초록 ▼

A multi-stage setting tool actuated by hydrostatic pressure downhole is provided with a selectable force-time profile during setting. A first port opens a first piston chamber to hydrostatic pressure which drives a first piston. A force-transmitting member, attached to the piston, is driven in respo

A multi-stage setting tool actuated by hydrostatic pressure downhole is provided with a selectable force-time profile during setting. A first port opens a first piston chamber to hydrostatic pressure which drives a first piston. A force-transmitting member, attached to the piston, is driven in response to the fluid pressure increase in the chamber. The process is repeated with sequential ports and piston chambers. A settable tool is set in response to the driving of the force-transmitting member by the pistons. The combined stroke distances and forces of the pistons are selected to set the tool. Opening of the ports can occur in response to electrical signal and can be conditional on occurrence of a selected event or condition. Speed of setting can be regulated.

대표청구항 ▼

1. A setting tool assembly for providing setting force to a settable downhole tool positioned in a subterranean wellbore, the setting tool assembly comprising: a housing defining a first pressure chamber and second pressure chamber, the pressure chambers fluidly isolated from one another within the

1. A setting tool assembly for providing setting force to a settable downhole tool positioned in a subterranean wellbore, the setting tool assembly comprising: a housing defining a first pressure chamber and second pressure chamber, the pressure chambers fluidly isolated from one another within the housing;a first piston member slidingly mounted in the first pressure chamber and a second piston member slidingly mounted in the second pressure chamber;a first selectively openable port positioned between the first pressure chamber and a hydrostatic fluid, wherein the first piston member is movable in response to the hydrostatic fluid upon opening of the first selectively openable port;a second selectively openable port positioned between the second pressure chamber and a hydrostatic fluid, wherein the second piston member is movable in response to the hydrostatic fluid upon opening of the second selectively openable port;a first force-transmitting member attached to the first piston member, attachable to the settable downhole tool, and operable to exert a first force on the settable downhole tool upon opening of the first selectively openable port; anda second force-transmitting member attached to the second piston member and operable to exert a second force on the first force-transmitting member upon opening of the second selectively openable port, and wherein the combined first and second forces are operable to fully set the settable downhole tool. 2. The assembly of claim 1, wherein the first chamber is initially filled with a compressible fluid. 3. The assembly of claim 1, wherein the first and second force-transmitting members form a single piece, are releasably attached to one another, or are each attached to the first piston member. 4. The assembly of claim 1, wherein the first piston member, upon opening of the first selectively openable port, is operable to transmit a first force to the first force-transmitting member, and wherein the second piston member, upon opening of the second selectively openable port, is operable to transmit a second force to the first force-transmitting member, and wherein the sum of the first and second forces is sufficient to set the settable downhole tool. 5. The assembly of claim 1, further comprising a first fluid metering device positioned to meter hydrostatic fluid entry into the first or second pressure chamber. 6. The assembly of claim 1, further comprising a first temporary fluid barrier positioned across the first selectively openable port and a second temporary fluid barrier positioned across the second selectively openable port. 7. The assembly of claim 6, wherein the temporary fluid barriers include at least one rupture disc. 8. The assembly of claim 6, further comprising a first and second actuation assemblies positioned adjacent to and operable to actuate the first and second temporary fluid barriers, respectively. 9. The assembly of claim 8, wherein electrical power to operate the actuation assemblies is supplied from a battery source carried on the tool assembly, from an electrical line to the surface, or from a wireless power transmission. 10. The assembly of claim 1, wherein the first and second selectively openable ports further comprise selectively openable mechanical valves, ball valves, gate valves, solenoid valves, or flapper valves. 11. The assembly of claim 9, wherein the first and second actuation assemblies are actuable upon receipt of spaced first and second signals, respectively. 12. The assembly of claim 1, wherein the second selectively openable port is initially covered by a port cover, the port cover connected to the first piston member. 13. A method for providing a multi-stage setting force for setting a settable downhole tool positioned in a subterranean wellbore, the method comprising the steps of: a) selectively opening a first port to a first piston chamber having a first piston mounted therein for sliding movement;b) flowing a fluid at hydrostatic pressure into the first pressure chamber through the first port, thereby driving the first piston;c) driving a force-transmitting member attached to the first piston in response to step b);d) selectively opening a second port to a second piston chamber, the second piston chamber fluidly isolated from the first piston chamber;e) flowing a fluid at hydrostatic pressure into the second piston chamber through the second port, thereby driving the second piston;f) driving the force-transmitting member in response to step e); andg) setting the settable downhole tool in response to the driving of the force-transmitting member. 14. The method of claim 13, wherein step c) further comprises the step of driving the force-transmitting member a first stroke distance in response to step b). 15. The method of claim 14, wherein step f) further comprises the step of driving the force-transmitting member a second stroke distance in response to step e). 16. The method of claim 15, wherein the first and second stroke distances, combined, are sufficient to perform step g). 17. The method of claim 15, wherein step d) occurs only after movement of the force-transmitting member the first stroke distance. 18. The method of claim 13, wherein step a) occurs upon an electrical signal from a timer, upon a signal from the surface, or upon a signal initiated only upon the occurrence of a selected event or condition. 19. The method of claim 13, wherein steps a) and d) further comprise rupturing a rupturable disc or opening a valve. 20. The method of claim 13, wherein steps b) and e) further comprise flowing the fluid through fluid metering devices. 21. The method of claim 13, wherein step d) occurs after step a) and before the completion of step c). 22. The method of claim 13, further comprising the steps of: selectively opening additional ports corresponding to additional piston chambers, each having a piston mounted therein for sliding movement; sequentially flowing wellbore fluid at hydrostatic pressure into the additional pressure chambers through the additional ports; and, in response thereto, driving the force-transmitting member additional stroke distances. 23. The method of claim 13, wherein step d) further comprises the step of sliding a port cover from a closed position over the second port to an open position in response to driving the first piston in step b).