Formation fluid sampling apparatus and method
First Claim
1. A sample module for use in a downhlole tool to obtain fluid from a subsurface formation penetrated by a wellbore, comprising:
- a sample chamber carried by the module for collecting a sample of formation fluid obtained from the formation via the downhole tool; and
a validation chamber carried by the module, the validation chamber being smaller than said sample chamber and capable of collecting a representative sample of the formation fluid collected by said sample chamber;
wherein said validation chamber is independently removable from the sample module and adapted for evaluation of said representative sample at the surface whereby the viability of the sample of formation fluid in said sample chamber is determined without disturbing said sample chamber.
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Accused Products
Abstract
A sample module is provided for use in a downhole tool to obtain fluid from a subsurface formation penetrated by a wellbore. The sample module includes a sample chamber carried by the module for collecting a sample of formation fluid obtained from the formation via the downhole tool, and a validation chamber carried by the module for collecting a substantially smaller sample of formation fluid than the sample chamber. The validation chamber is removable from the sample module at the surface without disturbing the sample chamber. A sample chamber is also provided that includes a subtantially cylindrical body capable of safely withstanding heating at the surface, following collection of a formation fluid sample via the downhole tool and withdrawal of the sample chamber from the wellbore, to temperatures necessary to promote recombination of the sample components wihtin the chambers. Additionally, the body is equipped so as to be certified for transportation. At least one floating piston is slidably positioned within the body so as to define a fluid collection cavity and a pressurization cavity, whereby the pressurization cavity may be charged to control the pressure of the sample collected in the collection cavity. A second such piston may be provided to create a third cavity wherein a buffer fluid may be utilized during sample collection. Metal-to-metal seals act as the final shut-off seals for the sample collected in the collection cavity of the body. A method related to the use of the sample module and sample chamber described above is also provided.
125 Citations
31 Claims
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1. A sample module for use in a downhlole tool to obtain fluid from a subsurface formation penetrated by a wellbore, comprising:
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a sample chamber carried by the module for collecting a sample of formation fluid obtained from the formation via the downhole tool; and
a validation chamber carried by the module, the validation chamber being smaller than said sample chamber and capable of collecting a representative sample of the formation fluid collected by said sample chamber;
wherein said validation chamber is independently removable from the sample module and adapted for evaluation of said representative sample at the surface whereby the viability of the sample of formation fluid in said sample chamber is determined without disturbing said sample chamber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A sample chamber for use in a downhole tool to obtain fluid from a subsurface formation penetrated by a wellbore, comprising:
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a substantially cylindrical body capable of safely withstanding heating at the surface, following collection of a formation fluid sample via the downhole tool and withdrawal of the sample chamber from the wellbore, to temperatures necessary to promote recombination of the sample components within said chamber, said body being sufficiently equipped so as to be certified for transportation;
a floating piston slidably positioned within said body so as to define a fluid collection cavity and a pressurization cavity, whereby the pressurization cavity is charged with a minimum ten percent gas cap by volume to control the pressure of the sample collected in the collection cavity; and
metal-to-metal seals extending through the cylindrical body that serve as final shut-off seals for the sample collected in the collection cavity of said body.
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13. An apparatus for obtaining fluid from a subsurface formation penetrated by a wellbore, comprising:
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a probe assembly for establishing fluid communication between the apparatus and the formation when the apparatus is positioned in the wellbore;
a pump assembly for drawing fluid from the formation into the apparatus;
a sample chamber for collecting a sample of the formation fluid drawn from the formation by said pumping assembly; and
a validation chamber smaller than said sample chamber, said validation chamber being capable of collecting a representative sample of the formation fluid in said sample chamber, said validation chamber being independently removable from the apparatus at the surface for evaluation of said representative sample whereby the viability of the formation fluid collected in said sample chamber is determined at the wellbore without disturbing said sample chamber. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21)
a flow line establishing fluid communication between said probe assembly, said pump assembly, and the fluid collection cavity of said sample chamber; and
a pressurization system for charging the pressurization cavity to control the pressure of the collected sample fluid within the collection cavity via the floating piston.
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16. The apparatus of claim 15, wherein said pressurization system includes a valve positioned for fluid communication with the pressurization cavity of said sample chamber, the valve being movable between positions closing the pressurization cavity and opening the pressurization cavity to a source of fluid at a greater pressure than the pressure of the formation fluid delivered to the collection cavity.
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17. The apparatus of claim 16, wherein said pressurization system controls the pressure of the collected sample fluid within the collection cavity during collection of the sample from the formation.
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18. The apparatus of claim 17, wherein the source of fluid at a greater pressure than the pressure of the collected sample fluid is wellbore fluid.
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19. The apparatus of claim 16, wherein said pressurization system controls the pressure of the collected sample fluid within the collection cavity during retrieval of the apparatus from the wellbore to the surface.
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20. The apparatus of claim 19, wherein the source of fluid at a greater pressure than the pressure of the collected sample fluid is a source of inert gas carried by the apparatus.
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21. The apparatus of claim 13, wherein the apparatus is a wireline-conveyed formation testing tool.
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22. A method for obtaining fluid from a subsurface formation penetrated by a wellbore, comprising:
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positioning an apparatus within the wellbore;
establishing fluid communication between the apparatus and the formation;
inducing movement of fluid from the formation into the apparatus;
delivering a sample of the formation fluid moved into the apparatus to a sample chamber for collection therein;
delivering a representative sample of the formation fluid moved into the sample chamber to a validation chamber for collection therein, the validation chamber being smaller than the sample chamber;
withdrawing the apparatus from the wellbore;
removing the validation chamber from the apparatus without disturbing the sample chamber; and
evaluating the representative sample whereby the viability of the sample in the sample chamber is determined. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31)
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Specification