The invention relates to the field of sealed connections of threaded tubular components used in particular for drilling or operating hydrocarbon wells. When drilling or operating, the connections are subjected to large compressive and tensile loads and they must be prevented from coming apart. The connections are subjected to axial tension or compression, internal or external fluid pressure, bending or twisting, which may be combined, and of an intensity which can fluctuate. The seal has to be guaranteed despite the loads and despite the harsh conditions of use on site. The threaded connections are susceptible of being made up and broken out several times without degrading their performance, especially by galling. After break-out, the tubular components can be reused under other service conditions.
Under tension, a phenomenon of jump-out may occur and propagate from one thread to another, with the risk of the connection coming apart. This phenomenon is facilitated by a high internal pressure.
The Applicant has observed that this phenomenon can also be favoured by a high external pressure. Application WO 01/29476 proposes a threaded connection with a tapered threading, the male and female threadings respectively comprising a single threaded zone with a central sealing surface disposed in a central zone of the threaded zone. An abutment is provided at the free end of the male element. Other sealing surfaces are provided in the vicinity of the abutment. That connection has been highly satisfactory for many years.
A need has now arisen for a leap in the performance of a connection, in particular under combined tension and external pressure after strong compression, as well as in terms of the efficiency of the connection. The efficiency is generally defined as being the ratio of the critical section of the connection over the section of a regular portion of a tube between the two ends of a component. The critical section of the connection is equal to the minimum of the critical section of the male element and the critical section of the female element.