CN103941634A - System and method based on internal model control method to restrain stick-slip vibration of drill stems - Google Patents

Abstract

The invention discloses a system and method based on an internal model control method to restrain stick-slip vibration of drill stems. The method comprises the steps that a frequency converter gives out the main given rotation speed of a motor through a PLC control system, the main given rotation speed is transmitted to a controlled object to obtain the actual rotation speed of the motor and the actual torque of the motor, the frequency converter can transmit the actual torque of the motor to a control unit, meanwhile a man-machine interaction device can transmit drill stem and drill tool combination structure information to the control unit, the control unit can carry out optimization operation on the achieved actual torque of the motor and the drill stem and drill tool combination structure information to obtain the auxiliary given optimized rotation speed, the control unit can transmit the auxiliary given optimized rotation speed to the frequency converter through a CAN bus, the auxiliary given optimized rotation speed is overlapped with the main given rotation speed of the motor, and the overlapped rotation speed can control the rotation speed for driving the motor. The method can control the actual output of the system to be constantly equal to the expected output, the actual rotation speed and the actual torque of the motor can be displayed in real time, and accordingly the purpose of restraining the stick-slip vibration of the drill stems can be achieved.

Description

A kind of system and method that suppresses the vibration of drilling rod stick-slip based on internal model control method

Technical field

The invention belongs to the technical fields such as petroleum drilling, geologic prospecting, relate to a kind of system and method that suppresses the vibration of drilling rod stick-slip based on internal model control method, bus communication technology and human-computer interaction technology.

Background technology

In Process of Oil Well Drilling, because the motion of complex formation, drilling rod is uncertain, easily there is drilling rod vibration, comprise transverse vibration, axial vibration and the stick-slip vibration of drilling rod.Wherein, stick-slip vibration is the torque oscillation that the moment of friction due to drill bit and stratum causes, bit speed or stop or turn, moment rotating speed very large, easily cause the performance deterioration of drilling rod and drill bit; This phenomenon not only affects the safety that drilling efficiency also threatens drilling well, therefore need to take rational method to suppress stick-slip vibration.

For stick-slip vibration, vibration damping approach and measure mainly contain: (1) increases top rotating speed; (2) increase system equivalence torsional rigidity; (3) increase system equivalent damping; (4) top moment of torsion negative feedback.

Develop at present some abroad and suppressed the method and system of stick-slip vibration.

Navarro-Lo ' pez in 2004 and Suarez-Cortez propose at drilling rod bottom mounting dampers; 2000, Richardson and K ü ttel proposed to install hydraulic torque drive system on make-up of string.But these methods have all increased complicacy and the cost of drilling rod system, and do not there is versatility while using.

Halsey in 1988, Kyllingstad and Kylling have proposed the degenerative method of drilling rod moment of torsion; Canudas-de-Wit et al in 2005 has proposed drilling well vibration jinx Drilling Oscillation Killer (D-OSKIL), and it utilizes weight on drill bit as additional control parameter.That these methods have and immature, result of use is not very good yet.The domestic research in field at present is also relatively short of, so the research and development of this respect have good engineering using value.

Summary of the invention

The object of the invention is for the normal stick-slip oscillation phenomenon occurring in petroleum drilling, a kind of system and method that suppresses the vibration of drilling rod stick-slip based on internal model control method is provided, adopt system of the present invention, can obtain exactly actual drilling rod parameter, show in real time motor actual speed and motor actual torque curve and numerical value, can send rotating speed order and control drive motor, thus torque oscillation and the speed oscillation of inhibition drilling rod and make-up of string.This system solved in prior art hardware connect complicated, system works is unstable, realize the undesirable problem of effect.

In order to realize technique scheme, the present invention takes following technical solution:

A system that suppresses the vibration of drilling rod stick-slip based on internal model control method, comprising:

---controlled device, comprise the gear case that drive motor connects, and the drilling rod being driven by gear case and make-up of string, for realizing petroleum drilling;

---frequency converter, comprise PLC control system, PLC control system control drive motor startup, stop the duty with speed governing, and set the main given rotating speed of motor, frequency converter feeds back to control module by the current state of drive motor;

---control module, comprise internal mode controller, internal mode controller, for the current state of drive motor is controlled to adjustment, suppresses torque oscillation and the speed oscillation of drilling rod and make-up of string;

---human-computer interaction device, comprise ARM chip, complete the data management of control module, man-machine controlling;

---CAN bus, for realizing the free communication of frequency converter and control module;

Described frequency converter is connected with drive motor, and drive motor is connected with make-up of string with the drilling rod being driven by gear case, and frequency converter is by CAN bus connection control unit, and control module connects human-computer interaction device by serial ports.

Further, described internal mode controller comprises feedforward internal mode controller, multiplier and feedback filter, feedforward internal mode controller is connected with multiplier with frequency converter respectively, and frequency converter connects respectively controlled device, multiplier and feedback filter, and feedback filter is connected to feedforward internal mode controller.

Feedforward internal mode controller obtains motor expectation rotating speed and auxiliary given optimization rotating speed according to the main given rotating speed of the motor of inverter PLC control default, auxiliary given optimization rotating speed exports frequency converter to, motor expectation rotating speed exports multiplier to, and the two difference of the output quantity motor actual torque of frequency converter and the output quantity motor of multiplier expectation moment of torsion transfers to feedforward internal mode controller through feedback filter and circulates; Simultaneously, auxiliary given optimization rotating speed is transferred to frequency converter, and with maximum (top) speed, auxiliary given optimization rotating speed carrying out to amplitude limit, the stack rotating speed co-controlling drilling rod of the auxiliary given optimization rotating speed after the main given rotating speed of motor and amplitude limit and the rotary drilling of make-up of string, suppress the vibration of drilling rod stick-slip.

Correspondingly, the present invention and then provided the control method that internal model control method suppresses the system of drilling rod stick-slip vibration, the method comprises the steps:

1) frequency converter provides the main given rotating speed of motor of setting by PLC control system, transfers to controlled device, drives drilling rod to run up;

2) frequency converter transfers to control module by CAN bus by motor actual torque;

3) simultaneously, human-computer interaction device by drilling rod and structure of downhole assembly communication to control module;

4) control module will obtain motor actual torque and drilling rod and structure of downhole assembly information and be optimized computing, obtain auxiliary given optimization rotating speed,, and with maximum (top) speed, auxiliary given optimization rotating speed is carried out to amplitude limit;

5) control module transfers to frequency converter by CAN bus by the auxiliary given optimization rotating speed after amplitude limit, and the stack rotating speed co-controlling drilling rod of the auxiliary given optimization rotating speed after the main given rotating speed of motor and amplitude limit and the rotary drilling of make-up of string suppress the vibration of drilling rod stick-slip;

6) simultaneously, human-computer interaction device is preserved in real time and is shown motor actual speed and motor actual torque data.

Further, the optimization computing of described control module realizes by following method:

A) build multiplier, passing ratio gain Kn realizes;

B) build feedforward internal mode controller, feedforward internal mode controller obtains motor expectation rotating speed and auxiliary given optimization rotating speed according to the contrary of the main given rotating speed of the motor of inverter PLC control default and proportional gain Kn in conjunction with low-pass filter, through frequency converter, obtains motor actual torque;

C) motor expectation rotating speed exports multiplier to, obtains motor expectation moment of torsion;

D) build feedback filter, feedback filter expects that by motor the difference of moment of torsion and motor actual torque feeds back to feedforward internal mode controller and circulates;

E) feedforward internal mode controller is optimized computing by this difference, obtains auxiliary given optimization rotating speed.

Further, described multiplier is realized by proportional gain Kn, and method is as follows:

Kn＝m/n

In formula, m represents motor expectation moment of torsion, and n represents motor expectation rotating speed.

Described feedforward internal mode controller is as follows by the method against obtain motor expectation rotating speed and auxiliary given optimization rotating speed in conjunction with low-pass filter of the main given rotating speed of motor and proportional gain Kn:

1. build low-pass filter f (z):

$f\left(z\right)=\frac{1}{1-{\mathrm{\βz}}^{-1}}---\left(1\right)$

In formula, β is low-pass filter filtering factor, and z is auxiliary complex variable, and boundary condition is Kn*f (1)=1, can obtain thus the value of β;

2. build feedforward internal mode controller G _c(z):

$G_c\left(z\right)=\frac{y_c}{y_r}={\mathrm{Kn}}^{-1}f\left(z\right)---\left(2\right)$

In formula, f (z) is low-pass filter, y _cfor motor expectation rotating speed, y _rfor the main given rotating speed of motor;

3. obtain motor expectation rotating speed y _c:

y _c＝G _c(z)*y _r (3)；

4. obtain auxiliary given optimization rotating speed y:

y＝y _c-y _r (4)。

Further, described feedback filter construction method is as follows:

$G_f\left(s\right)=\frac{1}{\mathrm{Kn}}\frac{1-{\mathrm{\α}}_f}{1-{\mathrm{\α}}_f{z}^{-1}}---\left(5\right)$

In formula, G _f(s) be feedback filter, α _ffor feedback filter filtering factor, z ^-1contrary for auxiliary complex variable z.

With respect to prior art, feature of the present invention is:

(1) system of the present invention is the ground control technology based on top drive drilling technology, and hardware configuration is simple, without adding any bottom equipment, just can realize the vibration of inhibition drilling rod stick-slip;

(2) the present invention has adopted internal model control controller, and to drive PLC control system seamless integrated with existing frequency converter top, and its calculation process speed is fast, has good real-time performance;

(3) the present invention has adopted internal model control controller to be optimized computing, and the auxiliary given optimization rotating speed obtaining and the main given rotating speed superposing control of motor drive motor can suppress the vibration of drilling rod stick-slip effectively;

(4) transport function of controller is the contrary of multiplier transport function, and the actual output of control system is constantly equal to desired output, and irrelevant with multiplier and external disturbance, has good robustness and anti-interference ability;

(5) controller Internal Model Control Algorithm can access auxiliary given optimization rotating speed, and with motor maximum (top) speed, auxiliary given optimization rotating speed is carried out to amplitude limit, reaches the object of control on the basis that can guarantee security of system;

(6) there is human-computer interaction interface, simple operation, dirigibility is high;

(7) system communication is stable, has good anti-interference.

Accompanying drawing explanation

Fig. 1 is hardware configuration and overall system design figure;

Fig. 2 is stick-slip control system structural drawing;

Fig. 3 is the control curve of drilling rod stick-slip control system drilling rod moment of torsion;

Fig. 4 is the control curve of drilling rod stick-slip control system drill speed.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in detail.

As shown in Figure 1, the system that suppresses the vibration of drilling rod stick-slip based on internal model control method of the present invention, comprising:

Controlled device, comprises the gear case that drive motor connects, and the drilling rod being driven by gear case and make-up of string, for realizing petroleum drilling; Frequency converter, comprises PLC control system, PLC control system control drive motor startup, stop the duty with speed governing, and set the main given rotating speed of motor, frequency converter can feed back to control module by the current state of drive motor; Control module, comprises internal model control controller, for the current state of drive motor is controlled to adjustment, suppresses torque oscillation and the speed oscillation of drilling rod and make-up of string; Human-computer interaction device, comprises ARM chip, completes the data management of control module, man-machine controlling, and can obtain thus the structural information of drilling rod and make-up of string, can also preserve in real time and show the data such as motor actual speed and motor actual torque; CAN bus, for realizing the free communication of frequency converter and control module.Frequency converter is connected with drive motor, and drive motor is connected with make-up of string with the drilling rod being driven by gear case, and frequency converter is by CAN bus connection control unit, and control module connects human-computer interaction device by serial ports.

Wherein, control module is the core apparatus of control system, mainly by internal mode controller, adopts Internal Model Control Algorithm to realize.Internal mode controller comprises plant model, multiplier, feedforward internal mode controller, feedback filter.The motor expectation rotating speed of controller output is incorporated into controlled device, the auxiliary given optimization rotating speed of controller output is incorporated into multiplier, the output quantity of the two, be that drilling rod actual torque and drilling rod expectation moment of torsion are poor, the main given rotating speed of motor that difference is incorporated into controller and inverter PLC control default compares computing, obtain auxiliary given optimization rotating speed, and with maximum (top) speed, auxiliary given optimization rotating speed is carried out to amplitude limit, auxiliary given optimization rotating speed after amplitude limit is transferred to frequency converter, the stack rotating speed co-controlling drilling rod of the auxiliary given optimization rotating speed after the main given rotating speed of motor and amplitude limit and the rotary drilling of make-up of string, suppress the vibration of drilling rod stick-slip.As shown in Figure 2.

Under the present invention, mask body has provided the control method of the system of internal model control method inhibition drilling rod stick-slip vibration, comprises the steps:

1) frequency converter provides the main given rotating speed of motor of setting by PLC control system, transfers to controlled device, obtains motor actual speed and motor actual torque;

2) frequency converter transfers to control module by motor actual torque;

3) simultaneously, human-computer interaction device by drilling rod and structure of downhole assembly communication to control module;

4) control module is optimized computing by the motor actual torque obtaining and drilling rod and structure of downhole assembly information, obtains auxiliary given optimization rotating speed;

The optimization computing of control module realizes by following method:

A) build multiplier, passing ratio gain Kn realizes, and computing method are as follows:

Kn＝m/n

In formula, m represents motor expectation moment of torsion, and n represents motor expectation rotating speed;

B) build feedforward internal mode controller, feedforward internal mode controller obtains motor expectation rotating speed and auxiliary given optimization rotating speed according to the contrary of the main given rotating speed of the motor of inverter PLC control default and proportional gain Kn in conjunction with low-pass filter, and method is as follows:

1. build low-pass filter f (z):

$f\left(z\right)=\frac{1}{1-{\mathrm{\βz}}^{-1}}---\left(1\right)$

In formula, β is low-pass filter filtering factor, and z is auxiliary complex variable, and boundary condition is Kn*f (1)=1, can obtain thus the value of β;

2. build feedforward internal mode controller G _c(z):

$G_c\left(z\right)=\frac{y_c}{y_r}={\mathrm{Kn}}^{-1}f\left(z\right)---\left(2\right)$

In formula, f (z) is low-pass filter, y _cfor motor expectation rotating speed, y _rfor the main given rotating speed of motor;

3. obtain motor expectation rotating speed y _c:

y _c＝G _c(z)*y _r (3)；

4. obtain auxiliary given optimization rotating speed y:

y＝y _c-y _r (4)。

C) motor expectation rotating speed exports multiplier to, obtains motor expectation moment of torsion;

D) build feedback filter, feedback filter expects that by motor the difference of moment of torsion and motor actual torque feeds back to feedforward internal mode controller and circulates, and described feedback filter construction method is as follows:

$G_f\left(s\right)=\frac{1}{\mathrm{Kn}}\frac{1-{\mathrm{\α}}_f}{1-{\mathrm{\α}}_f{z}^{-1}}---\left(5\right)$

In formula, G _f(s) be feedback filter, α _ffor feedback filter filtering factor, z ^-1contrary for auxiliary complex variable z;

E) feedforward internal mode controller is optimized computing, obtains auxiliary given optimization rotating speed, and with maximum (top) speed, auxiliary given optimization rotating speed is carried out to amplitude limit;

5) control module transfers to frequency converter by CAN bus by the auxiliary given optimization rotating speed after amplitude limit, and the stack rotating speed co-controlling drilling rod of the auxiliary given optimization rotating speed after the main given rotating speed of motor and amplitude limit and the rotary drilling of make-up of string suppress the vibration of drilling rod stick-slip;

6) simultaneously, human-computer interaction device is preserved in real time and is shown the data such as motor speed and Motor torque.

Advantage of the present invention can further illustrate by following emulation experiment:

1. simulated conditions

Based on above analysis, built plant model, and set up the realistic model that drilling rod stick-slip is controlled.Frequency converter is inputted the main given rotating speed of motor before 100s, simulates stick-slip vibration mode, is input as the stack rotating speed of the main given rotating speed of motor and auxiliary given optimization rotating speed after 100s.Wherein, the main given rotating speed of motor is n=2000rpm, and the maximum (top) speed of auxiliary given optimization rotating speed is n _max=400rpm.

2. simulation result

Utilize above simulated conditions to set up control system model, the main given rotating speed of motor is input to after feedforward internal mode controller, the motor expectation rotating speed of feedforward internal mode controller output is incorporated into multiplier, the output quantity of the two, be that drilling rod actual torque and drilling rod expectation moment of torsion are poor, difference is incorporated into controller and carries out Internal Model Control Algorithm, obtains auxiliary given optimization rotating speed, the stack rotating speed that the main given rotating speed summation of auxiliary given optimization rotating speed and motor obtains is sent to frequency converter, and then controls drive motor.Drilling rod moment of torsion is controlled curve as shown in Figure 3, and drill speed is controlled curve as shown in Figure 4.

From figure, result can be found out, drilling rod moment of torsion and bit speed just enter steady state (SS) after 50s, and this controller can suppress stick-slip vibration rapidly and accurately as seen, and dynamic property and steady-state behaviour are good.

The above, be only the embodiment that the present invention is directed to the present invention's application, can make those skilled in the art more fully understand the present invention, but not the present invention be done to any restriction.According to technical solution of the present invention, above-described embodiment can be enumerated a lot of examples.Every according to the given scope of technical solution of the present invention with to any simple modifications and changes made for any of the above embodiments, all belong to the protection domain of technical solution of the present invention.A large amount of experimental results show that the scope proposing at the claims in the present invention book all can reach object of the present invention.

Claims (7)

1. based on internal model control method, suppress a system for drilling rod stick-slip vibration, it is characterized in that, comprising:

---controlled device, comprise the gear case that drive motor connects, and the drilling rod being driven by gear case and make-up of string, for realizing petroleum drilling;

---frequency converter, comprise PLC control system, PLC control system control drive motor startup, stop the duty with speed governing, and set the main given rotating speed of motor, frequency converter feeds back to control module by the current state of drive motor;

---control module, comprise internal mode controller, for the current state to drive motor, control, suppress torque oscillation and the speed oscillation of drilling rod and make-up of string;

---human-computer interaction device, comprise ARM chip, complete the data management of control module, man-machine controlling;

---CAN bus, for realizing the free communication of frequency converter and control module;

Described frequency converter is connected with drive motor, and drive motor is connected with make-up of string with the drilling rod being driven by gear case, and frequency converter is by CAN bus connection control unit, and control module connects human-computer interaction device by serial ports.

2. system according to claim 1, it is characterized in that, described internal mode controller comprises feedforward internal mode controller, multiplier and feedback filter, feedforward internal mode controller is connected with multiplier with frequency converter respectively, frequency converter connects respectively controlled device, multiplier and feedback filter, and feedback filter is connected to feedforward internal mode controller.

3. based on internal model control method described in claim 1, suppress the control method of the system of drilling rod stick-slip vibration, it is characterized in that, the method comprises the steps:

1) the main given rotating speed of motor that frequency converter is set by PLC control system transfers to controlled device, drives drilling rod to run up;

2) frequency converter transfers to control module by CAN bus by motor actual torque;

3) simultaneously, human-computer interaction device by drilling rod and structure of downhole assembly communication to control module;

4) control module is optimized computing to the motor actual torque obtaining and drilling rod and structure of downhole assembly information, obtains auxiliary given optimization rotating speed;

5) control module transfers to frequency converter by CAN bus by auxiliary given optimization rotating speed, and with maximum (top) speed, auxiliary given optimization rotating speed is carried out to amplitude limit, the stack rotating speed co-controlling drilling rod of the auxiliary given optimization rotating speed after the main given rotating speed of motor and amplitude limit and the rotary drilling of make-up of string, suppress the vibration of drilling rod stick-slip;

6) simultaneously, human-computer interaction device is preserved in real time and is shown motor actual speed and motor actual torque data.

4. method according to claim 3, is characterized in that, the optimization computing of described control module realizes by following method:

A) build multiplier, by proportional gain, Kn realizes;

B) build feedforward internal mode controller, feedforward internal mode controller obtains motor expectation rotating speed and auxiliary given optimization rotating speed according to the contrary of the main given rotating speed of the motor of inverter PLC control default and proportional gain Kn in conjunction with low-pass filter;

C) motor expectation rotating speed exports multiplier to, obtains motor expectation moment of torsion;

D) build feedback filter, feedback filter expects that by motor the difference of the motor actual torque that moment of torsion and frequency converter obtain feeds back to feedforward internal mode controller and circulates;

E) feedforward internal mode controller is optimized computing to this difference, obtains auxiliary given optimization rotating speed.

5. method according to claim 4, is characterized in that, described multiplier is realized by proportional gain Kn, and method is as follows:

Kn＝m/n

In formula, m represents motor expectation moment of torsion, and n represents motor expectation rotating speed.

6. according to the method described in claim 4 or 5, it is characterized in that, described feedforward internal mode controller is as follows by the method against obtain motor expectation rotating speed and auxiliary given optimization rotating speed in conjunction with low-pass filter of the main given rotating speed of motor and proportional gain Kn:

1. build low-pass filter f (z):

$f\left(z\right)=\frac{1}{1-{\mathrm{\βz}}^{-1}}---\left(1\right)$

In formula, β is low-pass filter filtering factor, and z is auxiliary complex variable, and boundary condition is Kn*f (1)=1, can obtain thus the value of β;

2. build feedforward internal mode controller G _c(z):

$G_c\left(z\right)=\frac{y_c}{y_r}={\mathrm{Kn}}^{-1}f\left(z\right)---\left(2\right)$

In formula, f (z) is low-pass filter, y _cfor motor expectation rotating speed, y _rfor the main given rotating speed of motor;

3. by step, 2. obtain motor expectation rotating speed y _c:

y _c＝G _c(z)*y _r (3)；

4. obtain auxiliary given optimization rotating speed y:

y＝y _c-y _r (4)。

7. method according to claim 4, is characterized in that, described feedback filter construction method is as follows:

$G_f\left(s\right)=\frac{1}{\mathrm{Kn}}\frac{1-{\mathrm{\α}}_f}{1-{\mathrm{\α}}_f{z}^{-1}}---\left(5\right)$

In formula, G _f(s) be feedback filter, α _ffor feedback filter filtering factor, z ^-1contrary for auxiliary complex variable z.