Patent EA-004560-B1 (EA)
Title: Tubular threaded joint capable of being subjected to diametrical expantion
Inventor: COULON JEAN-LUC
IPC: E21B17/042
Filed: 2001-06-25
Abstract: 1. A threaded tubular connection capable being subjected to diametral expansion comprising: a male threaded element (1) at one end of a first pipe (11); and a female threaded element (2) at one end of a second pipe (12); the male threaded element comprising a male threading (3) and a male lip (5) between a free end and said male threading, said male lip comprising an external peripheral surface (7) terminating transversely with respect to an axis of the threaded tubular connection by a male end surface (9) that is annular in shape; the female threaded element (2) comprising a female threading (4) corresponding to the male threading (3) and a non-threaded female housing portion (6) for housing the male lip, said female housing portion comprising an internal peripheral surface (8) and a female shoulder surface (10), which is annular and with a partially transverse orientation, the male threading (3) being made up into the female threading (4) to a position in which the male annular end surface (9) is engaged against the female shoulder surface (10), wherein to provide sealing and a maximum internal passage cross-section after being subjected to diametral expansion in the zone of plastic deformations, annular end surface of the male end surface (9) and the female shoulder (10) have complementary shapes for embedding the male end surface (9) with the female shoulder surface (10), and wherein the external peripheral surface (7) of the male lip (5) is disposed with a small clearance from the internal peripheral surface (8) of the female housing (6). 2. A threaded tubular connection according to claim 1, wherein the male end surface (9) has a shape of a rabbet constituted by a transverse surface (15) on an internal side of the threaded tubular connection and on a side opposite the rabbet by an axially projecting annular tongue (13), and wherein the female shoulder surface (10) has a shape of a rabbet constituted by a transverse surface (16) on a side directed towards an interior of the threaded tubular connection and by an annular groove (14) on an opposite side, the transverse surface of the male rabbet (15) co-operating with the transverse surface of the female rabbet (16) and the tongue (13) cooperating with the groove (14). 3. A threaded tubular connection according to claim 2, wherein annular walls of the tongue (13) and the groove (14) are disposed such that in a connected position of the threaded connection, the annular walls (18, 26) of the groove radially interference fit with the annular walls (17, 25) of the tongue. 4. A threaded tubular connection according to claim 3, wherein the annular walls of die tongue (13) are slightly tapered and converge towards a free end of the tongue, and wherein the annular walls (18, 26) of the groove (14) are slightly tapered and converge towards abase of the groove, an inclination of the walls of the groove being equal to an inclination of the walls of the tongue. 5. A threaded tubular connection according to any one of claims 2-4, wherein the transverse surfaces of the male and female rabbet (15, 16) abut against each other. 6. A threaded tubular connection according to any one of claims 2-5, wherein a radial thickness (ed) of the tongue (13) is substantially equal to a radial thickness of the transverse surface (15) of the male lip (9). 7. A threaded tubular connection according to any one of claims 2-6, wherein an axially measured height (hd) of the tongue (13) is substantially equal to its radial thickness (ed). 8. A threaded tubular connection according to any one of claims 1-7, wherein the external peripheral surface (7) of the male lip and internal peripheral surface (8) of the female housing are cylindrical. 9. A threaded tubular connection according to any one of claims 1-8, wherein the male lip (5) has a thickness (el) in a range of 1/3 to 2/3 of a thickness of the first pipe (11). 10. A threaded tubular connection according to any one of claims 1-9, wherein the male lip (5) has a length (ll) and thickness (el) such that a ratio of the length of the male lip to its thickness is in a range of 1 to 4. 11. A threaded tubular connection according to any one of claims 1-10, wherein the male threaded element (1) has a groove (21) at an end of the male threading (3) between the male threading and the male lip (5). 12. A threaded tubular connection according to claim 11, wherein the groove (21) has a depth (hg) equal to a height of the male threading (3). 13. A threaded tubular connection according claim11 or 12, wherein the groove (21) has a length (lg) and a depth (hg) such that its length is in a range of 2 to 8 times its depth. 14. A threaded tubular connection according to any one of claims 1-13, wherein the first pipe and the second pipe (11, 12) have a same internal diameter (D1) both at the threaded elements (1, 2) and in a pipe body. 15. A threaded tubular connection according to claim 14, wherein the first pipe and the second pipe (11, 12) have a same external diameter (DE), both at the threaded elements (1, 2) and in the pipe body. 16. A Threaded tubular connection according to claim 14, wherein the threaded tubular connection is integral. 17. A sealed threaded tubular connection, wherein it is a threaded tubular connection according to any one of claims 1-6, which is being subjected to diametral expansion in the zone of plastic deformations. 18. A sealed threaded tubular connection according to claim 17, wherein the diametrical expansion by the threaded tubular connection is more than 10%. 19. A threaded tubular connection according to any one of claims 1-18, wherein the threaded elements (1, 2) are made of steel comprising in its composition elements combining with nitrogen which renders the steel insensitive to ageing after cold-hardening or cold-working wherein the steel is heat treated for maximalyzing its characteristics of high uniform elongation properties. 20. A process for producing a sealed threaded tubular, wherein a tubular threaded connection realized according to any one of claims 1-16 and described as "an initial tubular threaded connection" for which any other sealing characteristics are required, is subjected to diametrical expansion in the zone of plastic deformations by an expansion mandrel made in the form of rotating body a diameter of which is greater than an internal diameter (D1) of the first and second pipes, said mandrel being axially displaced via an initial threaded connection, dimensions of the male lip 950 and the female housing (6) being such that during passage of the mandrel, the male lip and the female housing initially together undergo plastic bending deformation while only the female housing then undergoes plastic deformation in a reverse, straightening direction, which interference fits the male lip with the female housing. 21. The process for producing a sealed treaded tubular connection according to claim 20, wherein bending of the male lip (5) is delimited by a presence of a groove (21) at an end of the male lip on a side of the male treading. 22. The process for producing a sealed treaded tubular connection according to claim 20 or 21, wherein an initial threaded tubular connection is a threaded tubular connection of in integral type wherein the expansion mandrel (30) is displaced from the male threaded element (1) towards the female threaded element (2).