Patent Application
20160130896
None
1. Field of the Disclosure
This disclosure relates generally to oilfield downhole tools and more particularly to methods and devices for hydrostatically setting a downhole tool.
2. Description of the Related Art
As the oil and gas industry continues to explore and produce from wells that are deeper and have higher hydrostatic pressures, designing downhole tools that can operate in high temperatures and high hydrostatics becomes a challenge. Hydrostatically setting a tool in a high hydrostatic environment can be difficult due to the strength limitations of tools. In some aspects, the present disclosure is directed to methods and devices for hydrostatically setting a downhole tool even in high hydrostatic pressures.
In one aspect, the present disclosure provides a setting tool for performing a wellbore operation. The setting tool may include a mandrel, a cylinder slidably engaged with the mandrel, a variable volume first chamber formed between the mandrel and the cylinder, a containment member having a second chamber adjacent to the first chamber, and a support fluid disposed in the first chamber. The setting tool may also have a valve disposed between the first chamber and the second chamber, wherein the valve flows the support fluid from the first chamber to the second chamber, and a slidable support axially and circumferentially distributed inside the first chamber, wherein the support fluid and the slidable support support the cylinder against a downhole pressure.
In another aspect, the present disclosure provides a method for performing a wellbore operation. The method may include connecting a consumer to a setting tool, conveying the consumer and the setting tool into a wellbore, and actuating the setting tool to set the consumer. The setting tool may include a mandrel, a cylinder slidably engaged with the mandrel, a variable volume first chamber formed between the mandrel and the cylinder, a containment member having a second chamber adjacent to the first chamber, a support fluid disposed in the first chamber. The setting tool may also have a valve disposed between the first chamber and the second chamber, wherein the valve flows the support fluid from the first chamber to the second chamber, and a slidable support axially and circumferentially distributed inside the first chamber, wherein the support fluid and the slidable support support the cylinder against a downhole pressure.
Illustrative examples of some features of the disclosure thus have been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the disclosure that will be described hereinafter and which will form the subject of the claims appended hereto.
For detailed understanding of the present disclosure, references should be made to the following detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, in which like elements have been given like numerals and wherein:
The present disclosure relates to devices and methods for setting a downhole tool in subterranean hydrostatics. As used herein, ‘hydrostatics’ refers to the hydrostatic pressure of the fluid present in a wellbore. Illustrative devices provide a liquid filled structural support that allows the use of hydrostatic pressure to set the downhole tool without crushing the device.
The first chamber 60 may be formed as an annular space between the mandrel 20 and the cylinder 30. The pressure in the first chamber 60 is selected to create the pressure difference across the piston wall 31 of the cylinder 30 to move the cylinder 30 and thereby set a consumer 100 (
The slidable support 80 cooperates with the support fluid to support the first chamber 60. In embodiments, the slidable support 80 may be a structure that provides a frame that can accept the loading caused by hydrostatics. For example, the slidable support 80 can be collets that include a male 40 and female 44 interlocking bodies. The male and female interlocking bodies 40, 44 may be reciprocally engaging collet fingers. The interlocking bodies 40, 44 can be spaced apart such that when they move towards each other, a bottom end 41 of the male body 40 meets a lower end 43 of the female body 44. Therefore, the slidable support 80 has two states: an elongated state when the first chamber 60 is fully extended and a compacted state when the cylinder 30 strokes. The slidable support 80 accommodates the reduced volume of the first chamber 60 by transitioning to the compacted state. During this transition, the male body 40 engages with the female body 44, and/or teeth of the male body 40 fills the gap between teeth of the female body 44.
The second chamber 70 provides a reservoir to receive the support fluid flowing out of the first chamber 60 via the valve 50. The second chamber 70 may be at a pressure, such as atmospheric pressure or a lower or higher pressure, or vacuum. The second chamber 70 may be filled with a fluid such as air, nitrogen or other fluid. The second chamber 70 can be contained in a containment member 72 such as tubes, pipes, hoses, canisters, tanks, etc. The containment member 72 may be sealed and axially constrained with respect to the mandrel 20.
The valve 50 controls fluid communication between the first chamber 60 and the second chamber 70. One port of the valve 50 is connected to the first chamber 60 and the other port is connected to the second chamber 70. An electronic member 54 may be located next to the valve 50 between the mandrel 20 and the cylinder 30. The electronic member 54 can be used to open, close, or meter the valve 50. When opened, the valve 50 allows the support fluid in the first chamber 60 to flow into the second chamber 70. During setting, the valve 50 may selectively communicate the support fluid from the first chamber 60 to the second chamber 70. As used herein, the term selective means that a tool or device is configured to behave in a specific manner when subjected to a predetermined condition.
Illustrative methods for using the setting tool 10 to actuate the consumer 100 will be discussed with reference to
The differential pressure across the cylinder 30, between the annulus 12 and the first chamber 60, also acts as the collapse pressure. The collapse pressure tries to crush the cylinder 30 elastically or plastically. Alternatively, the mandrel 20 may also be susceptible to crush due to pressure differential between a flow bore inside the mandrel 20 and the first chamber 60. In either case, the support fluid and the slidable support 80 counteract the pressure acting on the cylinder 30 and thereby mitigating this undesirable pressure condition.
Prior to the setting operation, as the hydrostatic pressure increases, the cylinder 30 will try to compress the support fluid. A relatively incompressible support fluid will prevent the cylinder 30 from stroking and the pressure of the support fluid will effectively equalize with the hydrostatic pressure. This will significantly reduce the external pressure differential trying to crush the cylinder 30 to a manageable level.
After the locking mechanism 90 is unlocked, the cylinder 30 is still stationary with respect to the mandrel 20 because the valve 50 is closed and prevents the support fluid from flowing out of the first chamber 60. Therefore, the pressure is balanced between the first chamber 60 and the annulus 12. This pressure balance eliminates the external pressure differential acting on the cylinder 30, preventing the cylinder 30 from stroking axially or being crushed.
Referring to
From the above, it should be appreciated that the support fluid may be used to support the cylinder 30 before and during the stroke against high hydrostatic pressures in the annulus 12. Further, the fluid flow from the first chamber 60 may be metered. Metering the flow can maintain a sufficient amount of support fluid within the first chamber 60 to continue counteracting the hydrostatic force as the cylinder 30 moves.
After the support fluid leaves the first chamber 60, the slidable support 80 in the first chamber 60 takes over to provide support to the structure against the collapse pressure at full stroke. Of course, the slidable support 80 may also support the cylinder 30 during the stroke against high hydrostatic pressures in the annulus 12. The cylinder 30 may be exposed to a maximum collapse pressure at full stroke. A safety factor may be employed to compensate for material properties or downhole conditions.
The cylinder 30 can stroke all the way until the slidable support 80 is completely compact or may stroke less than a full length, whichever is necessary to actuate the consumer 100. In either case, the setting tool 10 can be designed to provide, at a minimum, a required setting pressure to set the consumer 100.
In an embodiment, the second chamber 70 may provide enough vacuum to take the support fluid. Optionally, sets of the chambers 60, 70 may be stacked in series to reach the setting force. Accordingly, multiple first chamber 60 and second chamber 70 combinations may push the slidable support 80. In that case, each first chamber 60 will have a slidable support 80.
It should be understood that the teachings of the present disclosure are susceptible to numerous variants. Certain non-limiting variations are described below.
In an embodiment, an intermediate member 102 may connect the cylinder 30 and the consumer 100. Optionally, the consumer 100 and the setting tool 10 may be run separately into the wellbore and connected downhole. Alternatively, the cylinder 30 may stroke in uphole or downhole direction depending on the axial positioning of the consumer 100 with respect to the setting tool 10 and the need to push or pull the consumer 100.
Also, in some embodiments, the mandrel 20, instead of the cylinder 30 may stroke and push the consumer 100. The cylinder 30 may also rotate while stroking axially. Accordingly, the teeth of the interlocking bodies 40 and 44 may helically engage. Alternatively, the cylinder 30 or mandrel 20 may include additional cylinders, mandrels or parts. In other embodiments, multiple valves 50 may be disposed in the setting tool 10 for contingency or increased stroke force. Optionally, the valve 50 may be located in the mandrel 20 or some other member between the chambers 60 and 70.
The valve 50 is a fluid restriction device engineered to control flow based on technical requirements. The valve 50 may be a check valve, a diaphragm, a rupture disc, an electrically actuated valve, a magnetically activated valve, a poppet valve, a ball valve, a dissolvable element and/or other fluid restriction device. The valve 50 may be an adjustable flow control device that can be set to permit fluid communication between the chambers 60 and 70. In some embodiments, several different types of valves 50 may be employed in one setting tool 10. The electronic member 54 or mechanical shifting methods may both operate the valve 50 for redundancy.
The electronic member 54 may be connected to the valve 50 and monitor the pressure or the pressure changes of the annulus 12. Alternatively, the electronic member 54 may activate the valve 50 based on a clock or passage of time or after a conditional event. Or, the electronic member 54 may be omitted, and the valve 50 may be operated by mechanical means only.
The valve 50 may actively be controlled from the surface or may open in response to a specific detected condition. The valve 50 may allow the pressurized support fluid flow into the second chamber 70 in a selective and controlled manner before or after the locking mechanism 90 is released to prevent an impulse of the slidable support 80. In some embodiments, the impulse may be desired. Then, the valve 50 can be designed accordingly.
In another mode of operation, the valve 50 may be opened before the locking mechanism 90 is released. In that case, the support fluid fills the second chamber 70 before the cylinder 30 strokes. However, the valve 50 can control the amount and rate of support fluid flow. The support fluid flow may be below or above a predetermined flow rate, or in a range. Once the locking mechanism 90 is unlocked, the cylinder 30 strokes.
A fluid property of the support fluid may be viscosity, density, surface tension, phase, etc. The fluid property of the support fluid may be selected to allow a friction between the cylinder 30 and the mandrel 20 to be below or above a predetermined frictional force, or in a range. The support fluid in the first chamber 60 may be water and/or oil. In another variant, a compressible fluid such as nitrogen gas and/or some other gas may be used. In that case, the setting tool 10 may stroke without the valve 50 being opened. Also, the cylinder 30 may shift and abut a wall 51 of the first chamber 60. In that case, the hydrostatic pressure applied to the cylinder 30 is exerted on the consumer 100.
In
Also, alternatively, as depicted in
In another embodiment, as depicted in
In above embodiments, the hydrostatic pressure or the annulus pressure may be substituted for convenience. The hydrostatic pressure may include a pump pressure.
The foregoing description is directed to particular embodiments of the present disclosure for the purpose of illustration and explanation. It will be apparent, however, to one skilled in the art that many modifications and changes to the embodiment set forth above or embodiments of different forms are possible without departing from the scope of the disclosure. It is intended that the following claims be interpreted to embrace all such modifications and changes.
