CN105298389A - Rotary steering drilling tool control method based on eccentric distance equality - Google Patents

Abstract

A control method for rotary steerable drilling tools based on equal eccentricity. Three motive forces are used to directly drive the rotating jacket, inner eccentric ring, and outer eccentric ring so that the three can obtain speed. By adjusting the speed ω ₁ of the outer eccentric ring and the speed of the inner eccentric ring ω ₂ , the speed ω ₃ of the rotating jacket, make the outer eccentric ring, the inner eccentric ring, and the rotating jacket produce relative displacement, and then change the spatial attitude of the steering shaft to realize the adjustment of the steering azimuth and steering angle of the rotary steerable drilling tool. When the guide angle is adjusted to a predetermined position, the outer eccentric ring and the inner eccentric ring are relatively static by adjusting the speed ω ₁ of the outer eccentric ring and the speed ω ₂ of the inner eccentric ring. When the guiding azimuth is adjusted to the predetermined position, the outer eccentric ring, the inner eccentric ring and the rotating outer sleeve are relatively static to complete the guidance by adjusting the speed ω ₁ of the outer eccentric ring, the speed ω ₂ of the inner eccentric ring, and the speed ω ₃ of the rotating outer sleeve; Rapid response, high reliability and good stability.

Description

A Control Method of Rotary Steerable Drilling Tools Based on Equal Eccentricity

technical field

The invention belongs to the technical field of rotary steerable drilling, and in particular relates to a control method of a dynamic bias pointing rotary steerable drilling tool based on eccentric ring offset steering with equal eccentricity.

Background technique

The current downhole rotary steerable drilling tools can be basically divided into four types according to the working mode: static offset pushing type, dynamic offset (modulated) pushing type, static offset pointing type and dynamic offset pointing type. The push-and-return rotary steerable drilling tool is guided by the hydraulic cylinder to control the drilling tool. This kind of steering method will generate a large pushing force in the process of realizing the drill bit steering, and the adaptability to the formation is poor, and the wear of the drill bit and the drill bit bearing is relatively high. Seriously, the working life is short, and the structure is complex and difficult to miniaturize. The existing Tianjin University static offset directional drilling tool is guided by a hollow universal joint, two servo motors and a transmission system, but it does not give a specific control method, and the core bearing in the work Under high-intensity alternating stress, the mandrel is prone to fatigue damage.

Contents of the invention

In order to overcome the deficiencies of the above-mentioned prior art, the object of the present invention is to propose a control method for rotary steerable drilling tools based on equal eccentricity, by using three driving forces to directly drive the inner eccentric ring, the outer eccentric ring and the rotating outer casing respectively for control , which reduces the space mechanism and greatly saves the internal space of the tool; the guiding process is continuous without gaps, and the guiding axis has high pointing accuracy; the stress condition of the drilling tool is improved and the service life is longer; it is not affected by the formation and can Realize precise control of wellbore trajectory; at the same time, it has rapid response, high reliability and good stability.

A control method for a rotary steerable drilling tool based on equal eccentricity, the drilling tool involved includes a rotary casing 11, and an eccentric mechanism, a guide shaft 7, a torque transmission mechanism 8 and a sealing device are sequentially connected in the rotary casing 11 from left to right 9. The eccentric mechanism includes an inner eccentric ring 4 and an outer eccentric ring 3. The inner eccentric ring 4 is installed inside the outer eccentric ring 3 and is sleeved on the ball seat 10. The inner eccentric ring 4 passes through the right end surface of the second flange 5 and the second The output shaft of the frameless motor 6 is connected, the outer eccentric ring 3 is connected to the output shaft of the first frameless motor 1 through the right end face of the first flange 2, and the inner eccentric ring 4 and the outer eccentric ring 3 are connected to the frameless motor 1 through the flange. The motor is directly connected and directly driven by the frameless motor, the left end of the guide shaft 7 is inserted into the ball seat 10, the right end of the guide shaft 7 is equipped with a torque transmission mechanism 8, and the right end of the torque transmission mechanism 8 is provided with a sealing device 9. The control method includes the following steps:

Step 1. When it is necessary to conduct directional drilling, first determine the size of the directional angle and the directional azimuth;

Step 2. Adjust the speed ω ₁ of the outer eccentric ring and the speed ω ₂ of the inner eccentric ring. There is a certain relationship between the speed ω ₁ of the outer eccentric ring, the speed ω ₂ of the inner eccentric ring and the steering angle. The steering angle is the steering shaft 4 and the axis of the drilling tool , the guide eccentricity ρ is proportional to the size of the guide angle and is related to the tool structure, so the relationship between the guide angle and the speed ω ₁ of the outer eccentric ring and the speed ω ₂ of the inner eccentric ring is expressed as:

$\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; =</span>\sqrt{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; e</span>}\sqrt{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}$

In the formula, ρ is the guide eccentricity, mm; e is the eccentricity of the inner and outer eccentric rings, mm; ω ₁ is the speed of the outer eccentric ring, rad/s; ω ₂ is the speed of the inner eccentric ring, rad/s; t ₁ is the guide Angle adjustment time, s;

Step 3. When the guide angle is adjusted to the predetermined position, it is necessary to adjust the outer eccentric ring speed ω ₁ and the inner eccentric ring speed ω ₂ to stabilize the guide angle at this position, then the outer eccentric ring speed ω ₁ and the inner eccentric ring speed ω ₂ are There are the following relations:

ω ₁ = ω ₂ ;

Step 4: After the guide angle is adjusted to the predetermined position, then adjust the guide azimuth γ, the rotation directions of the outer eccentric ring speed ω ₁ , the inner eccentric ring speed ω ₂ and the rotating jacket speed ω ₃ are always opposite; During the process, the guiding azimuth γ has the following relationship with the speed of the outer eccentric ring ω ₁ , the speed of the inner eccentric ring ω ₂ , and the speed of the rotating jacket ω ₃ :

$\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}$

After the guide angle adjustment is completed, the guide azimuth γ has the following relationship with the outer eccentric ring speed ω ₁ , the inner eccentric ring speed ω ₂ , and the rotating jacket speed ω ₃ :

$\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>$

or $\mathrm{\&gamma;}=\frac{{\mathrm{\&omega;}}_1+{\mathrm{\&omega;}}_2}{2}{t}_1+{\mathrm{\&omega;}}_1{t}_2-{\mathrm{\&omega;}}_3(t_1+t_2)$

In the formula: γ is the guiding azimuth, rad; ω ₁ is the speed of the outer eccentric ring, rad/s; ω ₂ is the speed of the inner eccentric ring, rad/s; ω ₃ is the speed of the rotating jacket, rad/s; t ₁ is the steering angle Adjustment time, s; t ₂ is the guide azimuth time, s;

Step 5. When the guiding azimuth γ is adjusted to the predetermined position, stabilize the guiding azimuth γ at the predetermined position. At this time, the outer eccentric ring speed ω ₁ , the inner eccentric ring speed ω ₂ , and the rotating jacket speed ω ₃ have the following relationship:

ω ₁ = ω ₂ = ω ₃

At this time, the guidance is completed, and the value of the guidance orientation γ is:

$\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>$

or $\mathrm{\&gamma;}=\frac{{\mathrm{\&omega;}}_1+{\mathrm{\&omega;}}_2}{2}{t}_1+{\mathrm{\&omega;}}_1{t}_2-{\mathrm{\&omega;}}_3(t_1+t_2)$

In the formula: γ is the guiding azimuth, rad; ω ₁ is the speed of the outer eccentric ring, rad/s; ω ₂ is the speed of the inner eccentric ring, rad/s; ω ₃ is the speed of the rotating jacket, rad/s; t ₁ is the steering angle Adjustment time, s; t ₂ guide azimuth time, s.

Control principle of the present invention is:

Use _three driving forces to directly drive the rotating jacket, the inner eccentric ring and the outer eccentric _ring , so that the _three can obtain speed. The relative displacement of the inner eccentric ring and the rotating outer casing changes the spatial attitude of the steering shaft to adjust the steering azimuth and steering angle of the rotary steering drilling tool. When the guide angle is adjusted to a predetermined position, the outer eccentric ring and the inner eccentric ring are relatively static by adjusting the speed ω ₁ of the outer eccentric ring and the speed ω ₂ of the inner eccentric ring. When the guiding azimuth is adjusted to the predetermined position, the outer eccentric ring, inner eccentric ring and rotating outer sleeve are relatively static to complete the guidance by adjusting the speed ω ₁ of the outer eccentric ring, the speed ω ₂ of the inner eccentric ring, and the speed ω ₃ of the rotating outer sleeve.

The advantages of the present invention are: the three driving forces directly drive the inner and outer eccentric rings and the rotating jacket respectively for control, which reduces the space mechanism and greatly saves the inner space of the tool, the guiding process is continuous without gaps, and the guiding shaft has high pointing accuracy; The force condition of the drilling tool has a longer life; the steering is not affected by the formation, and can realize the precise control of the wellbore trajectory; at the same time, it has rapid response, high reliability and good stability.

Description of drawings

Figure 1 is a schematic diagram of a dynamic offset rotary steerable drilling tool.

Fig. 2 Schematic diagram of eccentric structure.

Fig. 3 Motion model of eccentric structure.

Fig. 4 Simulation diagram of guide angle adjustment.

Fig. 5 The simulation diagram of guiding azimuth adjustment.

detailed description

The present invention is described in detail below in conjunction with accompanying drawing.

Referring to Fig. 1, a control method of a rotary steerable drilling tool based on equal eccentricity, the drilling tool involved includes a rotary casing 11, and an eccentric mechanism, a guide shaft 7, and a torque transmission mechanism are sequentially connected in the rotary casing 11 from left to right 8 and sealing device 9; the eccentric mechanism includes an inner eccentric ring 4 and an outer eccentric ring 3, the inner eccentric ring 4 is installed inside the outer eccentric ring 3, and is socketed on the ball seat 10, the inner eccentric ring 4 passes through the right end of the second flange 5 The surface is connected with the output shaft of the second frameless motor 6, the outer eccentric ring 3 is connected with the output shaft of the first frameless motor 1 through the right end face of the first flange 2, and the inner eccentric ring 4 and the outer eccentric ring 3 are both passed through the The blue is directly connected with the frameless motor and directly driven by the frameless motor, the left end of the guide shaft 7 is inserted into the ball seat 10, the right end of the guide shaft 7 is equipped with a torque transmission mechanism 8, and the right end of the torque transmission mechanism 8 is provided with a sealing device 9, the control method Include the following steps:

Step 1: The wellbore trajectory is measured by the measurement-while-drilling tool or the logging-while-drilling tool, and then the values of the steering angle and steering azimuth to be adjusted by the controllable bend joint are determined according to the measured data.

Step 2: Refer to Figure 2 to establish a kinematic model for the eccentric ring group, as shown in Figure 3, adjust the outer eccentric ring speed ω ₁ and the inner eccentric ring speed ω ₂ , the relationship between the outer eccentric ring speed ω ₁ , the inner eccentric ring speed ω ₂ and the guide angle There is a certain relationship between the steering angle. The steering angle is the angle between the steering shaft 4 and the drilling tool axis. The steering eccentricity ρ is proportional to the size of the steering angle and is related to the tool structure. Therefore, the steering angle is related to the speed of the outer eccentric ring ω ₁ The relationship of ring velocity _ω2 can be expressed as:

$\mathrm{<span\; class="notranslate">\; \&rho;</span>}<span\; class="notranslate">\; =</span>\sqrt{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; e</span>}\sqrt{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}$

In the formula: ρ is the guide eccentricity, mm; e is the eccentricity of the inner and outer eccentric rings, mm; ω ₁ is the speed of the outer eccentric ring, rad/s; ω ₂ is the speed of the inner eccentric ring, rad/s; t ₁ is Steering angle adjustment time, s.

Steering angle adjustment, that is, the size of the guide eccentricity ρ is first adjusted, and continuous adjustment can be realized through the difference of (ω ₂ t-ω ₁ t). From the angle adjustment formula, it can be seen that the guide eccentricity ρ is periodic.

(ω ₂ t-ω ₁ t)/(2π)=n+α

In the formula: n is an integer; α is the initial amount of angle adjustment per unit time, rad/s.

With the increase of time, the value of ρ changes continuously between 0 and 2e, and the speed of angle adjustment is realized by adjusting the value of initial angle adjustment α per unit time.

Step 3. When the guide angle is adjusted to the predetermined position, it is necessary to adjust the outer eccentric ring speed ω ₁ and the inner eccentric ring speed ω ₂ to stabilize the guide angle at this position, then the outer eccentric ring speed ω ₁ and the inner eccentric ring speed ω ₂ There is the following relationship:

ω ₁ = ω ₂

When the guide angle is adjusted to a predetermined position, it is necessary to study how to stabilize the angle to this position. Taking the increment of the guide eccentricity as the starting point to study the change of the guide eccentricity, firstly, the derivative of ρ with respect to t is obtained:

$\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; \&rho;</span>}}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\frac{\sqrt{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; e</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\frac{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&Center\; Dot;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; )</span>}$

The value of dρ/dt is the increment of ρ in unit time. To keep ρ stable at a certain value, the value of the increment dρ/dt must be constant at zero. For dρ/dt to be equal to zero, there must be:

(ω ₁ -ω ₂ )·t=n·π(1)

ω ₁ −ω ₂ =0(2)

In the above formula, n is an integer.

Equation (1) is a stable state related to time t, which is an instantaneous steady state and cannot meet the actual work requirements; the stable state of Equation (2) is a continuous stable state independent of time, which meets the actual work needs. Therefore, ω ₁ =ω ₂ is necessary to keep the angle constant with time.

Fig. 4 is the simulation diagram of the steering angle adjustment process of the present invention, in the angle adjustment simulation process, each parameter of curve a is ω ₁ =7·π/90, ω ₂ =4·π/45, each parameter of curve b is ω ₁ =7·π/90, ω ₂ =17·π/180, and the adjustment time is also 9s. Figure 4 proves that the adjustment and maintenance of the steering angle of the present invention can be realized.

Step 4: After the guide angle is adjusted to the predetermined position, then adjust the guide azimuth γ, the rotation directions of the outer eccentric ring speed ω ₁ , the inner eccentric ring speed ω ₂ and the rotating jacket speed ω ₃ are always opposite. In the process of steering angle adjustment, the steering orientation γ has the following relationship with the speed of the outer eccentric ring ω ₁ , the speed of the inner eccentric ring ω ₂ , and the speed of the rotating jacket ω ₃ :

$\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}$

After the guide angle adjustment is completed, the guide azimuth γ has the following relationship with the outer eccentric ring speed ω ₁ , the inner eccentric ring speed ω ₂ , and the rotating jacket speed ω ₃ :

$\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>$

or $\mathrm{\&gamma;}=\frac{{\mathrm{\&omega;}}_1+{\mathrm{\&omega;}}_2}{2}{t}_1+{\mathrm{\&omega;}}_1{t}_2-{\mathrm{\&omega;}}_3(t_1+t_2)$

In the formula: γ is the guiding azimuth, rad; ω ₁ is the speed of the outer eccentric ring, rad/s; ω ₂ is the speed of the inner eccentric ring, rad/s; ω ₃ is the speed of the rotating jacket, rad/s; t ₁ is the steering angle Adjustment time, s; t ₂ is the guide azimuth time, s.

After the guide angle adjustment is completed, ω ₁ = ω ₂ . At this time, if it is necessary to adjust the guide azimuth and keep the adjusted guide angle unchanged, the speed of the inner and outer eccentric rings must be adjusted by the same amount at the same time.

At this time, ω ₁ = ω ₂ , so γ=t·(ω ₁ +ω ₂ )/2-ω ₃ ·t becomes γ=ω ₁ ·t-ω ₃ ·t, and the azimuth γ is also periodic .

γ/2π＝(ω ₁ t-ω ₃ t)/(2π)＝n+β

In the formula: n is an integer; β is the azimuth adjustment amount per unit time, rad/s.

When changing the angle β that the eccentric ring group turns relative to the rotating jacket per unit time, the eccentric ring group can reach any specified orientation with the step length of β as time increases.

Step 5. When the guiding azimuth γ is adjusted to the predetermined position, it is also necessary to stabilize the guiding azimuth γ at the predetermined position. At this time, the outer eccentric ring speed ω ₁ , the inner eccentric ring speed ω ₂ , and the rotating jacket speed ω ₃ have the following relationship:

ω ₁ = ω ₂ = ω ₃

At this time, the steering is completed, and the value of the steering angle γ is:

$\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>$

or $\mathrm{\&gamma;}=\frac{{\mathrm{\&omega;}}_1+{\mathrm{\&omega;}}_2}{2}{t}_1+{\mathrm{\&omega;}}_1{t}_2-{\mathrm{\&omega;}}_3(t_1+t_2)$

In the formula: γ is the guiding azimuth, rad; ω ₁ is the speed of the outer eccentric ring, rad/s; ω ₂ is the speed of the inner eccentric ring, rad/s; ω ₃ is the speed of the rotating jacket, rad/s; t ₁ is the steering angle Adjustment time, s; t ₂ is the guide azimuth time, s.

When adjusting the guiding azimuth, when the guiding azimuth reaches the predetermined position, it needs to be stabilized at the predetermined position. In the same way as the steering angle adjustment method, we also start from the incremental angle, and first derivate the azimuth formula, that is, derivate γ with respect to t:

$\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}$

dγ/dt is the increment of γ in unit time. To keep the value of γ constant, the value of dγ/dt must be equal to zero. So:

$\frac{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}$

After adjusting the guiding azimuth to reach the working position, make ω ₁ =ω ₂ =ω ₃ immediately, and then the azimuth can be stabilized to this position.

Fig. 5 is a simulation process diagram of guidance orientation adjustment, each parameter in curve c is ω ₁ =7·π/90, ω ₂ =4·π/45, ω ₃ =π/15, and each parameter in curve d is ω ₁ = 7·π/90, ω ₂ =17·π/180, ω ₃ =π/15, and the adjustment time is also 25s. Figure 5 proves that the adjustment and maintenance of the orientation of the present invention can be realized.

Claims (1)

1., based on the rotary steering drilling tool control method that eccentric throw is equal, it is characterized in that, comprise the following steps:

Step one, when needs carry out guide digging, first determine size and the direct bearing of guide angle;

Step 2, the outer eccentric hoop speed omega of adjustment ₁with interior eccentric hoop speed omega ₂, outer eccentric hoop speed omega ₁, interior eccentric hoop speed omega ₂and there is certain relation between guide angle, guide angle is the angle of the axis of guide 4 and drilling tool axis, and guide eccentric is proportional and relevant with tool construction with the size of guide angle apart from ρ, so guide angle and outer eccentric hoop speed omega ₁, interior eccentric hoop speed omega ₂relation be expressed as:

$\mathrm{\&rho;}=\sqrt{2}e\sqrt{1+cos({\mathrm{\&omega;}}_2{t}_1-{\mathrm{\&omega;}}_1{t}_1)}$

In formula, ρ is guide eccentric distance, mm; E is inside and outside eccentric hoop eccentric throw, mm; ω ₁for outer eccentric hoop speed, rad/s; ω ₂for interior eccentric hoop speed, rad/s; t ₁for guide angle regulating time, s;

Step 3, be adjusted to precalculated position when guide angle, need to regulate outer eccentric hoop speed omega ₁with interior eccentric hoop speed omega ₂guide angle is stabilized in this position, then outer eccentric hoop speed omega ₁with interior eccentric hoop speed omega ₂just there is following relation:

ω ₁＝ω ₂；

Step 4, after guide angle is adjusted to precalculated position, next direct bearing γ to be regulated, outer eccentric hoop speed omega ₁, interior eccentric hoop speed omega ₂with rotary sleeve speed omega ₃direction of rotation contrary all the time; In guide angle adjustment process, direct bearing γ and outer eccentric hoop speed omega ₁, interior eccentric hoop speed omega ₂, rotary sleeve speed omega ₃there is following relation:

$\mathrm{\&gamma;}=\frac{{\mathrm{\&omega;}}_1+{\mathrm{\&omega;}}_2}{2}{t}_1-{\mathrm{\&omega;}}_3{t}_1$

After guide angle has regulated, direct bearing γ and outer eccentric hoop speed omega ₁, interior eccentric hoop speed omega ₂, rotary sleeve speed omega ₃there is following relation:

$\mathrm{\&gamma;}=\frac{{\mathrm{\&omega;}}_1+{\mathrm{\&omega;}}_2}{2}{t}_1+{\mathrm{\&omega;}}_2{t}_2-{\mathrm{\&omega;}}_3(t_1+t_2)$

Or $\mathrm{\&gamma;}=\frac{{\mathrm{\&omega;}}_1+{\mathrm{\&omega;}}_2}{2}{t}_1+{\mathrm{\&omega;}}_1{t}_2-{\mathrm{\&omega;}}_3(t_1+t_2)$

In formula: γ is direct bearing, rad; ω ₁for outer eccentric hoop speed, rad/s; ω ₂for interior eccentric hoop speed, rad/s; ω ₃for rotary sleeve speed, rad/s; t ₁for guide angle regulating time, s; t ₂for the direct bearing time, s;

Step 5, when direct bearing γ is adjusted to pre-position, direct bearing γ is stabilized in pre-position, now, outer eccentric hoop speed omega ₁, interior eccentric hoop speed omega ₂, rotary sleeve speed omega ₃there is following relation:

ω ₁＝ω ₂＝ω ₃

Now led, the value of direct bearing γ is:

$\mathrm{\&gamma;}=\frac{{\mathrm{\&omega;}}_1+{\mathrm{\&omega;}}_2}{2}{t}_1+{\mathrm{\&omega;}}_2{t}_2-{\mathrm{\&omega;}}_3(t_1+t_2)$

Or $\mathrm{\&gamma;}=\frac{{\mathrm{\&omega;}}_1+{\mathrm{\&omega;}}_2}{2}{t}_1+{\mathrm{\&omega;}}_1{t}_2-{\mathrm{\&omega;}}_3(t_1+t_2)$

In formula: γ is direct bearing, rad; ω ₁for outer eccentric hoop speed, rad/s; ω ₂for interior eccentric hoop speed, rad/s; ω ₃for rotary sleeve speed, rad/s; t ₁for guide angle regulating time, s; t ₂for the direct bearing time, s.