CN109869140B - Measurement method of offset well distance based on magnetic field gradient - Google Patents

Abstract

The invention discloses a magnetic field gradient-based offset well distance measurement method, which is applied to a magnetic field gradient-based offset well distance measurement device. The device comprises: a downhole magnetic field gradient measurement probe pipe, a downhole injection electrode, a surface electrode, and a surface interface A box, a computing device and a power supply; the method includes: controlling a surface interface box to supply power to a downhole injection electrode in a rescue well, wherein the downhole injection electrode is used to inject alternating current into the surrounding formation, so that the tubing string in the accident well generates a gathering current; receiving rescue The alternating magnetic field signal detected by the downhole magnetic field gradient measurement probe in the well; wherein, the alternating magnetic field signal is the alternating magnetic field signal generated around the pipe string in the accident well; according to the alternating magnetic field signal, the relative position of the rescue well and the accident well is determined. The invention realizes the technical effect that the relative positions of the rescue well and the accident well can be determined without estimating the magnitude of the current on the accident well pipe string.

Description

Measurement method of offset well distance based on magnetic field gradient

technical field

The invention relates to the field of oil and gas well engineering, in particular to a method for measuring the distance of adjacent wells based on magnetic field gradients.

Background technique

This section is intended to provide a background or context to the embodiments of the invention recited in the claims. The descriptions herein are not admitted to be prior art by inclusion in this section.

In oil and gas well engineering, drilling rescue wells is not only an effective means to deal with blowout accidents, but also can replace normal production wells for production operations, such as water injection, exhaust, etc., with multiple functions. Rescue wells are different from conventional directional wells in that the trajectory design and control are relatively difficult, and there are many factors to be considered. Due to the uncertainty of the wellbore trajectory, the accurate detection of the relative position of the rescue well and the accident well is one of the key links for the success of rescue well technology. In addition, the vicinity of the wellhead of the accident well is generally more dangerous. In order to ensure the safety of personnel and drilling equipment, the wellhead of the rescue well is generally several hundred meters or even further away from the wellhead of the accident well. In order to make the rescue well intersect with the accident well, the wellbore trajectory of the rescue well is generally complicated, which also increases the uncertainty of the relative position measurement of the accident well and the rescue well.

The difficulty of rescue well drilling technology is that traditional well trajectory inclination tools cannot avoid cumulative errors in wellbore trajectory measurement, and it is difficult to achieve efficient connection between rescue wells and accident wells by using traditional inclination tools (such as MWD, etc.). The relative position detection method of the rescue well and the accident well disclosed in the prior art is to calculate the relative positional relationship between the rescue well and the accident well by detecting the magnetic field intensity around the accident well pipe string through the probe pipe in the rescue well. The main methods for generating the magnetic field around the accident well string are as follows: one is to put an injection electrode in the rescue well, which can be a single electrode, three electrodes or a gathering electrode; the other is to put a high-power electromagnetic pulse generator in the rescue well ; The third is the magnetic field generated by the pipe string itself. Field practice shows that placing injection electrodes in rescue wells is the most effective method.

At present, in the prior art scheme to determine the relative position of the rescue well and the accident well by placing an injection electrode in the rescue well, the relative position of the rescue well and the accident well can only be calculated by estimating the magnitude of the current intensity on the pipe string of the accident well. However, the magnitude of the current intensity on the accident well pipe string cannot be obtained accurately, which makes the calculation results of the relative positions of the rescue well and the accident well have a large error.

SUMMARY OF THE INVENTION

The embodiment of the present invention provides a method for measuring the distance of an offset well based on a magnetic field gradient, which is applied to a device for measuring the distance of an offset well based on a magnetic field gradient, so as to solve the problem of determining the relative relationship between an accident well and a rescue well in the prior art according to the magnitude of the current on the pipe string of the accident well. The location scheme, due to the inaccurate estimation of the current on the accident well tubing string, leads to a technical problem that the relative position error between the accident well and the rescue well is relatively large. The offset well distance measurement device includes: downhole magnetic field gradient measurement probe, downhole injection Electrode, surface electrode, surface interface box, computing equipment and power supply; the power supply is respectively connected with computing equipment, downhole injection electrode, surface electrode and downhole magnetic field gradient measurement probe through the surface interface box for power supply;

Among them, the surface electrode is set at the wellhead of the rescue well; the downhole injection electrode and the downhole magnetic field gradient measurement probe are connected by armored cables, and are lowered into the rescue well through the armored cables, and the downhole injection electrodes are used to inject alternating current into the surrounding formations , which makes the pipe string in the accident well adjacent to the rescue well generate a concentrated current; the downhole magnetic field gradient measurement probe is used to detect the alternating magnetic field signal generated around the pipe string in the accident well, and transmits it to the ground interface box through the armored cable, and the ground interface The box is transmitted to the computing device, and the computing device is used to determine the relative position of the rescue well and the accident well according to the alternating magnetic field signal;

Among them, the downhole magnetic field gradient measurement probe includes: stop plug, interface end plug, non-magnetic bearing cylinder, non-magnetic skeleton, inclination sensor, first three-axis fluxgate sensor, second three-axis fluxgate Sensors, drive coding circuit boards and data acquisition circuit boards;

The inclination sensor, the first three-axis fluxgate sensor, the second three-axis fluxgate sensor, the drive coding circuit board and the data acquisition circuit board are fixed on the non-magnetic skeleton; the inclination sensor, the first three-axis fluxgate sensor , The second three-axis fluxgate sensor, the drive coding circuit board, the data acquisition circuit board and the non-magnetic skeleton are arranged in the non-magnetic pressure cylinder; the first end of the non-magnetic pressure cylinder is connected with the end stop plug, and the non-magnetic The second end of the pressure-bearing cylinder is connected with the plug at the interface end;

The first three-axis fluxgate sensor and the second three-axis fluxgate sensor are arranged on the same transverse surface of the non-magnetic bearing cylinder at a preset distance, and are symmetrical with the central axis of the non-magnetic bearing cylinder, used for Detect the alternating magnetic field signal generated by the pipe string in the accident well and the three-axis magnetic induction signal generated by the geomagnetic field; wherein, the Z-axis of the first three-axis fluxgate sensor and the second three-axis fluxgate sensor and the non-magnetic bearing cylinder The central axes are parallel; the X-axis of the first three-axis fluxgate sensor and the second three-axis fluxgate sensor are collinear, and intersect with the central axis of the non-magnetic bearing pressure cylinder in the same direction;

The inclination sensor is arranged on the side of the non-magnetic skeleton near the end stop plug, and the X axis, Y axis and Z axis of the inclination sensor are the same as the first three-axis fluxgate sensor and the second three-axis fluxgate sensor. The X-axis, Y-axis and Z-axis are parallel and in the same direction, respectively, and are used to detect the inclination angle, azimuth angle, roll angle and temperature of the downhole magnetic field gradient measurement probe.

The method for measuring the distance from an offset well comprises: controlling a surface interface box to supply power to a downhole injection electrode in a rescue well, wherein the downhole injection electrode is used to inject alternating current into surrounding formations, so that a pipe string in an accident well generates a concentrated current; receiving a downhole magnetic field in the rescue well The alternating magnetic field signal detected by the gradient measurement probe; wherein, the alternating magnetic field signal is the alternating magnetic field signal generated around the pipe string in the accident well; according to the alternating magnetic field signal, the relative position of the rescue well and the accident well is determined;

Among them, according to the alternating magnetic field signal, the relative position of the rescue well and the accident well is determined, including: determining the radial distance between the rescue well and the accident well, and the distance between the high side of the rescue well and the X-axis of the inclination sensor through the following equations The included angle:

与第一三轴磁通门传感器或第二三轴磁通门传感器X轴之间的夹角；|B_1x|和|B_2x|分别为第一三轴磁通门传感器和第二三轴磁通门传感器检测到X轴向磁感应强度波形的振幅；|B_1y|和|B_2y|分别为第一三轴磁通门传感器和第二三轴磁通门传感器检测到Y轴向磁感应强度波形的振幅；|B_1z|和|B_2z|分别为第一三轴磁通门传感器和第二三轴磁通门传感器检测到Z轴向磁感应强度波形的振幅。Among them, r is the radial distance between the rescue well and the accident well; A _r1r2 is the angle formed by the first three-axis fluxgate sensor and the second three-axis fluxgate sensor in the rescue well and the accident well; A _hx is the rescue well The angle between the eye height side and the X-axis of the inclinometer sensor, that is, the roll angle detected by the inclinometer sensor; d is half of the distance between the first three-axis fluxgate sensor and the second three-axis fluxgate sensor 1; θ is the unit vector

The angle between the first three-axis fluxgate sensor or the X-axis of the second three-axis fluxgate sensor; |B _1x | and |B _2x | are the first three-axis fluxgate sensor and the second three-axis fluxgate sensor, respectively The fluxgate sensor detects the amplitude of the X-axis magnetic induction intensity waveform; |B _1y | and |B _2y | are the Y-axis magnetic induction intensity detected by the first three-axis fluxgate sensor and the second three-axis fluxgate sensor, respectively The amplitudes of the waveforms; |B _1z | and |B _2z | are the amplitudes of the Z-axis magnetic induction intensity waveforms detected by the first three-axis fluxgate sensor and the second three-axis fluxgate sensor, respectively.

The embodiment of the present invention also provides a computer device to solve the solution of the prior art scheme of determining the relative positions of the accident well and the rescue well according to the magnitude of the current on the accident well pipe string. Since the current estimation on the accident well pipe string is not accurate, the determination of The technical problem that the relative position error between the accident well and the rescue well is relatively large. The computer equipment includes a memory, a processor and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the above-mentioned magnetic field gradient-based The distance measurement method of the offset well.

The embodiment of the present invention also provides a computer-readable storage medium, which is used to solve the solution in the prior art that the relative position of the accident well and the rescue well is determined according to the magnitude of the current on the accident well tubing string. Since the current estimation on the accident well tubing string is inaccurate , resulting in a technical problem that the relative position error of the determined accident well and the rescue well is relatively large.

In the embodiment of the present invention, an alternating current is injected into the surrounding strata through the downhole injection electrode laid down in the rescue well, so that the pipe string in the accident well adjacent to the rescue well generates a concentrated current; The alternating magnetic field signal around the accident well pipe string is collected underground, and transmitted to the computing equipment on the ground through the cable and the surface interface box, so that the computing equipment can calculate the gradient of the magnetic field around the accident well pipe string according to the collected alternating magnetic field signal, and then determine The relative position of the rescue well and the accident well.

Through the embodiment of the present invention, the relative positions of the rescue well and the accident well are determined based on the distribution law of the magnetic field around the accident well pipe string. Since it is not necessary to estimate the magnitude of the current intensity on the accident well pipe string, the relative position of the rescue well and the accident well is improved. calculation accuracy. Since there are no tools or instruments in the accident well, it is convenient for on-site promotion and application.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts. In the attached image:

1 is a schematic diagram of a magnetic field gradient-based offset well distance measurement device provided in an embodiment of the present invention;

2 is a schematic diagram of a downhole magnetic field gradient measurement probe provided in an embodiment of the present invention;

3 is a flowchart of a method for measuring the distance of an offset well based on a magnetic field gradient provided in an embodiment of the present invention;

FIG. 4 is a schematic diagram of a calculation model for determining the relative positions of a rescue well and an accident well according to an embodiment of the present invention.

Reference number:

1. Accident well; 2. Rescue well; 3. Downhole magnetic field gradient measurement probe; 4. Downhole injection electrode; 5. Surface electrode; 6. Ground interface box; 7. Computing equipment; 8. Armored cable; 9. Interchange Variable current; 10. Upward accumulation current; 11. Downward accumulation current; 12. Alternating magnetic field; 31. Inclination sensor; 32. First three-axis fluxgate sensor; 33. Second three-axis fluxgate sensor.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention more clearly understood, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but not to limit the present invention.

An embodiment of the present invention provides a magnetic field gradient-based offset well distance measurement device. FIG. 1 is a schematic diagram of a magnetic field gradient-based offset well distance measurement device provided in an embodiment of the present invention. As shown in FIG. 1 , the device Including: downhole magnetic field gradient measurement probe 3, downhole injection electrode 4, surface electrode 5, surface interface box 6, computing device 7 and power supply (not shown in Figure 1); , the surface electrode and the downhole magnetic field gradient measurement probe are respectively connected to supply power to the computing equipment, the downhole injection electrode, the surface electrode and the downhole magnetic field gradient measurement probe.

Among them, the surface electrode 5 is arranged at the wellhead of the rescue well 2; the downhole injection electrode 4 and the downhole magnetic field gradient measurement probe 3 are connected by the armored cable 8, and are lowered into the rescue well 2 through the armored cable 8, and the downhole injection electrode 4 It is used to inject alternating current into the surrounding strata, so that the pipe string in the accident well 1 adjacent to the rescue well 2 generates a concentrated current; the downhole magnetic field gradient measurement probe 3 is used to detect the alternating magnetic field generated around the pipe string in the accident well 1 The signal is transmitted to the ground interface box 6 through the armored cable 8, and is transmitted from the ground interface box 6 to the computing device 7. The computing device 7 is used to determine the relative position of the rescue well and the accident well according to the alternating magnetic field signal.

It should be noted that the above computing device 7 may be any device with computing functions, including but not limited to smart devices such as computers, notebook computers, mobile phones, and tablet computers.

The working principle of the magnetic field gradient-based offset well distance measurement device provided by the embodiment of the present invention is as follows:

When the rescue well 2 is close to the accident well 1, the drilling tool in the rescue well 2 is taken out, and the downhole magnetic field gradient measurement probe 3 and the downhole injection electrode 4 connected by the cable 8 (for example, armored cable) are put into the rescue well 2 In the middle, the ground interface box 6 is connected with the downhole injection electrode 4 and the surface electrode 5 through the cable, the surface electrode 5 is arranged near the wellhead of the rescue well 2, and the ground interface box 6 is connected with the power supply (220V), which is used for the downhole magnetic field gradient measurement probe. Pipe 3 and downhole injection electrode 4 supply power, downhole injection electrode 4 injects alternating current 9 into the surrounding formation, and the pipe string in accident well 1 adjacent to rescue well 2 will generate accumulated current (upward accumulation current 10 and downward accumulation current 9). Current 11), so that an alternating magnetic field 12 is generated around the accident well 1 pipe string, and the downhole magnetic field gradient measurement probe 3 detects the alternating magnetic field signal, and transmits the detected signal to the ground through the cable and the ground interface box 6. A device 7 (eg, a computer), the computing device 7 determines the relative positions of the rescue well 2 and the accident well 1 according to the alternating magnetic field signal detected by the downhole magnetic field gradient measurement probe 3 .

In order to detect the magnetic field gradient around the pipe string in the accident well, and then determine the relative distance between the accident well and the rescue well according to the detected magnetic field gradient, the downhole magnetic field gradient measurement probe provided by the embodiment of the present invention may include: a stop plug, an interface end plug Head, non-magnetic bearing cylinder, non-magnetic skeleton, inclination sensor, first three-axis fluxgate sensor, second three-axis fluxgate sensor, drive coding circuit board and data acquisition circuit board;

Among them, the inclination sensor, the first three-axis fluxgate sensor, the second three-axis fluxgate sensor, the drive coding circuit board and the data acquisition circuit board are fixed on the non-magnetic skeleton; the inclination sensor, the first three-axis magnetic flux The door sensor, the second three-axis fluxgate sensor, the drive coding circuit board, the data acquisition circuit board and the non-magnetic skeleton are arranged in the non-magnetic pressure cylinder; the first end of the non-magnetic pressure cylinder is connected with the end stop plug, The second end of the non-magnetic pressure-bearing cylinder is connected with the interface end plug.

Optionally, the first three-axis fluxgate sensor and the second three-axis fluxgate sensor can be arranged at a preset distance on the same transverse surface of the non-magnetic bearing cylinder, and the center of the non-magnetic bearing cylinder can be arranged. Axisymmetric, wherein the Z-axis of the first three-axis fluxgate sensor and the second three-axis fluxgate sensor are parallel to the central axis of the non-magnetic bearing cylinder; the first three-axis fluxgate sensor and the second three-axis fluxgate sensor are The X-axis of the through door sensor is collinear and intersects with the central axis of the non-magnetic bearing cylinder in the same direction.

Further, the inclination sensor is arranged on the side of the non-magnetic skeleton close to the end stop plug, and the X-axis, Y-axis and Z-axis of the inclination sensor are connected with the first three-axis fluxgate sensor and the second three-axis magnetic flux. The X, Y and Z axes of the door sensor are parallel and in the same direction.

It should be noted that the above inclination sensor is used to detect the inclination angle, azimuth angle, roll angle and temperature of the downhole magnetic field gradient measurement probe; the first three-axis fluxgate sensor and the second three-axis fluxgate sensor It is used to detect the alternating magnetic field signal generated by the pipe string in the accident well and the three-axis magnetic induction signal generated by the geomagnetic field. It should be noted that the basic parameters such as inclination angle, azimuth angle and roll angle measured by the inclinometer sensor can be used to determine the downhole magnetic field gradient measurement probe's own attitude downhole, and provide data for later orientation. The temperature measurement by the inclinometer sensor can ensure that the downhole magnetic field gradient measurement probe works in the environment where the temperature allows.

For example, FIG. 2 is a schematic diagram of a downhole magnetic field gradient measurement probe provided in an embodiment of the present invention. As shown in FIG. 2 , the icon 31 shows the inclination sensor, and the icon 32 shows the first three-axis fluxgate sensor , the icon 33 shows the second three-axis fluxgate sensor, the end plug, the interface end plug, the non-magnetic bearing cylinder, the non-magnetic skeleton, the drive coding circuit board and the data acquisition circuit board are not shown in Figure 2 and other parts. The three axes of the inclinometer sensor 31 are parallel and in the same direction as those of the first three-axis fluxgate sensor 32 and the second three-axis fluxgate sensor 33; the first three-axis fluxgate sensor 32 and the second three-axis fluxgate The Z axis of the fluxgate sensor 33 is parallel to the central axis of the non-magnetic bearing cylinder, and the X axes of the first three-axis fluxgate sensor 32 and the second three-axis fluxgate sensor 33 are collinear and in the same direction as the non-magnetic bearing cylinder. The central axes of the pressure cylinders intersect. Since the first three-axis fluxgate sensor 32 and the second three-axis fluxgate sensor 33 are symmetrical with the central axis of the non-magnetic bearing cylinder, it is assumed that the first three-axis fluxgate sensor 32 and the second three-axis fluxgate sensor 33 The distance between 33 is 2d, then the distance from the center of the first three-axis fluxgate sensor 32 to the center axis of the non-magnetic bearing cylinder is d, and the center of the second three-axis fluxgate sensor 33 to the center of the non-magnetic bearing cylinder The distance of the axis is also d.

It should also be noted here that the first three-axis fluxgate sensor 32 and the second three-axis fluxgate sensor 33 in the downhole magnetic field gradient measurement probe 3 in the embodiment of the present invention both use high-precision sensors.

It can be seen from the above that the magnetic field gradient-based offset well distance measurement device provided by the embodiment of the present invention uses the downhole magnetic field gradient measurement probe to collect the crossover around the accident well pipe string in the rescue well according to the magnetic field distribution law around the adjacent accident well pipe string. Change the magnetic field signal, and transmit it to the ground computing equipment synchronously and in real time, calculate the gradient of the magnetic field around the accident well pipe string according to the alternating magnetic field signal, and then determine the relative position of the rescue well and the accident well. Since the embodiment of the present invention does not need to estimate the current magnitude of the accident well pipe string, it avoids the problem that the current intensity on the accident well pipe string cannot be accurately calculated, resulting in a large relative position error between the determined rescue well and the accident well. The magnetic field gradient-based offset well distance measuring device can determine the relative position data of the rescue well and the accident well, which can provide a scientific basis for the directional well engineer to control the drill bit for the next drilling.

It should be noted here that the embodiments of the present invention can be applied to but not limited to rescue wells, and can also be applied to the determination of relative positions of adjacent wells in cluster wells and dual horizontal well directional drilling projects.

The embodiment of the present invention also provides a method for measuring the distance of an offset well based on a magnetic field gradient, which can be applied to the above-mentioned device for measuring the distance of an offset well based on a magnetic field gradient, as described in the following embodiments. Since the principle of solving the problem in this embodiment of the method is similar to that of an offset well distance measurement device based on magnetic field gradient, the implementation of this embodiment of the method may refer to the implementation of the embodiment of the device, and repeated details will not be repeated.

FIG. 3 is a flowchart of a method for measuring the distance of an offset well based on a magnetic field gradient provided in an embodiment of the present invention. As shown in FIG. 3 , the method includes the following steps:

S301, controlling the surface interface box to supply power to the downhole injection electrode in the rescue well, wherein the downhole injection electrode is used to inject alternating current into the surrounding formation, so that the tubing string in the accident well generates a gathering current;

S302, receiving the alternating magnetic field signal detected by the downhole magnetic field gradient measuring probe in the rescue well; wherein, the alternating magnetic field signal is the alternating magnetic field signal generated around the pipe string in the accident well;

S303, according to the alternating magnetic field signal, determine the relative positions of the rescue well and the accident well.

It should be noted that the above-mentioned S301 causes the pipe string in the accident well to generate a gathering current including an upward gathering current and a downward gathering current; the following describes the principle of measuring the distance between adjacent wells based on the magnetic field gradient provided by the embodiment of the present invention with reference to FIG. 4 : When the downhole magnetic field gradient measurement probe 3 detects the well inclination angle, azimuth angle, roll angle and temperature at the downhole magnetic field gradient measurement probe through the inclination sensor 31, and through the first three-axis fluxgate sensor 32 and The second three-axis fluxgate sensor 33 detects the alternating magnetic field 12 generated by the current on the pipe string of the adjacent accident well 1 and the three-axis magnetic induction intensities B _1x , B _1y , B _1z , B _2x , B _2y and After B _2z , it is transmitted to the computing device 7 through the armored cable 8 and the ground interface box 6 to provide data for the computing device 7 to calculate the relative position of the rescue well 2 and the accident well 1 .

之间的夹角A_hr。在具体应用中，救援井到事故井的径向间距r，以及救援井井眼高边Hs与单位矢量

之间的夹角A_hr可以通过如下方程组计算得到：As shown in Figure 4, the relative position data of the rescue well and the accident well include: the radial distance r from the rescue well to the accident well, and the high side Hs of the rescue well and the unit vector

The included angle A _hr between them. In specific applications, the radial distance r from the rescue well to the accident well, as well as the high side Hs of the rescue well and the unit vector

The angle A _hr between can be calculated by the following equations:

与第一三轴磁通门传感器或第二三轴磁通门传感器X轴之间的夹角；|B_1x|和|B_2x|分别为第一三轴磁通门传感器和第二三轴磁通门传感器检测到X轴向磁感应强度波形的振幅；|B_1y|和|B_2y|分别为第一三轴磁通门传感器和第二三轴磁通门传感器检测到Y轴向磁感应强度波形的振幅；|B_1z|和|B_2z|分别为第一三轴磁通门传感器和第二三轴磁通门传感器检测到Z轴向磁感应强度波形的振幅。Among them, r is the radial distance between the rescue well and the accident well; A _r1r2 is the angle formed by the first three-axis fluxgate sensor and the second three-axis fluxgate sensor in the rescue well and the accident well; A _hx is the rescue well The angle between the eye height side and the X-axis of the inclinometer sensor, that is, the roll angle detected by the inclinometer sensor; d is half of the distance between the first three-axis fluxgate sensor and the second three-axis fluxgate sensor 1; θ is the unit vector

The angle between the first three-axis fluxgate sensor or the X-axis of the second three-axis fluxgate sensor; |B _1x | and |B _2x | are the first three-axis fluxgate sensor and the second three-axis fluxgate sensor, respectively The fluxgate sensor detects the amplitude of the X-axis magnetic induction intensity waveform; |B _1y | and |B _2y | are the Y-axis magnetic induction intensity detected by the first three-axis fluxgate sensor and the second three-axis fluxgate sensor, respectively The amplitudes of the waveforms; |B _1z | and |B _2z | are the amplitudes of the Z-axis magnetic induction intensity waveforms detected by the first three-axis fluxgate sensor and the second three-axis fluxgate sensor, respectively.

The embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and running on the processor, when the processor executes the computer program, the above-mentioned magnetic field gradient-based offset well distance measurement is implemented method.

Embodiments of the present invention further provide a computer-readable storage medium, where the computer-readable storage medium stores a computer program for executing the above method for measuring the distance between offset wells based on magnetic field gradients.

To sum up, the magnetic field gradient-based offset well distance measurement solution provided by the embodiment of the present invention can achieve the following technical effects: (1) Since it is not necessary to place any tools or instruments in the accident well during the operation, it is convenient for on-site popularization and application (2) Determine the relative position of the rescue well and the accident well based on the magnetic field gradient, without estimating the magnitude of the current intensity on the accident well pipe string, which improves the calculation accuracy of the relative position of the rescue well and the accident well; (3) Not only applicable to rescue The determination of the relative position of the well and the accident well can also be applied to the determination of the relative position of the adjacent wells in the directional drilling project of cluster wells and dual horizontal wells.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block in the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in a flow or flow of a flowchart and/or a block or blocks of a block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions The apparatus implements the functions specified in the flow or flows of the flowcharts and/or the block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in the flow or blocks of the flowcharts and/or the block or blocks of the block diagrams.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned specific embodiments are only specific embodiments of the present invention, and are not intended to limit the scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (3)

1. An adjacent well distance measuring method based on magnetic field gradient is characterized in that the method is applied to an adjacent well distance measuring device based on magnetic field gradient, and the adjacent well distance measuring device comprises: the system comprises an underground magnetic field gradient measurement probe, an underground injection electrode, a surface electrode, a ground interface box, computing equipment and a power supply; the power supply is respectively connected with the computing equipment, the underground injection electrode, the surface electrode and the underground magnetic field gradient measurement probe through a ground interface box and is used for supplying power;

the earth surface electrode is arranged at the wellhead of the relief well; the underground injection electrode is connected with the underground magnetic field gradient measurement probe tube through an armored cable and is placed in a relief well through the armored cable, and the underground injection electrode is used for injecting alternating current into surrounding strata so that a tubular column in the accident well adjacent to the relief well generates gathered current; the underground magnetic field gradient measurement probe is used for detecting an alternating magnetic field signal generated around a tubular column in the accident well, transmitting the alternating magnetic field signal to the ground interface box through an armored cable, and transmitting the alternating magnetic field signal to the computing equipment through the ground interface box, wherein the computing equipment is used for determining the relative position of the rescue well and the accident well according to the alternating magnetic field signal;

wherein the downhole magnetic field gradient measurement probe comprises: the sensor comprises a stop end plug, an interface end plug, a non-magnetic pressure bearing barrel, a non-magnetic framework, an inclination measuring sensor, a first triaxial fluxgate sensor, a second triaxial fluxgate sensor, a driving coding circuit board and a data acquisition circuit board;

the inclination measuring sensor, the first triaxial fluxgate sensor, the second triaxial fluxgate sensor, the driving coding circuit board and the data acquisition circuit board are fixed on the nonmagnetic framework; the inclination measuring sensor, the first triaxial fluxgate sensor, the second triaxial fluxgate sensor, the driving encoding circuit board, the data acquisition circuit board and the nonmagnetic framework are arranged in the nonmagnetic pressure bearing cylinder; the first end of the non-magnetic pressure bearing cylinder is connected with the stop end plug, and the second end of the non-magnetic pressure bearing cylinder is connected with the interface end plug;

the first triaxial fluxgate sensor and the second triaxial fluxgate sensor are arranged on the same cross-section plane of the nonmagnetic pressure bearing cylinder at a preset interval, are symmetrical about the central axis of the nonmagnetic pressure bearing cylinder, and are used for detecting an alternating magnetic field signal generated by a tubular column in the accident well and a triaxial magnetic induction signal generated by a geomagnetic field; the Z axis of the first triaxial fluxgate sensor and the Z axis of the second triaxial fluxgate sensor are parallel to the central axis of the nonmagnetic pressure bearing cylinder; the X axes of the first triaxial fluxgate sensor and the second triaxial fluxgate sensor are collinear and are intersected with the central axis of the nonmagnetic pressure bearing cylinder in the same direction;

the inclination measuring sensor is arranged on one side, close to the stop end plug, of the nonmagnetic framework, and an X axis, a Y axis and a Z axis of the inclination measuring sensor are respectively parallel and in the same direction as the X axis, the Y axis and the Z axis of the first triaxial fluxgate sensor and the second triaxial fluxgate sensor, and are used for detecting a well inclination angle, an azimuth angle, a roll angle and a temperature at the position of the underground magnetic field gradient measurement probe;

the adjacent well distance measuring method comprises the following steps:

controlling a ground interface box to supply power to an underground injection electrode in a rescue well, wherein the underground injection electrode is used for injecting alternating current into surrounding strata, so that a tubular column in an accident well generates an aggregation current;

receiving an alternating magnetic field signal detected by an underground magnetic field gradient measurement probe in a relief well; wherein the alternating magnetic field signal is an alternating magnetic field signal generated around a tubular column in the accident well;

determining the relative position of the rescue well and the accident well according to the alternating magnetic field signal;

wherein, according to the alternating magnetic field signal, confirm the relative position of relief well and accident well, include: determining the radial distance between the relief well and the accident well and the included angle between the high side of the relief well and the X axis of the inclination measuring sensor through the following equation sets:

wherein r is the radial distance between the rescue well and the accident well; a. the_r1r2An included angle formed by the first triaxial fluxgate sensor and the second triaxial fluxgate sensor in the rescue well and the accident well is formed; a. the_hxThe included angle between the high side of the rescue well borehole and the X axis of the inclination measuring sensor is the transverse roll angle detected by the inclination measuring sensor; d is one half of the distance between the first triaxial fluxgate sensor and the second triaxial fluxgate sensor; theta is a unit vector

An included angle between the first triaxial fluxgate sensor and the X axis of the second triaxial fluxgate sensor; i B_1xI and I B_2xI is the amplitude of the X-axis magnetic induction intensity waveform detected by the first triaxial fluxgate sensor and the second triaxial fluxgate sensor respectively; i B_1yI and I B_2yI is the amplitude of the Y-axis magnetic induction intensity waveform detected by the first triaxial fluxgate sensor and the second triaxial fluxgate sensor respectively; i B_1zI and I B_2zAnd l is the amplitude of the Z-axis magnetic induction intensity waveform detected by the first triaxial fluxgate sensor and the second triaxial fluxgate sensor respectively.

2. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor implements the magnetic field gradient-based adjacent well distance measurement method of claim 1 when executing the computer program.

3. A computer-readable storage medium storing a computer program for performing the magnetic field gradient-based adjacent well distance measurement method of claim 1.

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