Torque resistant coupling for oilwell toolstring

Abstract

A downhole oilwell toolstring having an adapter having a male threaded portion, a longitudinally extending tubular female housing having a female threaded portion on an inner surface of the housing, a first end located proximate to the female threaded portion, a second end located distal to the female threaded portion, and a recessed groove extending around the circumference of the interior surface of the female housing at a location between the first end the female threaded portion. The adapter has a first end that is distal from the threaded portion and a second end that is proximate to the threaded portion, and a recessed groove extending around the outer circumference of the adapter at a location between the threaded portion and the first end of the adapter. The female housing is connected with the male adapter by way of the female threaded portion and the male threaded portion engaging one another. A ring is located in the recessed groove in the adapter and the recessed groove in the female housing.

1 . A downhole oilwell toolstring, comprising:
 an adapter having a male threaded portion;   a longitudinally extending tubular female housing having a female threaded portion on an inner surface of the housing, a first end and a second end, a recessed groove extending around the circumference of the inner surface of the female housing at a location between the first end the female threaded portion;   the adapter having a first end and a second end, a recessed groove extending around the outer circumference of the adapter at a location between the threaded portion and the first end of the adapter;   the female housing being connected with the male adapter by way of the female threaded portion and the male threaded portion engaging one another;   a ring located in the recessed groove in the adapter and the recessed groove in the female housing.   
     
     
         2 . The downhole oilwell toolstring of  claim 1 , wherein the first end of the female housing comprises a flat end portion, and
 an angled portion connects the flat end portion with the interior surface of the female housing thereby defining a bevel portion.   
     
     
         3 . The downhole oilwell toolstring of  claim 1 , wherein the ring has a circular cross section. 
     
     
         4 . The downhole oilwell toolstring of  claim 1 , wherein the ring has a rectangular cross section. 
     
     
         5 . The downhole oilwell toolstring of  claim 1 , wherein the groove connects with the interior surface of the female housing by way of an angled portion. 
     
     
         6 . The downhole oilwell toolstring of  claim 1 , wherein the groove in the adapter has a semi-circular cross section. 
     
     
         7 . The downhole oilwell toolstring of  claim 1 , wherein the groove in the female housing has a semi-circular cross section. 
     
     
         8 . The downhole oilwell toolstring of  claim 1 , wherein the housing is a housing of a perforating gun, the perforating gun comprising at least one shaped charge. 
     
     
         9 . A downhole oilwell toolstring, comprising:
 an adapter having a male threaded portion;   a longitudinally extending tubular female housing having a female threaded portion on an inner surface of the housing, a first end and a second end, a recessed groove extending around the circumference of the interior surface of the female housing at a location between the first end the female threaded portion;   the adapter having a first end and a second end, a raised portion located around the outer circumference of the adapter at a location between the threaded portion and the first end of the adapter;   the female housing being connected with the male adapter by way of the female threaded portion and the male threaded portion engaging one another;   the raised portion being located in the recessed groove in the female housing.   
     
     
         10 . A method of connecting tools in a toolstring in a downhole oilwell, the toolstring comprising an adapter having a male threaded portion;
 a longitudinally extending tubular female housing having a female threaded portion on an inner surface of the housing, a first end and a second end, a recessed groove extending around the circumference of the interior surface of the female housing at a location between the first and the female threaded portion;   the adapter having a first end and a second end, a recessed groove extending around the outer circumference of the adapter at a location between the threaded portion and the first end of the adapter;   a ring being located in the recessed groove in the adapter;   the method comprising:   connecting the female housing with the male adapter by screwing the female threaded portion onto the male threaded portion so that the ring located in the recessed groove in the adapter is compressed until the groove in the female housing is located over the ring and the ring moves into the recessed groove in the female housing.   
     
     
         11 . The downhole oilwell toolstring of  claim 10 , wherein the first end of the female housing comprises a flat end portion, and
 an angled portion connects the flat end portion with the interior surface of the female housing thereby defining a bevel portion.   
     
     
         12 . The downhole oilwell toolstring of  claim 10 , wherein the ring has a circular cross section. 
     
     
         13 . The downhole oilwell toolstring of  claim 10 , wherein the ring has a rectangular cross section. 
     
     
         14 . The downhole oilwell toolstring of  claim 10 , wherein the groove connects with the interior surface of the female housing by way of an angled portion. 
     
     
         15 . The downhole oilwell toolstring of  claim 10 , wherein the groove in the adapter has a semi-circular cross section. 
     
     
         16 . The downhole oilwell toolstring of  claim 10 , wherein the groove in the female housing has a semi-circular cross section. 
     
     
         17 . The downhole oilwell toolstring of  claim 10 , wherein the housing is a housing of a perforating gun, the perforating gun comprising at least one shaped charge.