초록 ▼

Disclosed herein is a device that relates to a non-return valve. The valve comprising, a valve seat, a valve piston in operable communication with the valve seat. The valve further comprising, a first seal disposed at the piston to interact with the valve seat, and a second seal positioned at the pi

Disclosed herein is a device that relates to a non-return valve. The valve comprising, a valve seat, a valve piston in operable communication with the valve seat. The valve further comprising, a first seal disposed at the piston to interact with the valve seat, and a second seal positioned at the piston to interact with the valve seat temporally after the first seal.

대표청구항 ▼

What is claimed is: 1. A downhole non-return valve, comprising: a first housing defining a valve inlet, a valve outlet, a housing bore and a shield perimetrically surrounding the housing bore at the valve outlet; a plug having a first seal and a second seal, the plug being moveable between an open

What is claimed is: 1. A downhole non-return valve, comprising: a first housing defining a valve inlet, a valve outlet, a housing bore and a shield perimetrically surrounding the housing bore at the valve outlet; a plug having a first seal and a second seal, the plug being moveable between an open position, a partially sealed position, and a fully sealed position, the first seal sealingly engaged with the housing bore defining the partially sealed position, the first seal and the second seal sealingly engaged with the housing bore defining the fully sealed position, and neither the first seal nor the second seal sealingly engaged with the housing bore defining the open position; a second housing engagable by a mandrel of the plug being configured to prevent fluids at well pressure from acting on the mandrel when the downhole non-return valve is in the open position while allowing fluids at well pressure to act on the mandrel when in the fully sealed position; and a biasing member urging the plug towards the fully sealed position wherein the urging force of the biasing member is sufficient to move the plug to the partially sealed position but is selected to be insufficient to move the plug to the fully sealed position. 2. The non-return valve of claim 1, wherein in the partially sealed position an outlet side of the plug is exposed to well pressure that aids in moving the plug to the fully sealed position. 3. The non-return valve of claim 1, wherein the shield is configured to redirect fluid flow from the outlet of the valve to substantially a longitudinal direction. 4. The non-return valve of claim 3, wherein the shield circumferentially surrounds the housing bore at the valve outlet. 5. The non-return valve of claim 1, wherein the biasing member is a spring. 6. The non-return valve of claim 1, further comprising: a seal surface at the plug engagable with a seal seat at the first housing. 7. The non-return valve of claim 6, wherein the seal surface and seal seat are metal. 8. The non-return valve of claim 1, wherein the first seal is a wiper seal. 9. The non-return valve of claim 1, wherein the second seal is a V-packing seal. 10. The non-return valve of claim 1, further comprising: run-in-configuration retainers that lock the plug in the fully sealed position during shipping, installation into the downhole environment, and initial pressure testing before releasing the plug from the run-in-configuration. 11. The non-return valve of claim 10, wherein the run-in-configuration retainers are releasable at a selected pressure. 12. The non-return valve of claim 10, wherein the run-in-configuration retainers are shear screws. 13. The non-return valve of claim 10, further comprising: a ring receptive of the run-in-configuration retainers and movable relative to the plug, the ring configured to position the plug in the fully sealed position prior to release of the run-in-configuration retainers and to not restrict travel of the plug after release of the run-in-configuration retainers. 14. The non-return valve of claim 1, wherein the shield fully surrounds the valve outlet at the housing bore. 15. The non-return valve of claim 1, wherein the second housing has an inner bore engagably receptive to at least one of the first seal and the second seal when the plug is in the open position. 16. The non-return valve of claim 1, wherein the second housing includes ports configured to allow fluids to enter therethrough to act on the mandrel when the downhole non-return valve is in the fully sealed position. 17. The non-return valve of claim 16, wherein in the mandrel is configured to occlude fluid access through the ports when the downhole non-return valve is in the open position. 18. A method of injecting fluid into a well bore through a non-return valve, comprising: porting fluids at well pressure to a portion of a plug when the non-return valve is in a fully sealed position; injecting fluid into the non-return valve the valve being in the fully sealed position defined by a first seal disposed at a plug and a second seal disposed at the plug both being sealingly engaged with a housing bore; pressurizing the fluid sufficiently to overcome a closing force comprising a combination of a biasing force and well pressure to open a valve outlet; preventing fluids at well pressure from acting on the portion of the plug when the non-return valve is in the open position; injecting fluid through the valve outlet into a well; redirecting the fluid toward a substantially longitudinal direction; and ceasing injection of the fluid thereby permitting movement of the plug to a partially sealed position defined by sealing engagement of the housing bore with the first seal and not the second seal with the biasing force prior to fully sealing the valve outlet with the closing force. 19. The method of claim 18, further comprising: cleaning the housing bore with the first seal prior to the second seal engaging the housing bore. 20. The method of claim 18, wherein the first seal is a wiper seal and the second seal is a V-packing seal. 21. The method of claim 18, further comprising: shielding well bore components from fluid erosion with a sacrificial shield. 22. The method of claim 18, wherein the biasing force is provided by a biasing member. 23. The method of claim 18, further comprising engaging at least one of the first seal and the second seal in an inner bore of a second housing.