Methods and apparatus for rapidly measuring pressure in earth formations
First Claim
1. A probe for use with a borehole tool for measuring pressure in an earth formation, said probe comprising:
- a) a first piston cylinder having an end which is movable into contact with the formation;
b) a first piston movable within said first piston cylinder; and
c) a pressure sensor in fluid communication with said first piston cylinder, whereinsaid pressure sensor is mountedinside and fixed to said first piston, with said fluid communication being provided by a bore in the first piston.
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Accused Products
Abstract
Methods and apparatus for rapidly measuring pressure in earth formations are disclosed. According to a first embodiment of the apparatus, a probe is provided with a movable piston having a sensor built into the piston. According to a second embodiment of the apparatus, the pressure sensor is mounted adjacent to or within the piston cylinder and a fluid pathway is provided from the sensor to the interior of the cylinder. Methods of operating the first and second embodiments include delivering the probe to a desired location in a borehole, setting the probe against the formation, and withdrawing the piston to draw down fluid for pressure sensing. A third embodiment of the probe is similar to the second but is provided with a spring loaded metal protector surrounding the cylinder and an annular rubber facing. The third embodiment is preferably used in a semi-continuous pressure measuring tool or an LWD tool having a piston controlled bowspring and a piston controlled articulated member carrying the probe. The tool is moved in a semi-set mode and when located at a desired depth is rapidly put in a fully-set mode.
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Citations
30 Claims
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1. A probe for use with a borehole tool for measuring pressure in an earth formation, said probe comprising:
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a) a first piston cylinder having an end which is movable into contact with the formation; b) a first piston movable within said first piston cylinder; and c) a pressure sensor in fluid communication with said first piston cylinder, wherein said pressure sensor is mounted inside and fixed to said first piston, with said fluid communication being provided by a bore in the first piston. - View Dependent Claims (2)
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3. A probe for use with a borehole tool for measuring pressure in an earth formation, said probe comprising:
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a) a first piston cylinder having an end which is movable into contact with the formation; b) a first piston movable within said first piston cylinder; c) a pressure sensor in fluid communication with said first piston cylinder; and d) an electrical conductor which extends through said first piston and is coupled to said sensor. - View Dependent Claims (4, 5, 6, 7)
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8. A probe for use with a borehole tool for measuring pressure in an earth formation, said probe comprising:
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a) a first piston cylinder having an end which is movable into contact with the formation; b) a first piston movable within said first piston cylinder; c) a pressure sensor in fluid communication with said first piston cylinder; and d) a spring biased metal protector surrounding said first piston cylinder. - View Dependent Claims (9, 10, 11, 12)
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13. A borehole tool, comprising:
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a) a tool body; b) a pressure probe coupled to said tool body; and c) a spring coupled to said tool body allowing said tool to travel through a borehole in a semi-set mode, wherein said pressure probe includes i) a first piston cylinder having an end which is movable into contact with the borehole formation; ii) a first piston movable within said first piston cylinder; and iii) a pressure sensor in fluid communication with said first piston cylinder, wherein said pressure sensor is mounted inside and fixed to said first piston with said fluid communication being provided by a bore in the first piston. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A probe for use with a borehole tool for measuring pressure in an earth formation, said probe comprising:
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a) a piston cylinder having an end which is movable into contact with the formation; b) a piston movable within said piston cylinder; c) a pressure sensor mounted within and fixed to said piston in fluid communication with said piston cylinder; and d) a protective barrier located between said pressure sensor and said piston cylinder. - View Dependent Claims (28, 29, 30)
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Specification