Wireline core barrel with resilient latch fingers

Claim 2

A core barrel that may be transported through a drill string, comprising: a core barrel body that is smaller in diameter than the interior of said drill string; a core sample container connected to said core barrel body, said core sample container being smaller in diameter than the interior of said drill string; at least one flexible latch finger with resilient characteristics, said flexible latch finger having a portion rigidly affixed to said core barrel body and a latch portion wherein said flexible latch finger and said core barrel body have a maximum diameter that is smaller than the interior diameter of said drill string when said latch finger is in an unflexed position; and an actuator means for changing the position of said latch portion thereby bending and stressing said flexible latch finger and moving said latch portion to a position wherein said flexible latch finger and said core barrel have a maximum diameter than is larger than the interior diameter of said drill string.

Claim 3

The core barrel of claim 1 wherein said actuator means is an actuator element that is movable relative to said core barrel body and includes a surface that contacts said latch finger to change the position of said latch portion.

Claim 4

The core barrel of claim 2 wherein said core barrel body includes a portion having an enlarged diameter and a fluid passage through said core barreL to channel fluid by said portion having an enlarged diameter and wherein said actuator means includes a valve means for closing the fluid passage.

Claim 5

The core barrel of claim 3 wherein said portion having an enlarged diameter is a packing rubber mounted on said core barrel body between a movable back-up ring and an adjustable packing nut.

Claim 6

The core barrel of claim 4 wherein said core sample container is connected to said core barrel body by bearing means for allowing the core barrel body to rotate relative to said core sample container and wherein said bearing means includes means for moving said actuator element to close said valve means.

Claim 7

In a system for obtaining a core sample that includes a drill string extending into a borehole, a core bit connected to said drill string, a latch seat on said drill string and a retriever adapted to be transported through said drill string; a retractable core barrel comprising: a core barrel body that is smaller in diameter than the interior of said drill string; a core sample container connected to said core barrel body, said core sample container being smaller in diameter than the interior of said drill string; at least one flexible and resilient latch finger with a portion rigidly affixed to said core barrel body and a latch portion adapted to fit in said latch seat wherein said flexible latch finger and said core barrel body have a maximum diameter that is smaller than the interior diameter of said drill string when said latch finger is in an unflexed position; an actuator means, movable relative to said core barrel body, for moving said latch portion of said latch finger into said latch seat, thereby bending and stressing said flexible latch finger; a seal element mounted on said core barrel body that forms a fluid seal between said core barrel body and said drill string; a fluid passage through said core barrel body to allow fluid to flow through said core barrel; and means on said actuator means for blocking and for unblocking said fluid passage.

Claim 8

In a system for obtaining a core sample that includes a drill string extending into a borehole, a core bit connected to said drill string, a latch seat on said drill string and a retriever adapted to be transported through said drill string; a retractable core barrel comprising: a core barrel body that is smaller in diameter than the interior of said drill string; a core sample container connected to said core barrel body, said core sample container being smaller in diameter than the interior of said drill string; at least one flexible and resilient latch finger with a portion rigidly affixed to said core barrel body and a latch portion adapted to fit in said latch seat wherein said flexible latch finger and said core barrel body have a maximum diameter that is smaller than the interior diameter of said drill string when said latch finger is in an unflexed position; an actuator means, movable relative to said core barrel body, for moving said latch portion of said latch finger into said latch seat, thereby bending and stressing said flexible latch finger; a seal element mounted on said core barrel body that forms a fluid seal between said core barrel body and said drill string; a fluid passage through said core barrel body to allow fluid to flow through said core barrel; and means on said actuator means for blocking and for unblocking said fluid passage.

Claim 9

The core barrel of claim 6 wherein said actuator means is an actuator element with an actuating surface that contacts said latch finger to move said latch portion of said latch finger into said latch seat in a first actuator position and allows said latch portion of said latch finger to move out of said latch seat in a second actuator position.

Claim 10

The core barrel of claim 7 wherein said actuator element includes a pressure surface exposed to the interior of the drill string above said core barrel for allowing the pressure of the fluid to move said actuator element into said first actuator position.

Claim 11

The core barrel of claim 8 wherein said means for blocking and unblocking said fluid passage includes a valve element connected to said actuator element.

Claim 12

The core barrel of claim 9 wherein said actuator element includes means for contacting and withdrawing said latch portion of said latch finger from said latch seat in a third actuator position.

Claim 13

The core barrel of claim 10 wherein said actuator includes a connection for said retriever to allow said retriever to move said actuator to said third actuator position and said valve element out of said fluid passage.

Claim 14

The core barrel of claim 11 wherein said seal element is a resilient packing element located between a movable back-up ring and an adjustable packing nut.

Claim 15

The core barrel of claim 12 wherein said core sample container is connected to said core barrel body by bearing means for allowing said core barrel body to rotate relative to said core sample container.

Claim 16

The core barrel of claim 13 including means between said core sample container and said actuator to move the valve element connected to said actuator to a position blocking said fluid passage.

Claim 17

In a system for obtaining a core sample of an earth formation that includes a drill string extending into a borehole in the earth formation, rotary drilling equipment for rotating said drill sTring, a coring bit connected to the lower end of said drill string, a fluid circulation system connected to said drill string for circulating drilling fluid through said drill string, a latch seat on said drill string and a retriever that may be transported through said drill string; a retractable core barrel comprising: a core barrel body adapted to fit within said drill string, said core barrel having a maximum diameter smaller than the diameter of said drill string; a core sample container connected to said core barrel body, said core sample container being smaller in diameter than the interior of said drill string; at least one flexible and resilient latch finger, said finger having a portion rigidly affixed to said core barrel body and a latch portion adapted to fit in said latch seat wherein said flexible latch finger and said core barrel body have a maximum diameter that is smaller than the interior diameter of said drill string when said latch finger is in an unflexed position; a seal element mounted on said core barrel body that forms a fluid seal between said tubular core barrel body and said drill string; at least one fluid passage through aid tubular core barrel body; actuator means responsive to pressure of the drilling fluid for moving the latch portion of said at least one latch finger into the latch seat when the pressure of the drilling fluid exceeds a predetermined value; and valve means connected to said actuator means for opening and closing said fluid passage.

Claim 18

In a system for obtaining a core sample of an earth formation that includes a drill string extending into a borehole in the earth formation, rotary drilling equipment for rotating said drill sTring, a coring bit connected to the lower end of said drill string, a fluid circulation system connected to said drill string for circulating drilling fluid through said drill string, a latch seat on said drill string and a retriever that may be transported through said drill string; a retractable core barrel comprising: a core barrel body adapted to fit within said drill string, said core barrel having a maximum diameter smaller than the diameter of said drill string; a core sample container connected to said core barrel body, said core sample container being smaller in diameter than the interior of said drill string; at least one flexible and resilient latch finger, said finger having a portion rigidly affixed to said core barrel body and a latch portion adapted to fit in said latch seat wherein said flexible latch finger and said core barrel body have a maximum diameter that is smaller than the interior diameter of said drill string when said latch finger is in an unflexed position; a seal element mounted on said core barrel body that forms a fluid seal between said tubular core barrel body and said drill string; at least one fluid passage through aid tubular core barrel body; actuator means responsive to pressure of the drilling fluid for moving the latch portion of said at least one latch finger into the latch seat when the pressure of the drilling fluid exceeds a predetermined value; and valve means connected to said actuator means for opening and closing said fluid passage.

Claim 19

The core barrel of claim 15 wherein said actuator means is a movable actuator element with a pressure surface exposed to the drilling fluid and an actuating surface adapted to contact said latch finger to move said latch portion of said latch finger into said latch seat.

Claim 20

The core barrel of claim 16 wherein said valve means includes a valve element connected to said movable actuator element and positioned to open said fluid passage when said latch portion of said latch finger moves into said latch seat.