A horizontal well automatic drilling system device and control method based on bottom hole drilling pressure

Abstract

A horizontal well automatic drilling system device and control method based on bottom hole drilling pressure, comprising a derrick arranged on an upper plate, a safety fence arranged on the top of the derrick, a pulley arranged on one side of the safety fence, a steel wire rope passing through the pulley, one end of the steel wire rope connected to the winch drum, and the other end connected to a large hook, the lower end of the large hook load is connected to a tension sensor, the lower end of the tension sensor is connected to a drill string, and the end of the drill string is a drill bit. The present invention improves the mechanical drilling speed, maintains stable drilling of the downhole drilling tool assembly, and ultimately achieves the purpose of real-time and accurate control of the bottom hole drilling pressure.

Description

Technical Field

[0001] The present invention relates to the fields of intelligent automatic drill feeding system and drilling rig automation technology, and in particular to a horizontal well automatic drill feeding system device based on bottom hole drilling pressure and a control method. Background Art

[0002] Horizontal wells have large friction and are not easy to apply bottomhole drilling pressure. The drilling pressure given by the conventional five-point test drilling method or driller experience is less accurate, which can easily lead to a large difference between the bottomhole drilling pressure and the ground drilling pressure, and it is impossible to obtain a more accurate bottomhole drilling pressure: the drill bit performance cannot be fully utilized, resulting in too low rock breaking efficiency; excessive bottomhole drilling pressure will cause increased drill bit wear, making it difficult to apply drill bit load, resulting in a shorter drill tool life, especially affecting horizontal wells on land. The relationship between the bottomhole drilling pressure and the ground drilling pressure during horizontal well drilling is very complicated, and the difference between the bottomhole drilling pressure and the ground drilling pressure cannot be ignored. Summary of the invention

[0003] In order to overcome the deficiencies of the above-mentioned prior art, the object of the present invention is to provide a horizontal well automatic drilling system device and control method based on bottom hole drilling pressure, so as to improve the mechanical drilling speed, maintain stable drilling of the downhole drilling tool assembly, and ultimately achieve the purpose of real-time and accurate control of bottom hole drilling pressure.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A horizontal well automatic drilling system device based on bottom hole drilling pressure includes a derrick 6 arranged on an upper plate 18, a safety fence 2 is arranged on the top of the derrick 6, a pulley 1 is arranged on one side of the safety fence 2, a steel wire rope 3 passes through the pulley 1, one end of the steel wire rope 3 is connected to a winch drum 13, and the other end is connected to a large hook 4, the lower end of the large hook 4 is connected to a large hook load sensor 5, the lower end of the large hook load sensor 5 is connected to a drill string 12, and the end of the drill string 12 is a drill bit 22.

[0006] The winch drum 13 is connected to a stepper motor 15 via a coupling 14 .

[0007] The stepper motor 15 is controlled by a control box 7 , and a touch screen 8 is provided on the control box 7 .

[0008] The pressure detected by the hook load sensor 5 is transmitted to the smart meter 16.

[0009] A wellbore 19 is arranged outside the drill string 12. The wellbore 19 is a plexiglass tube. The drill string 12 is made of an extended curved tube spring.

[0010] A bottom hole pressure sensor 21 for detecting drilling pressure is disposed at the front end of the drill bit 22 . The bottom hole pressure sensor 21 directly displays the bottom hole drilling pressure on the hook load display instrument 17 .

[0011] A control method for a horizontal well automatic drilling system based on bottom hole drilling pressure comprises the following steps;

[0012] Step 1:

[0013] Determine the drillability range under a certain wellbore structure: set the ideal bottom hole drilling pressure with equal tolerance from small to large on the touch screen 8, measure the real values ​​of the bottom hole drilling pressure and the hook load through the bottom hole drilling pressure sensor 21 and the hook load sensor 5, repeat the test for many times, and record the average real value of the bottom hole drilling pressure and the average real value of the hook load;

[0014] The downhole drilling pressure sensor 21 converts the force signal of the downhole drilling pressure into a current signal through the downhole drilling pressure display instrument 16 and transmits it to the control box 7 to realize monitoring and input on the touch screen 8; the hook load sensor 5 converts the force signal on the hook into a current signal through the hook load display instrument 17 and transmits it to the control box 7 to realize monitoring and input on the touch screen 8;

[0015] Step 2:

[0016] Determine the regression equation, take the average true value of the hook load obtained in the previous step as the setting reference of the hook load, set ideal hook loads with equal tolerances from large to small on the touch screen 8 of the control box 7, measure the true values ​​of the bottom hole drilling pressure and the hook load through the bottom hole drilling pressure sensor 21 and the hook load sensor 5, repeat the test for many times, record the average true value of the bottom hole drilling pressure and the average true value of the hook load, and fit the regression equation of the hook load and the bottom hole drilling pressure under the wellbore structure according to the recorded average true value of the hook load and the average true value of the bottom hole drilling pressure;

[0017] Step 3:

[0018] The bottom hole drilling pressure is predicted. The big hook load value under different bottom hole drilling pressures can be predicted according to the regression equation, and the big hook load is directly input on the touch screen 8 on the control box 7 to control and realize the automatic drilling based on the bottom hole drilling pressure. This system is called the automatic drilling system based on the bottom hole drilling pressure.

[0019] Beneficial effects of the present invention:

[0020] In the process of horizontal well drilling, the present invention can directly obtain the optimal surface drilling pressure that should be input according to the drilling pressure recommended by the drill bit at the factory, combined with the regression equation fitted between the bottom hole drilling pressure and the hook load. The drilling pressure obtained by the automatic drill feeding system based on the bottom hole drilling pressure of the horizontal well is both accurate and can be automatically input. Under certain circumstances, the cumbersome test drilling method can be reduced or even eliminated. The performance of the drill bit can be fully utilized, the mechanical drilling speed can be improved, and the stable drilling of the downhole drilling tool assembly can be maintained, and the purpose of real-time and accurate control of the bottom hole drilling pressure can be finally achieved. Thereby shortening the drilling time and ultimately saving the drilling cost.

[0021] In the process of automatic drilling, accurate control of the bottom hole drilling pressure can be achieved. The device can obtain the ground drilling pressure through the prediction of the bottom hole drilling pressure. When drilling a horizontal well with the same drilling conditions next time, the ground drilling pressure can be directly input to obtain accurate bottom hole drilling pressure, ensuring economy while greatly improving safety. The automatic drilling system based on bottom hole drilling pressure makes drilling more automated, and provides new theoretical calculations and technical support for accelerating the pace of intelligent drilling in my country and improving unconventional horizontal well drilling technology. It has the characteristics of simple structure, convenient operation and easy implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the structure of the automatic drilling system for horizontal wells based on bottom hole drilling pressure.

[0023] Figure 2 This is a schematic diagram of the structure of a roller drill bit.

[0024] Figure 3 It is a schematic diagram of the regression equation curve of bottom hole drilling pressure and hook load. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0026] Reference Figure 1 , an automatic drill feeding system device based on bottom hole drilling pressure; including drilling pressure loading system, wellbore simulation system, monitoring system, control system, and detection system.

[0027] The drilling pressure loading system includes a stepper motor 15, which is connected to the winch drum 13 through a coupling 14 so that the wire rope 3 is retracted and released to drive the hook 4 to move up and down through the pulley 1. The control box 7 sets different hook loads through the touch screen 8 to drive the motor 15 to adjust the bottom hole drilling pressure, and provides tension for the hook load, applies pressure to the bottom hole drill bit, and then directly displays the bottom hole drilling pressure on the hook load display instrument 17 through the bottom hole pressure sensor 22. The hook 4 measured by the hook load sensor 5 is directly displayed on the intelligent instrument 16. By adjusting the stepper motor 15, real drilling can be simulated to display the corresponding bottom hole drilling pressure values ​​under different hook loads.

[0028] The wellbore simulation system is the main system of the drill string test device, which can be used to observe the movement state of the drill string in the wellbore and adjust the wellbore structure. The pulley 1 and the safety fence 2 are welded and fixed on the upper plate 18 together with the derrick 6; the bottom drilling tool assembly consists of a drill string 12, a wellbore 18, a drill bit 21 and a wellbore fixed guide rail 23. The drill string 12 is made of an extended curved spring material, and the wellbore 19 is a plexiglass tube. The movement of the drill string 12 can be effectively observed.

[0029] The detection system is composed of a hook load sensor 5, a bottom hole drilling pressure detection pressure sensor 22, a control box 7, a touch screen 8 and intelligent instruments 16, 17. The hook load sensor 5 is installed between the hook 4 and the drill string 12 to detect the hook load; one end of the bottom hole drilling pressure sensor is fixed on the guide rail 23, and the other end detects the drilling pressure of the roller drill bit 22 after the drill string is lowered, that is, the bottom hole drilling pressure; the control box 7 is used to detect the pressure signals fed back by the two sensors through the intelligent instruments 16, 17. Its beneficial effect is that the hook load and the bottom hole drilling pressure signal can be detected quickly and accurately.

[0030] The control system is composed of a control box 7, a touch screen 8 and intelligent instruments 16 and 17. After being programmed, the programmable controller in the control box 7 can directly input the ideal hook load and bottom drilling pressure on the touch screen by feeding back the signals obtained through the intelligent instruments 16 and 17, which has the beneficial effect of controlling the starting and ending of the drill string 12 in real time.

[0031] The control box 7 is equipped with a programmable controller, the model of the programmable controller is SIMATIC S7-200SMART, and the CPU is ST20; the model of the touch screen 8 is Smart-700IE-V30; the model of the stepper motor 15 is 57BYGH711AA; the model of the bottom hole drilling pressure force sensor 22 is DHZ-101; the model of the tension and pressure sensor 5 at the big hook end is DH4011 / TJL-1s, and the models of the intelligent instrument 16 and the big hook load display instrument 17 are both DH300 type high-precision measuring instruments.

[0032] The present invention simulates the relationship between the surface drilling pressure and the bottom hole drilling pressure during the horizontal well drilling process through a unique device. In similar wellbores, the corresponding surface target drilling pressure can be directly predicted and input to obtain the accurate bottom hole drilling pressure, so that the bottom hole drilling pressure can be accurately controlled. Therefore, it is necessary to study a horizontal well automatic drilling system device based on the bottom hole drilling pressure.

[0033] like Figure 2 As shown, the drill bit 22 is a roller drill bit.

[0034] like Figure 3As shown in the figure, in the regression equation, X is the hook load, unit N, and Y is the bottom hole drilling pressure, unit N. B1 and B2 are the coefficients of the first and second terms of the regression equation respectively. R square is called the coefficient of determination. The R square value is a value ranging from 0 to 1. When the R square value of the trend line is equal to 1 or close to 1, its reliability is the highest, otherwise the reliability is low.

[0035] Working principle of the present invention:

[0036] An automatic drilling system for horizontal wells based on bottom hole drilling pressure is designed based on similarity principle, combined with static analysis, dynamic analysis and kinematic analysis to simulate different wellbore structures. This device includes a lifting system, a power drive system, a transmission system, a horizontal wellbore simulation system, a control system and monitoring instruments. The well depth simulation system includes a vertical well section, a curved well section and a horizontal well section. Therefore, the test device can simulate the relationship between the bottom hole drilling pressure and the ground drilling pressure of a complete horizontal well to achieve accurate control of the bottom hole drilling pressure. It has the characteristics of simple structure, convenient operation and easy implementation.

[0037] The control box 7 collects the force signals of the hook load and the bottom hole drilling pressure sensor 21 transmitted by the intelligent instrument 16 and the hook load display instrument 17 from the hook 4 end, and realizes the modification of the two forces on the touch screen 8, thereby outputting a signal to control the motor 15 to stop, and controlling the rotation of the winch drum 13 through the coupling 14, retracting and releasing the wire rope 3 so that the hook 4 and the drill string 13 tighten the hook sensor 5 and transmit the signal, and at the same time, the drill string 8 is lifted and lowered to drive the roller drill bit 21 to apply pressure to the bottom hole drilling pressure sensor 21; by setting different loads at the end of the hook 5 to record the corresponding drilling pressure of the bottom hole sensor 22, multiple groups of tests are performed to fit the regression equation between the two. Finally, the bottom hole drilling pressure is predicted by the fitted regression equation, and the manual input of the load at the end of the hook 5 is realized, and the accurate bottom hole drilling pressure can be obtained, so as to realize the accurate prediction and control of the bottom hole drilling pressure. This device achieves the purpose of accurately controlling the bottom hole drilling pressure, and provides an effective reference idea for future automated drilling technology in combination with the conventional automatic drilling system.

[0038] The control box 7 is equipped with SIEMENS S7-200 Smart PLC as a controller to control the motor. It also communicates with the Smart-700IE-V30 touch screen, and the motor forward and reverse rotation and speed setting can be realized through the touch screen. The large hook load and bottom drilling pressure and other functions can be freely set according to the sensor to achieve stable, fast and accurate feedback. Strictly follow the electrical specifications and reasonably layout the electrical components: PLC and touch screen are installed in the control cabinet to ensure safety and stability, neat and beautiful wiring, reasonable placement of components, and different wires are distinguished by wire marks for debugging and subsequent inspection and repair. At the same time, this platform grounds the metal casing to ensure the personal safety of the test personnel.

Claims

1. A control method for a horizontal well automatic drilling system based on bottom hole drilling pressure, characterized in that: The steps include: Step 1: Determine the drillability range of a certain wellbore structure: set ideal bottom hole drilling pressures with equal tolerances from small to large on the touch screen (8), measure the real values ​​of the bottom hole drilling pressure and the hook load through the bottom hole pressure sensor (21) and the hook load sensor (5), perform repeated tests, and record the average real value of the bottom hole drilling pressure and the average real value of the hook load; The bottom hole pressure sensor (21) converts the bottom hole drilling pressure force signal into a current signal through the bottom hole drilling pressure display instrument (16) and transmits it to the control box (7) to realize monitoring and input on the touch screen (8); the hook load sensor (5) converts the hook force signal into a current signal through the hook load display instrument (17) and transmits it to the control box (7) to realize monitoring and input on the touch screen (8); Step 2: Determine the regression equation, use the average true value of the hook load obtained in the previous step as the setting reference of the hook load, set ideal hook loads with equal tolerances from large to small on the touch screen (8) of the control box (7), measure the bottom hole drilling pressure and the true value of the hook load through the bottom hole pressure sensor (21) and the hook load sensor (5), repeat the test for many times, record the average true value of the bottom hole drilling pressure and the average true value of the hook load, and fit the regression equation of the hook load and the bottom hole drilling pressure under the wellbore structure based on the recorded average true value of the hook load and the average true value of the bottom hole drilling pressure; Step 3: The bottom hole drilling pressure is predicted, and the hook load value under different bottom hole drilling pressures is predicted according to the regression equation, and the hook load is directly input on the touch screen (8) on the control box (7), so as to control and realize automatic drilling based on the bottom hole drilling pressure. This system is called an automatic drilling system based on bottom hole drilling pressure; The automatic drilling system based on bottom hole drilling pressure comprises a derrick (6) arranged on an upper plate (18), a safety fence (2) being arranged on the top of the derrick (6), a pulley (1) being arranged on one side of the safety fence (2), a steel wire rope (3) passing through the pulley (1), one end of the steel wire rope (3) being connected to a winch drum (13), and the other end being connected to a hook (4), the hook (4) being connected to a hook load sensor (5), the lower end of the hook load sensor (5) being connected to a drill string (12), and the end of the drill string (12) being a drill bit (22); The winch drum (13) is connected to a stepper motor (15) via a coupling (14); The stepper motor (15) is controlled by a control box (7), and a touch screen (8) is provided on the control box (7); The pressure detected by the hook load sensor (5) is transmitted to the drilling pressure display instrument (16) at the bottom of the well; A wellbore (19) is arranged outside the drill string (12), the wellbore (19) is a plexiglass tube, and the drill string (12) is made of an extended curved tube spring material; A bottom hole pressure sensor (21) for detecting drilling pressure is arranged at the front end of the drill bit (22); the bottom hole pressure sensor (21) directly displays the bottom hole drilling pressure on the hook load display instrument (17).

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