Jet flow adjustment method for rotary steerable downhole release

Abstract

A jet flow adjustment method for rotary steerable downhole release relates to a technical field of downhole drilling equipment for oil wells, which includes steps of: defining a diversion ratio p of a jet nozzle (2) by a ground control system according to a cleaning requirement of a cuttings bed; and sending the diversion ratio p of the jet nozzle (2) to a control unit of a downhole rotary steerable system; and determining an opening area s of the jet nozzle (2) by the control unit of the downhole rotary steerable system according to the diversion ratio p of the jet nozzle (2) and an equivalent channel area S of a drilling tool, wherein a calculation formula is: s=p*S/(1−p); controlling an adjustable bypass valve (3) by the control unit of the downhole rotary steerable system according to the calculated opening area s of the jet nozzle (2), so as to control an overlapping area between sector holes (9) of a rotor end (7) and a stator end (8), thereby opening the jet nozzle (2) for release. The present invention has simple control and strong release ability, which can effectively solve the jamming problem of the rotary steerable downhole tool.

Claims

1-5. (canceled)

6. A jet flow adjustment method for rotary steerable downhole release, comprising steps of: defining a diversion ratio p of a jet nozzle (2) by a ground control system according to a cleaning requirement of a cuttings bed; and sending the diversion ratio p of the jet nozzle (2) to a control unit of a downhole rotary steerable system; and determining an opening area s of the jet nozzle (2) by the control unit of the downhole rotary steerable system according to the diversion ratio p of the jet nozzle (2) and an equivalent channel area S of a drilling tool, wherein a calculation formula is: s=p*S/(1−p); controlling an adjustable bypass valve (3) by the control unit of the downhole rotary steerable system according to the calculated opening area s of the jet nozzle (2), so as to control an overlapping area between sector holes (9) of a rotor end (7) and a stator end (8), thereby opening the jet nozzle (2); after cleaning, waiting for the ground control system to close the jet nozzle (2); wherein the adjustable bypass valve (3) comprises a drive motor (4), the rotor end (7) and the stator end (8), wherein an output shaft of the drive motor (4) is connected to the rotor end (7); the sector holes (9) are drilled on both the rotor end (7) and the stator end (8); the drive motor (4) drives the rotor end (7) to rotate relative to the stator end (8), thereby changing the overlapping area between the sector holes (9) of the rotor end (7) and the stator end (8) to open and close the jet nozzle (2).

7. The jet flow adjustment method for the rotary steerable downhole release, as recited in claim 6, wherein according to a downhole accumulation state of the cuttings bed, the ground control system performs a rough classification based on a ground friction torque, and sets three diversion ratios which are 20%, 40% and 60%.

8. The jet flow adjustment method for the rotary steerable downhole release, as recited in claim 6, wherein the jet nozzle (2) is arranged on a drill string (1) and is tilted towards a drill bit, and an exit angle of the jet nozzle (2) is 30°-45°.

9. The jet flow adjustment method for the rotary steerable downhole release, as recited in claim 6, wherein the adjustable bypass valve (3) further comprises an external cylinder (6) arranged in the jet nozzle (2).

10. The jet flow adjustment method for the rotary steerable downhole release, as recited in claim 9, wherein the drive motor (4) is fixed on an internal wall of the external cylinder (6) by a motor support plate (5), and the stator end (8) is also fixed on the internal wall of the external cylinder (6).

11. The jet flow adjustment method for the rotary steerable downhole release, as recited in claim 9, wherein a bypass hole (10) is drilled on a side wall of the external cylinder (6); and a through hole (11) is drilled on the stator end (8) to communicate with the bypass hole (10).

12. The jet flow adjustment method for the rotary steerable downhole release, as recited in claim 11, wherein a connecting hole is drilled on the rotor end (7) to communicate with the through hole (11) of the stator end (8).

13. The jet flow adjustment method for the rotary steerable downhole release, as recited in claim 6, wherein the equivalent channel area of the drilling tool is a constant parameter known before the drilling tool enters a well.

14. The jet flow adjustment method for the rotary steerable downhole release, as recited in claim 13, wherein calculation of the constant parameter is done in the control unit of the downhole rotary steerable system; according to the required diversion ratio, the opening area of the jet nozzle is calculated; based on the relationship between the open area of the jet nozzle and a relative angle of a rotor and a stator, the drive motor drives the rotor to a set position.

15. The jet flow adjustment method for the rotary steerable downhole release, as recited in claim 6, wherein the rotor end and the stator end are both wear-resistant alloy sector columns.

16. The jet flow adjustment method for the rotary steerable downhole release, as recited in claim 8, wherein the jet nozzle (2) is arranged on the drill string (1) and is tilted towards the drill bit, and the exit angle of the jet nozzle (2) is 30°.

17. The jet flow adjustment method for the rotary steerable downhole release, as recited in claim 8, wherein the jet nozzle (2) is arranged on the drill string (1) and is tilted towards the drill bit, and the exit angle of the jet nozzle (2) is 45°.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 is a perspective view of according to a preferred embodiment of the present invention.

[0024] FIG. 1 is a flow chart of a jet flow adjustment method of the present invention;

[0025] FIG. 2 is a structural view of a drill string of jet flow adjustment of the present invention;

[0026] FIG. 3 is a structural view of an adjustable bypass valve of the present invention; and

[0027] FIG. 4 is an A-A sectional view of FIG. 3 of the present invention.

[0028] Element reference: 1—drill string, 2—jet nozzle, 3—adjustable bypass valve, 4—drive motor, 5—motor support plate, 6—external cylinder, 7—rotor end, 8—stator end, 9—sector hole, 10—bypass hole, 11—through hole, 12—connecting hole.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0029] Referring to the drawings, present invention will be further illustrated.

Embodiment 1

[0030] As a preferred embodiment of the present invention, referring to FIG. 1, the embodiment 1 provides:

[0031] a jet flow adjustment method for rotary steerable downhole release, comprising steps of:

[0032] defining a diversion ratio p of a jet nozzle 2 by a ground control system according to a cleaning requirement of a cuttings bed; and sending the diversion ratio p of the jet nozzle 2 to a control unit of a downhole rotary steerable system; and

[0033] determining an opening area s of the jet nozzle 2 by the control unit of the downhole rotary steerable system according to the diversion ratio p of the jet nozzle 2 and an equivalent channel area S of a drilling tool, wherein a calculation formula is: s=p*S/(1−p); controlling an adjustable bypass valve 3 by the control unit of the downhole rotary steerable system according to the calculated opening area s of the jet nozzle 2, so as to control an overlapping area between sector holes 9 of a rotor end 7 and a stator end 8, thereby opening the jet nozzle 2; after cleaning, waiting for the ground control system to close the jet nozzle 2.

[0034] According to a downhole accumulation state of the cuttings bed, the ground control system performs a rough classification based on a ground friction torque, and sets three diversion ratios which are 20%, 40% and 60%. A higher diversion ratio is suitable for a more serious cuttings bed, which uses a larger friction torque. The equivalent channel area of the drilling tool is a constant parameter known before the drilling tool enters the well. The calculation is done on the control unit of the downhole rotary steerable system. According to the required diversion ratio, the opening area of the jet nozzle 2 is calculated. Based on the relationship between the open area of the jet nozzle 2 and a relative angle of rotor and stator (this relationship is an inherent attribute and can be calibrated in the laboratory), a motor drives the rotor to a set position.

[0035] According to the required diversion ratio, the opening area of the jet nozzle 2 is calculated. Based on the relationship between the open area of the jet nozzle 2 and the relative angle of rotor and stator (this relationship is an inherent attribute and can be calibrated in the laboratory), the motor drives the rotor to the set position. There is a lower limit for the flow rate, because a low jet flow rate cannot sufficiently break the cuttings bed. On a drill collar, there is a requirement for the opening area, which is determined according to Bernoulli's equation. At the minimum required diversion ratio, the jet flow rate should be at least 30 m/s, and the opening area should be larger than the opened sector area between the rotor end and the stator end. In the present invention, it is only necessary to control the opening area since the opening area itself determines the diversion ratio that determines the jet flow rate. There is no requirement for the medium.

Embodiment 2

[0036] As another preferred embodiment of the present invention, referring to FIGS. 1-4, the embodiment 2 provides:

[0037] a jet flow adjustment method for rotary steerable downhole release, comprising steps of:

[0038] defining a diversion ratio p of a jet nozzle 2 by a ground control system according to a cleaning requirement of a cuttings bed; and sending the diversion ratio p of the jet nozzle 2 to a control unit of a downhole rotary steerable system; and determining an opening area s of the jet nozzle 2 by the control unit of the downhole rotary steerable system according to the diversion ratio p of the jet nozzle 2 and an equivalent channel area S of a drilling tool, wherein a calculation formula is: s=p*S/(1−p); controlling an adjustable bypass valve 3 by the control unit of the downhole rotary steerable system according to the calculated opening area s of the jet nozzle 2, so as to control an overlapping area between sector holes 9 of a rotor end 7 and a stator end 8, thereby opening the jet nozzle 2; after cleaning, waiting for the ground control system to close the jet nozzle 2. According to a downhole accumulation state of the cuttings bed, the ground control system performs a rough classification based on a ground friction torque, and sets three diversion ratios which are 20%, 40% and 60%. A higher diversion ratio is suitable for a more serious cuttings bed, which uses a larger friction torque. The equivalent channel area of the drilling tool is a constant parameter known before the drilling tool enters the well. The calculation is done on the control unit of the downhole rotary steerable system. According to the required diversion ratio, the opening area of the jet nozzle 2 is calculated. Based on the relationship between the open area of the jet nozzle 2 and a relative angle of rotor and stator (this relationship is an inherent attribute and can be calibrated in the laboratory), a motor drives the rotor to a set position. According to the required diversion ratio, the opening area of the jet nozzle 2 is calculated. Based on the relationship between the open area of the jet nozzle 2 and the relative angle of rotor and stator (this relationship is an inherent attribute and can be calibrated in the laboratory), the motor drives the rotor to the set position. There is a lower limit for the flow rate, because a low jet flow rate cannot sufficiently break the cuttings bed. On a drill collar, there is a requirement for the opening area, which is determined according to Bernoulli's equation. At the minimum required diversion ratio, the jet flow rate should be at least 30 m/s, and the opening area should be larger than the opened sector area between the rotor end and the stator end. In the present invention, it is only necessary to control the opening area since the opening area itself determines the diversion ratio that determines the jet flow rate. There is no requirement for the medium.

[0039] The jet nozzle 2 is arranged on a drill string 1 and is tilted towards a drill bit, and an exit angle of the jet nozzle 2 is 30°-45°. The adjustable bypass valve 3 comprises a drive motor 4, the rotor end 7 and the stator end 8, wherein an output shaft of the drive motor 4 is connected to the rotor end 7; the sector holes 9 are drilled on both the rotor end 7 and the stator end 8; the drive motor 4 drives the rotor end 7 to rotate relative to the stator end 8, thereby changing the overlapping area between the sector holes 9 of the rotor end 7 and the stator end 8 to open and close the jet nozzle 2.

Embodiment 3

[0040] As yet another preferred embodiment of the present invention, referring to FIGS. 1-4, the embodiment 3 provides:

[0041] a jet flow adjustment method for rotary steerable downhole release, comprising steps of:

[0042] defining a diversion ratio p of a jet nozzle 2 by a ground control system according to a cleaning requirement of a cuttings bed; and sending the diversion ratio p of the jet nozzle 2 to a control unit of a downhole rotary steerable system; and determining an opening area s of the jet nozzle 2 by the control unit of the downhole rotary steerable system according to the diversion ratio p of the jet nozzle 2 and an equivalent channel area S of a drilling tool, wherein a calculation formula is: s=p*S/(1−p); controlling an adjustable bypass valve 3 by the control unit of the downhole rotary steerable system according to the calculated opening area s of the jet nozzle 2, so as to control an overlapping area between sector holes 9 of a rotor end 7 and a stator end 8, thereby opening the jet nozzle 2; after cleaning, waiting for the ground control system to close the jet nozzle 2. According to a downhole accumulation state of the cuttings bed, the ground control system performs a rough classification based on a ground friction torque, and sets three diversion ratios which are 20%, 40% and 60%. A higher diversion ratio is suitable for a more serious cuttings bed, which uses a larger friction torque. The equivalent channel area of the drilling tool is a constant parameter known before the drilling tool enters the well. The calculation is done on the control unit of the downhole rotary steerable system. According to the required diversion ratio, the opening area of the jet nozzle 2 is calculated. Based on the relationship between the open area of the jet nozzle 2 and a relative angle of rotor and stator (this relationship is an inherent attribute and can be calibrated in the laboratory), a motor drives the rotor to a set position. According to the required diversion ratio, the opening area of the jet nozzle 2 is calculated. Based on the relationship between the open area of the jet nozzle 2 and the relative angle of rotor and stator (this relationship is an inherent attribute and can be calibrated in the laboratory), the motor drives the rotor to the set position. There is a lower limit for the flow rate, because a low jet flow rate cannot sufficiently break the cuttings bed. On a drill collar, there is a requirement for the opening area, which is determined according to Bernoulli's equation. At the minimum required diversion ratio, the jet flow rate should be at least 30 m/s, and the opening area should be larger than the opened sector area between the rotor end and the stator end. In the present invention, it is only necessary to control the opening area since the opening area itself determines the diversion ratio that determines the jet flow rate. There is no requirement for the medium.

[0043] The jet nozzle 2 is arranged on a drill string 1 and is tilted towards a drill bit, and an exit angle of the jet nozzle 2 is 30°-45°. The adjustable bypass valve 3 comprises a drive motor 4, the rotor end 7 and the stator end 8, wherein an output shaft of the drive motor 4 is connected to the rotor end 7; the sector holes 9 are drilled on both the rotor end 7 and the stator end 8; the drive motor 4 drives the rotor end 7 to rotate relative to the stator end 8, thereby changing the overlapping area between the sector holes 9 of the rotor end 7 and the stator end 8 to open and close the jet nozzle 2.

[0044] The adjustable bypass valve 3 further comprises an external cylinder 6 arranged in the jet nozzle 2, wherein the drive motor 4 is fixed on an internal wall of the external cylinder 6 by a motor support plate 5, and the stator end 8 is also fixed on the internal wall of the external cylinder 6. A bypass hole 10 is drilled on a side wall of the external cylinder 6; a through hole 11 is drilled on the stator end 8 to communicate with the bypass hole 10; and a connecting hole is drilled on the rotor end 7 to communicate with the through hole 11 of the stator end 8.