Downhole mechanism

Abstract

A tubular downhole tool string component having a sidewall with a fluid passageway formed therein between a first end and second end, and a valve mechanism disposed within the fluid passageway adapted to substantially cyclically build-up and release pressure within the fluid passageway such that a pressure build-up results in radial expansion of at least a portion of the sidewall and wherein a pressure release results in a radial contraction of the portion of the sidewall. The valve mechanism disposed within the fluid passageway comprises a spring. Radial expansion and contraction of the portion of the sidewall varies a weight loaded to a drill bit disposed at a drilling end of the drill string.

Description

BACKGROUND OF THE INVENTION

This invention relates to the field of downhole drill strings. Increasing the rate of penetration in drilling saves substantial amount of time and money in the oil and gas, geothermal, exploration, and horizontal drilling industries.

U.S. Pat. No. 6,588,518 to Eddison, which is herein incorporated by reference for all that it contains, discloses a downhole drilling method comprising the production of pressure pulses in drilling fluid using measurement-while-drilling (MWD) apparatus and allowing the pressure pulses to act upon a pressure responsive device to create an impulse force on a portion of the drill string.

U.S. Pat. No. 4,890,682 to Worrall, et al., which is herein incorporated by reference for all that it contains, discloses a jarring apparatus provided for vibrating a pipe string in a borehole. The apparatus thereto generates at a downhole location longitudinal vibrations in the pipe string in response to flow of fluid through the interior of said string.

U.S. Pat. No. 4,979,577 to Walter et al., which is herein incorporated by reference for all that it contains, discloses a flow pulsing apparatus adapted to be connected in a drill string above a drill bit. The apparatus includes a housing providing a passage for a flow of drilling fluid toward the bit. A valve which oscillates in the axial direction of the drill string periodically restricts the flow through the passage to create pulsations in the flow and a cyclical water hammer effect thereby to vibrate the housing and the drill bit during use. Drill bit induced longitudinal vibrations in the drill string can be used to generate the oscillation of the valve along the axis of the drill string to effect the periodic restriction of the flow or, in another form of the invention, a special valve and spring arrangement is used to help produce the desired oscillating action and the desired flow pulsing action.

BRIEF SUMMARY OF THE INVENTION

In one aspect of the invention, a downhole tool string component comprises a fluid passageway formed between a first and second end. A valve mechanism is disposed within the fluid passageway adapted to substantially cyclically build-up and release pressure within the fluid passageway such that a pressure build-up results in radial expansion of at least a portion of the fluid passageway and wherein a pressure release results in a contraction of the portion of the fluid passageway. The valve mechanism disposed within the fluid passageway comprises a spring. Expansion and contraction of the portion of the fluid passageway assisting in advancing the drill string within a subterranean environment. This advancing may be accomplished by varying a weight loaded to a drill bit disposed or helping to propel the drill string along a horizontal well.

The spring is adapted to oppose the travel of a fluid flow. The spring is a tension spring or a compression spring. The spring is disposed intermediate a carrier and a centralizer and is aligned coaxially with the downhole tool string component.

The valve mechanism comprises a shaft radially supported by a bearing and the centralizer. The carrier is mounted to the shaft. The centralizer is adapted to align the shaft coaxially with the downhole tool string component. The bearing is disposed intermediate the shaft and the centralizer. The carrier comprises at least one port. The carrier comprises a first channel formed on a peripheral edge substantially parallel with an axis of the tool string component.

The drilling fluid is adapted to push against a fluid engaging surface disposed on the carrier. The valve mechanism comprises an insert disposed intermediate and coaxially with the first end and the carrier. The centralizer and the insert are fixed within the fluid passageway. The insert comprises a taper adapted to concentrate the flow of the downhole tool string fluid into the carrier. The engagement of the fluid against the carrier resisted by the spring of the valve mechanism causes the first and second set of ports to align and misalign by oscillating the shaft. The insert further comprises a second channel on its peripheral edge. The valve mechanism comprises a fluid by-pass. The bit is adapted to cyclically apply pressure to the formation. The drill bit comprises a jack element with a distal end protruding from a front face of the drill bit and substantially coaxial with the axis of rotation of the bit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective diagram of an embodiment of a string of downhole tools suspended in a borehole.

FIG. 2 is a cross-sectional diagram of an embodiment of a downhole tool string component.

FIG. 3 a is a cross-sectional diagram of another embodiment of a downhole tool string component.

FIG. 3 b is a cross-sectional diagram of another embodiment of a downhole tool string component.

FIG. 4 is a cross-sectional diagram of an embodiment of a downhole tool string component with a drill bit.

FIG. 5 is a cross-sectional diagram of another embodiment of a downhole tool string.

FIG. 6 is a cross-sectional diagram of another embodiment of a downhole tool string.

FIG. 7 is a perspective diagram of a tubular assembly.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENT

FIG. 1 is a perspective diagram of an embodiment of a string of downhole tools 100 suspended by a derrick 101 in a borehole 102. A bottomhole assembly 103 may be located at the bottom of the borehole 102 and may comprise a drill bit 104. As the drill bit 104 rotates downhole the tool string 100 may advance farther into the earth. The drill string 100 may penetrate soft or hard subterranean formations 105. The bottom hole assembly 103 and/or downhole components may comprise data acquisition devices which may gather data. The data may be sent to the surface via a transmission system to a data swivel 106. The data swivel 106 may send the data to the surface equipment. Further, the surface equipment may send data and/or power to downhole tools and/or the bottom-hole assembly 103. In some embodiments of the invention, no downhole telemetry system is used.

FIG. 2 is a cross-sectional diagram of an embodiment of a downhole tool string component 200 comprised of a first end 210 and a second end 211. The central bore or fluid passageway 201 may comprise a valve mechanism 202. The valve mechanism 202 may comprise a shaft 203 aligned coaxially with the downhole tool string component 200 by a centralizer 218. The valve mechanism 202 may also comprise a fluid by-pass 204. The valve mechanism 202 may also comprise a spring 205 adapted to oppose the travel of a flow of drilling fluid. The drilling fluid may follow a path indicated by the arrows 233. The spring 205 may be aligned coaxially with the downhole tool string component 200 and may be a compression spring or a tension spring.

The valve mechanism 202 may also comprise a carrier 206 comprised of ports 220 and a first channel 221. The valve mechanism 202 may also comprise an insert 207 disposed coaxially with the axis of the downhole tool string component 200. The insert 207 may comprise a set of ports 222 and a second channel 223. The insert 207 may comprise a taper 208 adapted to concentrate the flow of the drilling fluid into the carrier 206.

The spring 205 may be adapted to resist the engagement of the fluid flow against the carrier 206. Without the fluid flow the ports may be misaligned due to the force of the spring. Once flow is added, the misaligned ports may obstruct the flow causing a pressure build-up. As the pressure increases the force of the spring may be overcome and eventual align the ports. Once the ports are aligned, the flow may pass through the ports relieving the pressure build-up such that the spring moves the carrier to misalign the ports.

This cycle of aligning and misaligning the carrier ports 220 and insert ports 222 aids in the advancing the drill string within its subterranean environments. As both sets of ports 220,222 are misaligned, the pressure build up from the drilling fluid may cause the sidewall 230 of the downhole drill string component 200 to expand. As both sets of ports 220,222 are aligned, the pressure build up from the drilling fluid may be released as the drilling fluid is allowed to flow from the first channel 221, through the ports 220,222 and into the second channel 223. The shaft 203 and carrier 206 may be secured to each other by means of press-fitting the shaft 203 into the carrier 206 or shrink fitting the carrier 206 over the shaft 203. The shaft 203 may be allowed to move axially by a bearing 235 disposed intermediate the centralizer 218 and shaft 203.

FIG. 3 a shows a cross-sectional diagram of another embodiment of a downhole tool string component 200a. With the ports 220a on the carrier 206a misaligned in relation to the ports 222a on the insert 207a, the drilling fluid 233a is allowed to build up within the central bore or fluid passageway 201a causing the sidewalls 230a of the downhole drill string component 200a to expand radially outward.

FIG. 3 b shows a cross-sectional diagram of another aspect of the embodiment of the downhole tool string component 200a shown in FIG. 3a. With the ports 220a on the carrier 206a aligned with the ports 222a on the insert 207a, the drilling fluid is allowed to pass from the first end 210a to the second end 211a, thus releasing the build up of pressure within the fluid passageway 201a and allowing the sidewalls 230a of the downhole drill string component 200a to radially contract back to their original position.

As the sidewall 230a of the downhole drill string component 200a or pipe radially contracts, the length of the downhole drill string component 200a or pipe is believed to expand axially. This axial expansion is believed to increase the weight loaded to the drill bit and transfer a pressure wave into the formation. In some embodiments, the pressure relief above the valve mechanism 202a will increase the pressure below the valve mechanism 202a thereby pushing against the drill bit 104, further increasing the weight loaded to the drill bit. Also in some embodiments the affect of the oscillating valve mechanism's mass will fluctuate the weight loaded to the drill bit.

FIG. 4 shows a cross-sectional diagram of a downhole drill string component 300 having a valve mechanism 360 installed within a drill bit 310. The drill bit 310 may be made in two portions. The first portion 320 may comprise the shank 322. The second portion 340 may comprise the working face 344 and the bit body 342. The two portions 320, 40 may be welded together or otherwise joined together at a joint 315. The drill bit 310 can further include a shaft 364 protruding out of its working face 344, and which shaft 364 can also form a portion of the valve mechanism 360.

FIG. 5 shows a perspective diagram of another embodiment of a downhole tool string component 400. In this embodiment, the downhole tool string component 400 may comprise a valve mechanism 402. The valve mechanism 402 may comprise a carrier 406 which may be comprised of at least one hole 420 disposed on the carrier 406. The at least one hole 420 may be disposed offset at least one port 422 disposed on a guide 408 such that drilling fluid is unable to pass from the first end 410 to second end 411 if the carrier 406 is against the guide 408. The drilling fluid may follow the path indicated by the arrow 433. The guide 408 may be secured to the sidewalls 430 of the downhole drill string component 400 and may serve to align the shaft 403 axially with the downhole drill string component 400. A bearing 435 may be disposed intermediate the carrier 206 and the sidewall 430 of the downhole drill string component 400. The valve mechanism 402 may also comprise an insert 407 disposed intermediate the sidewall 430 of the downhole drill string component 400 and the shaft 403. A spring 405 may be disposed intermediate the insert 407 and the carrier 406 and coaxially with the downhole drill string component 400.

FIG. 6 shows a perspective diagram of another embodiment of a downhole tool string component 500. In this embodiment, the valve mechanism 502 may comprise a spring 505 disposed intermediate a carrier 506 and insert 507 and coaxially with the downhole tool string component 500. The insert 507 may comprise a set of ports 5522 and a bearing 535 disposed intermediate a shaft 503 and the insert 507. The drilling fluid may follow the path indicated by the arrow 533.

FIG. 7 is a perspective diagram of a tubular assembly 600 penetrating into a subterranean environment 605. Preferable the tubular assembly 600 is a drill string which comprises a central bore for the passing drilling mud through. The tubular assembly 600 may comprise a mechanism for contracting and expanding a diameter of the tubular assembly such that a wave is generated which travels a portion of the length of the tubular assembly. This mechanism may be a valve mechanism such as any of the valve mechanisms described in FIGS. 2-6. In horizontal drilling applications the length 602 of the tubular assembly 600 may be engaged with the wall of the well bore and waves 610 may aid in moving the tubular assembly in its desired trajectory. In some embodiments of the present invention, the tubular assembly is not rotated such as in traditionally oil and gas exploration, but is propelling along its trajectory through the waves 610.

The tubular assembly may be used in oil and gas drilling, geothermal operations, exploration, and horizontal drilling such as for utility lines, coal methane, natural gas, and shallow oil and gas.

In one aspect of the present invention a method for penetrating a subterranean environment includes the steps of providing a tubular assembly with a oscillating valve mechanism disposed within its bore, the valve mechanism comprising the characteristic such that as a fluid is passing through the valve, the valve will oscillate between an open and closed position; generating a wave along a length of the tubular assembly by radially expanding and contracting the tubular assembly by increasing and decreasing a fluid pressure by oscillating the valve mechanism; and engaging the length the tubular assembly such that the wave moves the tubular assembly along a trajectory.

In another aspect of the present invention a method for penetrating a subterranean environment comprises the steps of providing a tubular assembly with a mechanism disposed within its bore adapted to expand and contract a diameter of the tubular assembly; generating a wave along a length of the tubular assembly by radially expanding and contracting a diameter of the tubular assembly; and engaging the length the tubular assembly such that the wave moves the tubular assembly along a trajectory.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.

Claims

1. A method for penetrating a subterranean environment, comprising the steps of: providing a tubular assembly with an oscillating valve mechanism disposed within its bore, the valve mechanism comprising the characteristic such that as a fluid is passing through the valve, the valve mechanism will oscillate between an open and closed position;generating a wave along a length of the tubular assembly by radially expanding and contracting the tubular assembly by increasing and decreasing a fluid pressure by oscillating the valve mechanism; andengaging the length the tubular assembly such that the wave moves the tubular assembly along a trajectory.

2. The method of claim 1, wherein the tubular assembly is a drill string.

3. The method of claim 2, wherein the drill string comprises a drill bit having a working face, and with a shaft protruding out of its working face.

4. The method of claim 3, wherein the shaft is part of the valve mechanism.

5. The method of claim 1, wherein the tubular assembly comprises multiple valve mechanisms.

6. The method of claim 1, wherein the tubular assembly secretes a lubricant.

7. The method of claim 1, wherein the step of engaging the length of the tubular assembly is accomplished by drilling a substantially horizontal well.

8. The method of claim 1, wherein the fluid is a drilling mud.

9. The method of claim 1, wherein the valve mechanism comprises a spring adapted to resist a fluid flow passing through the bore.

10. The method of claim 9, wherein the spring forces the valve shut and generates a pressure build-up until the pressure is high enough to open the valve.

11. The method of claim 1, wherein the valve mechanism comprises multiple ports.

12. The method of claim 1, wherein the valve mechanism comprises an upper and lower bearing to support a shaft.

13. The method of claim 12, wherein the shaft is substantially coaxial with the tubular assembly.

14. A method for drilling a well bore through a subterranean environment, comprising: disposing a tubular assembly into a well bore, the tubular assembly including a sidewall, a central bore, and an expansion mechanism disposed within the central bore, the expansion mechanism operable to alternately radially expand and radially contract at least a portion of the sidewall of the tubular assembly;operating the expansion mechanism to radially expand the sidewall; andoperating the expansion mechanism to radially contract the sidewall and thereby generate an axial expansion traveling a length of the tubular assembly to vary a weight applied to a lower end of the tubular assembly.

15. The method of claim 14, wherein the tubular assembly is a drill string.

16. The method of claim 15, further comprising a drill bit coupled to the lower end of the drill string, the drill bit having a working face engagable with the subterranean environment with the applied weight.

17. The method of claim 16, wherein the expansion mechanism includes a shaft extending downwardly from the working face of the drill bit to engage with the subterranean environment.

18. A method for drilling a well bore through a subterranean environment, comprising: disposing a tubular assembly within said well bore, said tubular assembly including: a sidewall;a central bore;a valve mechanism disposed within said central bore, said valve mechanism operable to restrict a flow of fluid through said central bore in a closed position and to allow said flow through said central bore in an open position; anda drill bit coupled to a bottom end of said tubular assembly, said drill bit having a working face engagable with said subterranean environment with a weight applied thereto;introducing said fluid into said central bore;closing said valve mechanism to restrict said flow and generate an internal pressure within a portion of said central bore to radially expand a portion of said sidewall;opening said valve mechanism to allow said flow through said central bore and release said internal pressure to radially contract said portion of said sidewall, and thereby generate an axial expansion traveling a length of said tubular assembly to vary said weight applied to said drill bit.

19. The method of claim 18, further comprising oscillating said valve mechanism between said open and said closed positions to generate a series of axial expansions operable to cyclically vary said weight applied to said drill bit.

20. The method of claim 19, further comprising a spring mechanically associated with said valve mechanism and operable to close said valve mechanism when said internal pressure falls below a first predetermined value.

21. The method of claim 20, wherein said spring is operable to open said valve mechanism when said internal pressure exceeds a second predetermined value.

22. The method of claim 19, further comprising disposing a plurality of valve mechanisms within said central bore to provide a plurality of series of axial expansions traveling said length of said tubular assembly.

23. The method of claim 18, wherein said fluid is drilling mud.