A near-drill-bit geosteering drilling system

Abstract

The present invention discloses a near-drill-bit geological guidance drilling system, including a screw drill connected to a drill bit, a near-drill-bit measuring subsection integrated with the screw drill, a downhole receiving subsection, an MWD downhole subsection and a ground information processing system. The near-drill-bit measuring subsection obtains near-drill-bit geological parameter information and trajectory parameter information, and transmits the information to the downhole receiving subsection through a wired transmission method; the downhole receiving subsection forwards the received information to the MWD downhole subsection, and the MWD downhole subsection classifies and encodes the information to generate a regular mud pressure change signal. The ground information processing system collects the mud pressure change signal and processes the mud pressure change signal to display the corresponding information. The present invention integrates the near-drill-bit measuring subsection with the screw drill so that the screw drill can drill normally, and adopts a wired signal transmission method to improve the stability of information transmission.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas exploration, and in particular to a near-drill-bit geosteering drilling system. Background Art

[0002] Oil logging is an essential technical service component of drilling engineering in the process of oil and gas exploration and development. Conventional logging tools used for measurement belong to post-drilling measurement, which cannot effectively analyze and control the borehole trajectory in real time. With the demand for mining, engineering and technical personnel are required to understand the changes in borehole trajectory and formation information more timely and adjust their posture in time, which is of great significance for identifying thin oil layers and improving drilling efficiency. With the continuous development of downhole measurement technology, measurement while drilling (MWD) and logging while drilling (LWD) can meet the above needs. Measurement while drilling (MWD) can continuously perform directional drilling and measure some information near the drill bit, and transmit the information to the surface immediately; logging while drilling (LWD) can not only monitor directional drilling, but also perform comprehensive logging to obtain directional data (well inclination, azimuth, tool face angle), formation characteristics (gamma ray, resistivity logging records), drilling parameters, etc.

[0003] In the current measurement while drilling system and logging while drilling system, the collected information is sent to the downhole signal receiving system by wireless transmission. However, in some formations, the formation may shield the wireless signal, making the wireless signal transmission unstable. In addition, in the current measurement while drilling system and logging while drilling system, the near-bit measurement sub and the screw drill bit adopt a split design to adapt to different screw drill bits. However, when the split design is adopted, there is a risk that the near-bit measurement sub of the screw drill bit will be detached during the drilling process, affecting the drilling of the drill bit. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a near-drill-bit geosteering drilling system with stable signal transmission and normal drilling of a screw drill.

[0005] To achieve the above object, the present invention proposes the following technical solution: a near-bit geosteering drilling system, the system comprising

[0006] A screw drill, connected to the drill bit;

[0007] A near-drill-bit measuring sub is integrated with the screw drill tool and is used to obtain geological parameter information and trajectory parameter information near the drill bit and transmit the information to a downhole receiving sub;

[0008] The downhole receiving sub is connected to the screw drill and is connected to the near-bit measuring sub through a data transmission signal line, and is used to forward the received information to the MWD downhole sub.

[0009] An MWD downhole short section is connected to the downhole receiving short section and is used to classify and encode the information and generate a regular mud pressure change signal;

[0010] The ground information processing system is connected to the MWD downhole sub and is used to collect mud pressure change signals and process the mud pressure change signals to display corresponding information.

[0011] Preferably, the near-drill-bit measuring sub comprises a measuring sub drill collar body and a first sealing cover plate arranged on the measuring sub drill collar body, a first receiving space is formed between the first sealing cover plate and the measuring sub drill collar body, and a

[0012] Signal processing circuit module;

[0013] A communication interface module, connected to the signal processing circuit module, and connected to the downhole receiving short section via a data transmission signal line;

[0014] The first measurement module is connected to the signal processing circuit module and is used to obtain geological parameter information near the drill bit and trajectory parameter information.

[0015] Preferably, the first measurement module includes one or more of an azimuth gamma measurement module, a well deviation measurement module, and a resistivity measurement module.

[0016] Preferably, the downhole receiving pup joint comprises a receiving pup joint drill collar body and a second sealing cover plate provided on the measuring pup joint drill collar body, a second receiving space is formed between the second sealing cover plate and the measuring pup joint drill collar body, and a second receiving space is provided in the second receiving space.

[0017] Control unit module;

[0018] A second measurement module, connected to the control unit module, for obtaining geological parameter information near the drill bit;

[0019] The FSK sensing module is connected to the control unit module and the MWD downhole short section, and is used to send geological parameter information near the drill bit to the MWD downhole short section.

[0020] Preferably, the second measuring module comprises an annulus pressure measuring module for measuring annulus pressure.

[0021] Preferably, the MWD downhole sub comprises

[0022] Directional measurement probe tube short section, used to measure directional parameter information;

[0023] A pulse signal generator, used to generate a mud pressure change signal;

[0024] The probe control center is connected to the directional measurement probe short section and the pulse signal generator, and is used to receive and analyze the parameter information forwarded by the downhole receiving short section, classify and encode the effective data and the parameter information measured by the directional measurement probe short section to form a complete sequence, and control the pulse signal generator to generate a regular mud pressure signal, and send the mud pressure signal to the ground information processing system.

[0025] Preferably, the distance between the near-drill-bit measuring sub and the drill bit is less than or equal to 2 m.

[0026] Preferably, the distance between the near-drill-bit measuring sub and the drill bit is 1.5 m.

[0027] Preferably, the well inclination measurement module includes a first accelerometer for measuring the acceleration of the object in a first direction, a second accelerometer for measuring the acceleration of the object in a second direction, and a third accelerometer for measuring the acceleration of the object in a third direction, wherein the first direction, the second direction and the third direction are perpendicular to each other.

[0028] Preferably, one end of the downhole receiving short section is connected to the screw drill tool through a thread, and the opposite end is connected to the MWD downhole short section through a thread.

[0029] The beneficial effects of the present invention are:

[0030] (1) The near-drill-bit geosteering drilling system of the present invention, on the one hand, integrates the near-drill-bit measuring subsection with the screw drill bit to avoid the risk of detachment of the near-drill-bit measuring subsection, thereby improving the overall stability of the screw drill bit and allowing the screw drill bit to drill normally. On the other hand, data transmission signal lines are used instead of wireless signal transmission to improve the stability of information transmission, thereby making the near-drill-bit geosteering drilling system more applicable.

[0031] (2) The near-drill-bit geosteering drilling system described in the present invention can collect near-drill-bit geological parameters during rotary drilling, with the data measurement point close to the drill bit, and can implement azimuth gamma measurement function during rotation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the system structure block diagram of the present invention;

[0033] Figure 2 yes Figure 1 Schematic diagram of the structure of the mid-near drill bit measurement sub;

[0034] Figure 3 yes Figure 1 Schematic diagram of the structure of the receiving short section in the middle well;

[0035] Figure 4 yes Figure 1 Schematic diagram of the structure of the MWD downhole short section.

[0036] Figure numerals: 10, screw drilling tool, 20, near-drill bit measuring pup joint, 21, measuring pup joint drill collar body, 22, first sealing cover plate, 23, signal processing circuit module, 24, communication interface module, 25, azimuth gamma detection module, 26, well inclination measurement module, 27, resistivity measurement module and antenna, 30, downhole receiving pup joint, 31, receiving pup joint drill collar body, 32, second sealing cover plate, 33, control unit module, 34, FSK sensing module, 35, power supply module, 36, annulus pressure measurement module, 40, MWD downhole pup joint, 41, directional measurement probe pup joint, 42, pulse signal generator, 50, ground information processing system, 60, drill bit, 70, data transmission signal line. DETAILED DESCRIPTION

[0037] The technical solutions of the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention.

[0038] A near-drill-bit geological steering drilling system disclosed in the present invention integrates a near-drill-bit measuring pup section 20 with a screw drill tool 10 so that the screw drill tool 10 can drill normally. At the same time, a wired signal transmission method is used to transmit the information measured by the near-drill-bit measuring pup section 20 to a ground information processing system 50, thereby improving the stability of information transmission.

[0039] like Figure 1As shown, a near-drill-bit geological steering drilling system disclosed in the present invention includes a screw drill 10, a near-drill-bit measuring subsection 20, a downhole receiving subsection 30, an MWD downhole subsection 40 and a ground information processing system 50, wherein the screw drill 10 is connected to a drill bit 60 and is used to drive the drill bit 60 to work, and includes a motor assembly and a transmission assembly; the near-drill-bit measuring subsection 20 is integrated with the screw drill 10 and is used to obtain near-drill-bit geological parameter information and trajectory parameter information, and transmit the information to the downhole receiving subsection 30, such as the near-drill-bit measuring subsection 20 transmits the obtained formation information, wellbore trajectory, etc. to the downhole receiving subsection. The downhole receiving subsection 30 is connected to the screw drill 10 by a threaded manner, and the downhole receiving subsection 30 is connected to the near-bit measuring subsection 20 by a data transmission signal line 70, and is used to forward the received information to the MWD downhole subsection 40; the MWD downhole subsection 40 is connected to the downhole receiving subsection 30 by a threaded manner, and is used to classify and encode the information and generate a regular mud pressure change signal; the ground information processing system 50 is connected to the MWD downhole subsection 40, and is used to collect the mud pressure change signal, and demodulate, filter and decode the mud pressure change signal and display the corresponding information.

[0040] In this embodiment, the distance between the near-drill-bit measuring subsection 20 integrated in the screw drill 10 and the drill bit 60 is less than 2 meters. During implementation, the best distance between the near-drill-bit measuring subsection 20 and the drill bit 60 is 1.5 meters. Of course, in other embodiments, the distance between the near-drill-bit measuring subsection 20 and the drill bit 60 can be set according to actual needs.

[0041] like Figure 2 As shown, the near-bit measuring sub 20 includes a measuring sub drill collar body 21 and a first sealing cover plate 22. The measuring sub drill collar body 21 is provided with a mud channel a. The first sealing cover plate 22 is installed on the measuring sub drill collar body 21, and a first receiving space is formed between the first sealing cover plate 22 and the measuring sub drill collar body 21. The first receiving space is used to install various functional modules, so that each functional module is isolated from the external mud. A signal processing circuit module 23, a communication interface module 24 and a first measuring module are arranged in the first receiving space, wherein the communication interface module 24 is connected to the downhole receiving sub 30 through a data transmission signal line, and the communication interface module 24 is also connected to the signal processing circuit module 23, and the first measuring module is connected to the signal processing circuit module 23. When implemented, the first measuring module sends the various parameter information collected to the signal processing circuit module 23, and the information is uploaded to the downhole receiving sub 30 in real time through the communication interface module 24 after being processed by the signal processing circuit module 23. Compared with the prior art, the use of data transmission signal lines instead of wireless signal transmission can improve the stability of information transmission, making the application range of the near-drill-bit 60 geosteering drilling system wider.

[0042] Furthermore, the first measurement module includes but is not limited to an azimuth gamma detection module 25, a well inclination measurement module 26, a resistivity measurement module and an antenna 27. In other embodiments, corresponding measurement modules can be set according to actual needs. Among them, the well inclination measurement module 26 calculates the inclination by measuring the component of the actual gravity in the axial direction of the object. It includes a first accelerometer, a second accelerometer and a third accelerometer. The first accelerometer is used to measure the gravity acceleration Gx of the object in the first direction, the second accelerometer is used to measure the gravity acceleration Gy of the object in the second direction, and the third accelerometer is used to measure the gravity acceleration Gz of the object in the third direction. The first direction, the second direction and the third direction are perpendicular to each other. After obtaining the gravity acceleration of the object in the above three directions, the total gravity acceleration Gt, the inclination angle α and the high-side tool face angle β can be calculated by the following formula:

[0043]

[0044]

[0045]

[0046] In this embodiment, after the near-bit measurement pup section 20 collects the corresponding data through each measurement module, it converts and analyzes it, stores the effective data, and further extracts the data required on the ground. The signal processing circuit module 23 controls the data and transmits the data to the downhole receiving pup section 30 through the data transmission signal line.

[0047] like Figure 3 As shown, the downhole receiving pup joint 30 includes a receiving pup joint drill collar body 31 and a second sealing cover plate 32. The receiving pup joint drill collar body 31 is also provided with a mud channel a. The second sealing cover plate 32 is installed on the receiving pup joint drill collar body 31 and forms a second receiving space between the second sealing cover plate 32 and the receiving pup joint drill collar body 31. The second receiving space is used to install various functional modules to isolate each functional module from external mud. The second receiving space is provided with a control unit module 33, an FSK sensing module 34, a power module 35 and a second measuring module, wherein the second measuring module is connected to the control unit module 33, and the power module 35 is connected to the near-bit measuring subsection 20 and the control unit module 33. During implementation, the power module 35 outputs a DC power supply to provide power support for each module in the near-bit measuring subsection 20, such as the signal processing circuit module 23, the azimuth gamma detection module 25, the well inclination measurement module 26, etc. At the same time, the second measuring module converts and analyzes the corresponding data collected, stores the valid data, further extracts the data required on the ground and transmits it to the control unit module 33, and the control unit module 33 further transmits the data to the MWD downhole subsection 40 through the FSK sensing module 34.

[0048] In this embodiment, the control unit module 33 controls the data exchange between the modules and the function realization of each module through the CAN bus.

[0049] Furthermore, the second measurement module includes but is not limited to an annulus pressure measurement module 36, which can be selected according to actual needs during implementation.

[0050] like Figure 4 As shown, the MWD downhole sub 40 includes a directional measurement probe sub 41, a pulse signal generator 42 and a probe control center, wherein the directional measurement probe sub 41 is connected to the probe control center for measuring directional parameter information, such as well inclination, azimuth or tool face angle, etc., and sending the parameter information to the probe control center; the pulse signal generator 42 is connected to the probe control center for generating a mud pressure change signal. During implementation, the MWD downhole sub 40 receives the near-bit measurement parameter information transmitted by the downhole receiving sub 30 through the probe control center on the basis of completing conventional directional measurement through the directional measurement probe sub 41, that is, on the basis of completing the measurement of directional data, and further analyzes the near-bit measurement parameter information, classifies and codes the effective data and the data measured by itself to form a complete sequence, and controls the pulse signal generator 42 to generate a regular mud pressure signal, and the mud pressure signal is further transmitted to the ground information processing system 50. In this embodiment, the pulse signal generator 42 can be configured with different specifications and models according to actual needs.

[0051] The near-drill-bit 60 geological steering drilling system described in the present invention, on the one hand, improves the overall stability of the screw drill tool 10 by integrating the near-drill-bit measuring short section 20 with the screw drill tool 10, so that the screw drill tool 10 can drill normally; on the other hand, data transmission signal lines are used instead of wireless signal transmission to improve the stability of information transmission, thereby making the near-drill-bit geological steering drilling system more applicable.

[0052] In addition, the near-drill-bit geosteering drilling system of the present invention can collect near-drill-bit geological parameters during rotary drilling, with the data measurement point close to the drill bit, and can implement azimuth gamma measurement function during rotation.

[0053] The technical contents and technical features of the present invention have been disclosed as above. However, those skilled in the art may still make various substitutions and modifications based on the teachings and disclosures of the present invention without departing from the spirit of the present invention. Therefore, the protection scope of the present invention should not be limited to the contents disclosed in the embodiments, but should include various substitutions and modifications that do not depart from the present invention and are covered by the claims of this patent application.

Claims

1. A near-bit geosteering drilling system for oil and gas exploration, characterized in that: include: A screw drill, connected to the drill bit; The near-bit measuring sub is integrated with the screw drill and is used to obtain geological parameter information and trajectory parameter information near the bit and transmit the information to the receiving sub in the well. The downhole receiving sub is connected to the screw drill and is connected to the near-bit measuring sub through a data transmission signal line, and is used to forward the received information to the MWD downhole sub; The MWD downhole short section is connected to the downhole receiving short section and is used to classify and encode the information and generate regular mud pressure change signals; The ground information processing system is connected to the MWD downhole short section, and is used to collect mud pressure change signals and process the mud pressure change signals to display corresponding information; the near-drill-bit measuring short section includes a measuring short section drill collar body and a first sealing cover plate provided on the measuring short section drill collar body, a first receiving space is formed between the first sealing cover plate and the measuring short section drill collar body, and the first receiving space is provided with: Signal processing circuit module; A communication interface module is connected to the signal processing circuit module and is connected to the downhole receiving short section through a data transmission signal line; A first measurement module, connected to the signal processing circuit module, is used to obtain near-bit geological parameter information and trajectory parameter information; The downhole receiving pup joint includes a receiving pup joint drill collar body and a second sealing cover plate arranged on the measuring pup joint drill collar body, a second receiving space is formed between the second sealing cover plate and the measuring pup joint drill collar body, and the second receiving space is provided with: Control unit module; A second measurement module, connected to the control unit module, for obtaining geological parameter information near the drill bit; The FSK sensing module is connected to the control unit module and the MWD downhole short section and is used to send geological parameter information near the drill bit to the MWD downhole short section.

2. The system according to claim 1, characterized in that MWD downhole sub includes: Directional measurement probe tube short section, used to measure directional parameter information; A pulse signal generator, used to generate a mud pressure change signal; The probe control center is connected to the directional measurement probe short section and the pulse signal generator. It is used to receive and analyze the parameter information transmitted by the downhole receiving short section, classify and encode the effective data and the parameter information measured by the directional measurement probe short section to form a complete sequence, and control the pulse signal generator to generate a regular mud pressure signal, and send the mud pressure signal to the ground information processing system.

3. The system according to claim 1, characterized in that The first measurement module includes one or more of an azimuth gamma measurement module, a well deviation measurement module, and a resistivity measurement module.

4. The system according to claim 1, characterized in that The second measuring module comprises an annulus pressure measuring module, which is used for measuring the annulus pressure.

5. The system according to claim 1, characterized in that The distance between the near-bit measuring pup joint and the drill bit is less than or equal to 2m.

6. The system according to claim 5, characterized in that The distance between the near-drill-bit measuring pup section and the drill bit is 1.5 m.

7. The system according to claim 3, characterized in that The well inclination measurement module includes a first accelerometer for measuring the acceleration of an object in a first direction, a second accelerometer for measuring the acceleration of an object in a second direction, and a third accelerometer for measuring the acceleration of an object in a third direction, wherein the first direction, the second direction and the third direction are perpendicular to each other.

8. The system according to claim 1, characterized in that One end of the downhole receiving short section is connected to the screw drill tool through a thread, and the opposite end is connected to the MWD downhole short section through a thread.

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