Down-hole tools
AssigneePetroleum Engineering Services Limited
InventorGeorge Maitland
Life of this patent
Estimating the term…
Abstract
A time delay mechanism wherein there is provided a time delay between the application of a pressure to the mechanism and an action being carried out as a result of the application of said pressure. The mechanism may comprise a first piston and piston chamber and a second piston and piston chamber. Communication of a viscous fluid between said piston chambers may be achieved by means of at least one contoured flow passage.
Claims20
A time delay device for use with a down-hole tool, the time delay device comprising:
- a first chamber communicable with a second chamber via at least one restrictor;
- means for controllably transporting a fluid from said first chamber to said second chamber;
- and
- a one-way check valve provided between the first chamber and the second chamber, wherein the one-way check valve allows fluid to flow from the second chamber to the first chamber at a flow rate greater than the flow rate of the fluid through the at least one restrictor.
A down-hole tool including a time delay device, the time delay device comprising:
- a first chamber communicable with a second chamber via at least one restrictor;
- means for controllably transporting a fluid from said first chamber to said second chamber;
- and
- a one-way check valve provided between the first chamber and the second chamber, wherein the one-way check valve allows fluid to flow from the second chamber to the first chamber at a flow rate greater than the flow rate of the fluid through the at least one restrictor.
A method of providing a time delay for a down-hole tool between the application of pressure and an action being carried out as a result of said application of pressure, comprising the steps of:
- providing a first chamber having a fluid;
- providing a second chamber communicable with said first chamber via at least one orifice;
- controllably transporting said fluid from said first chamber through said at least one orifice to said second chamber in response to pressure applied to the down-hole tool;
- and
- providing a one-way check valve between the first chamber and the second chamber to allow fluid to flow from the second chamber to the first chamber at a flow rate greater than the flow rate of the fluid through the at least one orifice.
A down-hole pressure equalizing device comprising a body having at least one closing port and openable closure means for closing the at least one port wherein, in use, the openable closure means are controllably opened by means of a time delay mechanism, the time delay mechanism comprising a first chamber communicable with a second chamber via at least one restrictor and means for controllably transporting a fluid from the first chamber to the second chamber, wherein a one-way check valve is provided between the second chamber and the first chamber to allow fluid to flow from the second chamber to the first chamber at a flow rate greater than the flow rate of the fluid through the at least one restrictor.
A method of controlling pressure down-hole by providing a down-hole pressure equalizing device comprising a body having at least one port and openable closure means for closing the at least one port, the method comprising controllably opening the openable closure means by means of a time delay mechanism, the time delay mechanism comprising a first chamber communicable with a second chamber via at least one restrictor and means for controllably transporting a fluid from the first chamber to the second chamber, wherein a one-way check valve is provided between the second chamber and the first chamber to allow fluid to flow from the second chamber to the first chamber at a flow rate greater than the flow rate through the at least one restrictor.
Dependencies are inferred from the claim text.