Method and apparatus for multiple packer pressure relief
First Claim
1. A method of inflating a packer means disposed about a casing in an annular space between an exterior of said casing and a wall of a well bore containing said casing, said packer means having valve means responsive to an increase in fluid pressure of a pressurized fluid supplied thereto for admitting the pressurized fluid to an interior of said packer means to thereby deploy said packer means, the method including the steps of:
- supplying a supply fluid at a first predetermined pressure to said packer means for initially deploying said packer means,providing said casing, prior to inserting of said casing into the bore, with a relief valve means in the vicinity of sa d packer means, said relief valve means having inlet means in fluid communication with said annular space and outlet means in fluid communication with an interior of said casing, said relief valve means including actuating means responsive to said first predetermined pressure of the supply fluid of said packer means for placing said inlet means in fluid communication with said cutlet means, said actuating means being further responsive to a second predetermined pressure for closing said communication between said inlet means and said outlet means, wherein said second predetermined pressure is greater than said first predetermined pressure;
whereby said actuating means of said relief valve means places said inlet means in communication with said outlet means to thereby allow bleeding of fluid within said annular space to the interior of said casing during inflation of said packer means; and
characterized by varying the pressure of the fluid supplied to said packer means to said second predetermined pressure during a termination of the deploying of said packer means, whereby said actuator means of said relief valve means closes communication between the said annular space and the interior of said casing.
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Accused Products
Abstract
A system for relieving pressurized fluid entrapped in a annular space between a casing (12) and the surrounding wall (11) of a well bore hole (10) during deployment of a packer exterior (14) of the casing (12) for sealing engagement with the wall (11). When packer (14) is inflated in a zone (17) where fluid is entrapped, such as an intermediate packer between two previously inflated packers (13, 14), the squeeze pressure developed by the inflating packer (14) has been found to be sufficient to prevent effective and lasting sealing of the intermediate packer (14). The present system includes a valve mechanism (35) which is activated by the pressurized fluid providing for inflating the packer (14) to open a passageway (90, 94, 91) to bleed the entrapped fluid into the casing (12) and to then close the passageway (90, 94, 91) as inflation of the intermediate packer (14) is completed.
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Citations
16 Claims
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1. A method of inflating a packer means disposed about a casing in an annular space between an exterior of said casing and a wall of a well bore containing said casing, said packer means having valve means responsive to an increase in fluid pressure of a pressurized fluid supplied thereto for admitting the pressurized fluid to an interior of said packer means to thereby deploy said packer means, the method including the steps of:
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supplying a supply fluid at a first predetermined pressure to said packer means for initially deploying said packer means, providing said casing, prior to inserting of said casing into the bore, with a relief valve means in the vicinity of sa d packer means, said relief valve means having inlet means in fluid communication with said annular space and outlet means in fluid communication with an interior of said casing, said relief valve means including actuating means responsive to said first predetermined pressure of the supply fluid of said packer means for placing said inlet means in fluid communication with said cutlet means, said actuating means being further responsive to a second predetermined pressure for closing said communication between said inlet means and said outlet means, wherein said second predetermined pressure is greater than said first predetermined pressure; whereby said actuating means of said relief valve means places said inlet means in communication with said outlet means to thereby allow bleeding of fluid within said annular space to the interior of said casing during inflation of said packer means; and characterized by varying the pressure of the fluid supplied to said packer means to said second predetermined pressure during a termination of the deploying of said packer means, whereby said actuator means of said relief valve means closes communication between the said annular space and the interior of said casing. - View Dependent Claims (2, 3)
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4. A relief valve system for use in a casing positioned in a well bore, said valve system providing relief of entrapped pressurized fluid in said casing having inflatable packer means on an exterior surface of said casing for allowing effective sealing of said packer means against an interior wall of said well bore, said casing providing a sealed annular space between said exterior surface of said casing and the interior wall of said well bore on expansion of said inflatable packer means,
said packer means being of the type having packer valve means for permitting the flow into said packer means of inflating fluid transmitted to said packer means at pressures controlled from ground surface, said packer valve means being responsive to an increasing pressure of said inflatable fluid to open said packer valve means and allow flow of said inflating fluid to the interior or said packer means; characterized by the relief valve system including; a housing defining an inlet means in fluid communication with said annular space and an outlet means in fluid communication with the interior of said casing, means defining a passage in said housing for placing said inflating fluid in communication with a control chamber in said housing, and a valve member in said housing and in an initial position closing fluid communication between said inlet means and said outlet means, said valve member being movable to an open position in response to the inflating fluid in said control chamber reaching a first predetermined pressure and thereby permitting fluid flow from said inlet means to said outlet means of said housing, said valve member being movable to a closed position in response to said inflating fluid in said control chamber reaching a second predetermined pressure greater than said first predetermined pressure and thereby closing the fluid communication between said inlet means and outlet means of said housing. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
Specification