Surface pulse valve for inducing vibration in downhole tubulars

1. An apparatus for generating vibration in a downhole tubular, comprising:

a pulse valve that is configured to open and close intermittently, so as to intermittently vary a pressure of a fluid that flows into the downhole tubular and thereby generate the vibration in the downhole tubular, wherein the downhole tubular comprises a coiled tubing, and wherein the vibration temporarily separates a portion of the coiled tubing from a surrounding tubular, thereby reducing friction between the portion of the coiled tubing and the surrounding tubular, which increases a depth to which the coiled tubing is able to extend in a well; and

a driver coupled to the pulse valve and configured to open and close the pulse valve, wherein the driver is powered by a source of energy that is not in fluid communication with the downhole tubular.

2. The apparatus of claim 1 , wherein the pulse valve is positioned at a top surface of the well, and wherein the downhole tubular is configured to be deployed into the well.

3. The apparatus of claim 1 , wherein the pump is in fluid communication with the pulse valve, so as to provide the fluid thereto and into the downhole tubular.

4. The apparatus of claim 3 , wherein the pump is configured to provide a generally constant flow of the fluid to the pulse valve.

5. The apparatus of claim 1 , wherein the driver comprises an electric motor, and wherein the source of energy comprises a generator, a power grid, or both.

6. An apparatus for generating vibration in a downhole tubular, comprising:

a pulse valve that is configured to open and close intermittently, so as to intermittently vary pressure of a fluid that flows into the downhole tubular and thereby generate vibration in the downhole tubular, wherein the pulse valve comprises:

a housing having an inlet and an outlet;

a valve sleeve positioned in the housing and in communication with the inlet, wherein the valve sleeve comprises a first opening; and

a valve shaft positioned in the housing and at least partially in the valve sleeve, wherein the valve shaft is rotatable relative to the valve sleeve, wherein the valve shaft comprises a second opening that is configured to intermittently align with the first opening as the valve shaft is rotated relative to the valve sleeve, and wherein the first opening being aligned with the second opening opens the pulse valve, such that fluid communication between the inlet and outlet is permitted, and the first opening not being aligned with the second opening closes the pulse valve, such that fluid communication between the inlet and the outlet is blocked; and

a driver coupled to the pulse valve and configured to open and close the pulse valve, wherein the driver is powered by a source of energy that is not in fluid communication with the downhole tubular.

7. The apparatus of claim 6 , wherein the valve shaft is rotated relative to the housing by operation of the driver, and wherein the valve sleeve is configured to remain stationary with respect to the housing.

8. The apparatus of claim 6 , wherein valve sleeve comprises a plurality of first openings, including the first opening, that are axially offset from one another and positioned at different angular intervals around the valve sleeve.

9. The apparatus of claim 8 , wherein valve shaft comprises a plurality of second openings, including the second opening, that are axially offset from one another and positioned at different angular intervals around the valve shaft, wherein each of the second openings are intermittently aligned with a respective one of the first openings as the valve shaft rotates relative to the valve sleeve.

10. The apparatus of claim 6 , wherein the valve sleeve comprises a multiplicity of separate holes that together define the first opening, and wherein the valve shaft comprises a multiplicity of holes that together define the second opening.

11. The apparatus of claim 6 , wherein the inlet is axially-oriented and the outlet is radially-oriented, such that the inlet and outlet are oriented perpendicular to one another.

12. The apparatus of claim 6 , wherein:

the valve shaft comprises a shoulder; and

the pulse valve comprises an axial thrust bearing positioned between the housing and the shoulder, a radial bearing positioned radially between the valve shaft and the valve sleeve, and a shaft seal positioned between the valve shaft and the housing.

13. An apparatus for generating vibration in a downhole tubular, comprising:

a pulse valve that is configured to open and close intermittently, so as to intermittently vary pressure of a fluid that flows into the downhole tubular and thereby generate vibration in the downhole tubular;

a driver coupled to the pulse valve and configured to open and close the pulse valve, wherein the driver is powered by a source of energy that is not in fluid communication with the downhole tubular;

a pump in fluid communication with the downhole tubular; and

a shutoff valve in communication with the pump and in communication with the pulse valve, wherein the shutoff valve is configured to open to allow fluid communication from the pump to the pulse valve, and wherein the shutoff valve is configured to close to block fluid communication from the pump to the pulse valve.

14. The apparatus of claim 13 , wherein the pulse valve comprises an inlet in communication with the shutoff valve, and an outlet in communication with an inlet of the pump.

15. An apparatus for generating vibration in a downhole tubular, comprising:

a pulse valve that is configured to open and close intermittently, so as to intermittently vary pressure of a fluid that flows into the downhole tubular and thereby generate vibration in the downhole tubular, wherein the pulse valve comprises:

a housing having an inlet and an outlet;

a driver configured to open and close the pulse valve, wherein the driver is powered by a source of energy that is not in fluid communication with the downhole tubular;

a shaft extending into the housing and coupled to the driver, such that the driver is configured to rotate the shaft; and

a valve element positioned in the housing and coupled to the shaft, such that the valve element rotates along with the shaft, wherein the valve element defines a through-port that is intermittently aligned with the inlet and the outlet, permitting fluid communication therebetween, and intermittently misaligned with the inlet and the outlet, blocking fluid communication therebetween.

16. A method, comprising:

pumping a fluid into a downhole tubular using a pump;

intermittently opening and closing a pulse valve positioned downstream from the pump and upstream from the downhole tubular using a driver, wherein intermittently opening and closing the pulse valve causes intermittent pressure variations of the fluid in the downhole tubular, so as to vibrate the downhole tubular; and

flowing the fluid from an outlet of the pulse valve when the pulse valve is open back to the pump.

17. The method of claim 16 , wherein the driver is not in fluid communication with the downhole tubular.

18. The method of claim 16 , further comprising adjusting a speed of the driver so as to change a frequency of the intermittent opening and closing of the pulse valve.

19. A method, comprising:

pumping a fluid into a downhole tubular using a pump; and

intermittently opening and closing a pulse valve positioned downstream from the pump and upstream from the downhole tubular using a driver, wherein intermittently opening and closing the pulse valve causes intermittent pressure variations of the fluid in the downhole tubular, so as to vibrate the downhole tubular, and wherein intermittently opening and closing the pulse valve comprises rotating a valve element comprising a first opening relative to a valve sleeve having a second opening.

20. A method, comprising:

pumping a fluid into a downhole tubular using a pump; and

intermittently opening and closing a pulse valve positioned downstream from the pump and upstream from the downhole tubular using a driver, wherein intermittently opening and closing the pulse valve causes intermittent pressure variations of the fluid in the downhole tubular, so as to vibrate the downhole tubular, wherein intermittently opening and closing the pulse valve comprises rotating a valve element relative to a housing, wherein the valve element comprises a through-bore that is aligned between an inlet of the housing and an outlet of the housing when the pulse valve is open, and wherein the through-bore is not aligned with the inlet and the outlet, such that valve element blocks communication between the inlet and the outlet, when the pulse valve is closed.