Abstract: A threaded joint for production of tubing includes a male element and female elements, having outer surface and inner surfaces, respectively, whose ends are configured with a trapezoidal tapered thread and with sealing surfaces, auxiliary surfaces and abutting end surfaces, which form an inner sealing assembly. The threads have characteristics described in the present disclosure. Auxiliary surfaces are provided between the sealing surfaces and the abutting end surfaces. The junction between the sealing surfaces and the auxiliary surfaces is configured in the form of a concave spherical surface on the male element and a convex spherical surface on the female element. This provides for the formation of a tight joint under high mechanical loads by virtue of improved coupling characteristics and the prevention of damage to the surfaces.

Abstract: There is proposed a thread connection for casings used for construction of vertical, directional and horizontal wells. The connection includes male and female elements, whose ends, both externally and internally, are produced correspondingly with tapered trapezoidal threads, sealing, transition and shoulder end surfaces. Crests and roots of the thread turn profile are parallel to the axial line of thread. Additional surfaces are formed as a taper surface on the female element and a taper surface or convex spherical surface on the male element. Transition from the sealing surfaces to additional surfaces are formed as concave spherical surface on the male element and of convex spherical surface on the female element. High tightness of the connection under sufficient mechanical loads is achieved by improving characteristics of the connection make-up, prevention of jamming of the connection at the initial stage of make-up, lack of damages (galling) of sealing surfaces.

Abstract: Threaded connections of casing pipes comprising male and female members with trapezoidal tapered threads arranged on outer and inner surfaces of end sections. Radial sealing surfaces and stop end surfaces contact forming an internal sealing zone. Threads on male and female members have a 1:16 taper ratio, a 23-25° stab flank angle, and a ?3 to ?5° load flank angle. During assembly, crests and stab flanks of thread profile form clearances. Radial sealing surfaces on male and female members are tapered and positioned at a 71-73° angle relative to the normal. Stop end surfaces on male and female members are positioned at a 14-16° angle relative to the normal. Stop end thickness of male member constitutes at least 50% of wall thickness. Tight sealing of connection is preserved under considerable combined loads, including high-torque exposure.

Abstract: A joint for pipes includes male and female portions, trapezoidal threads at taper sealing and bearing end surfaces, with slope angles between thread lead-in flanks and the thread axis normal line of 10-24° and between load flanks and the thread axis normal line of ?4° to +5°. The bearing end surfaces have a 10-20° slope angle from the thread axis normal line. There is 13-18° slope angle between the male portion sealing surface and thread axis normal line, and an 8-12° slope angle between the female portion sealing surface and thread axis normal line. The female portion thread run-out area and mating areas of the sealing and the bearing end surfaces have circumferential grooves. The female element sealing surface and circumferential groove surface and the male portion sealing surface and thread run-out surface are rounded.

Abstract: The invention belongs to the oil and gas-extraction industry. The joint contains male (1) and female (2) elements with trapezoidal threads (3) with 1:16 taper and contacting each other taper sealing (5) and bearing (6) end surfaces. The slope angle between the thread profile lead-in flank (7) and the thread axis normal line amounts to 10-24°, the slope angle between the load flank (8) and the thread axis normal line amounts to ?4 to +5°. The thread profile crests (9) and lead-in flanks make gaps (10, 11) in between, 0.05-0.15 mm wide, during joint make-up process. The thread profile on the area of mating of the load flank and the crest and on the area of mating of lead-in flank and the crest is produced rounded, with the different rounding radii for the male and female elements. The bearing end surfaces have a 10-20° slope angle with the thread axis normal line.

Abstract: A threaded joint for oil field pipes includes a male pipe having a male thread and a female pipe having a female thread. The male thread and the female thread engage along a thread profile, the male pipe with a first end face and the female pipe with a second end face. The male pipe also has as first sealing surface and the female pipe has a second sealing surface. The first end face and second end face are substantially perpendicular to the first sealing surface and second sealing surface. When the male pipe and female pipe are fully adjoined, the first sealing surface abuts the second sealing surface, the first end face abuts the second end face, and the trailing face abuts female thread, while leaving a space between the female thread and the top face, and leaving a space between the female thread and the leading face.

Abstract: A highly-tight screw joint comprising internal and external mating elements with conical surfaces used in connection with oil and gas wells. The internal and external elements are provided with a thread with supporting and embedded faces. A sealing unit is made in the form of a wedge on the side of a small diameter. The sealing unit is provided on the internal and external elements and consists of parts of the internal and external elements. The internal and external elements are formed by conical radial and conical supporting faces. The conical radial face is made at an angle of 25°-35° to the normal to the thread axis. The conical supporting surface is made at the angle of 10°-25° to the normal to thread axis.

Abstract: The invention relates to building and operating vertical, controlled, directional and horizontal holes of oil and gas fields with difficult operating conditions, and can be used for process casing pipes. The inventive tightly threaded joint for oil field pipes comprises male and female pipes with a conical thread and stop and sealing surfaces. The stop surfaces are brought into contact by the end surface of the male pipe and the mating end surface of the female pipe. The conical thread configuration has a negative angle along a bearing face. The height of thread of the male pipe is less than the height of thread of the female pipe. The end surfaces are designed so that the area thereof is equal to or greater than 60% of the pipe body. The invention makes it possible to increase the operational reliability and effectiveness of the tight joint and to minimize ecological risks.