US3853187A — Duplex hydraulic-mechanical jar tool

Claim 1

Independent Claim 384 words

In a duplex hydraulic-mechanical jar tool, the combination of: inner and outer telescopically related tubular elements; means for connecting one of said elements to a drill string; means for connecting the other element to an object to be jarred, referred to herein as a ''''fish'''', telescopically overlapping portions of said elements providing an annular chamber for confining an operating liquid; an annular packer supported on one element and slidably engaging the other element to close one end of said chamber; an annular floating packer disposed between and slidably engaging both of said elements to close the other end of said chamber; a relatively short piston extending radially outwardly from said inner element into said chamber; a relatively short cylinder provided inwardly on said outer element in which cylinder said piston slidably fits to effect a dash pot retarding action on telescopic movement between said elements when said piston and cylinder are in conjunction; the inner surface of said outer element being relieved in areas immediately above and below the zone of said cylinder, thereby releasing said elements from said dash pot retarding action when said piston and cylinder are out of conjunction; said cylinder, when in conjunction with said piston, dividing said chamber into a low pressure section, adjacent to and containing said floating packer and a high pressure section adjacent said first mentioned packer; two pairs of impact shoulders provided on said elements which come respectively into axial abutting engagement when opposite ends of the entire range of relative telescopic movement between said elements are reached, said tool having an optional operation starting posItion wherein said cylinder has just passed out of conjunction with said piston and entered said high pressure chamber section; and annular cam responsive spring resistance means provided on said elements in said low pressure chamber section and operative temporarily to halt further movement of said cylinder into said high pressure chamber section, until a predetermined heavy downward pressure has been applied through said drill string to said spring resistance means to cause the latter to suddenly release and thus produce a snap action downward jar operation, an upward snap action jar operation being optionally automatically accomplished, starting with the tool in said starting position, by imposing and holding an upward strain of a predetermined value on said drill string.

Claim 2

Dependent Claim 384 words

In a duplex hydraulic-mechanical jar tool, the combination of: inner and outer telescopically related tubular elements; means for connecting one of said elements to a drill string; means for connecting the other element to an object to be jarred, referred to herein as a ''''fish'''', telescopically overlapping portions of said elements providing an annular chamber for confining an operating liquid; an annular packer supported on one element and slidably engaging the other element to close one end of said chamber; an annular floating packer disposed between and slidably engaging both of said elements to close the other end of said chamber; a relatively short piston extending radially outwardly from said inner element into said chamber; a relatively short cylinder provided inwardly on said outer element in which cylinder said piston slidably fits to effect a dash pot retarding action on telescopic movement between said elements when said piston and cylinder are in conjunction; the inner surface of said outer element being relieved in areas immediately above and below the zone of said cylinder, thereby releasing said elements from said dash pot retarding action when said piston and cylinder are out of conjunction; said cylinder, when in conjunction with said piston, dividing said chamber into a low pressure section, adjacent to and containing said floating packer and a high pressure section adjacent said first mentioned packer; two pairs of impact shoulders provided on said elements which come respectively into axial abutting engagement when opposite ends of the entire range of relative telescopic movement between said elements are reached, said tool having an optional operation starting posItion wherein said cylinder has just passed out of conjunction with said piston and entered said high pressure chamber section; and annular cam responsive spring resistance means provided on said elements in said low pressure chamber section and operative temporarily to halt further movement of said cylinder into said high pressure chamber section, until a predetermined heavy downward pressure has been applied through said drill string to said spring resistance means to cause the latter to suddenly release and thus produce a snap action downward jar operation, an upward snap action jar operation being optionally automatically accomplished, starting with the tool in said starting position, by imposing and holding an upward strain of a predetermined value on said drill string.

Claim 3

Dependent Claim 98 words

A combination as recited in claim 1 wherein said piston makes a substantially liquid tight peripheral fit with said cylinder when said piston and cylinder are in conjunction, said piston being provided with an axial hole allowing for the escape of operating liquid past said piston during the tensioning of said drill string; a pin occupying said hole loosely to determine the rate of escape of said liquid, and means for locking said pin in said hole yet readily permitting replacement of said pin with another differing in diameter to vary the rate of escape of said liquid.

Claim 4

Dependent Claim 93 words

A combination as recited in claim 1 wherein said spring resistance means comprises: a split tubular head co-axially spaced outwardly from said inner element and mounted at its lower end on said element, said head thus providing an annular series of circumferentially spaced radially flexible arms bearing at their upper ends outwardly, downwardly sloping cam faces, and a ring means having an inwardly-upwardly sloping cam face and fixed on said outer element to concentrically overly said cam faces of said arms and be closely juxtaposed therewith when said tool is in starting position.

Claim 5

Dependent Claim 26 words

A combination as recited in claim 3 wherein the angles of said cam faces on said head and said cam ring are approximately 20* with horizontal.

Claim 6

Dependent Claim 178 words

A combination as recited in claim 1 wherein a lower end portion of said inner element comprises a male spline sub in which are integrally united a central male spline section and upper and lower annular head sections the external diameters of which head sections substantially exceed that of said male spline section; said head sections having provided respectively thereon opposed upper and lower anvil impact faces; and wherein a lower end portion of said outer element comprises a longitudinally split female spline sub including two longitudinally separate halves which fit together on said male spline section to provide matching female splines; ring means encircling said male spline sub and axially shiftable over the lower end of said assembled split female spline sub; and tapered pin thread means provided on an upper end portion of said female spline sub, there being matching threaded box means on the adjacent end portion of said outer element into which said tapered pin thread means screws to complete the assembly of said split female spline sub on said integral male spline sub.

Claim 7

Dependent Claim 257 words

In a duplex hydraulic-mechanical jar tool, the combination of: inner and outer telescopically related tubular elements; means for connecting one of said elements to a drill string; means for connecting the other element to an object to be jarred, referred to herein as a ''''fish;'''' longitudinally spaced seal means forming a chamber between said elements for confining a body of operating liquid; dash pot valve means temporarily restricting flow of said liquid lengthwise in said chamber under a heavy strain imposed on said drill string, then subsequently permitting said flow to produce an upward snap action jarring blow on said fish; annular cam responsive spring resistance means provided on said elements and operative To temporarily halt telescopic contraction of said elements caused by lowering said drill string, following said blow, until sufficient pressure has built up to produce a downward snap action jarring blow; and a spline unit at one end of said tool including an integral male spline sub having heavy external annular heads at its opposite ends, said sub comprising a portion of said inner tubular element, a female spline sub, split lengthwise and assembled broadside on said male spline sub and united when so assembled with said outer tubular element; and two pairs of movement limiting annular impact faces, one face of each pair being provided by an end of said female spline sub and the other face of said pair being provided by an end face of the annular male spline head located in juxtaposed relation with said first face of said pair.

Claim 8

Dependent Claim 257 words

In a duplex hydraulic-mechanical jar tool, the combination of: inner and outer telescopically related tubular elements; means for connecting one of said elements to a drill string; means for connecting the other element to an object to be jarred, referred to herein as a ''''fish;'''' longitudinally spaced seal means forming a chamber between said elements for confining a body of operating liquid; dash pot valve means temporarily restricting flow of said liquid lengthwise in said chamber under a heavy strain imposed on said drill string, then subsequently permitting said flow to produce an upward snap action jarring blow on said fish; annular cam responsive spring resistance means provided on said elements and operative To temporarily halt telescopic contraction of said elements caused by lowering said drill string, following said blow, until sufficient pressure has built up to produce a downward snap action jarring blow; and a spline unit at one end of said tool including an integral male spline sub having heavy external annular heads at its opposite ends, said sub comprising a portion of said inner tubular element, a female spline sub, split lengthwise and assembled broadside on said male spline sub and united when so assembled with said outer tubular element; and two pairs of movement limiting annular impact faces, one face of each pair being provided by an end of said female spline sub and the other face of said pair being provided by an end face of the annular male spline head located in juxtaposed relation with said first face of said pair.

Claim 9

Dependent Claim 263 words

In a deep well jar tool, the combination of: inner and outer telescopically related tubular elements; means for connecting one of said elements to a drill string; means for connecting the other element to an object to be jarred, referred to herein as a ''''fish;'''' means between said elements operating to restrain free telescopic movement between said elements in a given direction responsive to a strain imposed by said drill string for a relatively short distance and then permitting free movement between said elements; an integral male spline sub having heavy external annular heads at its opposite ends, said sub comprising a portion of said inner tubular element; a female spline sub, split lengthwise and assembled broadside on said male spline sub, an upper end portion of said female spline sub being provided with male pin threads; a relatively thick walled stabilizer sleeve, comprising a lower portion of said outer tubular element, and provided, at its lower end, with female box threads matching said male pin threads, the latter being screwed into said threads of said stabilizer sleeve in assembling said female spline sub on said male spline sub, the upper external annular head of said male spline sub making a sliding fit within said stabilizer sleeve thereby mutually reinforcing each other in all operating positions of the tool; and means providing hammer and anvil impact faces on said spline stubs which are brought into collision, when said restraint is relaxed, to transmit a snap action jarring blow to said fish upon the termination of said telescopic relative movement between said tubular elements.

Claim 10

Dependent Claim 263 words

In a deep well jar tool, the combination of: inner and outer telescopically related tubular elements; means for connecting one of said elements to a drill string; means for connecting the other element to an object to be jarred, referred to herein as a ''''fish;'''' means between said elements operating to restrain free telescopic movement between said elements in a given direction responsive to a strain imposed by said drill string for a relatively short distance and then permitting free movement between said elements; an integral male spline sub having heavy external annular heads at its opposite ends, said sub comprising a portion of said inner tubular element; a female spline sub, split lengthwise and assembled broadside on said male spline sub, an upper end portion of said female spline sub being provided with male pin threads; a relatively thick walled stabilizer sleeve, comprising a lower portion of said outer tubular element, and provided, at its lower end, with female box threads matching said male pin threads, the latter being screwed into said threads of said stabilizer sleeve in assembling said female spline sub on said male spline sub, the upper external annular head of said male spline sub making a sliding fit within said stabilizer sleeve thereby mutually reinforcing each other in all operating positions of the tool; and means providing hammer and anvil impact faces on said spline stubs which are brought into collision, when said restraint is relaxed, to transmit a snap action jarring blow to said fish upon the termination of said telescopic relative movement between said tubular elements.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1977-12-09	1978-06-10	1978-12-10	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1981-12-09	1982-06-10	1982-12-10	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1985-12-09	1986-06-10	1986-12-10	$7700.00	Window Closed / Lapsed

Duplex hydraulic-mechanical jar tool

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