CN107060644A - A kind of wheel rotating state directional type rotary steering system and guiding control method - Google Patents

Abstract

The invention discloses a full-rotation dynamic pointing type rotary guiding system and a guiding control method, comprising an upper casing and a lower casing, a hollow shaft coaxial with the upper casing is arranged in the upper casing, and one end of the hollow shaft is sealed with the upper casing The other end is connected to a hollow transmission shaft, and a guiding drive mechanism is provided between this end of the hollow shaft and the upper casing; the guiding driving mechanism, the upper casing and the hollow shaft form an oil pressure closed cavity, and the oil pressure is closed The drilling fluid pressure in the cavity is higher than the drilling fluid pressure outside the steering drive mechanism; the steering drive mechanism drives a yaw wheel set on the transmission shaft to deflect laterally, and a universal joint for maintaining the pointing direction is installed on the transmission shaft , a drill bit is installed at the end of the transmission shaft, and the yaw wheel deflects sideways under the drive of the guide drive mechanism, and the yaw wheel continues to push outward against the inner wall of the lower shell, generating a dynamic direction perpendicular to the inner wall of the lower shell. Continuous lateral force makes the lower casing drive the drill bit to rotate an angle along the rotation center of the universal joint to achieve the purpose of dynamic pointing.

Description

A full-rotation dynamic pointing rotary steering system and steering control method

technical field

The invention relates to advanced oil and gas drilling equipment technology, in particular to a rotary steerable drilling technology, which can be applied to directional drilling in different formations on sea and land.

Background technique

Rotary steerable drilling technology is a new drilling technology developed in the 1990s with rotary steerable drilling tools as the core. By controlling the wellbore trajectory in real time, it can accurately hit the drilling target. It has high mechanical penetration rate and high precision of wellbore trajectory control. The wellbore cleaning effect is good, and the displacement extension ability is strong, which is a qualitative leap from the traditional directional drilling technology. Rotary steerable drilling technology is becoming an important drilling method for various types of complex structure wells (horizontal wells, extended-reach wells, multilateral wells, 3D multi-target wells, and thin pay zone wells) both offshore and onshore. important role in development. At present, the rotary steerable drilling technology is still in the stage of rapid development, and the international competition is very fierce. Foreign drilling service companies such as Halliburton and Schlumberger have launched their own rotary steerable tools and achieved huge economic benefits.

Rotary steerable drilling tools can be divided into three types: push-by type, pointing type and hybrid type according to the steering method. The push-type rotary steerable system pushes against the well wall with the palm near the drill bit on the drill pipe, so that the drill bit generates lateral force and changes the direction of the drill bit. It is mainly divided into static push and dynamic push. The static push-back rotary steerable system uses three sets of 120°phase electromechanical-hydraulic drive modules to drive the piston to push the palm to the well wall to achieve quasi-static push. The wall rotates slowly in a small range (here referred to as "quasi-static jacket"), and the measurement and control processes in its execution system are in a relatively stable state. The control calculation is relatively simple, but the electromechanical-hydraulic drive unit with strong environmental adaptability is very complex. The dynamic pushing type is a full-rotation steering system, which uses mud power to drive the piston to the well wall to realize dynamic pushing, and uses pulse modulation force to realize deflection. The stable platform used for measurement control moves in reverse at the same rate as the drill string, and remains relatively still with the ground. It has high requirements for precise synchronous control in complex wellbore environments, and the actuator that pushes against the palm is relatively simple. Compared with the pointing rotary steerable system, its advantages include: high build-up rate in hard formations; good drill string strength, stable and reliable operation, and its disadvantages mainly include: spiral boreholes will appear after slapping on the well wall; for soft formations When drilling, the slap may sink into the well wall and cannot provide a large lateral force; when the slap is fully extended, it may not touch the well wall and cannot provide lateral force.

The pointing rotary steerable system controls the direction of the drill bit by making the axis of the drill bit drive shaft deviate from the axis of the wellbore through a lateral thrust, mainly including static pointing type and dynamic pointing type. The dynamic pointing rotary steerable system is a fully rotary system, and its actuators rotate together with the drill collar, while the static pointing rotary steerable system's actuators are installed on the quasi-static jacket. Both the static pointing type and the dynamic pointing type rotary steerable system change the direction of the drill bit by bending the drive shaft, and the driving mechanisms used mainly include eccentric ring mechanisms, hydraulic pistons, etc. Compared with the push-to-push structure, the advantages of the pointing rotary steerable system are: the drilling of the wellbore is smoother, the friction and torque are small, and the side load of the drill bit and the drill bit bearing is small, which helps to exert the performance of the drill bit. Its disadvantages are: because the drive shaft of the drill bit needs to be bent, the position of the drive shaft is easy to wear, the strength of the drill string is not as good as that of the push-on type, and the inclination rate of the hard formation is low.

The hybrid rotary steerable system in the patent US8701795 uses the pushing force generated by the pushing actuator to deflect the axial direction of the drill bit. The actuator is offset from the connected drill pipe, and rotates at an angle with the drum centralizer near the drill bit as the fulcrum to change the direction of the drill bit. Once the drum centralizer touches the well wall, it will provide lateral force, and its function is also similar to that of the push-on rotary steerable system. However, the hybrid rotary steerable system still uses intermittent pulse force to achieve steering, and the drill bit will deflect during the time interval of the pulse force. On the other hand, whether the steering angle needs to be changed downhole, the push mechanism will provide lateral push force to deflect the direction of the drill bit.

Contents of the invention

The purpose of the present invention is to provide a dynamic pointing type rotary steering system, which uses a motor to drive the yaw wheel, so that the yaw wheel continues to push outwards to generate a continuous external push force, so that the direction of the drill bit is deflected, and the direction of the drill bit is accurately pointed to the predetermined position. direction to realize the dynamic pointing function of the rotary steerable system.

The technical scheme that the present invention adopts is as follows:

A full-rotation dynamic pointing rotary guide system, comprising an upper casing and a lower casing, the upper casing is provided with a hollow shaft coaxial with it, one end of the hollow shaft is sealed with the upper casing, and the other end is connected with the A hollow transmission shaft is connected, and a guide driving mechanism is provided between this end and the upper casing; the guide driving mechanism, the upper casing and the hollow shaft form an oil pressure closed cavity, and the drilling hydraulic pressure in the oil pressure closed cavity The force is higher than the drilling fluid pressure outside the steering drive mechanism; the steering drive mechanism drives a yaw wheel set on the transmission shaft to deflect laterally, and a universal wheel for maintaining the pointing direction is installed on the transmission shaft. A drill bit is installed at the end of the transmission shaft, and the yaw wheel is driven by the guide drive mechanism to yaw laterally, and the yaw wheel continues to push outward against the inner wall of the lower shell, producing a direction perpendicular to the inner wall of the lower shell. The dynamic and continuous lateral force makes the lower casing drive the drill bit to rotate an angle along the rotation center of the universal joint to achieve the purpose of dynamic pointing.

Further, a piston is provided between the hollow shaft and the upper housing, and a compression spring is sleeved on the hollow shaft. One end of the compression spring is pressed on the upper housing, and the other end is pressed on the piston. The upper casing has a mud hole at the place where the spring is installed, which is used to transmit the pressure of the external drilling fluid; the piston is driven by the compression spring to ensure that the pressure of the drilling fluid in the oil pressure closed cavity is higher than that of the drilling fluid outside the guiding drive mechanism, so as to prevent Drilling fluid enters the steering drive mechanism, causing damage to motors, reducers, bearings and other components.

Further, the yaw wheel is a cylindrical structure, and a central hole is provided in the center of the yaw wheel, and a driving hole symmetrical to the axial center of the yaw wheel is respectively provided on both sides of the yaw wheel; the yaw wheel It is placed inside the lower casing and has a certain slight gap with the lower casing; the yaw wheel is sleeved on the transmission shaft through the center hole and has a certain gap with the transmission shaft.

Further, the guide driving mechanism includes an eccentric shaft I, an eccentric shaft II, a support member, a motor I, a reducer I, a motor II, a reducer II, an angle measuring device I and an angle measuring device II; the motor I and the reducer I Connection, reducer I is connected with eccentric shaft I, motor II is connected with reducer II, reducer II is connected with eccentric shaft II, one end of eccentric shaft I and eccentric shaft II is installed in the guide drive mechanism support through bearing I, eccentric The other ends of the shaft I and the eccentric shaft II are matched with the swing driving hole of the yaw wheel and can rotate relatively;

Further, rotary seals I and II are respectively installed between the eccentric shafts I, II and the support member of the guiding drive mechanism to realize the dynamic sealing of the guiding driving mechanism; the eccentric distances of the eccentric shaft I and the eccentric shaft II are equal.

The motors I and II drive the reducers I and II, and the reducers I and II drive one end of the eccentric shafts I and II to rotate, and the other ends of the eccentric shafts I and II generate a cam motion, thereby driving the balance wheel to swing laterally; angle measurement The devices I and II are respectively installed on one side of the motor I and II or the output ends of the reducers I and II to detect the angular position of the eccentric shaft I and II so as to determine the swing direction of the yaw wheel.

Further, the universal joint includes an upper joint, a lower joint, an intermediate piece, a connecting pin shaft, a flexible sleeve, and a sleeve support member; one end of the upper joint is fixedly connected to the transmission shaft, and the other end is connected through the connecting pin shaft connected with the middle piece; one end of the lower joint is connected with the middle piece through a connecting pin, the outer side of the other end is fixedly and sealedly connected with the lower casing, and the inner side is fixedly and sealedly connected with the casing support member; the upper joint and the lower joint , the middle piece and the sleeve support are all provided with a center hole; a flexible sleeve is installed in the center hole, and one end of the flexible sleeve is connected to the transmission shaft with a seal I seal, and the other end is connected with the sleeve support with a seal II seal ; A central hole is also provided in the flexible casing for circulating drilling fluid.

After the lower joint of the universal joint is connected with the lower casing, the whole can freely rotate at a certain angle relative to the upper joint and the transmission shaft along the center of rotation of the universal joint. With this rotation, the flexible casing bends, and the drilling fluid passes through the transmission shaft. The shaft enters the flexible casing and enters the drill bit through the casing support to ensure that all the drilling fluid in the drill string enters the drill bit. Due to the flexibility of the flexible sleeve, the bending process does not affect its structural performance.

Further, it also includes a cross slider mechanism, and the cross slider mechanism mainly includes an upper slider, a lower slider, a center slider, a connecting piece I, and a connecting piece II; the upper slider passes through the connecting piece I It is fixedly connected with the lower casing, the lower slider is fixedly connected with the transmission shaft through the connecting piece II, and the center slider is floatingly installed between the upper slider and the lower slider; the upper slider, the lower slider Both the block and the center slider are provided with a center hole, and are sleeved on the transmission shaft. The cross slider mechanism is used to directly transmit the torsional moment on the lower casing to the transmission shaft, so as to reduce the torsional moment borne by the universal joint and improve the mechanical performance of the structure.

The method of guiding control using the above system:

First determine the yaw distance r of the yaw wheel according to the pointing angle θ, and then determine the initial phase α ₁ of the eccentric shaft I and the initial phase α ₂ of the eccentric shaft II according to the pointing direction of the rotary steerable system;

Then detect the rotation speed ω of the bottom hole drilling tool in real time, and then drive the eccentric shaft I and the eccentric shaft II to rotate in real time with the rotation speed ω opposite to the rotation direction of the bottom hole drilling tool, so that the pointing direction of the drill bit remains unchanged.

Specifically, the specific method is as follows:

The pointing angle θ=atan(r/L); the yaw distance of the yaw wheel

Among them, L represents the distance between the yaw wheel and the center of rotation of the universal joint in the axial direction; r ₁ represents the eccentricity of the eccentric axis I and eccentric shaft II; relative to the initial set yaw direction reference, α ₁ and α ₂ represent the eccentricity The initial phase of shaft I and eccentric shaft II; ω ₁ and ω ₂ represent the rotational speeds of eccentric shaft I and eccentric shaft II; in order to ensure that the eccentric wheel yaw distance does not change with time, it is necessary to control the steering and rotational speed of eccentric shaft I and eccentric shaft II Equal ω ₁ =ω ₂ =ω; and the yaw distance can be changed by changing the initial phase difference between the eccentric shaft I and the eccentric shaft II; because the rotational speeds of the eccentric shaft I and the eccentric shaft II are the same, according to the vector synthesis method, the eccentric shaft can be obtained The deflection direction of the balance wheel is ωt+(α ₁ +α ₂ )/2; if the rotation speed of the BHA during drilling is ω, the deflection direction of the balance wheel will remain at (α ₁ +α ₂ )/ 2. This direction is opposite to the pointing direction of the rotary steerable system.

The beneficial effects of the present invention are as follows:

(1) The present invention uses a guide drive mechanism to drive the yaw wheel to continuously push outward against the inner wall of the lower housing, generating a continuous pushing force on the lower housing. Compared with the guide method of the hybrid rotary guide system, the guide ability is stronger , The steering direction is more accurate, and the shaft is smoother.

(2) The present invention adopts two motor-driven guiding and driving mechanisms, which can realize the dynamic adjustment of the pointing angle very conveniently and accurately, so as to meet the on-site requirements of different formations and different slope building rates.

(3) The present invention uses the lower casing to drive the drill bit to deflect an angle to realize the change of the rotation guiding angle. Because the yaw wheel and the lower casing do not rotate relative to each other, the contact position between the yaw wheel and the lower casing wears less , a better structure.

(4) In addition to the feature of full rotation, the structure and stress of the present invention are similar to those of the adjustable angle screw drilling tool, and compared with the dynamic pointing rotary steerable system in the form of shaft bending or offset, its structure is simple , better mechanical properties.

(5) In the guiding control method proposed in the present invention, it is only necessary to perform synchronous motion control on the two motors. After adjusting the guiding angle, it is enough to ensure that the two motors move in the same direction and at the same speed. The control method is relatively simple and easy to implement .

Description of drawings

Fig. 1 is a front view of the present invention;

Fig. 2 is a structural characteristic diagram of the balance wheel in the present invention;

Fig. 3 is a cross-sectional view of the guide drive mechanism of the present invention;

Fig. 4 is a sectional view of the universal joint of the present invention;

Fig. 5 is a sectional view of the cross slider mechanism of the present invention;

Fig. 6 is a diagram of the drilling fluid flow process in the present invention;

Fig. 7 is a schematic diagram of the guidance control method of the present invention;

Fig. 8 is a schematic diagram of the driving control principle of the balance wheel in the present invention.

In the figure: 1. Drill bit, 2. Universal joint, 3. Lower housing, 4. Cross slider mechanism, 5. Transmission shaft, 6. Balance wheel, 7. Guide drive mechanism, 8. Upper housing, 9 .Central hole, 10. Swing drive hole, 11. Eccentric shaft I, 12. Eccentric shaft II, 13. Guide drive mechanism support, 14. Bearing I, 15. Bearing II, 16. Motor I, 17. Reducer I , 18. Motor II, 19. Reducer II, 20. Angle measuring device I, 21. Angle measuring device II, 22. Rotary seal I, 23. Rotary seal II, 24. Hollow shaft, 25. Oil pressure closed chamber, 26. Compression spring, 27. Piston, 28. Mud hole, 29. Upper joint, 30. Lower joint, 31. Intermediate piece, 32. Connecting pin, 33. Flexible casing, 34. Sleeve support, 35. Seal I, 36. Seal II, 37. Upper slider, 38. Lower slider, 39. Center slider, 40. Connector I, 41. Connector II, 42. Drilling fluid, 43. Annulus.

detailed description

Below in conjunction with accompanying drawing and embodiment the present invention will be further described:

As shown in Figure 1, the full-rotation dynamic pointing rotary steering system disclosed in the present invention includes a drill bit 1, a universal joint 2, a lower housing 3, a cross slider mechanism 4, a transmission shaft 5, a balance wheel 6, a guide drive Mechanism 7, upper casing 8; the drill bit 1 is fixedly connected with the lower casing 3; the lower casing 3 is fixedly and sealed connected with one end of the universal joint 2; the yaw wheel 6 is installed in the lower casing The inside of the body 3 and the outside of the drive shaft 5 are connected to the output end of the guide drive mechanism 7; the other end of the universal joint 2 is fixedly connected to the drive shaft 5; the drive shaft 5 is fixed and sealed to one end of the guide drive mechanism 7, Or become one with the guide drive mechanism 7, the other end of the guide drive mechanism 7 is fixed and sealed with the upper housing 8; the cross slider mechanism 4 is installed between the universal joint 2 and the guide drive mechanism 7, and as far as possible Close to the guide drive mechanism 7 , one end of the cross slider mechanism 4 is fixedly connected to the transmission shaft 5 , and the other end of the cross slider mechanism 4 is fixedly connected to the lower housing 3 .

The guide drive mechanism 7 drives the yaw wheel 6 to yaw laterally, and the yaw wheel 6 continues to push outward against the inner wall of the lower casing 3, generating a dynamic and continuous lateral force perpendicular to the inner wall of the lower casing 3, so that the lower casing 3 Drive the drill bit 1 to rotate an angle along the rotation center of the universal joint 2 to achieve the purpose of dynamic pointing; the cross slider mechanism 4 directly transmits the torque acting on the lower casing 3 to the upper transmission shaft 5, reducing the torque acting on the The torsional force on the universal joint 2 improves the reliability of the structure.

As shown in Figure 2 and Figure 3, the yaw wheel 6 is placed inside the lower casing 3, and there is a certain small gap with the lower casing 3; the yaw wheel 6 is sleeved on the transmission shaft 5 through the central hole 9, and The transmission shaft 5 has a certain gap; there are at least two swing drive holes 10 on the yaw wheel 6, which are used to connect with the eccentric shaft I 11 and the eccentric shaft II 12 in the guide drive mechanism 7, and the swing drive holes 10 are along the yaw wheel. 6 Axially symmetrical.

As shown in Figure 3, the guide drive mechanism 7 is used to realize the lateral deflection of the yaw wheel 6, including the eccentric shaft I 11, the eccentric shaft II 12, the guide drive mechanism support 13, the bearing I 14, and the bearing II 15 , motor I 16, reducer I 17, motor II 18, reducer II 19, angle measuring device I 20, angle measuring device II 21, rotary seal I 22, rotary seal II23; motor I 16 is connected to reducer I 17, Reducer I 17 is connected with eccentric shaft I 11, motor II 18 is connected with reducer II 19, reducer II 19 is connected with eccentric shaft II 12, and one end of eccentric shaft I 11 and eccentric shaft II 12 is installed on the guide through bearing I 14 In the drive mechanism support 13, the other ends of the eccentric shaft I 11 and the eccentric shaft II 12 are connected to the swing drive hole 10 of the yaw wheel 6, and the other ends of the eccentric shaft I 11 and the eccentric shaft II 12 are connected to the yaw wheel 6. The swing drive hole 10 can rotate relatively; the rotary seals I 22, II 23 are respectively installed between the eccentric shafts I 11, II 12 and the guide drive mechanism support member 13, for realizing the dynamic seal of the guide drive mechanism 7; the eccentric shaft The eccentric distances of I 11 and eccentric shaft II 12 are equal.

The reducers I 17 and II 19 are driven by the motors I 16 and II 18, and the reducers I 17 and II 19 drive one end of the eccentric shafts I11 and II 12 to rotate, and the other ends of the eccentric shafts I 11 and II 12 generate a cam motion, thereby driving The yaw wheel 6 swings sideways; the angle measuring devices I 20 and II 21 are respectively installed on one side of the motors I 16 and II 18 or the output ends of the reducers I 17 and II 19 to detect the eccentric shafts I 11 and II 12 The angular position of the yaw wheel 6 in order to determine the swing direction.

The guide drive mechanism 7, the upper casing 8 and the hollow shaft 24 form an oil pressure closed cavity 25, and the compression spring 26, the piston 27, the rotary seal I 22, and the rotary seal II 23 are used to realize the pressure balance and Dynamic seals at eccentric shaft I11 and eccentric shaft II 12. The specific structure is as follows: the guide drive mechanism 7 is fixed and sealed connected with the upper casing 8; one end of the hollow shaft 24 is fixed and sealed connected with the guide drive mechanism 7, and the other end is sealed connected with the upper casing 8. The piston 27 is installed between the hollow shaft 24 and the upper housing 8, and forms an oil pressure closed chamber 25 with the hollow shaft 24, the upper housing 8 and the guide drive mechanism 7, and the oil pressure closed chamber 25 is filled with hydraulic oil; The compression spring 26 is installed on the hollow shaft 24, and one end of the compression spring 26 is pressed on the upper casing 8, and the other end is pressed on the piston 27. The upper casing 8 has a mud hole 28 at the spring 26 for use Used to transmit external drilling fluid pressure. The compression spring 26 pushes the piston 27 to move to ensure that the drilling fluid pressure in the oil pressure closed chamber 25 is higher than the drilling fluid pressure outside the guide drive mechanism 7, so as to prevent the drilling fluid from entering the guide drive mechanism 7 and causing damage to the motor, reducer, bearing, etc. damage to components.

As shown in Figure 4, the universal joint 2 mainly includes an upper joint 29, a lower joint 30, an intermediate piece 31, a connecting pin 32, a flexible sleeve 33, a sleeve support 34, a seal I 35, and a seal II 36 . One end of the upper joint 29 is fixedly connected to the transmission shaft 5, and the other end is connected to the middle piece 31 through the connecting pin 32; one end of the lower joint 30 is connected to the middle piece 31 through the connecting pin 32, and the outer side of the other end is connected to the lower shell The body 3 is fixed and sealed, and the other side is fixed and sealed with the casing support 34; the upper joint 29, the lower joint 30, the middle part 30 and the casing support 34 are all provided with a central hole; The flexible sleeve 33 is installed in the central hole of the upper joint 29, the lower joint 30, the middle piece 31 and the sleeve support 34. One end of the flexible sleeve 33 is connected with the transmission shaft 5 by sealing I 35, and the other end is sealed with the sleeve. The pipe support 34 is sealed and connected by seal II 36; the flexible casing 33 is provided with a central hole for circulating drilling fluid; the flexible casing 33 is made of wear-resistant and erosion-resistant materials, and has good flexibility, such as Martensitic stainless steel, etc. After the lower joint 30 of the universal joint 2 is connected with the lower housing 3, the whole can rotate freely along the center of rotation of the universal joint 2 and relative to the upper joint 29 and the transmission shaft 5 at a certain angle. With this rotation, the flexible sleeve 33 Bending occurs, the drilling fluid enters the flexible casing 33 through the transmission shaft 5, and enters the drill bit 1 through the casing support 34, so as to ensure that all the drilling fluid in the drill string enters the drill bit 1. Since the flexible sleeve 33 is flexible, its structural performance will not be affected during the bending process.

As shown in FIG. 5 , the cross slider mechanism 4 mainly includes an upper slider 37 , a lower slider 38 , a center slider 39 , a connecting piece I 40 , and a connecting piece II 41 . The upper slider 37 is fixedly connected to the lower casing 3 through the connector I 40, the lower slider 38 is fixedly connected to the transmission shaft 5 through the connector II 41, and the center slider 39 is floatingly installed on the upper slider Between the block and the lower slider; the upper slider 37, the lower slider 38 and the center slider 39 are all provided with a central hole, and are sleeved on the transmission shaft 5. The Oldham mechanism 4 is used to directly transmit the torsional moment on the lower casing 3 to the transmission shaft 5, so as to reduce the torsional moment borne by the universal joint 2 and improve structural mechanical properties.

Fig. 6 describes the flow process of the drilling fluid 42 flowing in from the upper drill string in the present invention. First, the drilling fluid 42 flows through the upper casing 8, the hollow shaft 24, the guiding drive mechanism 7, the transmission shaft 5, and the flexible sleeve 33 in sequence. 1. The conduit support 34 enters the inside of the drill bit 1 and enters the annular space 43 through the upper water hole of the drill bit 1 . There are sealed connections at the joints of all components flowing through to prevent the drilling fluid 42 from flowing into the annular space 43 before flowing into the drill bit 1 .

The fixed connection mentioned above refers to the fixed connection of two adjacent parts by screw connection or other connection methods. At the same time, the sealed connection mentioned in the article refers to the sealing of two adjacent parts by sealing rings or other sealing methods. .

Fig. 7 describes the steering control method, by dynamically controlling the lateral yaw distance r of the yaw wheel 6, and the magnitude and direction of the lateral yaw force F to achieve the purpose of dynamic pointing angle and pointing direction. Assuming that the distance between the balance wheel 6 and the rotation center of the universal joint 2 along the axial direction is L, the pointing angle θ can be expressed as

θ=atan(r/L)

FIG. 8 describes how to control the yaw distance r of the yaw wheel 6 . Set the eccentricity of eccentric shaft I 11 and eccentric shaft II 12 as r ₁ ; set the initial phases of eccentric shaft I 11 and eccentric shaft II 12 as α ₁ and α ₂ relative to the initially set yaw direction reference; set eccentric shaft I 11 The rotational speeds of the eccentric shaft II 12 are ω ₁ and ω ₂ respectively, and the yaw distance of the yaw wheel can be expressed as

In order to ensure that the yaw distance r of the eccentric wheel does not change with time, it is necessary to control the steering and rotational speed of the eccentric shaft I 11 and the eccentric shaft II 12 to be equal ω ₁ =ω ₂ =ω; and by changing the eccentric shaft I 11 and the eccentric shaft II 12 initial phase difference to change the yaw distance r.

Since the rotational speeds of the eccentric shaft I 11 and the eccentric shaft II 12 are the same, according to the vector synthesis method, the yaw direction of the yaw wheel 6 can be obtained as ωt+(α ₁ +α ₂ )/2. If the rotation speed of the BHA during drilling is ω, the yaw direction of the yaw wheel 6 will remain at (α ₁ +α ₂ )/2, which is opposite to the pointing direction of the rotary steerable system.

Therefore, as shown in FIG. 8, the guidance control method of the present invention is described as follows. Firstly, the yaw distance r of the yaw wheel 6 is determined according to the pointing angle θ, and then the initial phase α 1 of the eccentric shaft I 11 and the initial phase α ₂ of the eccentric shaft _II 12 are determined according to the pointing direction of the rotary steerable system. Then detect the rotational speed ω of the bottom hole drilling tool in real time, and then drive the eccentric shaft I 11 and the eccentric shaft II 12 to rotate in real time with the rotational speed as ω and the direction opposite to the rotation direction of the bottom hole drilling tool, so that the drill bit 1 points in the direction constant.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (10)

1. a kind of dynamic directional type rotary steering system, it is characterised in that including upper shell and lower house, in described upper shell Provided with a quill shaft being coaxial therewith, one end and the upper shell of quill shaft are tightly connected, the other end and a hollow transmission Axle is connected, and guiding driving mechanism is provided between the end of quill shaft and upper shell；Described guiding driving mechanism, upper shell with Drilling liquid pressure in quill shaft formation oil pressure closing chamber, and oil pressure closing chamber is higher than the drilling hydraulic outside guiding driving mechanism Power；Described guiding driving mechanism drives a lateral beat of beat wheel being sleeved on power transmission shaft, on described power transmission shaft Universal joint for remaining pointing to direction is installed, a drill bit is installed in the end of power transmission shaft, beat wheel is being oriented to driving Lateral beat under the driving of mechanism, beat wheel outwards continues backup lower house inwall, produces direction perpendicular to lower house inwall Dynamic continuance side force, makes lower house drive drill bit to rotate an angle along universal joint pivot, reaches dynamic sensing Purpose.

2. dynamic directional type rotary steering system as claimed in claim 1, it is characterised in that in described quill shaft and upper casing Provided with a piston between body, compression spring is set with described quill shaft, one end of compression spring is pressed on upper shell, The other end is pressed on piston, and upper shell is provided with mud hole at installation spring, for transmitting outside drilling liquid pressure；By compression bullet Spring promotes piston movement, it is ensured that the drilling liquid pressure in oil pressure closing chamber is higher than the drilling liquid pressure outside guiding driving mechanism.

3. dynamic directional type rotary steering system as claimed in claim 1, it is characterised in that the beat wheel is a cylinder Shape structure, at the center of beat wheel provided with centre bore, the both sides of centre bore are respectively provided with one relative to beat wheel shaft in The symmetrical drive hole of the heart.

4. dynamic directional type rotary steering system as claimed in claim 3, it is characterised in that described beat wheel is placed in lower casing , there is certain minim gap in internal portion with lower house；Beat wheel is enclosed on power transmission shaft by centre bore, and with power transmission shaft have it is certain between Gap.

5. dynamic directional type rotary steering system as claimed in claim 3, it is characterised in that described guiding driving mechanism bag Eccentric shaft I, eccentric shaft II, support member, motor I, reductor I motors II, reductor II, angle measurement unit I and angle is included to survey Measure device II；Motor I is connected with reductor I, reductor I is connected with eccentric shaft I, and motor II is connected with reductor II, reductor II is connected with eccentric shaft II, and eccentric shaft I and eccentric shaft II one end are arranged in guiding driving mechanism support member by bearing I, The wobble drive hole of eccentric shaft I and eccentric shaft the II other end and beat wheel coordinates and can relatively rotated.

6. dynamic directional type rotary steering system as claimed in claim 5, it is characterised in that driven in eccentric shaft I, II with being oriented to The dynamic sealing that I, II points of rotatory sealing is used to realize guiding driving mechanism is installed between dynamic mechanism support；The eccentric shaft I It is equal with eccentric shaft II eccentric throw.

7. dynamic directional type rotary steering system as claimed in claim 1, it is characterised in that described universal joint includes upper close Section, hypozygal, middleware, connection bearing pin, flexible sleeve and sleeve support；One end of the upper joint is fixed with power transmission shaft to be connected Connect, the other end is connected by connecting bearing pin with middleware；Described hypozygal one end is connected by connecting bearing pin with middleware, another End outside is fixed with lower house, is tightly connected, and inner side is fixed with sleeve support, is tightly connected；Described upper joint, ShiShimonoseki Section, middleware and sleeve support are equipped with a centre bore；Flexible sleeve is installed in centre bore, one end of flexible sleeve with Power transmission shaft is tightly connected using sealing I, and the other end is tightly connected with sleeve support using sealing II；In the flexible sleeve Centre bore also is provided with, for the drilling fluid that circulates.

8. dynamic directional type rotary steering system as claimed in claim 1, it is characterised in that also including a crosshead shoe machine Structure, described cross slides mainly include top shoe, sliding block, central slider, connector I, connector II；Described is upper Sliding block is fixedly connected by connector I with lower house, and described sliding block is fixedly connected by connector II with power transmission shaft, described Between central slider floating mount and top shoe and sliding block；Described top shoe, sliding block and central slider is equipped with center Hole, and be enclosed on power transmission shaft.

9. the method for carrying out being oriented to control using any described dynamic directional type rotary steering systems of claim 1-8, it is special Levy and be,

The beat of beat wheel is determined apart from r according to the sensing angle θ of beat wheel and universal joint pivot first, and then further according to rotation Turn the pointing direction of guidance system, determine eccentric shaft I initial phase α₁With eccentric shaft II initial phase α₂；

Then the rotating speed size ω of detection bottomhole in real time, then by ω of rotating speed size, the rotation of direction and bottomhole In the opposite direction, carry out Real Time Drive eccentric shaft I and eccentric shaft II rotations, the pointing direction of drill bit is kept constant.

10. dynamic directional type rotary steering system as claimed in claim 9 carries out the method for being oriented to control, it is characterised in that

Described sensing angle θ=atan (r/L)；The beat distance of beat wheel

Wherein, L represents beat wheel and the distance of universal joint pivot in axial direction；r₁Represent eccentric shaft I's and eccentric shaft II Eccentric throw；Relatively initial setting beat directional reference, α₁、α₂Represent eccentric shaft I and eccentric shaft II initial phase；ω₁、ω₂Table Show eccentric shaft I and eccentric shaft II rotating speed；In order to ensure eccentric wheel beat distance is not changed over time, need to control eccentric shaft I with Eccentric shaft II steering, the equal ω of rotating speed₁=ω₂=ω；And can be by changing eccentric shaft I and eccentric shaft II initial phase difference To change beat distance；Because eccentric shaft I is identical with eccentric shaft II rotating speed, according to vector synthesis, beat wheel can be obtained inclined Pendulum direction is ω t+ (α₁+α₂)/2.If the rotary speed of bottomhole is ω during drilling well, the beat direction of beat wheel will It is maintained at (α₁+α₂)/2, the direction is opposite with the pointing direction of rotary steering system.