Downhole drill bit track closed-loop control tool

Abstract

The invention discloses an underground drill bit track closed-loop control tool, and belongs to the field of drilling technologies and oil and gas exploitation. According to the tool, a closed-loop control framework integrating measurement, analysis and execution is adopted, and accurate regulation and control of the three-dimensional track of the drill bit are achieved through an electric control system. A high-precision electronic gyroscope is embedded in the end, close to the drill bit, of the tool, and drill bit track data are collected in real time and fed back to a ground control station; the front servo motor and the rear servo motor drive the bevel gear set and the rotary supporting mechanism respectively, and the transverse deflection angle and the azimuth angle of the drill bit are cooperatively controlled by combining linear motion and axial rotation of a push rod rack, so that dynamic adjustment of a three-dimensional track is achieved. A through type drilling fluid channel is formed in the tool, and drilling power supply and rock debris removal are ensured through a high-pressure hose and a built-in channel. The closed-loop control process comprises the steps of real-time data acquisition, deviation analysis, servo motor instruction generation and track correction circulation until the deviation between an actual track and a target track is smaller than a threshold value. In addition, the tool is integrated with a fault detection and redundancy control module, the motor, the sensor and the communication state are monitored in real time, a standby strategy or emergency shutdown is switched when abnormity occurs, and safety and reliability of the system are guaranteed. Through the electromechanical integration design, the precision, the efficiency and the automation level of underground drill bit track control are remarkably improved.

Description

Technical Field

[0001] The invention relates to the field of drilling technology and oil and gas exploitation, and in particular to a downhole drill bit trajectory closed-loop control tool. Background Art

[0002] With the extension of oil and gas resource exploration to deep formations, complex structures and unconventional reservoirs (such as shale gas and tight oil), higher requirements are placed on the accuracy, efficiency and adaptability of wellbore trajectory control. Traditional directional drilling technology mainly relies on the sliding guidance system, which achieves trajectory correction by periodically stopping drilling and adjusting the tool face angle, but there are problems such as high friction, rock debris deposition, and low mechanical drilling speed, especially in large-reach wells, horizontal wells and three-dimensional multi-target wells, which can easily cause the trajectory to deviate from the designed trajectory and extend the drilling cycle. Although the introduction of the rotary steerable tool (RSS) has significantly improved the continuity and efficiency of trajectory control, the current product has problems such as low deflection capability and real-time communication control delay, making it difficult to meet the "vertical well-deflection-horizontal" multi-well section one-trip drilling needs. Summary of the invention

[0003] In view of the defects existing in the prior art, the purpose of the present invention is to achieve the above purpose, and the technical solution adopted by the present invention is:

[0004] A downhole drill bit trajectory closed-loop control tool, characterized by adopting an integrated closed-loop control architecture of "measurement-analysis-execution", the tool as a whole adopts electronic control, a high-precision electronic gyroscope is embedded near the drill bit end to measure and feedback the drill bit trajectory information in real time, a front servo motor and a rear servo motor are arranged inside the tool, and the two servo motors are used to control the drill bit on a three-dimensional trajectory according to the real-time information fed back; at the same time, a drilling fluid channel is provided through the entire tool, so that the drill bit can drill using a screw drill tool;

[0005] The power supply and control circuit of the tool electronic control are located in the rear end plug of the tool. The communication module is embedded in the rear end plug of the tool to exchange information with the ground control station. The electronic control modules required in the tool are the front servo motor, the rear servo motor and the electronic gyroscope from back to front.

[0006] The near-drill-bit end is embedded with an electronic gyroscope, the front end is used to connect the drilling part of the drill bit, and the rear end is provided with two push rod hinge seats. The trajectory control directly acts on the near-drill-bit end and then is transmitted to the drill bit;

[0007] The output end of the front servo motor is connected to the front reducer and fixed as a whole on the front motor mounting plate. The output end of the front reducer is installed with the driving bevel gear of the bevel gear set. The left driven bevel gear and the right driven bevel gear are respectively installed on the two shafts of the gear fixing member. A spur gear is also installed on the left and right shafts respectively.

[0008] The rear end of the gear fixing part is two movable shafts, which are interference fit at the rear end of the gear fixing part through bearings, and the left driven bevel gear, the right driven bevel gear and the spur gear are connected by keys so that the gears on the two shafts can rotate concentrically; the gear fixing part has a built-in drilling fluid channel, and a hole is opened on the side to transfer the side drilling fluid channel to the center of the tool as a whole; the front end of the gear fixing part is connected to the drilling fluid channel connector, and communicates with the drilling fluid channel of the front end plug of the tool;

[0009] The spur gear is matched with a rack with a push rod, and the push rod passes through the front end plug of the tool and directly acts on the hinge seat at the rear end near the drill bit end. At the same time, the rear end near the drill bit end is connected to the front end plug of the tool through a large ball joint. A metal bellows is also provided at the periphery of the connection between the rear end near the drill bit end and the front end plug of the tool to protect the hinged part;

[0010] The output end of the rear servo motor is connected to the rear reducer and fixed as a whole on the rear motor mounting plate. The output end of the rear reducer is connected to the slewing support flange. The slewing support flange is connected to the slewing support inner ring. The slewing support inner ring is connected to the front end housing. At the same time, the slewing support outer ring is fixed to the rear end housing.

[0011] As a further solution, the drilling fluid channel runs through the entire tool, wherein the near-bit end, the large ball joint, the front plug of the tool, the gear fixing part and the rear plug of the tool are all built with drilling fluid channels. Since the drilling fluid channel cannot be opened from the center of the tool at the part where the motor is installed, a high-pressure hose is used to pass through the drilling fluid channel from the side;

[0012] As a further solution, the front servo motor directly drives the bevel gear set through the front reducer, and the bevel gear set then drives the two spur gears to rotate in opposite directions. The spur gears then drive the two racks with push rods to perform opposite linear motions, thereby converting the rotation of the servo motor into linear motions with push rod racks. The opposite linear motions of the two racks with push rods form a displacement difference, which can drive the end near the drill bit to deflect in a plane. The deflection angle is controlled by the telescopic displacement of the rack with push rods. Assume that the center distance between the two racks with push rods is d, and the extension distances of the push rods are l respectively. A With l B , then the drill bit deflection angle θ is

[0013] At the same time, the rear servo motor drives the slewing support flange through the rear reducer to rotate the front housing and the end near the drill bit. The front and rear mechanisms cooperate with each other to achieve precise control of the drill bit on a three-dimensional trajectory.

[0014] As a further solution, a downhole drill bit trajectory closed-loop control tool is characterized in that its closed-loop control process includes:

[0015] Step 1: The electronic gyroscope embedded near the drill bit end collects the three-dimensional trajectory data of the drill bit in real time, and uploads the data to the ground control station through the communication module in the plug at the rear end of the tool;

[0016] Step 2: The ground control station generates control instructions for the front servo motor and the rear servo motor based on the deviation between the preset target trajectory and the real-time trajectory data and the deflection angle calculation formula in claim 3;

[0017] Step 3: The front servo motor drives the spur gear and the rack with push rod through the bevel gear set to adjust the extension of the push rod so that the end near the drill bit deflects in the transverse plane; the rear servo motor drives the front end housing to rotate axially through the slewing support flange to adjust the drill bit azimuth;

[0018] Step 4: The electronic gyroscope continuously monitors the adjusted drill trajectory and feeds back the new data to the ground control station to form a closed-loop control cycle until the deviation between the actual trajectory and the target trajectory is less than a preset threshold;

[0019] Step 5: The drilling fluid is continuously delivered to the drill bit through the high-pressure hose and built-in channel of the through-tool to ensure power supply and cuttings removal during drilling;

[0020] As a further solution, a downhole drill bit trajectory closed-loop control tool is characterized in that it also includes a fault detection and redundant control module: real-time monitoring of the operating status of the front servo motor, rear servo motor, electronic gyroscope and communication module, and when the servo motor is detected to be overloaded, the sensor data is abnormal or the communication is interrupted, it automatically switches to the backup control strategy or triggers an emergency stop, sends the fault code and real-time status report to the ground control station through the communication module of the rear end plug of the tool, and records the abnormal data for subsequent analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a schematic diagram of the overall structure of a downhole drill bit trajectory closed-loop control tool of the present invention;

[0023] Figure 2 It is a schematic diagram of the near-bit end deflection in a downhole drill bit trajectory closed-loop control tool of the present invention;

[0024] Figure 3 It is a cross-sectional schematic diagram of a downhole drill bit trajectory closed-loop control tool of the present invention;

[0025] Figure 4 It is a schematic diagram of the installation of a bevel gear set in a downhole drill bit trajectory closed-loop control tool of the present invention;

[0026] Figure 5 It is a schematic diagram of the installation of a spur gear and a rack with a push rod in a downhole drill bit trajectory closed-loop control tool of the present invention;

[0027] Figure 6 It is a schematic diagram of a drill bit transverse plane deflection structure in a downhole drill bit trajectory closed-loop control tool of the present invention;

[0028] In the figure: 1. tool rear end plug, 2. rear servo motor, 3. rear reducer, 4. rear motor mounting plate, 5. slewing support flange, 6. slewing support outer ring, 7. slewing support inner ring, 8. front servo motor, 9. front reducer, 10. front motor mounting plate, 11. bevel gear set, 11-1. driving bevel gear, 11-2. right driven bevel gear, 11-3. left driven bevel gear, 12. gear fixing part, 13. drilling fluid channel connector, 14. tool front end plug, 15. large ball joint, 16. near drill bit end, 17. electronic gyroscope, 18. metal bellows, 19. front end housing, 20. rack with push rod, 21. spur gear, 22. rear end housing. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0030] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0031] A downhole drill bit trajectory closed-loop control tool, characterized in that it adopts an integrated closed-loop control architecture of "measurement-analysis-execution", the tool is electronically controlled as a whole, a high-precision electronic gyroscope 17 is embedded near the drill bit end 16 to measure and feedback the drill bit trajectory information in real time, a front servo motor 8 and a rear servo motor 2 are arranged inside the tool, and the two servo motors are used to control the drill bit on a three-dimensional trajectory according to the real-time information fed back; at the same time, a drilling fluid channel is provided through the entire tool, so that the drill bit can drill using a screw drill tool;

[0032] like Figure 1The power supply and control circuit of the tool electronic control are located in the tool rear end plug 1. The tool rear end plug 1 has an embedded communication module to exchange information with the ground control station. The electronic control modules required in the tool are the front servo motor 8, the rear servo motor 2 and the electronic gyroscope 17 from back to front.

[0033] like Figure 1 The near-drill-bit end 16 has an embedded electronic gyroscope 17, the front end of which is used to connect to the drilling part of the drill bit, and the rear end is provided with two push rod hinge seats, and the trajectory control directly acts on the near-drill-bit end 16 and then is transmitted to the drill bit;

[0034] like Figure 1 The output end of the front servo motor 8 is connected to the front reducer 9 and fixed on the front motor mounting plate 10 as a whole. The output end of the front reducer 9 is installed with the driving bevel gear 11-1 of the bevel gear set 11, and the left driven bevel gear 11-3 and the right driven bevel gear 11-2 are respectively installed on the two shafts of the gear fixing member 12, and a spur gear 21 is also installed on the left and right shafts respectively;

[0035] like Figure 1 and Figure 4 The rear end of the gear fixing part 12 is two movable shafts, which are interference fit at the rear end of the gear fixing part 12 through bearings, and the left driven bevel gear 11-3, the right driven bevel gear 11-2 and the spur gear 21 are connected by keys, so that the gears on the two shafts can rotate concentrically; the gear fixing part 12 has a built-in drilling fluid channel, and a hole is opened on the side to transfer the side drilling fluid channel to the center of the tool as a whole; the front end of the gear fixing part 12 is connected to the drilling fluid channel connector 13, and communicates with the drilling fluid channel of the front end plug 14 of the tool;

[0036] like Figure 1 and Figure 5 The spur gear 21 cooperates with a rack 20 with a push rod, and the push rod passes through the front end plug 14 of the tool and directly acts on the hinge seat at the rear end of the near drill end 16. At the same time, the rear end of the near drill end 16 is connected to the front end plug 14 of the tool through a large ball joint 15. A metal bellows 18 is also provided at the periphery of the connection between the rear end of the near drill end 16 and the front end plug 14 of the tool to protect the hinged part;

[0037] like Figure 1 The output end of the rear servo motor 2 is connected to the rear reducer 3 and fixed on the rear motor mounting plate 4 as a whole. The output end of the rear reducer 3 is connected to the slewing support flange 5, the slewing support flange 5 is connected to the slewing support inner ring 7, the slewing support inner ring 7 is connected to the front end housing 19, and the slewing support outer ring 6 is fixed to the rear end housing 22;

[0038] Further, such as Figure 3The drilling fluid channel runs through the entire tool, wherein the near-bit end 16, the large ball joint 15, the front plug 14 of the tool, the gear fixing part 12 and the rear plug 1 of the tool are all built with drilling fluid channels. Since the drilling fluid channel cannot be opened from the center of the tool at the part where the motor is installed, a high-pressure hose is used to pass through the drilling fluid channel from the side;

[0039] Further, such as Figure 2 , Figure 6 The front servo motor 8 directly drives the bevel gear set 11 through the front reducer 9, and the bevel gear set 11 then drives the two spur gears 21 to rotate in opposite directions. The spur gears 21 then drive the two racks with push rods 20 to perform opposite linear motions, thereby converting the rotation of the servo motor into the linear motion of the racks with push rods 20. The opposite linear motions of the two racks with push rods 20 form a displacement difference, which can drive the near drill bit end 16 to deflect in a plane. The deflection angle is controlled by the telescopic displacement of the racks with push rods 20. Assume that the center distance between the two racks with push rods 20 is d, and the extension distances of the push rods are l respectively. A With l B , then the drill bit deflection angle θ is

[0040] At the same time, the rear servo motor 2 drives the slewing support flange 5 through the rear reducer 3 to rotate the front housing 19 and the near-drill end 16. The front and rear mechanisms cooperate with each other to achieve precise control of the drill bit on a three-dimensional trajectory.

[0041] Furthermore, a downhole drill bit trajectory closed-loop control tool is characterized in that its closed-loop control process includes:

[0042] Step 1: The electronic gyroscope 17 embedded in the near-bit end 16 collects the three-dimensional trajectory data of the drill bit in real time, and uploads the data to the ground control station through the communication module in the tool rear end plug 1;

[0043] Step 2: The ground control station generates control instructions for the front servo motor 8 and the rear servo motor 2 based on the deviation between the preset target trajectory and the real-time trajectory data and the deflection angle calculation formula in claim 3;

[0044] Step 3: The front servo motor 8 drives the spur gear 21 and the rack with push rod 20 through the bevel gear set 11 to adjust the extension amount of the push rod so that the near drill end 16 deflects the angle in the transverse plane; the rear servo motor 2 drives the front end housing 19 to rotate axially through the slewing support flange 5 to adjust the drill bit azimuth angle;

[0045] Step 4: The electronic gyroscope 17 continuously monitors the adjusted drill trajectory and feeds back the new data to the ground control station to form a closed-loop control cycle until the deviation between the actual trajectory and the target trajectory is less than a preset threshold;

[0046] Step 5: The drilling fluid is continuously delivered to the drill bit through the high-pressure hose and built-in channel of the through-tool to ensure power supply and cuttings removal during drilling;

[0047] Furthermore, a downhole drill bit trajectory closed-loop control tool is characterized in that it also includes a fault detection and redundant control module: real-time monitoring of the operating status of the front servo motor 8, the rear servo motor 2, the electronic gyroscope 17 and the communication module, when the servo motor is detected to be overloaded, the sensor data is abnormal or the communication is interrupted, it automatically switches to the backup control strategy or triggers an emergency stop, sends a fault code and a real-time status report to the ground control station through the communication module of the tool rear end plug 1, and records the abnormal data for subsequent analysis.

[0048] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0049] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A downhole drill bit trajectory closed-loop control tool, characterized in that The tool adopts an integrated closed-loop control architecture of "measurement-analysis-execution". The tool is electronically controlled as a whole. A high-precision electronic gyroscope (17) is embedded near the drill bit end (16) to measure and feedback the drill bit trajectory information in real time. A front servo motor (8) and a rear servo motor (2) are arranged inside the tool. The two servo motors are used to control the drill bit on a three-dimensional trajectory according to the real-time information fed back. At the same time, a drilling fluid channel is provided through the entire tool, so that the drill bit can drill using a screw drill. The power supply and control circuit of the tool electric control are located in the tool rear end plug (1), the tool rear end plug (1) has an embedded communication module to exchange information with a ground control station, and the electric control modules required in the tool are respectively a front servo motor (8), a rear servo motor (2) and an electronic gyroscope (17) from back to front; The near-drill-bit end (16) is embedded with an electronic gyroscope (17), the front end is used to connect to the drilling part of the drill bit, and the rear end is provided with two push rod hinge seats, and the trajectory control directly acts on the near-drill-bit end (16) and is then transmitted to the drill bit; The output end of the front servo motor (8) is connected to the front reducer (9) and is fixed as a whole on the front motor mounting plate (10); the output end of the front reducer (9) is installed with a driving bevel gear (11-1) of a bevel gear set (11); the left driven bevel gear (11-3) and the right driven bevel gear (11-2) are respectively installed on two shafts of a gear fixing member (12); and a spur gear (21) is also installed on the left and right shafts respectively; The rear end of the gear fixing member (12) is two movable shafts, which are interference-fitted at the rear end of the gear fixing member (12) through bearings, and are keyed to connect the left driven bevel gear (11-3), the right driven bevel gear (11-2) and the spur gear (21), so that the gears on the two shafts can rotate concentrically; the gear fixing member (12) has a built-in drilling fluid channel, and a hole is opened on the side to transfer the side drilling fluid channel to the center of the tool; the front end of the gear fixing member (12) is connected to the drilling fluid channel connector (13), and is communicated with the drilling fluid channel of the front end plug (14) of the tool; The spur gear (21) cooperates with a rack (20) with a push rod, and the push rod passes through the front end plug (14) of the tool and directly acts on the hinge seat at the rear end near the drill bit end (16). At the same time, the rear end near the drill bit end (16) is connected to the front end plug (14) of the tool through a large ball joint (15). A metal bellows (18) is also provided at the periphery of the connection between the rear end near the drill bit end (16) and the front end plug (14) of the tool to protect the hinged part; The output end of the rear servo motor (2) is connected to the rear reducer (3) and is fixed as a whole on the rear motor mounting plate (4). The output end of the rear reducer (3) is connected to the slewing support flange (5). The slewing support flange (5) is connected to the slewing support inner ring (7). The slewing support inner ring (7) is further connected to the front end housing (19). At the same time, the slewing support outer ring (6) is fixed to the rear end housing (22).

2. According to claim 1, the drilling fluid channel runs through the entire tool, wherein the near drill bit end (16), the large ball joint (15), the front end plug (14) of the tool, the gear fixing part (12) and the rear end plug (1) of the tool are all equipped with built-in drilling fluid channels. Since the drilling fluid channel cannot be opened from the center of the tool at the part where the motor is installed, a high-pressure hose is used to open the drilling fluid channel from the side.

3. According to claim 1, the front servo motor (8) directly drives the bevel gear set (11) through the front reducer (9), and the bevel gear set (11) then drives the two spur gears (21) to rotate in opposite directions, and the spur gears (21) then drive the two racks with push rods (20) to perform opposite linear motions, thereby converting the rotation of the servo motor into linear motions of the racks with push rods (20). The opposite linear motions of the two racks with push rods (20) form a displacement difference, which can drive the near drill bit end (16) to deflect in a plane, and the deflection angle is controlled by the telescopic displacement of the racks with push rods (20). Assume that the center distance between the two racks with push rods (20) is d, and the extension distances of the push rods are l respectively. A With l B , then the drill bit deflection angle θ is At the same time, the rear servo motor (2) drives the slewing support flange (5) through the rear reducer (3), so that the front end housing (19) and the end near the drill bit (16) rotate. The front and rear mechanisms cooperate with each other to achieve precise control of the drill bit on a three-dimensional trajectory.

4. According to claims 1 to 3, a downhole drill bit trajectory closed-loop control tool, characterized in that: The closed-loop control process includes: Step 1: The three-dimensional trajectory data of the drill bit is collected in real time through the electronic gyroscope (17) embedded in the near-drill bit end (16), and the data is uploaded to the ground control station through the communication module in the tool rear end plug (1); Step 2: The ground control station generates control instructions for the front servo motor (8) and the rear servo motor (2) based on the deviation between the preset target trajectory and the real-time trajectory data and the deflection angle calculation formula in claim 3; Step 3: The front servo motor (8) drives the spur gear (21) and the rack with push rod (20) through the bevel gear set (11) to adjust the extension and retraction of the push rod so that the end near the drill bit (16) deflects in the transverse plane; the rear servo motor (2) drives the front end housing (19) to rotate axially through the slewing support flange (5) to adjust the azimuth angle of the drill bit; Step 4: The electronic gyroscope (17) continuously monitors the adjusted drill trajectory and feeds back the new data to the ground control station to form a closed-loop control cycle until the deviation between the actual trajectory and the target trajectory is less than a preset threshold; Step 5: The drilling fluid is continuously delivered to the drill bit through the high-pressure hose and built-in channels of the through-tool to ensure power supply and cuttings removal during drilling.

5. The downhole drill bit trajectory closed-loop control tool according to any one of claims 1 to 4, characterized in that: It also includes a fault detection and redundant control module: it monitors the operating status of the front servo motor (8), the rear servo motor (2), the electronic gyroscope (17) and the communication module in real time, and automatically switches to a backup control strategy or triggers an emergency stop when it detects that the servo motor is overloaded, the sensor data is abnormal, or the communication is interrupted, and sends a fault code and a real-time status report to the ground control station through the communication module of the tool rear end plug (1), and records the abnormal data for subsequent analysis.

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