Releasable coupling for tubing conveyed subterranean well perforating gun
First Claim
1. A releasable coupling for connecting a subterranean well perforating gun to a tubular tool string, said perforating gun being of the type including a hollow housing that receives a charge of pressured gas following discharge of the perforating gun, comprising, in combination:
- a first tubular assembly having means on its lower end for threadably connecting with said hollow housing;
a second tubular assembly having means on its upper end for threadably connecting with the tubular tool string;
the lower end of said second tubular assembly being disposed in concentric, overlapping relation to the upper end of said first tubular assembly;
radially shiftable latching means normally interconnecting said overlapped portions of said first and second tubular assemblies, thereby securing the perforating gun to the tubular tool string;
axially shiftable piston means operatively connected in one position to said radially shiftable latching means to hold same in said normal interconnecting position; and
conduit means for supplying pressured fluid from said hollow housing to said piston means to axially shift same out of said one position, thereby permitting said radially shiftable latching means to disconnect said first and second tubular assemblies.
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Accused Products
Abstract
A method and apparatus for releasing a subterranean well perforating gun from a tubular string after firing of the subterranean well perforating gun. The apparatus comprises two telescopically inter-related tubular assemblies which are interconnected for axial co-movement solely by a plurality of radially shiftable latching elements. Such latching elements are normally maintained in a locked position by an annular piston. One end of the annular piston is exposed to gas at surface ambient pressure and the other end is exposed to the gas pressure generated in the perforating gun by its discharge and subsequently to the well fluid pressures produced by flow of well fluids through the perforations. The movement of the annular piston under such fluid pressure forces permits the locking elements to be cammed radially inwardly and release the connection between the tubular tool string and the perforating gun without any action on the part of the operator.
57 Citations
18 Claims
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1. A releasable coupling for connecting a subterranean well perforating gun to a tubular tool string, said perforating gun being of the type including a hollow housing that receives a charge of pressured gas following discharge of the perforating gun, comprising, in combination:
- a first tubular assembly having means on its lower end for threadably connecting with said hollow housing;
a second tubular assembly having means on its upper end for threadably connecting with the tubular tool string;
the lower end of said second tubular assembly being disposed in concentric, overlapping relation to the upper end of said first tubular assembly;
radially shiftable latching means normally interconnecting said overlapped portions of said first and second tubular assemblies, thereby securing the perforating gun to the tubular tool string;
axially shiftable piston means operatively connected in one position to said radially shiftable latching means to hold same in said normal interconnecting position; and
conduit means for supplying pressured fluid from said hollow housing to said piston means to axially shift same out of said one position, thereby permitting said radially shiftable latching means to disconnect said first and second tubular assemblies. - View Dependent Claims (6, 7, 8)
- a first tubular assembly having means on its lower end for threadably connecting with said hollow housing;
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2. A releasable coupling for connecting a subterranean well perforating gun to a tubular tool string, said perforating gun being of the type including a hollow housing that receives a charge of pressured gas following discharge of the perforating gun, comprising, in combination:
- a first tubular assembly having means on its lower end for threadably connecting with said hollow housing;
a second tubular assembly having means on its upper end for threadably connecting with the tubular tool string;
the lower end of said second tubular assembly being disposed in concentric, overlapping relation to the upper end of said first tubular assembly;
radially shiftable latching means normally interconnecting said overlapped portions of said first and second tubular assemblies, thereby securing the perforating gun to the tubular tool string;
means on said first tubular assembly defining an annular fluid pressure chamber;
an annular piston mounted in said annular fluid pressure chamber for axial movement between a first position preventing radial movement of said radially shiftable, latching means to an unlatched position and a second position permitting radial movement of said radially shiftable latching means to said unlatched position; and
conduit means in said first tubular assembly for conducting pressured fluid resulting from the firing of the perforating gun to said annular fluid pressure chamber. - View Dependent Claims (3, 4, 5, 9, 10, 11)
- a first tubular assembly having means on its lower end for threadably connecting with said hollow housing;
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12. Apparatus for uncoupling a subterranean well perforating gun of the type having a hollow housing receiving explosive generated gases and well fluid subsequent to firing the perforating gun, comprising a coupling apparatus having two nested parts normally secured together for axial co-movement;
- fluid pressure responsive means for disconnecting said nested parts to permit axial separation thereof; and
conduit means for supplying fluid pressures from the hollow housing to said fluid pressure responsive means. - View Dependent Claims (13, 14)
- fluid pressure responsive means for disconnecting said nested parts to permit axial separation thereof; and
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15. The method of uncoupling a subterranean well perforating gun from a tubular tool string comprising the steps of:
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1. connecting a perforating gun, of the type having a hollow housing that is filled with pressured gas and well fluids after the gun is fired, to a tubular tool string by a tubular coupling assembly having two nested parts secured against axial separation by a radially shiftable locking element; 2. positioning an annular piston adjacent the radially shiftable locking element to prevent radial movement of the locking element in the direction to release the nested parts for axial separation; and 3. providing fluid communication between the interior of the perforating gun housing and one side of said piston, whereby said piston is shifted in a direction to permit radial movement of the locking element to disconnect the nested parts by fluid pressure generated in the hollow housing subsequent to firing the perforating gun. - View Dependent Claims (16)
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17. The method of uncoupling a well perforating gun from a tubular tool string comprising the steps of:
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1. disposing the charges of the perforating gun in a hollow housing; 2. connecting the hollow housing to the tubular tool string by a fluid pressure responsive uncoupling apparatus; and
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18. supplying fluid pressures developed in the hollow housing by firing of the charges to the fluid pressure responsive uncoupling apparatus.
Specification