Abstract: Embodiments provide a flush fluid connection having a first fluid connector having a male connector end including an elongated nose section having a front surface and a first external sealing surface. The male connector end includes an external shoulder extending outwardly relative to a longitudinal axis and a second external sealing surface adjacent the external shoulder, and external threads between the first external sealing surface and the second external sealing surface. The flush fluid connection includes a second fluid connector that has a female connector end having an elongated nose section comprising a front surface and a first internal sealing surface. The female connector end includes an internal shoulder extending inwardly relative to the longitudinal axis and a second internal sealing surface adjacent the internal shoulder, and internal threads between the first internal sealing surface and the second internal sealing surface.

Abstract: Couplings and/or connections include a female component engaged with a male component. A first shoulder of the female component abuts a first complementary shoulder of the male component to form a first radial seal. A second shoulder of the female component abuts a second complementary shoulder of the male component to form a second radial seal. A sealing surface of the female component abuts a complementary sealing surface of the male component to form an axial seal disposed between the first and second radial seals. Plastic and/or elastic deformation of the complementary sealing surface of the male component forms an axial seal between the female component and the male component.

Abstract: Threaded couplings and methods for use in drilling with casing can include first and second male members having exterior threads engaged with interior threads of a female member. Exterior shoulders of the male members can abut interior shoulders of the female member to facilitate placement of the male members such that pin noses thereof are positioned at the center of the female member, where abutment between the pin noses of the male members can form a seal. The shoulders can be provided with negative angles to prevent disengagement. Tapered surfaces can be provided on the male members, to contact tapered surfaces on the female member to form metal-to-metal seals for enhancing the integrity of the connection, a straight thread configuration can be used to maximize the thickness of the coupling, and bearing journals or guides can be used to facilitate engagement of the threads and retention of the engagement.

Abstract: Embodiments provide a flush fluid connection having a first fluid connector having a male connector end including an elongated nose section having a front surface and a first external sealing surface. The male connector end includes an external shoulder extending outwardly relative to a longitudinal axis and a second external sealing surface adjacent the external shoulder, and external threads between the first external sealing surface and the second external sealing surface. The flush fluid connection includes a second fluid connector that has a female connector end having an elongated nose section comprising a front surface and a first internal sealing surface. The female connector end includes an internal shoulder extending inwardly relative to the longitudinal axis and a second internal sealing surface adjacent the internal shoulder, and internal threads between the first internal sealing surface and the second internal sealing surface.