An integrated near-bit measurement tool

Abstract

The application provides an integrated near-bit measuring tool, which comprises a wire-through screw body and a variable length short section arranged in sequence from bottom to top; the wire-through screw body is provided with a measuring short section; the measuring short section is provided with a near-bit measuring chamber, and a measuring module is installed in the chamber; the measuring module is connected to an MWD short section through a communication line via the variable length short section; the variable length short section comprises a core body, an outer tube, an adjustable short section, a locking short section, a hanging component and a communication assembly; the outer tube is fixed on the core body, the lower part of the core body is located in the outer tube, the upper end of the locking short section is connected to the outer tube, the hanging component is located at the lower end of the locking short section, and the adjustable short section is fixed on the core body; a spring seat is arranged between the upper end of the adjustable short section and the core body, and a limiting spring is arranged on the spring seat; an adjusting seat is arranged between the lower end of the adjustable short section and the locking short section, and a slip ring and a gasket are installed on the adjusting seat; and the communication assembly comprises the communication line. The application reduces the risk of drill tool fracture and improves the safety of drilling.

Description

Technical Field

[0001] This invention relates to the field of oil drilling engineering tools, specifically to an integrated near-bit measurement tool. Background Technology

[0002] In oil and gas drilling engineering, with the increasing demand for extraction, technicians need to understand changes in geological engineering information more promptly and adjust the wellbore trajectory in a timely manner. This is especially important for identifying thin oil layers and improving drilling efficiency.

[0003] Currently, traditional remote logging-while-drilling (ROD) gamma ray logging tools are typically located in the logging-while-drilling instrument string connected to the screw-driven drill string. However, actual drilling operations have revealed that the distance between the measurement points of the remote ROD gamma ray logging tool and the drill bit leads to a lag in measurement information. By the time a reservoir is discovered, the drill bit has often already drilled a considerable distance. Therefore, in geologically guided drilling of thin, laterally variable reservoirs, problems such as lag in trajectory adjustment and low reservoir encounter rates are encountered, especially in thin oil layers or reservoirs with high trajectory requirements. This results in a low reservoir encounter rate, as adjusting the wellbore trajectory back into the reservoir after it has penetrated the formation is very difficult and can no longer meet the requirements for precise wellbore trajectory control and geological guidance. At the same time, the large bend distance of conventional screw-driven drills leads to a low build-up rate in sliding drilling; the long distance of the centralizer leads to a low composite stabilization and build-up rate.

[0004] To address these issues, near-bit logging-while-drilling (LWD) systems have emerged. These systems can effectively and quickly calculate and retrieve inverted geological parameters during drilling, accurately reflect bottom-hole conditions in real time, precisely identify the upper and lower boundaries of oil-bearing formations, and guide field engineers to optimize drilling trajectories in a timely manner, thereby improving the encounter rate of high-quality reservoirs. However, in production applications, they have revealed low measurement stability under high-speed and high-vibration environments of the power drill bit drive. Furthermore, in acquiring formation information such as resistivity and neutron density, the LWD system relies on MWD communication to upload data to the surface; therefore, a stable mechanical connection between the two is crucial. Existing conventional connection devices used between logging-while-drilling (MWD) tools and the MWD typically have several problems: Most existing connection devices employ a dynamic seal structure, where a movable outer cylinder engages with a telescopic rod, and a dynamic seal ring is installed internally. Under the influence of high-frequency vibrations downhole, the telescopic rod moves back and forth within a small range relative to the dynamic seal ring, easily damaging it. Over prolonged operation, this can lead to drilling fluid leakage due to high-pressure seal failure. Furthermore, the dimensional adjustments of existing connection devices are often spaced at intervals of only a few millimeters, requiring custom-made lengths for non-magnetic drill collars and non-magnetic suspensions. This results in limited flexibility in handling special situations such as drill string repair and instrument replacement. Therefore, providing an integrated near-bit measurement tool is of significant importance.

[0005] Chinese patent application number CN201420734804.X, entitled "Near-bit MWD Inclinometer", discloses a near-bit MWD inclinometer, which consists of a ground information processing device, a near-bit measuring sub, a near-bit receiving sub, and an MWD receiving sub. The MWD receiving sub is installed in the MWD inclinometer system, and its magnetic signal conversion device is located within the magnetic induction transmitting coil of the near-bit receiving sub. The MWD inclinometer is located at the upper end of the near-bit MWD inclinometer. The near-bit measuring sub is threaded between the drill bit and the screw. The near-bit receiving sub is threaded between the screw and the non-magnetic drill collar. The near-bit measuring sub and the near-bit receiving sub communicate wirelessly across a small gap in the screw, transmitting data through the drilling mud to the near-bit receiving sub. The near-bit receiving sub uses a wireless communication method that penetrates the metal wall, transmitting the parameter data measured by the near-bit measuring sub and its own measured parameter data to the MWD receiving sub. Finally, the real-time drilling parameter data required by the MWD inclinometer is sent to the surface information processing equipment. However, this instrument has a different structure than that of this application, its wireless communication stability is low, and it does not improve the stability of the connection between the measuring tools and the MWD. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to solve one or more problems existing in the prior art. For example, one objective of this invention is to provide an integrated near-bit measurement tool that ensures the applicability and stability of the docking structure between the measurement device (through-wire screw body) and the MWD, thereby improving drilling safety.

[0007] To achieve the above objectives, the present invention provides an integrated near-bit measurement tool, which may include a lead-through screw body and a variable extension sub arranged sequentially from bottom to top; wherein, the lead-through screw body contains a measurement sub located at the lower part of the tool; the measurement sub contains a near-bit measurement chamber, in which a measurement module is installed, configured to acquire near-bit wellbore inclination azimuth and gamma parameter information; the measurement module transmits information to the MWD sub via a communication line led out through the variable extension sub; the variable extension sub includes a core, an outer cylinder, an adjustable sub, a locking sub, a connector, and a communication component, the outer cylinder being threadedly fixed to the core, the core... The lower part of the body is located inside the outer cylinder. The upper end of the locking short section is threadedly fixed to the outer cylinder. The hanger is sealed and fixed to the lower end of the locking short section. The adjustable short section is threadedly fixed to the core body, and the adjustable short section can move up and down along the axial direction of the core body under force. The upper end of the adjustable short section is located between the outer cylinder and the core body, and the lower end is located inside the locking short section. A spring seat is provided between the upper end of the adjustable short section and the core body, and a limit spring is coaxially installed on the spring seat. An adjustment seat is provided between the lower end of the adjustable short section and the locking short section, and a slip ring and a washer for limiting the axial displacement of the adjustable short section are coaxially installed on the adjustment seat. The communication components are sealed and fixed inside the core body, the adjustable short section, the locking short section, and the hanger, and the communication components include a communication line.

[0008] According to one or more exemplary embodiments of one aspect of the present invention, the measurement module may include a gamma measurement module, a well deviation measurement module, and a central control circuit module; the measurement sub is provided with a plurality of circumferentially arranged near-bit measurement chambers, and different measurement modules are installed in different near-bit measurement chambers.

[0009] According to one or more exemplary embodiments of one aspect of the present invention, the lower middle part of the adjustable short section may be provided with a first inner boss, and the core is located above the first inner boss; the middle part of the locking short section may be provided with a second inner boss, and the adjustable short section and the hook member are respectively located at the upper end and the lower end of the second inner boss.

[0010] According to one or more exemplary embodiments of one aspect of the present invention, a triple sealing structure may be provided between the locking short section and the hanger. The first sealing structure is achieved by a fourth sealing ring and a high-pressure retaining ring fixedly disposed between the locking short section and the hanger. The second sealing structure is achieved by a sloping sealing surface that presses against each other between the locking short section and the hanger. The third sealing structure includes a shaped sealing sleeve fixed on the second inner boss and an arc apex disposed on the upper end of the hanger. The third sealing structure is achieved by the arc apex pressing against the shaped sealing sleeve.

[0011] According to one or more exemplary embodiments of one aspect of the present invention, the communication component may further include a multi-core conversion assembly, a plug-in assembly, and a multi-core socket. The multi-core conversion assembly is fixed to the upper end of the core body, the multi-core socket is fixed to the upper part of the hanger, the plug-in assembly is located in the adjustable short section and abuts between the first inner boss and the second inner boss, and the communication line is connected to the multi-core conversion assembly and the plug-in assembly respectively.

[0012] According to one or more exemplary embodiments of one aspect of the present invention, the multi-core conversion assembly may include an upper adapter, an aviation plug, a fixing screw, a lower adapter, a first sealing ring, and a high-pressure sealing plug. The upper adapter includes a mounting portion, a threaded connection section, and a sealing groove, which are successively reduced in inner diameter from top to bottom. The upper adapter is fixed to the core body through the threaded connection section, the first sealing ring is fixed in the sealing groove, the mounting portion is located outside the core body, and a threaded hole is provided on the mounting portion. The aviation plug is fixed to the mounting portion through the fixing screw and the threaded hole. The lower adapter is threadedly fixed to the lower end of the upper adapter, the high-pressure sealing plug is fixed between the upper adapter and the lower adapter, and the upper end of the communication line enters the upper adapter through the lower adapter and connects to the aviation plug.

[0013] According to one or more exemplary embodiments of one aspect of the present invention, the core may be provided with a first inner step for axially limiting the lower adapter, and the hook member may be provided with a second inner step for axially limiting the multi-core socket.

[0014] According to one or more exemplary embodiments of one aspect of the present invention, the plug-in assembly may include a plug sleeve, a compression spring, a limiting ring, a fixing cap, and a multi-core plug for connection with a multi-core socket. The upper part of the plug sleeve is provided with an upper positioning ring platform and a middle positioning ring platform. The upper positioning ring platform abuts against the first inner boss. The compression spring is sleeved on the plug sleeve and located between the first inner boss and the middle positioning ring platform. The limiting ring is threadedly fixed to the lower part of the plug sleeve. The multi-core plug is fixed to the lower end of the plug sleeve by the limiting ring. The fixing cap is threadedly fixed to the lower end of the adjustable short section for axial limiting of the limiting ring. The lower end of the communication line passes through the plug sleeve and is connected to the multi-core plug.

[0015] According to one or more exemplary embodiments of one aspect of the present invention, a positioning block may be fixed between the first inner boss and the core, the inner diameter of the positioning block being smaller than the inner diameter of the first inner boss, and the positioning block abutting against the upper positioning ring platform.

[0016] According to one or more exemplary embodiments of one aspect of the present invention, the core body may be provided with a short threaded section, a sealing section and a long threaded section in sequence from the middle downward along its surface, the outer cylinder is fixed to the core body through the short threaded section, the adjustable short section is fixed to the core body through the long threaded section, and a second sealing ring is fixed between the outer cylinder and the core body through the sealing section.

[0017] According to one or more exemplary embodiments of one aspect of the present invention, a third sealing ring may be provided between the locking section and the adjustable section, and the third sealing ring is located above the adjusting seat.

[0018] According to one or more exemplary embodiments of one aspect of the present invention, the MWD subsection may include a directional probe, a power module, and a drilling fluid pulser arranged sequentially from bottom to top; the power module supplies power to the drilling fluid pulser, the directional probe, and the measurement module in the near-bit measurement chamber.

[0019] According to one or more exemplary embodiments of one aspect of the present invention, the upper end of the core may be threadedly fixed with a mating short section for connection with a directional probe; a sleeve centralizer is fixed on the mating short section.

[0020] According to one or more exemplary embodiments of one aspect of the present invention, the upper part of the adjustable short section may be provided with an upper step by reducing the outer diameter, and the lower part may be provided with a lower step by reducing the outer diameter; the spring seat may be formed by the upper step cooperating with an external step pre-formed on the core, and the adjusting seat may be formed by the lower step cooperating with an internal step pre-formed on the locking short section.

[0021] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0022] (1) It can solve the problems in the existing technology, such as the long distance between the remote gamma logging tool and the drill bit and the unstable wireless transmission of the near-drill bit measurement system.

[0023] (2) By integrating the near-bit measurement sub with the screw drill bit, the lower end of this tool can be connected to the drill bit. Through wired connection, it integrates the dual functions of power drilling and near-bit measurement, which can effectively reduce the risk of drill bit breakage, improve drilling safety, and provide reliable technical support for precise wellbore trajectory control and geological guidance.

[0024] (3) It can solve the technical problems of large size matching of existing conventional connection devices, small adjustment range and easy high pressure sealing failure, improve the stability and operability of the connection structure between logging-while-drilling tools and MWD, reduce the failure rate of instrument strings, and is applicable to power supply and communication of different types of directional probes. It has a wide range of applications, direct docking at the wellhead, and better meets the needs of field operations. Attached Figure Description

[0025] The above and other objects and features of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0026] Figure 1 A schematic diagram of the integrated near-drill bit measurement tool is shown.

[0027] Figure 2A schematic diagram of the lead screw body of the integrated near-drill bit measuring tool is shown;

[0028] Figure 3 A schematic cross-sectional view of the measurement section of an integrated near-drill bit measurement tool is shown.

[0029] Figure 4 A schematic diagram of the azimuth gamma sector division model is shown;

[0030] Figure 5 A schematic diagram of the overall structure of the variable extension section is shown;

[0031] Figure 6 A schematic diagram of the cross-sectional structure of the variable extension section is shown;

[0032] Figure 7 A cross-sectional structural diagram of the docking position between the connector and the locking section is shown;

[0033] Figure 8 A schematic diagram of the cross-sectional structure of the core is shown;

[0034] Figure 9 A schematic cross-sectional view of the adjustable short section is shown.

[0035] Figure 10 A cross-sectional structural diagram of the upper adapter is shown;

[0036] Figure 11 A cross-sectional structural diagram of the connector sleeve is shown.

[0037] Explanation of key figure labels:

[0038] 1-Drill bit, 2-Wire-guided screw body, 201-Drive shaft assembly, 202-Adjustable bend angle, 203-Universal shaft assembly, 204-Measuring sub, 205-Measuring chamber near drill bit, 206-Wire-guided hole between measuring chambers, 207-Wire-guided hole in body, 208-Wire-guided screw body housing, 209-Communication interface module, 210-Measuring module, 211-Sealing cover plate, 212-Cavity space, 3-Non-magnetic drill collar, 301-Variable extension sub, 3011- Matching short section, 3012-Sleeve centralizer, 3013-Core body, 3014-Outer cylinder, 3015-Locking short section, 3016-Hanging tool, 3017-Hanging piece, 3018-Aviation plug, 3019-Fixing screw, 30110-Upper adapter, 30111-High pressure sealing plug, 30112-First inner step, 30113-Second sealing ring, 30114-Limit spring, 30115-Communication line, 30116-Adjustable short section, 301 17-Third sealing ring, 30118-Washer, 30119-Slip ring, 30120-Lower adapter, 30121-First sealing ring, 30122-Threaded hole, 30123-Threaded connection section, 30124-Sealing groove, 30125-Long threaded section, 30126-Second inner step, 30127-Spring seat, 30128-Adjusting seat, 30129-Internal thread, 30130-Compression spring, 30131-Fixing gland, 30132- 30133 - Arc apex, 30134 - Fourth sealing ring, 30135 - High-pressure retaining ring, 30136 - Sloping sealing surface, 30137 - Multi-core socket, 30138 - Multi-core plug, 30139 - Second inner boss, 30140 - Limiting ring, 30141 - Connecting sleeve, 30142 - First inner boss, 30143 - Positioning block; 302 - Directional probe, 303 - Power module, 304 - Drilling fluid pulser, 4 - Non-magnetic suspension sub. Detailed Implementation

[0039] In the following, an integrated near-bit measurement tool of the present invention will be described in detail with reference to the accompanying drawings and exemplary embodiments.

[0040] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "positive," and "negative," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," "third," "fourth," etc., are used only for the convenience of description and distinction, and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," "third," "fourth," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" or "several" means two or more. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] Exemplary Example 1

[0042] This exemplary embodiment provides an integrated near-bit measurement tool.

[0043] The following is combined Figures 1 to 11 This describes an integrated near-bit measurement tool for this exemplary embodiment.

[0044] It should be noted that the top-to-bottom direction described in the instruction manual is... Figures 5-11 The direction from left to right in the middle.

[0045] like Figures 1-11 As shown, the integrated near-drill bit measuring tool mainly includes: a wire-type screw body 2 and a variable extension sub 301 arranged sequentially from bottom to top.

[0046] The lead screw body 2 is equipped with a measuring section 204, which is located at the bottom of the tool. The measuring section 204 is equipped with a near-bit measuring chamber 205, which contains a chamber space 212. A measuring module 210 is installed in the chamber space 212. The measuring module 210 is configured to collect near-bit well inclination azimuth and gamma parameter information. The measuring module 210 is connected to the MWD section via a communication line 30115 (cable) and a variable extension section 301. The measuring module 210 transmits information to the MWD section.

[0047] The variable extension section 301 includes a core 3013, an outer cylinder 3014, an adjustable section 30116, a locking section 3015, a connector 3017, and a communication component. The outer cylinder 3014 is fixedly sleeved onto the core 3013 via a threaded connection structure. The length of the outer cylinder 3014 is less than the length of the core 3013, with the lower end of the outer cylinder 3014 located above the lower end of the core 3013, and the lower part of the core 3013 situated inside the outer cylinder 3014. The upper end of the locking section 3015 is threadedly fixed to the outer cylinder 3014, and the connector 3017 is sealed and fixed to the lower end of the locking section 3015. The adjustable section 30116 is threadedly fixed to the core 3013, and when subjected to rotational force, the adjustable section 30116 can move up and down along the axial direction of the core 3013, thereby achieving millimeter-level adjustment of the mating length. The upper end of the adjustable short section 30116 is located between the outer cylinder 3014 and the core 3013, and the lower end is located inside the locking short section 3015. A spring seat 30127 is provided between the upper end of the adjustable short section 30116 and the core 3013. A limit spring 30114 is coaxially installed on the spring seat 30127. When the adjustable short section 30116 changes position on the core 3013, the limit spring 30114 plays the role of axially supporting the adjustable short section 30116. An adjusting seat 30128 is provided between the lower end of the adjustable short section 30116 and the locking short section 3015. A slip ring 30119 and a washer 30118 for limiting the axial displacement of the adjustable short section 30116 are coaxially mounted on the adjusting seat 30128. The communication component is sealed and fixed in the core 3013, the adjustable short section 30116, the locking short section 3015 and the hanger 3017 respectively. The communication component includes a communication line 30115.

[0048] In this exemplary embodiment, the near-bit measurement chamber 205 can be formed by a measuring sub 204 housing and a sealing cover 211 disposed in the measuring sub 204; the chamber space 212 in the near-bit measurement chamber 205 is isolated from the drilling mud.

[0049] In this exemplary embodiment, the measuring section housing may be made of non-magnetic stainless steel.

[0050] In this exemplary embodiment, the measurement module may include functional measurement modules such as a gamma measurement module, a wellbore inclination measurement module, and a central control circuit module, capable of acquiring various parameter information such as near-bit wellbore inclination azimuth and gamma. The measurement sub may have several circumferentially evenly distributed near-bit measurement chambers. Different measurement modules are installed in different near-bit measurement chambers. If the number of near-bit measurement chambers exceeds the number of measurement modules, the remaining chamber space can be used as a spare. A certain measurement module can be repeatedly installed in the extra chambers, or other functional measurement modules can be added, such as measuring annular pressure, vibration, and resistivity. For example, the measurement sub may have four circumferentially evenly distributed near-bit measurement chambers, providing four chamber spaces. Three of these chamber spaces may house the gamma measurement module, the wellbore inclination measurement module, and the central control circuit module, respectively, while the fourth chamber space may house a second gamma measurement module.

[0051] Furthermore, the well inclination measurement module in the measurement section can measure the near-bit well inclination azimuth, which can have two functions: first, to provide data support for the division of gamma measurement sectors; and second, to measure and upload the near-bit data, which can be used as a reference with the far-bit well inclination azimuth measured by the directional probe in the MWD section. It is generally believed that the near-bit data is more timely than the far-bit data, but the error is larger.

[0052] Specifically, the measurement module, including the gamma measurement module, well inclination measurement module, and central control circuit module, can include the following functions: ① Gamma Measurement Module: Measures the natural radioactivity of the formation at different depths during drilling, obtaining the differences in natural gamma radioactivity intensity in different formations, which can guide the drilling direction. While drilling, natural gamma logging can also determine changes in formation lithology, estimate the location of clay layers and mud content, indicate the depositional environment, help determine pore pressure, and determine drill bit wear based on changes in lithology and drilling time. ② Well Inclination Measurement Module: Measures the well inclination angle and azimuth angle using gravity and magnetic sensors. Through a dynamic algorithm, the wellbore can be divided into four equal sectors (up, down, left, and right), and gamma data in each sector can be measured in real time. The measured gamma data can be distinguished by its corresponding azimuth, allowing for better judgment of formation conditions in each direction. ③ Central Control Circuit Module: Sends commands to the gamma measurement module and well inclination measurement module and stores the collected data.

[0053] In this exemplary embodiment, the gamma measurement module may include a gamma sensor and a gamma detector. Using this invention, a gravity sensor (which is part of the wellbore inclination measurement module) can be used to divide the wellbore perimeter into several sectors, for example, four sectors (90°). Figure 4The process involves collecting corresponding gamma data within each sector for filling; during screw rotation, the gamma sensor scans circumferentially and measures the gamma data in each sector in real time to complete the azimuth gamma measurement. The magnetic toolface (MTF) can be used as the toolface angle of the downhole drilling tool, i.e., the magnetic north pole direction is selected as the reference point for calculating the toolface. During rotation, the two-dimensional magnetic toolface angle value is first measured, and then, based on the angle difference between the magnetic coordinate system and the gravity coordinate system, a more accurate two-dimensional gravity toolface angle value is indirectly calculated, thereby determining the sector information. Since tool movement (i.e., vibration, impact, and rotation conditions) cannot affect the magnetic field state, this completely avoids the error caused by movement in calculating the toolface angle.

[0054] Furthermore, the gamma detector can use a high-sensitivity NaI(Tl) crystal with a size of 27mm×411mm, a measurement range of 0-2500API, a gamma measurement error of <5% at 150℃, and a gamma measurement error of <10% at 175℃.

[0055] In this exemplary embodiment, the measurement module can be fixed in the chamber space by means of vibration damping pads, silicone suspension fixation of the accelerometer, and potting encapsulation of the circuit board.

[0056] In this exemplary embodiment, a measuring chamber 205 near the drill bit is provided with a measuring chamber through hole 206. The measuring modules 210 in several chamber spaces 212 are interconnected by communication lines 30115 passing through the measuring chamber through hole 206. The communication lines 30115 led out from multiple measuring modules 210 converge, extend upward along the through-hole screw body housing 208 through the body through hole 207, and converge to the communication interface module 209. The communication lines 30115 are connected to the MWD section above the communication interface module 209 via the variable extension section 301.

[0057] Furthermore, the communication interface module serves as a communication line aggregation interface; it can employ an RS485 interface and connect to the measurement sub-section via a four-core shielded twisted-pair cable. The central control circuit module can utilize a DSP chip.

[0058] In this exemplary embodiment, the MWD section may include a drilling fluid pulser 304, a power module 303, and a directional probe 302; the directional probe 302 can measure the far-end wellbore inclination azimuth, providing supplementary parameters for the lower near-bit wellbore inclination azimuth measurement. The lower end of the drilling fluid pulser 304 is connected to the power module 303, and the power module 303 is connected to the directional probe 302.

[0059] Furthermore, the power module may include two or three lithium batteries to power the drilling fluid pulser, directional probe, and various measurement modules in the near-bit measurement chamber of the MWD sub. The drilling fluid pulser can generate mud pulses through mechanical actuation and transmit measurement parameter information from the MWD sub and the near-bit measurement chamber to the surface.

[0060] In this exemplary embodiment, the upper end of the core 3013 is threadedly fixed with a mating short section 3011 for connecting with the directional probe 302; a sleeve centralizer 3012 is fixed on the mating short section 3011 to achieve centering and alignment, and to effectively prevent damage to the docking part due to high vibration when the tool length is too long.

[0061] In this exemplary embodiment, the tool of the present invention has a hollow structure, comprising a mating section 3011, a core 3013, an outer cylinder 3014, an adjustable section 30116, a locking section 3015, and a mounting piece 3017. The mating section 3011, core 3013, outer cylinder 3014, locking section 3015, and mounting piece 3017 are sequentially and fixedly connected. The mating section 3011, core 3013, outer cylinder 3014, and locking section 3015 are all located inside the non-magnetic drill collar 3. The upper end of the mating section 3011 is fixedly connected to the directional probe 302 by a thread, and the lower end of the locking section 3015 is threadedly connected to the mounting tool 3016. The lower part of the mounting piece 3017 is located inside the mounting tool 3016 and is used to mount the lower end lead screw body 2.

[0062] In this exemplary embodiment, depending on the actual working conditions, the mating short section can be provided with different series and different lengths, such as 280mm, 300mm, 310mm, etc., and the locking short section can also be provided with different series and different lengths, such as 45mm, 50mm, 55mm, etc., so as to achieve precise adjustment of the overall length of the instrument string.

[0063] In this exemplary embodiment, the number of slip rings can be one, and the number of washers can be multiple. Different specifications of slip rings and different numbers of washers can be configured according to actual working conditions to facilitate axial locking of the adjustable short section after adjustment.

[0064] In this exemplary embodiment, the core 3013 has a short threaded section, a sealing section, and a long threaded section 30125 sequentially arranged from the middle downwards along its surface. The outer diameter of the short threaded section is smaller than the outer diameter of the upper part of the core 3013, the outer diameter of the sealing section is slightly smaller than the outer diameter of the short threaded section, and the outer diameter of the long threaded section 30125 is smaller than the outer diameter of the sealing section. The upper end of the outer cylinder 3014 is fixed to the core 3013 via the short threaded section. The adjustable short section 30116 has an internal thread 30129 that matches the long threaded section 30125, and the adjustable short section 30116 is fixed to the core 3013 via the long threaded section 30125 and the internal thread 30129. The outer diameter of the outer cylinder 3014 is the same as the outer diameter of the upper part of the core 3013, and the inner diameter of the outer cylinder 3014 is adapted to the outer diameter of the adjustable short section 30116; a sealing groove is provided on the sealing section, and a second sealing ring 30113 is fixed in the sealing groove. The outer cylinder 3014 and the core 3013 are sealed by the second sealing ring 30113 on the sealing section.

[0065] In this exemplary embodiment, the upper part of the adjustable short section 30116 has an upper step provided by reducing its outer diameter, and the lower part has a lower step provided by reducing its outer diameter. Correspondingly, the core 3013 has an external step pre-formed on it, which is the step between the sealing section and the long threaded section 30125 on the core 3013. The locking short section 3015 has an internal step pre-formed on it. The spring seat 30127 is formed by the cooperation of the upper step and the external step, and the adjusting seat 30128 is formed by the cooperation of the lower step and the internal step. The limiting spring 30114 is sleeved on the upper part of the adjustable short section 30116, and its two ends abut against the upper step and the external step of the core 3013, respectively. The slip ring 30119 and the washer 30118 are both sleeved on the lower part of the adjustable short section 30116, and the slip ring 30119 and the washer 30118 abut against the lower step and the internal step of the locking short section 3015, respectively.

[0066] In this exemplary embodiment, the lower middle portion of the adjustable short section 30116 may be provided with a first inner boss 30142, and the core 3013 is located above the first inner boss 30142. The first inner boss 30142 can be used to support the plug-in assembly. The middle portion of the locking short section 3015 may be provided with a second inner boss 30139, the adjustable short section 30116 is located at the upper end of the second inner boss 30139, and the hook member 3017 is located at the lower end of the second inner boss 30139.

[0067] In this exemplary embodiment, a third sealing ring 30117 is provided between the locking short section 3015 and the adjustable short section 30116, and the third sealing ring 30117 is located above the adjusting seat 30128. The locking short section 3015 and the adjustable short section 30116 are sealed by the third sealing ring 30117 to ensure the sealing performance at the connection between the two.

[0068] In this exemplary embodiment, a triple sealing structure is provided between the locking section 3015 and the hook member 3017.

[0069] The first sealing structure is achieved through the cooperation of the fourth sealing ring 30134 and the high-pressure retaining ring 30135. The second sealing structure is located below the first sealing structure and includes a sloping sealing surface 30136 formed inside the lower end of the locking short section 3015 and a corresponding sloping sealing surface 30136 formed on the outer surface of the hanger 3017. When the upper end of the hanger 3017 is fixed inside the locking short section 3015, the sloping sealing surfaces 30136 between the locking short section 3015 and the hanger 3017 are pressed into contact with each other. Based on this, the second sealing structure is achieved through the sloping sealing surfaces 30136 that are pressed into contact with each other. The third sealing structure includes a shaped sealing sleeve 30132 fixed on the second inner boss 30139 and an arc-shaped apex 30133 located on the upper end of the connector 3017. The arc-shaped apex 30133 is formed by making the upper end of the connector 3017 into an arc shape. The third sealing structure is achieved by the arc-shaped apex 30133 pressing against the shaped sealing sleeve 30132. With the cooperation of this triple sealing structure, the reliability of the high-pressure seal after the connector 3016 and the MWD short section are connected can be greatly improved, ensuring the long-term stable operation of the MWD short section.

[0070] In this exemplary embodiment, the communication component includes a multi-core conversion assembly, a plug-in assembly, a multi-core socket 30137, and a communication line 30115; the multi-core conversion assembly is sealed and fixed to the upper end of the core 3013, the multi-core socket 30137 is fixed to the upper part of the hanger 3017, the plug-in assembly is located inside the adjustable short section 30116 and abuts between the first inner boss 30142 and the second inner boss 30139, and the communication line 30115 is electrically connected to the multi-core conversion assembly and the plug-in assembly respectively.

[0071] Furthermore, the multi-core conversion assembly includes an upper adapter 30110, an aviation plug 3018, a fixing screw 3019, a lower adapter 30120, a first sealing ring 30121, and a high-pressure sealing plug 30111. The upper adapter 30110 includes a mounting portion with an inner diameter decreasing from top to bottom, a threaded connection section 30123, and a sealing groove 30124. The upper adapter 30110 is fixed in the core body 3013 through the threaded connection section 30123, and the first sealing ring 30121 is fixed in the sealing groove 30124. The upper adapter 30110 and the core body 3013 are sealed by the first sealing ring 30121. The mounting part can be a cuboid structure, with its outer diameter larger than the inner diameter of the opening at the upper end of the core 3013. The mounting part is located outside the core 3013 and has a threaded hole 30122. The aviation plug 3018 is fixed to the mounting part by fixing screws 3019 and threaded hole 30122. A communication line 30115 (with the number of cable cores configured) can be configured to connect to the aviation plug 3018 according to the directional probe 302 being connected. The lower adapter 30120 is threadedly fixed to the lower end of the upper adapter 30110. The high-pressure sealing plug 30111 is fixed between the upper adapter 30110 and the lower adapter 30120. The upper end of the communication line 30115 enters the upper adapter 30110 through the lower adapter 30120 and is electrically connected to the aviation plug 3018.

[0072] In this exemplary embodiment, the core 3013 has a first inner step 30112 for axially limiting the lower adapter 30120, and the mounting bracket 3017 has a second inner step 30126 for axially limiting the multi-pin socket 30137. After the multi-pin conversion assembly is fixed in the core 3013, the lower adapter 30120 abuts against the first inner step 30112, and after the multi-pin socket 30137 is fixed in the mounting bracket 3017, the multi-pin socket 30137 abuts against the second inner step 30126, thereby ensuring that the multi-pin conversion assembly is fixed in the tool more stably and reliably.

[0073] In this exemplary embodiment, the plug-in assembly includes a plug sleeve 30141, a compression spring 30130, a limiting ring 30140, a fixing cap 30131, and a multi-core plug 30138 for electrical connection with a multi-core socket 30137. The plug sleeve 30141 is hollow internally and has different outer diameter sections externally. The upper part of the plug sleeve 30141 has an upper positioning ring platform and a middle positioning ring platform, with the upper positioning ring platform abutting against the first inner boss 30142. The compression spring 30130 is sleeved on the plug sleeve 30141 and located between the first inner boss 30142 and the middle positioning ring platform. The limiting ring 30140 is threadedly fixed to the lower part of the plug sleeve 30141. The multi-core plug 30138... 0138 is fixed to the lower end of the connector sleeve 30141 by a limiting ring 30140; the fixing cap 30131 is threaded to the lower end of the adjustable short section 30116, and the fixing cap 30131 is located between the adjustable short section 30116 and the second inner boss 30139, used to axially limit the limiting ring 30140; the lower end of the communication line 30115 passes through the connector sleeve 30141 and connects to the multi-core plug 30138. When the multi-core plug 30138 is inserted into the multi-core socket 30137, normal power supply and communication of the instrument string can be realized.

[0074] In this exemplary embodiment, a hollow positioning block 30143 is fixed between the first inner boss 30142 and the core 3013. The inner diameter of the positioning block 30143 is smaller than the inner diameter of the first inner boss 30142. After the upper end of the connector sleeve 30141 passes through the positioning block 30143, its upper positioning ring is abutted and limited by the positioning block 30143 at the first inner boss 30142, thereby ensuring the stability of the connector sleeve 30141.

[0075] Exemplary Example 2

[0076] Based on Exemplary Example 1, this Exemplary Example provides another integrated near-drill bit measurement tool.

[0077] In addition to the structure of the integrated near-drill bit measurement tool described in Exemplary Example 1, such as Figures 1-2 As shown, this integrated near-drill bit measuring tool may also include: a non-magnetic suspension section 4, a drive shaft assembly 201, an adjustable bend angle 202, a universal joint assembly 203, and a drill bit 1.

[0078] Among them, the non-magnetic suspension section 4 is set above the MWD section, and the upper part of the drilling fluid pulser 304 is mostly located in the non-magnetic suspension section 4; the lower part of the through-wire screw body 2 is arranged from top to bottom as follows: universal joint assembly 203, adjustable angle 202 and drive shaft assembly 201, and the universal joint assembly 203, adjustable angle 202 and drive shaft assembly 201 are all located below the drill bit measuring chamber 205 of the through-wire screw body 2; the drill bit 1 is set at the lower end of the through-wire screw body 2 and is located below the drive shaft assembly 201.

[0079] In summary, the advantages proposed by this invention include at least one of the following:

[0080] (1) By integrating the measuring sub with the screw drill bit, the risk of the measuring sub detaching is avoided, the overall stability of the screw drill bit is improved, and the screw drill bit can drill normally, solving the problem of long distance between the traditional logging-while-drilling gamma tool and the drill bit and the lag in measurement information.

[0081] (2) The use of wired signal transmission instead of wireless signal transmission overcomes the influence of the strata on the shielding of wireless signals, improves the stability and reliability of information transmission, and ensures that the geological parameters and trajectory parameters near the drill bit can be transmitted to the pulse generator in a timely and accurate manner.

[0082] (3) In traditional near-bit measurement while drilling systems, the measuring equipment is located at the lower end of the universal joint assembly with adjustable bend angle and the screw drive shaft, at the upper end of the drill bit, very close to the drill bit. The high speed caused by the screw drive shaft and the high vibration caused by the position below the universal joint assembly with adjustable bend angle result in a high failure rate of the instrument series. In this invention, the measuring equipment (measuring module) is placed on the housing of the screw body at the upper end of the universal joint assembly with adjustable bend angle, which is slightly farther away from the drill bit. This avoids the high speed caused by the connection with the screw drive shaft (the drive shaft itself also rotates at high speed) and the high vibration caused by the bend angle of the universal joint assembly. At the same time, the wired connection avoids the problem of poor data stability of the wireless transmission method in traditional near-bit measurement while drilling systems.

[0083] (4) The adjustable short section and the core are fixed by a threaded structure. By applying rotational force, the adjustable short section can slide up and down along the axial direction of the core. The upper end of the adjustable short section is adjusted by a limit spring, and the lower end is restricted by a slip ring, washer and locking short section. The threaded engagement movement method can realize millimeter-level mating length adjustment. The corresponding slip ring and locking short section can be selected according to the required series of sizes and lengths. The corresponding washer is selected in appropriate quantities to achieve axial fixation, thereby realizing precise adjustment of the overall length of the instrument string, expanding the usable range of the stock of non-magnetic drill collars and non-magnetic suspensions, and improving the reliability of the docking tool and MWD wellhead docking.

[0084] (5) The inclined sealing surface of the locking short section and the hanger has a metal sealing effect. The locking short section is equipped with a fourth sealing ring and a high-pressure retaining ring to achieve high-pressure sealing after docking. The upper arc top of the hanger and the irregular sealing sleeve also have a sealing effect after compaction. After docking, they are all in a static sealing state. The triple sealing structure greatly improves the reliability of the hanger tool and the high-pressure sealing of the MWD docking, thereby ensuring the long-term stable operation of the instrument string.

[0085] (6) To address the issue of large differences in the mating length of different MWD strings, the tool of this invention can be used to set mating short sections of different spacing series sizes, and a sleeve straightener is added to effectively prevent damage to the mating parts due to high vibration when the device is too long; to address the issue of inconsistent power supply and communication interface protocols of different types of MWD strings, a multi-core conversion assembly is set to configure the corresponding number of cable cores, which has strong compatibility and expands the market application range of the hanging tool and MWD docking device.

[0086] Although the invention has been described above in conjunction with exemplary embodiments, those skilled in the art will understand that various modifications and changes can be made to the exemplary embodiments of the invention without departing from the spirit and scope defined by the claims.

Claims

1. An integrated near-drill bit measuring tool, characterized in that, The tool includes a lead screw body (2) and a variable extension section (301) arranged sequentially from bottom to top; wherein, The lead screw body (2) is provided with a measuring sub (204), which is located at the lower part of the tool; the measuring sub (204) is provided with a near-bit measuring chamber (205), and a measuring module (210) is installed in the near-bit measuring chamber (205). The measuring module (210) is configured to collect near-bit well inclination azimuth and gamma parameter information; the measuring module (210) transmits information to the MWD sub through a communication line (30115) and a variable extension sub (301); The variable extension section (301) includes a core (3013), an outer cylinder (3014), an adjustable section (30116), a locking section (3015), a connector (3017), and a communication component. The outer cylinder (3014) is threadedly fixed to the core (3013), with the lower part of the core (3013) located inside the outer cylinder (3014). The upper end of the locking section (3015) is threadedly fixed to the outer cylinder (3014). The connector (3017) is sealed and fixed to the lower end of the locking section (3015). The adjustable section (30116) is threadedly fixed to the core (3013), and the adjustable section (30116) can move up and down along the axial direction of the core (3013) under force. The upper end of the adjustable section (30116) is located between the outer cylinder (3014) and the core (30116). Between the core (3013), the lower end is located inside the locking short section (3015); the upper end of the adjustable short section (30116) is provided with a spring seat (30127) between the core (3013), and a limit spring (30114) is coaxially installed on the spring seat (30127); an adjustment seat (30128) is provided between the lower end of the adjustable short section (30116) and the locking short section (3015), and a slip ring (30119) and a washer (30118) for limiting the axial displacement of the adjustable short section (30116) are coaxially installed on the adjustment seat (30128); the communication components are respectively sealed and fixed inside the core (3013), the adjustable short section (30116), the locking short section (3015) and the hanger (3017), and the communication components include a communication line (30115).

2. The integrated near-drill bit measuring tool according to claim 1, characterized in that, The measurement module (210) includes a gamma measurement module, a well inclination measurement module, and a central control circuit module; the measurement sub (204) is provided with several circumferentially arranged near-bit measurement chambers (205), and different measurement modules (210) are installed in different near-bit measurement chambers (205).

3. The integrated near-drill bit measuring tool according to claim 1, characterized in that, The adjustable short section (30116) has a first inner boss (30142) in its lower middle part, and the core (3013) is located above the first inner boss (30142); the locking short section (3015) has a second inner boss (30139) in its middle part, and the adjustable short section (30116) and the hook (3017) are located at the upper and lower ends of the second inner boss (30139), respectively.

4. The integrated near-drill bit measuring tool according to claim 3, characterized in that, The locking short section (3015) and the hanger (3017) are provided with a triple sealing structure. The first sealing structure is achieved by a fourth sealing ring (30134) and a high-pressure retaining ring (30135) fixedly set between the locking short section (3015) and the hanger (3017). The second sealing structure is achieved by a sloping sealing surface (30136) that is mutually pressed and contacted between the locking short section (3015) and the hanger (3017). The third sealing structure includes a special-shaped sealing sleeve (30132) fixed on the second inner boss (30139) and an arc top (30133) set on the upper end of the hanger (3017). The third sealing structure is achieved by the arc top (30133) pressing and contacting the special-shaped sealing sleeve (30132).

5. The integrated near-drill bit measuring tool according to claim 3, characterized in that, The communication component also includes a multi-core conversion assembly, a plug-in assembly, and a multi-core socket (30137). The multi-core conversion assembly is fixed on the upper end of the core (3013), the multi-core socket (30137) is fixed on the upper part of the hanger (3017), the plug-in assembly is located in the adjustable short section (30116) and abuts between the first inner boss (30142) and the second inner boss (30139), and the communication line (30115) is connected to the multi-core conversion assembly and the plug-in assembly respectively.

6. The integrated near-drill bit measuring tool according to claim 5, characterized in that, The multi-core conversion assembly includes an upper adapter (30110), an aviation plug (3018), a fixing screw (3019), a lower adapter (30120), a first sealing ring (30121), and a high-pressure sealing plug (30111). The upper adapter (30110) includes a mounting part, a threaded connection section (30123), and a sealing groove (30124) with decreasing inner diameters from top to bottom. The upper adapter (30110) is fixed in the core body (3013) by the threaded connection section (30123), and the first sealing ring (30121) is fixed in the sealing groove (30124). The mounting part is located outside the core (3013), and a threaded hole (30122) is provided on the mounting part. The aviation plug (3018) is fixed to the mounting part by a fixing screw (3019) and the threaded hole (30122). The lower adapter (30120) is threadedly fixed to the lower end of the upper adapter (30110). The high-pressure sealing plug (30111) is fixed between the upper adapter (30110) and the lower adapter (30120). The upper end of the communication line (30115) enters the upper adapter (30110) through the lower adapter (30120) and is connected to the aviation plug (3018).

7. The integrated near-drill bit measuring tool according to claim 6, characterized in that, The core (3013) is provided with a first inner step (30112) for axially limiting the lower adapter (30120), and the hook (3017) is provided with a second inner step (30126) for axially limiting the multi-core socket (30137).

8. The integrated near-drill bit measuring tool according to claim 5, characterized in that, The plug assembly includes a plug sleeve (30141), a compression spring (30130), a limiting ring (30140), a fixing cap (30131), and a multi-core plug (30138) for connecting to a multi-core socket (30137). The upper part of the plug sleeve (30141) is provided with an upper positioning ring and a middle positioning ring. The upper positioning ring abuts against the first inner boss (30142). The compression spring (30130) is sleeved on the plug sleeve (30141) and located on the first inner boss (30144). 2) Between the positioning ring and the central positioning ring platform; the limiting ring (30140) is threadedly fixed to the lower part of the connector sleeve (30141), the multi-core plug (30138) is fixed to the lower end of the connector sleeve (30141) through the limiting ring (30140), and the fixing cover (30131) is threadedly fixed to the lower end of the adjustable short section (30116) for axial limiting of the limiting ring (30140); the lower end of the communication line (30115) passes through the connector sleeve (30141) and is connected to the multi-core plug (30138).

9. The integrated near-drill bit measuring tool according to claim 8, characterized in that, A positioning block (30143) is fixed between the first inner boss (30142) and the core (3013). The inner diameter of the positioning block (30143) is smaller than the inner diameter of the first inner boss (30142), and the positioning block (30143) abuts against the upper positioning ring platform.

10. The integrated near-drill bit measuring tool according to claim 1, characterized in that, The core (3013) is provided with a short thread section, a sealing section and a long thread section (30125) in sequence from the middle downward along its surface. The outer cylinder (3014) is fixed to the core (3013) through the short thread section. The adjustable short section (30116) is fixed to the core (3013) through the long thread section (30125). A second sealing ring (30113) is fixed between the outer cylinder (3014) and the core (3013) through the sealing section.

11. The integrated near-drill bit measuring tool according to claim 1, characterized in that, A third sealing ring (30117) is provided between the locking short section (3015) and the adjustable short section (30116), and the third sealing ring (30117) is located above the adjusting seat (30128).

12. The integrated near-drill bit measuring tool according to claim 1, characterized in that, The MWD section includes, from bottom to top, a directional probe (302), a power module (303), and a drilling fluid pulser (304); the power module (303) supplies power to the drilling fluid pulser (304), the directional probe (302), and the measurement module (210) of the near-bit measurement chamber (205).

13. The integrated near-drill bit measuring tool according to claim 12, characterized in that, The upper end of the core (3013) is threaded with a mating short section (3011) for connecting with the directional probe (302); a sleeve centralizer (3012) is fixed on the mating short section (3011).

14. The integrated near-drill bit measuring tool according to claim 1, characterized in that, The adjustable short section (30116) has an upper step at the top by reducing the outer diameter and a lower step at the bottom by reducing the outer diameter; the spring seat (30127) is formed by the upper step cooperating with the external step pre-opened on the core (3013), and the adjusting seat (30128) is formed by the lower step cooperating with the internal step pre-opened on the locking short section (3015).

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