High pressure coring assembly and method
First Claim
1. A coring tool retrievable to a surface position from a wellbore to obtain a cored formation from said wellbore, said coring tool being receivable within an outer barrel, a coring bit being interconnected with said outer barrel, comprising:
- an inner barrel operable to receive said cored formation within a core receiving region of said inner barrel;
a bottom valve operable to seal off an end of said inner barrel; and
at least one canister receivable within said outer barrel, said at least one canister comprising an expandable chamber connected to receive and store a fluid flow out of said cored formation in said inner barrel when said inner barrel and said at least one canister are retrieved from said well, said at least one canister being axially spaced from said core receiving region of said inner barrel and being on an opposite side of said inner barrel from said coring bit;
a fluid flow path between said core receiving region and said at least one canister through which said fluid flow out of said cored formation passes into said at least one canister;
and a relief valve mounted in said fluid flow path between said canister and said core receiving region constructed to be operable to open and close, said relief valve being operable to initially obstruct said fluid flow from said core receiving region to said at least one canister and subsequently allow said fluid flow in order to limit pressure in said core receiving region.
2 Assignments
0 Petitions
Accused Products
Abstract
A wireline or drill pipe retrievable coring tool with an inner barrel to receive a core, a bottom coring tool valve operable to seal off a bottom of the inner barrel and at least one pressure canister operable to receive fluid from the core in the inner barrel. The pressure canister is operable to significantly reduce the pressure inside the inner barrel utilizing an expandable chamber to receive fluid from the core as the tool is removed from the wellbore. In one embodiment, a bottom valve mechanism moves the cored formation materials out of the way of the bottom valve before the bottom valve is closed.
109 Citations
24 Claims
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1. A coring tool retrievable to a surface position from a wellbore to obtain a cored formation from said wellbore, said coring tool being receivable within an outer barrel, a coring bit being interconnected with said outer barrel, comprising:
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an inner barrel operable to receive said cored formation within a core receiving region of said inner barrel; a bottom valve operable to seal off an end of said inner barrel; and at least one canister receivable within said outer barrel, said at least one canister comprising an expandable chamber connected to receive and store a fluid flow out of said cored formation in said inner barrel when said inner barrel and said at least one canister are retrieved from said well, said at least one canister being axially spaced from said core receiving region of said inner barrel and being on an opposite side of said inner barrel from said coring bit; a fluid flow path between said core receiving region and said at least one canister through which said fluid flow out of said cored formation passes into said at least one canister; and a relief valve mounted in said fluid flow path between said canister and said core receiving region constructed to be operable to open and close, said relief valve being operable to initially obstruct said fluid flow from said core receiving region to said at least one canister and subsequently allow said fluid flow in order to limit pressure in said core receiving region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A coring tool retrievable to a surface position from a wellbore to obtain a cored formation from said wellbore, comprising:
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an inner barrel which is operable to receive said cored formation; a bottom valve operable to seal off an end of said inner barrel; a bottom valve mechanism operable to move said cored formation away from said bottom valve prior to closing said bottom valve; and a flapper for said bottom valve; a support mounted radially inwardly of said flapper within said bottom valve to prevent said bottom valve from closing, said support being moveable with said bottom valve mechanism to allow said bottom valve to close, said flapper comprising a first non-planar surface that fits around said support, a seat comprising a second non-planar surface, said second non-planar surface conforms to said first non-planar surface of said flapper when said flapper engages with said seat to form a seal between said flapper and said seat; and at least one canister operable to receive and store a fluid that flows out of said cored formation in said inner barrel as said coring tool is retrieved from said well and a relief valve through which said fluid flows, said relief valve constructed to be operable to open and close. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A coring tool retrievable to a surface position from a wellbore to obtain a cored formation from said wellbore, comprising:
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an inner barrel which is operable to receive said cored formation within a core receiving region; a bottom valve operable to seal off a bottom of said inner barrel, said bottom valve comprising a flapper, said flapper being configured to utilize a pressure in said core receiving region from said cored formation to increase a flapper closing force which holds said flapper closed against a flapper valve seat; a canister connected to receive a fluid flow that flows out of said cored formation; and a relief valve mounted in a fluid flow path between said core receiving region and said canister operable to initially prevent said fluid flow to said canister and to subsequently allow said fluid flow in order to release additional pressure in said inner barrel with said fluid flow into said canister, said relief valve being configured to be operable to open during an ascent of said inner barrel in said wellbore after said inner barrel is removed from a bottom of said wellbore.
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20. A method for making a coring tool retrievable to a surface position from a wellbore to capture a cored formation from said wellbore, comprising:
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providing an inner barrel which is operable to receive said cored formation; providing a bottom valve operable to seal off a bottom of said inner barrel; providing at least one canister to receive and store a fluid that flows in a fluid flow path out of said cored formation into said at least one canister; providing at least one relief valve in said fluid flow path to initially obstruct fluid flow to said at least one canister and subsequently allow said fluid flow in order to limit pressure in said inner barrel, and providing that said at least one relief valve is operable to open and close. - View Dependent Claims (21, 22, 23, 24)
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Specification