Backup arm mechanism and design method

Abstract

The invention provides a sidewall contact arm mechanism and a design method.The sidewall contact arm mechanism comprises a rotating shaft, a pressure-resistant shell, a sidewall contact arm, a slider-crank mechanism, a lead screw nut and a direct current motor, the rotating shaft penetrates through the pressure-resistant shell to install the sidewall contact arm on the pressure-resistant shell, one end of the slider-crank mechanism is connected to the rotating shaft, and the other end of the slider-crank mechanism is connected to the lead screw nut; the direct-current motor rotates to output torque to drive the lead screw nut, and then the lead screw nut pushes the slider-crank mechanism to move, so that the pushing arm is opened and retracted. The backup arm mechanism and the design method are arranged in a pressure-resistant shell of the in-well seismic acquisition instrument, meet the requirement for the high-temperature and high-pressure working environment in the well, are responsible for achieving the coupling function of the in-well seismic acquisition instrument and a shaft (or a sleeve wall), and effectively improve the seismic exploration and measurement operation quality of the shaft.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas exploration seismic data acquisition, and in particular to a push-and-leave arm mechanism and a design method thereof. Background Art

[0002] The method of placing the excitation system (source) and the receiving system (detector) in the wellbore at the same time or one of them to measure the seismic wave signal is usually called wellbore seismic technology. With the development of wellbore seismic technology, the application of 3DVSP, cross-well seismic, and micro-seismic fracturing monitoring technology in the well is becoming more and more extensive, and the requirements for the indicators of wellbore seismic wave signal acquisition equipment are also getting higher and higher, mainly manifested in the requirements of multiple levels, high sampling rate, high sensitivity, etc. Among them, the coupling effect between the wellbore seismic acquisition instrument and the wellbore (or casing wall) is a key factor affecting the quality of wellbore seismic technology measurement operations. At present, there is no complete solution in China.

[0003] In the Chinese patent application with publication number: CN114233222A, a six-arm pusher suitable for small-diameter oil wells is involved. The invention comprises a cylindrical main body, a high-pressure oil chamber with a piston and an electric pump are installed at one end of the main body, six mounting grooves are evenly distributed on the outer surface of the main body and arranged at intervals along the axial direction, and a pusher arm composed of a main arm, a plate and a secondary arm is movably installed in each mounting groove, and the main arm is connected to the piston through a push rod arranged on the main body, wherein the six pushers are divided into two groups, front and rear, based on a circumferential interval angle of 120 degrees, and the main arm and the secondary arm are parallel to each other during the opening process, and the connection ends of the six main arms and the main body are respectively located on the same annular line, and when the two groups of pushers are pushed by the piston at the opening angle, the rear end of the plate of the front group of pushers and the front end of the plate of the rear group of pushers are close to the same annular line. This embodiment can make the positions of the plates of the two groups of pushers as close to the same annular line as possible after the pushers are unfolded, so that the measurement area of ​​each plate is close, which greatly improves the measurement accuracy.

[0004] In the Chinese patent application with publication number: CN111648760A, a downhole pusher is involved. The embodiment of the present application discloses a downhole pusher, including: multiple push arms and a push unit; multiple push arms are connected to the push unit; the push unit is connected to the ground system; the push unit is used to control the opening or closing of any one or more push arms, calculate the well diameter according to the opening size of the push arm, collect the pressure transmitted by the push arm in real time, and transmit the well diameter and pressure to the ground system. Through this embodiment scheme, real-time ground control and real-time monitoring of push parameters are realized, and flexible control of the push arm is realized, which has good control characteristics and practicality.

[0005] In the Chinese patent application with publication number: CN113187421A, a pusher with adaptive well wall shape is involved, including a cylindrical main base, and a pusher arm arranged in a circumferential groove outside the main base, the pusher arm includes a main arm, a pole plate and a secondary arm connected in sequence, wherein the two ends of the main arm are rotatably connected to the main base and one end of the pole plate respectively, and the two ends of the secondary arm are rotatably connected to the other end of the pole plate and the main base respectively, and an adjustment device for automatically adjusting the contact angle between the pole plate and the well wall is arranged at the secondary arm. The present invention can be applied to any existing pusher with an expandable pusher arm, so as to adjust the existing pusher arm to a shape of four parallel lines after being opened to a quadrilateral with any angle after being opened. The extension of the secondary arm is asynchronous with the main arm through an elastic component, so that the connected pole plate can adjust the contact angle with the well wall according to the change of the supporting height of the secondary arm, so that the pole plate can better fit the well wall with different inclined shapes, greatly improving the stability effect of the pusher after support.

[0006] In the Chinese patent application with publication number: CN110374582A, a hydraulic pusher and a well logging instrument are involved. The hydraulic pusher includes a base body and a pushing mechanism arranged on the base body. The pushing mechanism includes a pushing arm and a piston assembly. The piston assembly includes a piston and a piston rod. The piston is slidably arranged in a cavity arranged in the base body and divides the cavity into a first chamber and a second chamber. One end of the piston rod is connected to the piston, and the other end is extended from the first chamber and connected to the pushing arm. Under the action of hydraulic pressure, the piston rod reciprocates and drives the pushing arm to open and close. In the hydraulic pusher of the present application, the pushing force is controlled by hydraulic pressure, and a large thrust pushing force can be achieved. In addition, in the case of multiple pushing arms, the action of each pushing arm can be independently hydraulically controlled, and a large thrust release can be achieved when an adsorption jam occurs.

[0007] The above existing technologies are all significantly different from the present invention and fail to solve the technical problem we want to solve. For this reason, we have invented a new push-and-lean arm mechanism and design method. Summary of the invention

[0008] The purpose of the present invention is to provide a push-and-leave arm mechanism and a design method for realizing the coupling function between a well seismic acquisition instrument and a wellbore (or casing wall) and effectively improving the quality of wellbore seismic exploration and measurement operations.

[0009] The object of the present invention can be achieved through the following technical measures: a pushing arm mechanism, which includes a rotating shaft, a pressure-resistant shell, a pushing arm, a crank slider mechanism, a screw nut, a reducer and a DC motor. The rotating shaft passes through the pressure-resistant shell to install the pushing arm on the pressure-resistant shell. One end of the crank slider mechanism is connected to the rotating shaft, and the other end is connected to one end of the screw nut. The DC motor rotates to output torque to drive the screw nut, and then the screw nut pushes the crank slider mechanism to move, so that the pushing arm is opened and retracted.

[0010] The purpose of the present invention can also be achieved by the following technical measures:

[0011] The pressure-resistant shell is in the shape of a long cylinder as a whole. A hole is provided on the pressure-resistant shell, and the rotating shaft is installed in the hole of the pressure-resistant shell.

[0012] The push arm mechanism also includes a rotary dynamic seal assembly, which is sleeved on the rotating shaft and installed in the hole of the pressure-resistant shell. The rotary seal assembly is used to achieve dynamic sealing between the rotating shaft and the pressure-resistant shell when the push arm rotates in a high-pressure environment underground.

[0013] The push arm mechanism also includes an energy storage spring, a screw rod, a bearing and a bearing seat. One end of the energy storage spring is connected to the other end of the screw rod nut, and the other end of the energy storage spring is connected to the screw rod. The tail input end of the screw rod and the bearing are installed in the bearing seat and then installed in the pressure-resistant shell.

[0014] The push arm mechanism also includes a safety clutch and a reducer, one end of the safety clutch is connected to the screw rod, the other end is connected to the reducer, and the tail end of the reducer is connected to the DC motor. The reducer reduces the high speed output by the motor and increases the output torque.

[0015] The crank slider mechanism comprises a crank rod, a connecting rod and a slider, wherein one end of the crank rod is connected to the rotating shaft, and the other end is connected to one end of the connecting rod, the other end of the connecting rod is connected to one end of the slider, and the other end of the slider is connected to the screw nut.

[0016] After receiving the control signal for opening the push arm, the DC motor rotates to output torque to drive the lead screw nut, and then the lead screw nut pulls the crank slider mechanism to move, thereby realizing the opening of the push arm.

[0017] When the pushing arm opens and contacts the wellbore or casing wall, the screw nut compresses the energy storage spring, and the energy storage spring starts to store energy. When the DC motor stops working, the energy storage spring will always provide continuous elastic energy for the pushing arm, providing the required coupling force for the in-well seismic acquisition instrument with the wellbore or casing wall, thereby realizing the coupling of the in-well seismic acquisition instrument with the wellbore or casing wall.

[0018] After receiving the control signal for retracting the push arm, the DC motor rotates and outputs torque to drive the lead screw nut, and then the lead screw nut drives the crank slider mechanism to move, thereby realizing the retraction of the push arm.

[0019] When the push arm cannot be recovered normally, the safety clutch will compress the push arm under the action of the recovery pulling force, and then pull the screw nut to reverse so that the safety clutch slips and disengages, thereby realizing the recovery of the push arm, thereby smoothly recovering the seismic acquisition instrument in the well.

[0020] The object of the present invention can also be achieved by the following technical measures: a design method of a push-to-arm mechanism, wherein the design method of the push-to-arm mechanism designs the push-to-arm mechanism, including:

[0021] Step 1, when the push arm of the logging instrument in the vertical cased well is in an open state, the entire push arm mechanism is regarded as a crank slider mechanism, the gravity of the mechanism itself is ignored, and the casing wall and all parts of the push arm are regarded as rigid bodies;

[0022] Step 2, establish a rectangular coordinate system of the push arm mechanism, with the push arm opening and closing rotation center point regarded as the origin O, the instrument axis regarded as the X-axis, the positive direction of the X-axis points from the origin to the screw direction and is parallel to the screw axis, and the Y-axis passes through the origin and is opposite to the positive pressure N of the casing wall on the push arm;

[0023] Step 3: Take the entire push-pull system as the research object and perform a stress analysis on the model.

[0024] The purpose of the present invention can also be achieved by the following technical measures:

[0025] In step 3, a rectangular coordinate system is established. Since the system is in a state of equilibrium, the main forces acting on the entire system are the positive pressure N of the casing wall on the push arm and the tension F of the screw rod on the slider. N1 is the support force on the slider, F2 is the tension of the slider on the connecting rod, the connecting rod length L1, the crank length L2, the push arm length L3, the connecting rod and the horizontal angle α1, the crank and the horizontal angle α2, the push arm opening angle α3, the push arm and the crank angle ψ, the slider offset h, and the distance l from the push arm rotation point to the well wall. The rectangular coordinate system is established by taking the push arm opening and closing rotation center point O. Since the system is in a state of equilibrium, the necessary and sufficient conditions for the equilibrium of the plane force system show that the resultant force moment M at point O O is zero, and the equilibrium equation is established:

[0026] ∑M o =0 NL3cosα3=N1(L1cosα1+L2cosα2)+Fh.

[0027] Step 3 includes:

[0028] Step 31, take the slider as the research object and conduct force analysis. F2 is the tension of the slider on the connecting rod, and establish the equilibrium equation:

[0029] ∑F x =0 F = F2cosα1

[0030] ∑F y =0 N = F2sinα1

[0031] have to:

[0032] N1=Ftanα1

[0033] Step 32, according to the geometric relationship:

[0034]

[0035] L1sinα1+h=L2sinα2

[0036] Step 33, according to steps 31 and 32:

[0037] NL3cosα3=Ftanα1(L1cosα1+L2cosα2)+Fh

[0038]

[0039] Substituting h = L2sinα2-L1sinα1 into the above formula, we can get:

[0040]

[0041] From this, we can get the analytical expression of the ratio of the screw rod pulling force F on the slider to the positive pressure N:

[0042]

[0043]

[0044] The optimization goal is to minimize the K value while satisfying the pushing force.

[0045] In step 33, it is found that the Kmin value is greatly affected by L3 and L2, while h and L1 have little effect on Kmin. The crank slider mechanism is restricted by the constraints of the outer diameter and the mechanism components. L2 takes the maximum value within the value range. Considering the unknown situation in the casing and the safe and smooth recovery, the push arm deployment angle α3 takes the value range of The expansion angle of the push arm during actual underground operation The length of the push arm is affected by the inner diameter of the sleeve. When the inner diameter Φd of the sleeve is known, the length of the push arm within the optimal working angle can be obtained as L3=lsinα3. At this time, α2 is used as the independent variable to find the minimum point and obtain the Kmin value.

[0046] The push-and-leave arm mechanism and design method in the present invention highlight ease of use, safety and the function of automatic recovery when power is off in design, including: under the command of the ground controller, controlling the motor output torque to drive the actuator to open the push-and-leave arm; under the command of the ground controller, controlling the motor output torque to drive the actuator to retract the push-and-leave arm on the well seismic acquisition instrument; the main design content includes the push-and-leave arm, the crank slider mechanism, the elastic energy storage device, the safety clutch, the pressure-resistant shell structure, and the rotary dynamic seal assembly design. The present invention is arranged inside the pressure-resistant shell of the well seismic acquisition instrument, and meets the high temperature and high pressure working environment requirements in the well. It is responsible for realizing the coupling function between the well seismic acquisition instrument and the wellbore (or casing wall), and effectively improving the quality of wellbore seismic exploration and measurement operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is an overall structural diagram of a pushing and leaning system in a specific embodiment of the pushing and leaning arm mechanism of the present invention;

[0048] Figure 2 It is a static equilibrium state diagram of the push-and-lean arm system in a specific embodiment of the present invention;

[0049] Figure 3 A mechanical model diagram of a push-to-pull system actuator in a specific embodiment of the present invention;

[0050] Figure 4 It is a force analysis diagram of a slider of a pushing system in a specific embodiment of the present invention;

[0051] In the figure, 1-pressure-resistant housing 2-rotating seal assembly 3-rotating shaft 4-pushing arm 5-crank rod 6-connecting rod 7-slider 8-screw nut 9-energy storage spring 10-screw 11-bearing seat 12-safety clutch 13-reducer

[0052] F: The pulling force of the screw on the sleeve slider

[0053] N: Positive pressure of the well wall on the push arm

[0054] L1: connecting rod length

[0055] L2-: crank length

[0056] L3- Push arm length

[0057] α1: Angle between connecting rod and horizontal

[0058] α2-: Angle between crank and horizontal

[0059] ψ: Angle between the push arm and the crank

[0060] h: The offset between the slider and the crank's rotation center

[0061] l- Distance from the rotation point of the push arm to the well wall

[0062] F2: Tension on the slider

[0063] O: Push arm opening and closing rotation center point

[0064] M O :Resultant force and moment at point O. DETAILED DESCRIPTION

[0065] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0066] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations and / or combinations thereof.

[0067] The push arm mechanism mainly includes: a DC motor and a reducer, a safety clutch, a lead screw nut, an energy storage spring, a crank slider mechanism, a rotary dynamic seal assembly, and a push arm.

[0068] The pressure-resistant shell is in the shape of a long cylinder as a whole. The circular cross-section can improve the overall pressure resistance of the shell, reduce the manufacturing difficulty, and improve the manufacturing economy.

[0069] The rotating shaft passes through the pressure-resistant shell to install the push arm on the pressure-resistant shell. The rotating shaft is installed in the hole of the pressure-resistant shell. The rotating seal assembly is sleeved on the rotating shaft and installed in the hole. The rotating seal assembly is used to realize dynamic sealing between the rotating shaft and the pressure-resistant shell when the push arm rotates in the high-pressure environment underground.

[0070] The crank slider mechanism consists of a crank rod, a connecting rod, and a slider. One end of the crank rod is connected to the shaft, and the other end is connected to the connecting rod. The other end of the connecting rod is connected to the slider. The screw nut is connected to the energy storage spring and the slider.

[0071] The input end of the screw rod and the bearing are installed in the bearing seat and then installed in the pressure-resistant housing. One end of the safety clutch is connected to the screw rod, and the other end is connected to the reducer, and the tail end of the reducer is connected to the DC motor.

[0072] When the push arm cannot be recovered normally due to obstruction or motor failure during the instrument recovery process, the safety clutch will be compressed by the recovery pulling force, and then the lead screw nut will be reversed to make the safety clutch slip and disengage, so as to realize the recovery of the push arm and successfully recover the seismic acquisition instrument in the well.

[0073] The following are several specific embodiments of the present invention.

[0074] Example 1

[0075] In a specific embodiment 1 of the present invention, Figure 1 As shown, during installation, the pressure-resistant shell 1 has a hole, the rotating shaft 3 passes through the pressure-resistant shell 1, and the pushing arm 4 is installed on the pressure-resistant shell 1, and the rotating shaft 3 is installed in the hole of the pressure-resistant shell 1.

[0076] The rotary seal assembly 2 is sleeved on the rotary shaft 3 and installed in the hole. The rotary seal assembly 2 is used to realize dynamic sealing between the rotary shaft 3 and the pressure-resistant housing 1 when the push arm 4 rotates in an underground high-pressure environment.

[0077] The crank rod 5, the connecting rod 6 and the slider 7 form a crank slider mechanism. One end of the crank rod 5 is connected to the rotating shaft 3, and the other end is connected to the connecting rod 6, and the other end of the connecting rod 6 is connected to the slider 7.

[0078] The other end of the slider 7 is connected to the screw nut 8, and the other end of the screw nut 8 is connected to the energy storage spring 9.

[0079] The other end of the energy storage spring 9 is connected to the screw rod 10 , and the rear input end of the screw rod 10 and the bearing are installed in the bearing seat 11 .

[0080] One end of the safety clutch 12 is connected to the screw rod 10 through the bearing seat 11, and the other end is connected to the reducer 13, and the tail end of the reducer 13 is connected to the DC motor.

[0081] The above components are connected in sequence and then installed in the pressure-resistant casing 1.

[0082] Example 2

[0083] In a specific embodiment 2 of the present invention, the working process of the present invention is that under the instruction of the ground controller, the DC motor is controlled by the winch cable (this part is not drawn), the DC motor rotates to output torque to drive the screw nut 8, and then the screw nut 8 pulls (pushes) the crank slider mechanism to move, and the crank slider mechanism is composed of a crank rod 5, a connecting rod 6, and a slider 7 connected in sequence, thereby realizing the opening of the push arm 4; when the push arm 4 is opened and contacts with the wellbore (or casing wall), the screw nut 8 compresses the energy storage spring 9, and the energy storage spring 9 starts to store energy. When the flow motor stops working, the energy storage spring 9 will always provide continuous elastic energy for the push arm 4, provide the coupling force required for the well seismic acquisition instrument to the wellbore (or casing wall), and realize the coupling between the well seismic acquisition instrument and the wellbore (or casing wall); the well seismic acquisition instrument completes the measurement work, and under the instruction of the ground controller, controls the DC motor to rotate and output torque to drive the screw nut 8, and then the screw nut 8 pushes (pull) the crank slider mechanism (composed of crank rod 5, connecting rod 6, and slider 7 connected in sequence) to move, thereby realizing the retraction of the push arm 4. When the well seismic acquisition instrument encounters resistance or the DC motor fails during the recovery process, causing the push arm 4 to fail to be recovered normally, the safety clutch 12 will press the push arm 4 under the action of the recovery pulling force, and then pull the screw nut 8 to reverse so that the safety clutch 12 slips and disengages, realizing the retraction of the push arm 4, thereby smoothly recovering the well seismic acquisition instrument.

[0084] Example 3

[0085] In a specific embodiment 3 of the present invention, the present invention provides a design method for optimizing the size parameters of each mechanism component of the push arm system.

[0086] The force analysis of the push arm is carried out. When the push arm is opened underground, it forms a reliable coupling with the casing wall. At this time, the state of the entire push system can be regarded as a static equilibrium state. Figure 2 The push arm system is simplified as shown below. Figure 3 The push-to-pull system actuator is simplified into the mechanical model shown in the figure.

[0087] 1. Take the entire push-to-pull system as the research object and conduct a force analysis on the model. Figure 3 :

[0088] Take point O to establish a rectangular coordinate system, because the system is in equilibrium.

[0089] ∑M o =0 NL3cosα3=N1(L1cosα1+L2cosα2)+Fh

[0090] F: The pulling force of the screw on the sleeve slider

[0091] N: Positive pressure of the well wall on the push arm

[0092] L1: connecting rod length

[0093] L2 : Crank length

[0094] L3- Push arm length

[0095] α1: Angle between connecting rod and horizontal

[0096] α2 : Angle between crank and horizontal

[0097] ψ: Angle between the push arm and the crank

[0098] h: The offset between the slider and the crank's rotation center

[0099] l- Distance from the rotation point of the push arm to the well wall

[0100] F2: The slider is subjected to the pulling force of the connecting rod

[0101] O: Push arm opening and closing rotation center point

[0102] M O :Resultant force and moment at point O.

[0103] 2. Take the slider as the research object and conduct force analysis. Figure 4 , establish the equilibrium equation:

[0104] ∑F x =0 F = F2cosα1

[0105] ∑F y =0 N = F2sinα1

[0106] have to:

[0107] N1=Ftanα1

[0108] 3. According to the geometric relationship:

[0109]

[0110] L1sinα1+h=L2sinα2

[0111] According to 1.2:

[0112] NL3cosα3=Ftanα1(L1cosα1+L2cosα2)+Fh

[0113]

[0114] Substituting h = L2sinα2-L1sinα1 into the above formula, we can get:

[0115]

[0116] From this, we can get the analytical expression of the ratio of the screw rod pulling force F on the slider to the positive pressure N:

[0117]

[0118]

[0119] The optimization goal is to minimize the K value while satisfying the pushing force.

[0120] The analysis shows that the Kmin value is greatly affected by L3 and L2, while h and L1 have little effect on Kmin. The crank slider mechanism is restricted by the constraints of the outer diameter and the mechanism components. L2 takes the maximum value within the value range. Considering the unknown situation in the casing and the safe and smooth recovery, the range of the push arm deployment angle α3 is The expansion angle of the push arm during actual underground operation The length of the push arm is affected by the inner diameter of the sleeve. When the inner diameter Φd of the sleeve is known, the length of the push arm within the optimal working angle can be obtained as L3=lsinα3. At this time, α2 is used as the independent variable to find the minimum point and obtain the Kmin value.

[0121] In actual use, the pushing arm of appropriate length can be replaced according to the casing diameter of the operating well to provide the required pushing force.

[0122] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0123] Except for the technical features described in the specification, all other technical features are known technologies to those skilled in the art.

Claims

1. A push arm mechanism, characterized in that: The pushing arm mechanism includes a rotating shaft, a pressure-resistant shell, a pushing arm, a crank slider mechanism, a screw nut and a DC motor. The rotating shaft passes through the pressure-resistant shell to install the pushing arm on the pressure-resistant shell. One end of the crank slider mechanism is connected to the rotating shaft, and the other end is connected to one end of the screw nut. The DC motor rotates to output torque to drive the screw nut, and then the screw nut pushes the crank slider mechanism to move, so that the pushing arm is opened and retracted.

2. The push arm mechanism according to claim 1, characterized in that: The pressure-resistant shell is in the shape of a long cylinder as a whole. A hole is provided on the pressure-resistant shell, and the rotating shaft is installed in the hole of the pressure-resistant shell.

3. The push arm mechanism according to claim 2, characterized in that: The push arm mechanism also includes a rotary dynamic seal assembly, which is sleeved on the rotating shaft and installed in the hole of the pressure-resistant shell. The rotary seal assembly is used to achieve dynamic sealing between the rotating shaft and the pressure-resistant shell when the push arm rotates in a high-pressure environment underground.

4. The push arm mechanism according to claim 1, characterized in that: The push arm mechanism also includes an energy storage spring, a screw rod, a bearing and a bearing seat. One end of the energy storage spring is connected to the other end of the screw rod nut, and the other end of the energy storage spring is connected to the screw rod. The tail input end of the screw rod and the bearing are installed in the bearing seat and then installed in the pressure-resistant shell.

5. The push arm mechanism according to claim 4, characterized in that: The push arm mechanism also includes a safety clutch and a reducer. One end of the safety clutch is connected to the screw rod, and the other end is connected to the reducer. The tail end of the reducer is connected to the DC motor. The reducer reduces the high speed output by the DC motor and increases the output torque.

6. The push arm mechanism according to claim 5, characterized in that: The crank slider mechanism comprises a crank rod, a connecting rod and a slider, wherein one end of the crank rod is connected to the rotating shaft, and the other end is connected to one end of the connecting rod, the other end of the connecting rod is connected to one end of the slider, and the other end of the slider is connected to the screw nut.

7. The push arm mechanism according to claim 5, characterized in that: After receiving the control signal for opening the push arm, the DC motor rotates to output torque to drive the lead screw nut, and then the lead screw nut pulls the crank slider mechanism to move, thereby realizing the opening of the push arm.

8. The push arm mechanism according to claim 7, characterized in that: When the pushing arm opens and contacts the wellbore or casing wall, the screw nut compresses the energy storage spring, and the energy storage spring starts to store energy. When the DC motor stops working, the energy storage spring will always provide continuous elastic energy for the pushing arm, providing the required coupling force for the in-well seismic acquisition instrument with the wellbore or casing wall, thereby realizing the coupling of the in-well seismic acquisition instrument with the wellbore or casing wall.

9. The push arm mechanism according to claim 5, characterized in that: After receiving the control signal for retracting the push arm, the DC motor rotates and outputs torque to drive the lead screw nut, and then the lead screw nut drives the crank slider mechanism to move, thereby realizing the retraction of the push arm.

10. The push arm mechanism according to claim 5, characterized in that: When the push arm cannot be recovered normally, the safety clutch will compress the push arm under the action of the recovery pulling force, and then pull the screw nut to reverse so that the safety clutch slips and disengages, thereby realizing the recovery of the push arm, thereby smoothly recovering the seismic acquisition instrument in the well.

11. A method for designing a push arm mechanism, characterized in that: The design method of the push-to-arm mechanism designs the push-to-arm mechanism described in claim 1, comprising: Step 1, when the push arm of the logging instrument in the vertical cased well is in an open state, the entire push arm mechanism is regarded as a crank slider mechanism, the gravity of the mechanism itself is ignored, and the casing wall and all parts of the push arm are regarded as rigid bodies; Step 2, establish a rectangular coordinate system of the push arm mechanism, with the push arm opening and closing rotation center point regarded as the origin O, the instrument axis regarded as the X-axis, the positive direction of the X-axis points from the origin to the screw direction and is parallel to the screw axis, and the Y-axis passes through the origin and is opposite to the positive pressure N of the casing wall on the push arm; Step 3: Take the entire push-pull system as the research object and perform a stress analysis on the model.

12. The design method of the push arm mechanism according to claim 11, characterized in that: In step 3, a rectangular coordinate system is established. Since the system is in a state of equilibrium, the main forces acting on the entire system are the positive pressure N of the casing wall on the push arm and the tension F of the screw rod on the slider. N1 is the support force on the slider, F2 is the tension of the slider on the connecting rod, the connecting rod length L1, the crank length L2, the push arm length L3, the connecting rod and the horizontal angle α1, the crank and the horizontal angle α2, the push arm opening angle α3, the push arm and the crank angle ψ, the slider offset h, and the distance l from the push arm rotation point to the well wall. The rectangular coordinate system is established by taking the push arm opening and closing rotation center point O. Since the system is in a state of equilibrium, the necessary and sufficient conditions for the equilibrium of the plane force system show that the resultant force moment M at point O O is zero, and the equilibrium equation is established: ∑M o =0NL3cosα3=N1(L1cosα1+L2cosα2)+Fh。 13. The design method of the push arm mechanism according to claim 12, characterized in that: Step 3 includes: Step 31, take the slider as the research object and conduct force analysis. F2 is the tension of the slider on the connecting rod, and establish the equilibrium equation: ∑F x =0 F=F2cosα1 ∑F y =0 N=F2sinα1 have to: N1=Ftanα1 Step 32, according to the geometric relationship: L1sinα1+h=L2sinα2 Step 33, according to steps 31 and 32: NL3cosα3=Ftanα1(L1cosα1+L2cosα2)+Fh Substituting h = L2sinα2-L1sinα1 into the above formula, we can get: From this, we can get the analytical expression of the ratio of the screw rod pulling force F on the slider to the positive pressure N: The optimization goal is to minimize the K value while satisfying the pushing force.

14. The design method of the push arm mechanism according to claim 13, characterized in that: In step 33, it is found that the Kmin value is greatly affected by L3 and L2, while h and L1 have little effect on Kmin. The crank slider mechanism is restricted by the constraints of the outer diameter and the mechanism components. L2 takes the maximum value within the value range. Considering the unknown situation in the casing and the safe and smooth recovery, the push arm deployment angle α3 takes the value range of The expansion angle of the push arm during actual underground operation The length of the push arm is affected by the inner diameter of the sleeve. When the inner diameter Φd of the sleeve is known, the length of the push arm within the optimal working angle can be obtained as L3=lsinα3. At this time, α2 is used as the independent variable to find the minimum point and obtain the Kmin value.

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