Abstract

A downhole magnet tool comprises a top sub having an inner bore terminating in a downhole facing open end, the inner bore defining a centralizer receptacle of smaller width than a width of the downhole facing open end, a mandrel terminating upwardly in a centralizer stem, the centralizer stem being fitted in the centralizer receptacle of the top sub, and a magnet mounted on a downhole facing surface of the mandrel. A method of assembly of a downhole magnet tool comprises mounting a magnet on the mandrel and inserting the centralizer stem into the centralizer receptacle.

IPC Classes  ?

• E21B 31/06 - Fishing for or freeing objects in boreholes or wells using magnetic means
• E21B 19/16 - Connecting or disconnecting pipe couplings or joints

Abstract

A downhole magnet tool is disclosed comprising: a top sub having an inner bore terminating in a downhole facing open end, the inner bore defining a centralizer receptacle of smaller width than a width of the downhole facing open end; a mandrel terminating upwardly in a centralizer stem, the centralizer stem being fitted in the centralizer receptacle of the top sub; and a magnet mounted on a downhole facing surface of the mandrel. A method of assembly of a downhole magnet tool is also disclosed.

IPC Classes  ?

• E21B 31/06 - Fishing for or freeing objects in boreholes or wells using magnetic means

Abstract

A jar comprises an outer housing; an inner mandrel within the outer housing to define a fluid chamber; a valve disposed within the fluid chamber with a restriction surface facing, during setting, a cooperating restriction surface on the outer housing and a pressure surface facing the inner mandrel, the valve movable between a seated position and an unseated position; the cooperating restriction surface cooperating with the restriction surface to set the jar for a jar in a first direction; the pressure surface being exposed to fluid within the fluid chamber when the jar is set and pressuring up for a jar in the first direction; the pressure surface being indented to cause uneven radial movement, in a plane perpendicular to a jar axis, of the restriction surface towards the cooperating restriction surface when the jar is set and pressuring up for a jar in the first direction; and jarring surfaces.

IPC Classes  ?

• E21B 31/113 - Fishing for or freeing objects in boreholes or wells using impact means for releasing stuck parts, e.g. jars hydraulically operated
• E21B 31/107 - Fishing for or freeing objects in boreholes or wells using impact means for releasing stuck parts, e.g. jars

Abstract

A jar is disclosed for downhole use, comprising: an outer housing; an inner mandrel; a sealed fluid chamber between the two; a valve within the fluid chamber, having a restriction surface facing, during setting, a cooperating restriction surface on one of the inner mandrel and the outer housing and a pressure surface facing the other; the cooperating restriction surface acting to set the jar for a jar in a first, uphole or downhole, direction; the pressure surface being exposed to fluid within the fluid chamber when the jar is set and pressuring up for said jar; the pressure surface being indented to cause uneven radial movement of the restriction surface towards the cooperating restriction surface when the jar is set and pressuring up for said jar; and jarring surfaces on the inner mandrel and the outer housing respectively for jarring contact with each other during said jar.

IPC Classes  ?

• E21B 31/113 - Fishing for or freeing objects in boreholes or wells using impact means for releasing stuck parts, e.g. jars hydraulically operated

Abstract

A double-acting compounder comprises: an outer housing; an inner mandrel disposed telescopically within the outer housing to define a fluid chamber; an equalizer, such as an equalizer piston, between the fluid chamber and an exterior of the outer housing for equalizing pressure; a movable seal assembly within the fluid chamber with a first end defining an end of the fluid chamber; the inner mandrel having an outer shoulder for moving the movable seal assembly with the inner mandrel when the inner mandrel moves in a first direction relative to the outer housing to compresses fluid within the fluid chamber; and the outer housing having an inner shoulder for preventing the movable seal assembly from moving with the inner mandrel when the inner mandrel moves in a second direction relative to the outer housing to compresses fluid within the fluid chamber.

IPC Classes  ?

• E21B 4/14 - Fluid operated hammers
• E21B 31/113 - Fishing for or freeing objects in boreholes or wells using impact means for releasing stuck parts, e.g. jars hydraulically operated
• E21B 17/07 - Telescoping joints for varying drill string lengthsShock absorbers

Abstract

A double-acting compounder comprises: an outer housing; an inner mandrel disposed telescopically within the outer housing to define a fluid chamber; an equalizer, such as an equalizer piston, between the fluid chamber and an exterior of the outer housing for equalizing pressure; a movable seal assembly within the fluid chamber with a first end defining an end of the fluid chamber; the inner mandrel having an outer shoulder for moving the movable seal assembly with the inner mandrel when the inner mandrel moves in a first direction relative to the outer housing to compresses fluid within the fluid chamber; and the outer housing having an inner shoulder for preventing the movable seal assembly from moving with the inner mandrel when the inner mandrel moves in a second direction relative to the outer housing to compresses fluid within the fluid chamber.

IPC Classes  ?

• E21B 31/113 - Fishing for or freeing objects in boreholes or wells using impact means for releasing stuck parts, e.g. jars hydraulically operated

Abstract

A double-acting jar is disclosed comprising: an outer housing; an inner mandrel at least partially disposed telescopically within the outer housing to define a fluid chamber between the inner mandrel and the outer housing, the fluid chamber containing fluid and being sealed; a valve disposed within the fluid chamber on one of the inner mandrel and the outer housing; the valve having a downhole portion that is movable between a downhole seated position in which the valve seats against the one of the inner mandrel and the outer housing and an unseated position, the downhole portion having a downhole restriction surface; the valve having an uphole portion that is movable between an uphole seated position in which the valve seats against the one of the inner mandrel and the outer housing and an unseated position, the uphole portion having an uphole restriction surface; the other of the outer housing and the inner mandrel having a cooperating restriction surface that cooperates with the downhole restriction surface and the uphole restriction surface to set the double-acting jar for a jar, the cooperating restriction surface being dimensioned so that, from relative movement of the inner mandrel and the outer housing, the cooperating restriction surface is movable from above to below the valve with a neutral position in which a portion of the cooperating restriction surface is between the downhole restriction surface and the uphole restriction surface; the downhole restriction surface incorporating a first bypass that is configured to allow bypass of fluid in the chamber when the downhole restriction surface and the cooperating restriction surface move past each other during re-setting of the jar; the uphole restriction surface incorporating a second bypass that is configured to allow bypass of fluid in the chamber when the uphole restriction surface and the cooperating restriction surface move past each other during re-setting of the jar; first jarring surfaces on the inner mandrel and outer housing respectively for jarring contact with each other during a jar in a downhole direction; and second jarring surfaces on the inner mandrel and outer housing respectively for jarring contact with each other during a jar in an uphole direction.

IPC Classes  ?

• E21B 31/113 - Fishing for or freeing objects in boreholes or wells using impact means for releasing stuck parts, e.g. jars hydraulically operated

Abstract

A double-acting compounder is disclosed having a first end and a second end, and comprising an outer housing, an upper mandrel, and a lower mandrel. The outer housing defines the first end. The upper mandrel is at least partially disposed telescopically within the outer housing to define an uphole fluid chamber between the upper mandrel and the outer housing, the upper mandrel defining the second end. The lower mandrel is at least partially disposed telescopically within the outer housing to define a downhole fluid chamber between the lower mandrel and the outer housing. The uphole fluid chamber and the downhole fluid chamber each contain fluid, have a variable stroke-dependent volume, and are sealed at an uphole end and a downhole end. The upper mandrel has a first shoulder engagable with and facing a second shoulder of the lower mandrel to move the lower mandrel during at least a portion of a stroke.

IPC Classes  ?

• E21B 31/113 - Fishing for or freeing objects in boreholes or wells using impact means for releasing stuck parts, e.g. jars hydraulically operated

Abstract

A double-acting jar comprises an inner mandrel and an outer housing. The inner mandrel is disposed telescopically within the outer housing to define a fluid chamber in between. There is an uphole restriction and a downhole restriction spaced from one another within the fluid chamber. An uphole valve is disposed within the fluid chamber, the uphole valve having a first seating surface engageable with an uphole facing sealing shoulder in the fluid chamber. There is a downhole valve disposed within the fluid chamber, the downhole valve having a second seating surface engageable with a downhole facing sealing shoulder in the fluid chamber.

IPC Classes  ?

• E21B 31/113 - Fishing for or freeing objects in boreholes or wells using impact means for releasing stuck parts, e.g. jars hydraulically operated

Abstract

A double-acting compounder is disclosed having a first end and a second end, and comprising an outer housing, an upper mandrel, and a lower mandrel. The outer housing defines the first end. The upper mandrel is at least partially disposed telescopically within the outer housing to define an uphole fluid chamber between the upper mandrel and the outer housing, the upper mandrel defining the second end. The lower mandrel is at least partially disposed telescopically within the outer housing to define a downhole fluid chamber between the lower mandrel and the outer housing. The uphole fluid chamber and the downhole fluid chamber each contain fluid, have a variable stroke-dependent volume, and are sealed at an uphole end and a downhole end. The upper mandrel has a first shoulder engagable with and facing a second shoulder of the lower mandrel to move the lower mandrel during at least a portion of a stroke.

IPC Classes  ?

• E21B 31/113 - Fishing for or freeing objects in boreholes or wells using impact means for releasing stuck parts, e.g. jars hydraulically operated

Abstract

A double-acting jar comprises an inner mandrel and an outer housing. The inner mandrel is disposed telescopically within the outer housing to define a fluid chamber in between. There is an uphole restriction and a downhole restriction spaced from one another within the fluid chamber. An uphole valve is disposed within the fluid chamber, the uphole valve having a first seating surface engageable with an uphole facing sealing shoulder in the fluid chamber. There is a downhole valve disposed within the fluid chamber, the downhole valve having a second seating surface engageable with a downhole facing sealing shoulder in the fluid chamber.

IPC Classes  ?

• E21B 31/107 - Fishing for or freeing objects in boreholes or wells using impact means for releasing stuck parts, e.g. jars

Abstract

An extension sub for a downhole fishing tool, the extension sub comprising a tubular having a threaded pin end and a threaded box end, the tubular having an interior wall defining a bore, and cutting elements fixed to the interior wall of the tubular and extending into the bore of the tubular. Such a device may be referred to as a string shoe.

IPC Classes  ?

• E21B 31/00 - Fishing for or freeing objects in boreholes or wells

Abstract

An extension sub for a downhole fishing tool, the extension sub comprising a tubular having a threaded pin end and a threaded box end, the tubular having an interior wall defining a bore,and cutting elements fixed to the interior wall of the tubular and extending into the bore of the tubular. Such a device may be referred to as a string shoe.

IPC Classes  ?

• E21B 31/16 - Grappling tools, e.g. tongs or grabs combined with cutting or destroying means