US 5,289,875 A · Apparatus for obtaining subterranean fluid samples

Abstract

Improved methods and apparatus are provided for obtaining multiple fluid samples from subterranean formations of interest. The present invention is particularly well suited for testing nuclear migration in ground water utilizing test wells surrounding a nuclear test site. A plurality of flow ports are provided in the casing each at a depth of a formation of interest, and a sliding sleeve is positioned over each port. A wireline tool is lowered to the selective depth, and downhole electric motor energized to power a pump and pass pressurized fluid to move a first dog radially outward. The downhole tool may be axially moved until the first dog locks into a groove provided in the casing. Fluid entering the casing is sealed above and below the sliding sleeve. Fluid pressure may then be applied to move a second dog radially outward to engage the sliding sleeve, and a control valve regulated to apply fluid pressure to axially move the sleeve and open the port. Entering fluid may be tested by a downhole tester, and a signal transmitted to the surface. If the fluid is determined to be representative of the downhole fluid to be tested, fluid is then passed to a chamber within the downhole tool so that it may subsequently be retrieved to the surface. The release of hydraulic pressure allows the dogs to disengage from the casing and the sliding sleeve, and the tool may be moved to another depth. Using the procedures of the present invention, multiple fluid samples may be reliably obtained at selected depths with a single wireline run, thereby substantially reducing costs.

Claims28

Dependent claims

A method of passing fluid into or from a subterranean formation of interest wherein a casing is provided within a wellbore within the formation, an outer surface of the casing being exposed to fluids within the formation, and the casing preventing the wellbore from caving in, the method comprising:

providing a flow port through the casing;
providing an axially slidable sleeve for normally covering the port to seal the interior of the casing from the formation and for uncovering the port for establishing fluid communication between the formation and the interior of the casing;
lowering a test tool assembly within the casing to a location adjacent the sliding sleeve, the test tool assembly including an actuating tool with an axially movable member for engaging the sliding sleeve;
securing the test tool assembly to the casing;
interconnecting the movable member of the actuating tool and the sliding sleeve;
sealing the interior of the casing below the sliding sleeve;
axially moving the movable member to move the sliding sleeve to an uncovered position and permit a fluid sample to pass through the uncovered port and into a test chamber, and
returning the sliding sleeve to a covered position;
disconnecting the movable member and the sliding sleeve;
disengaging the test tool assembly and the casing;
and
retrieving the test tool assembly and the fluid sample in the test chamber to the surface.

9 more elements

A method of passing fluid into or from subterranean formations of interest wherein a casing is provided within a wellbore with the formations of interest, the method comprising:

a) providing a plurality of flow ports through the casing each at a selected depth;
b) providing a plurality of axially slidable sleeves each for selectively covering a corresponding port to seal the interior of the casing from a formation and uncovering the port for establishing fluid communication between the formation and the interior of the casing;
c) providing a test tool assembly including an actuating tool including an axially movable member for selectively operating each of the plurality of sliding sleeves;
d) lowering the test tool assembly into the casing to a location adjacent a selected sliding sleeve;
e) interconnecting the movable member of the actuating tool and the selected sliding sleeve;
f) sealing the interior of the casing below the sliding sleeve;
g) supplying hydraulic pressure to axially move the sliding sleeve to an uncovered position and permit fluid to pass through the uncovered port;
h) thereafter supplying fluid pressure to return the sliding sleeve to the covered position;
i) disconnecting the movable member and the sliding sleeve;
j) unsealing the interior of the casing;
k) axially moving the test tool assembly to a location adjacent another sliding sleeve and repeating steps e) through j) above;
and
l) retrieving the test tool assembly to the surface.

10 more elements

A downhole actuating tool for passing fluid into or form a subterranean formation of interest wherein a casing is permanently positioned within a well bore within the formation and prevents the wellbore from caving in, a flow port is provided through the casing, and a sliding sleeve covers the flow port to seal the interior of the casing from the formation, the actuating tool comprising:

a tool body, a first dog movable radially outward with respect to the tool body for securing the actuating tool to the casing, a member axially movable with respect to the tool body, a second dog for interconnecting the axially movable member and the sliding sleeve to axially move the sliding sleeve in response to fluid pressure applied to the axially movable member, a first flow path within the actuating tool for applying fluid pressure to axially move the movable member and the sliding sleeve in a first direction to uncover the port, and a second flow path within the actuating tool for applying fluid pressure to axially move the movable member and the sliding sleeve in opposing second direction to cover the port.

A method of passing fluid into or from a subterranean formation of interest wherein a casing is provided within a wellbore within the formation, the method comprising:

providing a flow port through the casing;
providing an axially slidable sleeve for selectively covering the port to seal the interior of the casing from the formation and for uncovering the port for establishing fluid communication between the formation and the interior of the casing;
lowering a test tool assembly within the casing from coiled tubing extending from the surface to a location within the wellbore adjacent the sliding sleeve, the test tool assembly including an actuating tool with an axially movable member for engaging the sliding sleeve;
securing the test tool assembly to the casing;
interconnecting the movable member of the actuating tool and the sliding sleeve;
sealing the interior of the casing below the sliding sleeve;
transmitting fluid pressure through the coiled tubing for selectively moving the movable member and thereby the sliding sleeve to an uncovered position and permit a fluid sample to pass through the uncovered port and into a test chamber;
returning the sliding sleeve to a covered position;
disconnecting the movable member and the sliding sleeve;
disengaging the test tool assembly and the casing;
and
retrieving the test tool assembly and the fluid sample in the test chamber to the surface.

9 more elements

A method of passing fluid into or from a subterranean formation of interest wherein a casing is provided within a wellbore within the formation, the method comprising:

providing a flow port through the casing;
providing an axially slidable sleeve for selectively covering the port to seal the interior of the casing from the formation and for uncovering the port for establishing fluid communication between the formation and the interior of the casing;
lowering a test tool assembly within the casing from a wireline extending to the surface to a location within the wellbore adjacent the sliding sleeve, the test tool assembly including an actuating tool with an axially movable member for engaging the sliding sleeve;
providing a downhole motor powered through the wireline;
providing a downhole pump powered by the motor for generating hydraulic pressure;
securing the test tool assembly to the casing;
interconnecting the movable member of the actuating tool and the sliding sleeve;
sealing the interior of the casing below the sliding sleeve;
activating one or more of a plurality of control valves for applying the generated hydraulic pressure to move the sliding sleeve to an uncovered position and thereby permitting a fluid sample to pass through the uncovered port and into a test chamber;
actuating one or more of the plurality of control valves for applying the generated hydraulic pressure to return the sliding sleeve to the covered position;
disconnecting the movable member and the sliding sleeve;
disengaging the test tool assembly and the casing;
and
retrieving the test tool assembly and the fluid sample in the test chamber to the surface.

11 more elements

Dependencies are inferred from the claim text.

Apparatus for obtaining subterranean fluid samples

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Apparatus for obtaining subterranean fluid samples

Life of this patent

Abstract

Claims28