relative positions of the dynamic magnetic field acquisition instrument and the magnetic field generator, the positional change of the magnetic field generator is determined, and the drilling direction of the drill bit is further guided.

2. The high-precision magnetic ranging directional drilling method for horizontal reference wells according to claim 1, characterized in that, Determining the target formation target window point also includes drilling pilot wells to correct the position of the target window point.

3. The high-precision magnetic ranging directional drilling method for horizontal reference wells according to claim 2, characterized in that, The lateral distance between the target formation well section of the vertical / directional well and the target formation horizontal well section of the horizontal well section of the horizontal well is 1m to 20m; The horizontal distance between target window point A and target window point B in the horizontal well section of the target formation is greater than 200m; The horizontal distance between the wellhead location and the target window point A of the horizontal well section of the target formation is 100~800m.

4. The high-precision magnetic ranging directional drilling method for horizontal reference wells according to claim 3, characterized in that, The target formation section of the vertical / directional well includes a vertical section or an inclined section. If it is a directional well, the difference between the azimuth of the inclined section and the azimuth determined by the target window point of the horizontal well section of the target formation is less than 20°.

5. The high-precision magnetic ranging directional drilling method for horizontal reference wells according to claim 3, characterized in that, The number N of vertical / directional wells is determined by the horizontal distance between target window point A and target window point B of the target formation horizontal well section and the effective magnetic signal detection distance parameter of the ranging system.

6. The high-precision magnetic ranging directional drilling method for horizontal reference wells according to claim 5, characterized in that, N = |[L / (2L0)+0.5]| Where L represents the horizontal distance between target window point A and target window point B in the horizontal well section of the target formation, L0 represents the effective magnetic signal detection distance parameter of the ranging system, and |[…]| represents rounding the value calculated by the formula to the nearest integer.

7. The high-precision magnetic ranging directional drilling method for horizontal reference wells according to claim 2, characterized in that, The deployment of the Nth well, which is perpendicular to the target formation section of the horizontal well, includes: If no pilot well is drilled, the distances between the projection points of the N vertical or directional wells in the target formation on the horizontal well design trajectory and the target window point A of the horizontal well section of the target formation are arranged according to the sizes L0, 3L0, 5L0, ..., (2N-1)L0. If pilot wells are drilled, the distances between the projection points of the N vertical or directional wells in the target formation on the horizontal well design trajectory and the target window point A of the horizontal well section of the target formation are arranged according to the magnitudes of L0+Ld, 3L0+Ld, 5L0+Ld, ..., (2N-1)+Ld. Where L0 represents the effective magnetic signal detection distance parameter of the ranging system; Ld represents the stable non-ranging parameter.

8. The high-precision magnetic ranging directional drilling method for horizontal reference wells according to claim 1, characterized in that, The magnetic field generator includes natural magnets, magnets, and an energized solenoid coil; The magnetic field strength of the magnetic field generator is greater than the geomagnetic strength and the residual magnetic field strength of the drill string.

9. The high-precision magnetic ranging directional drilling method for horizontal reference wells according to claim 1, characterized in that, The magnetic field generator, which guides the drill bit through the dynamic magnetic field acquisition instrument, also includes measures to avoid magnetic signal interference between the magnetic field generator and the drill bit components.

10. The high-precision magnetic ranging directional drilling method for horizontal reference wells according to claim 9, characterized in that, The measures to avoid magnetic signal interference from the magnetic field generator and drill components include: Increase the magnetic field strength of the magnetic field generator, or; The effective magnetic signal detection distance range at the bottom of the drill bit component assembly is achieved using a non-magnetic material drill bit, or; Increase the distance between the horizontal section of the horizontal well and the wellbore track of the vertical or directional well to make it greater than 3m.

11. A high-precision magnetic ranging directional drilling system for horizontal reference wells, characterized in that, The system includes: a deployment unit, a first drilling unit, a lowering unit, and a second drilling unit. Deployment unit, used to determine the deployment of the well system; The first drilling unit is used to sequentially complete the drilling of non-target formation sections of vertical / directional wells and horizontal wells according to the deployment of the well system; The lowering unit is used to lower the ranging system, which includes a dynamic magnetic field acquisition instrument located in the vertical / directional well and a magnetic field generator located behind the drill bit; The second drilling unit is used to guide the drill bit to complete the drilling of the target formation section of the horizontal well based on the mutual cyclic leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator. The deployment unit deployment well system includes: One horizontal well and N vertical / directional wells approximately perpendicular to the target formation section of the horizontal well, wherein N ≥ 1; The horizontal well deployment includes the wellhead location, the build-up point, at least two target windows for the target formation horizontal well section, and the azimuth angle of the target formation horizontal well section determined based on the first target window point A and the last target window point B of the target formation horizontal well section; The second drilling unit is used to guide the drill bit to complete the drilling of the target formation section of the horizontal well based on the mutual cyclic leading motion of the dynamic magnetic field acquisition instrument and the magnetic field generator, including: The dynamic magnetic field acquisition instrument leads the magnetic field generator, and guides the drill bit to perform directional drilling operations in a direction offset from the dynamic magnetic field acquisition instrument by a predetermined distance based on the relative positional relationship between the dynamic magnetic field acquisition instrument and the magnetic field generator. The magnetic field generator is located to the side of the dynamic magnetic field acquisition instrument. It uses the stable directional drilling capability of the drill string assembly to quickly traverse the distance to the side of the dynamic magnetic field acquisition instrument. The magnetic field generator leads the dynamic magnetic field acquisition instrument. Based on the relative positions of the dynamic magnetic field acquisition instrument and the magnetic field generator, the positional change of the magnetic field generator is determined, and the drilling direction of the drill bit is further guided.

12. The high-precision magnetic ranging directional drilling system for horizontal reference wells according to claim 11, characterized in that, The lateral distance between the target formation well section of the vertical / directional well and the target formation horizontal well section of the horizontal well section of the horizontal well is 1m to 20m; The horizontal distance between target window point A and target window point B in the horizontal well section of the target formation is greater than 200m; The horizontal distance between the wellhead location and the target window point A of the horizontal well section of the target formation is 100~800m.

13. The high-precision magnetic ranging directional drilling system for horizontal reference wells according to claim 12, characterized in that, The number N of vertical / directional wells is determined by the horizontal distance between target window point A and target window point B of the target formation horizontal well section and the effective magnetic signal detection distance parameter of the ranging system.

14. The high-precision magnetic ranging directional drilling system for horizontal reference wells according to claim 13, characterized in that, N = |[L / (2L0)+0.5]| Where L represents the horizontal distance between target window point A and target window point B in the horizontal well section of the target formation, L0 represents the effective magnetic signal detection distance parameter of the ranging system, and |[…]| represents rounding the value calculated by the formula to the nearest integer.

15. The high-precision magnetic ranging directional drilling system for horizontal reference wells according to claim 12, characterized in that, The deployment of the Nth well, which is perpendicular to the target formation section of the horizontal well, includes: If no pilot well is drilled, the distances between the projection points of the N vertical or directional wells in the target formation on the horizontal well design trajectory and the target window point A of the horizontal well section of the target formation are arranged according to the sizes L0, 3L0, 5L0, ..., (2N-1)L0. If pilot wells are drilled, the distances between the projection points of the N vertical or directional wells in the target formation on the horizontal well design trajectory and the target window point A of the horizontal well section of the target formation are arranged according to the magnitudes of L0+Ld, 3L0+Ld, 5L0+Ld, ..., (2N-1)+Ld. Where L0 represents the effective magnetic signal detection distance parameter of the ranging system; Ld represents the stable non-ranging parameter.

16. The high-precision magnetic ranging directional drilling system for horizontal reference wells according to claim 11, characterized in that, The ranging system also includes an information transmission system, a ground information processing unit, and a guidance software system. The information transmission system is used to transmit the magnetic field information collected by the dynamic magnetic field acquisition instrument to the ground information processing instrument. The magnetic field information includes the intensity, direction and changes of the dynamically rotating magnetic field generated by the magnetic field generator. The ground information processing instrument is used to convert the collected magnetic field information into digital signals and send the digital signals to the guidance software system; The guidance software system is used to determine the relative positional relationship between the dynamic magnetic field acquisition instrument and the magnetic field generator based on the digital signal, and to determine the position of the drill bit based on the relative positional relationship to guide drilling operations.

17. The high-precision magnetic ranging directional drilling system for horizontal reference wells according to claim 11, characterized in that, The magnetic field generator, which guides the drill bit through the dynamic magnetic field acquisition instrument, also includes measures to avoid magnetic signal interference between the magnetic field generator and the drill bit components.

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