Thread form with multifacited flanks

A threaded pipe connection comprising:

• a box having internal threads with stab flanks and load flanks and flat roots and crests and a pin having external threads with stab flanks and load flanks and flat crests and roots for mating with the internal threads of the box to make up a pipe connection, the threads increasing in width in one direction on the box and in the other direction on the pin so that the roots, crests and flanks of the threads are helically structured as a wedge and move together during make up;
• the pin thread having a complex profile stab flank for engaging a mating stab flank of the complimentary box member to provide an interfit between the stab flanks of the pin and box members, the interfit serving to limit the radial movement of the pin threads into the mating box member complimentary thread structure to control radial make up of the pipe connection;
• and
• wherein the complex profile stab flank is a multi-facited flank having at least three facits and four radii per stab flank;
• wherein the pin thread also has a complex profile load flank for engaging a mating load flank of the complimentary box member;
• and
• wherein the complex profile load flank is a multi-facited flank having at least three facits and four radii per load flank.

A threaded pipe connection for a pipe having a horizontal axis, the connection comprising:

• a box having tapered, internal threads with stab flanks and load flanks and flat roots and crests that are non-parallel to the longitudinal axis of the pipe and a pin having tapered external threads with stab flanks and load flanks and flat crests and roots that are non-parallel to the longitudinal axis of the pipe for mating with the internal threads of the box to make up a pipe connection, the threads increasing in width in one direction on the box and in the other direction on the pin so that the roots, crests and flanks of the threads move together during make up;
• and
• the pin thread having a complex, multi-angled stab flank for engaging a mating stab flank of the complimentary box member to provide an interfit between the stab flanks of the pin and box members, the interfit serving to limit the radial movement of the pin threads into the mating box member complimentary thread structure to control radial make up of the pipe connection and provide an offset clearance between the pin and box thread crests and roots to allow venting of any entrapped thread lubricant;
• wherein the complex, multi-angle stab flank is a multi-facited flank having at least three facits and four radii per stab flank;
• and
• wherein the pin also has a complex, multi-angle load flank which is a multi-facited flank having at least three facits and four radii per stab flank.

A threaded tool joint adapter connection having encapsulated stresses, the adapter connection comprising:

• a box having internal threads with stab flanks and load flanks and flat roots and crests and a pin having external threads with stab flanks and load flanks and flat crests and roots for mating with the internal threads of the box to make up a pipe connection, the threads increasing in width in one direction on the box and in the other direction on the pin so that the roots, crests and flanks of the threads move together during make up;
• the pin thread having a complex profile stab flank for engaging a mating stab flank of the complimentary box member to provide an interfit between the stab flanks of the pin and box members, the interfit serving to limit the radial movement of the pin threads into the mating box member complimentary thread structure to control radial make up of the pipe connection;
• a metal-to-metal seal formed between mating surfaces of the box and pin at opposite extents of the threaded surfaces thereof, the metal-to-metal seals forming an internal seal and an oppositely arranged external seal which serve to encapsulate the threaded surfaces of the connection and thereby isolate the encapsulated surfaces from corrosive attack;
• wherein the complex profile stab flank is a multi-facited flank having at least three facits and four radii per stab flank;
• wherein the pin thread also has a complex profile load flank for engaging a mating load flank of the complimentary box member;
• and
• wherein the complex profile load flank is a multi-facited flank having at least three facits and four radii per stab flank.

A threaded tool joint adapter connection having encapsulated stresses, the adapter connection comprising:

• a box having internal threads with stab flanks and load flanks and flat roots and crests and a pin having external threads with stab flanks and load flanks and flat crests and roots for mating with the internal threads of the box to make up a pipe connection, the threads increasing in width in one direction on the box and in the other direction on the pin so that the roots, crests and flanks of the threads move together during make up;
• the pin thread having a complex profile stab flank for engaging a mating stab flank of the complimentary box member to provide an interfit between the stab flanks of the pin and box members, the interfit serving to limit the radial movement of the pin threads into the mating box member complimentary thread structure to control radial make up of the pipe connection;
• a metal-to-metal seal formed between mating surfaces of the box and pin at opposite extents of the threaded surfaces thereof, the metal-to-metal seals forming an internal seal and an oppositely arranged external seal which serve to encapsulate the threaded surfaces of the connection and thereby isolate the encapsulated surfaces from corrosive attack;
• and
• wherein the internal seal is a short, low angle seal of between 0.200″ and 0.400″ in engaged length and between 1° and 5° taper and the external seal is a long, low angle seal of at least 0.400″ in engaged length and between 1° and 5° taper.

A threaded adapter connection having encapsulated stresses, the adapter connection comprising:

• a box having internal threads with stab flanks and load flanks and flat roots and crests and a pin having external threads with stab flanks and load flanks and flat crests and roots for mating with the internal threads of the box to make up a pipe connection, the threads increasing in width in one direction on the box and in the other direction on the pin so that the roots, crests and flanks form a wedge interfit upon make up of the connection;
• a metal-to-metal seal formed between mating surfaces of the box and pin at opposite extents of the threaded surfaces thereof, the metal-to-metal seals forming an internal seal and an oppositely arranged external seal which serve to encapsulate the threaded surfaces of the connection and thereby isolate the encapsulated surfaces from corrosive attack and which also provide structural support for adjoining critical cross sections on the pin and box members for the purpose of decreasing stresses in said areas, whereby the entire connection has increased capacity to resist failure when in rotary fatigue service;
• and
• wherein the internal seal is a short, low angle seal of between 0.200″ and 0.400″ in engaged length and between 1° and 5° taper and the external seal is a long, low angle seal of at least 0.400″ in engaged length and between 1° and 5° taper.

A threaded pipe connection having encapsulated stresses, the threaded pipe connection comprising:

• a box having internal threads with stab flanks and load flanks and flat roots and crests and a pin having external threads with stab flanks and load flanks and flat crests and roots for mating with the internal threads of the box to make up a pipe connection, the threads increasing in width in one direction on the box and in the other direction on the pin so that the roots, crests and flanks form a wedge interfit upon make up of the connection;
• a metal-to-metal seal formed between mating surfaces of the box and pin at opposite extents of the threaded surfaces thereof, the metal-to-metal seals forming an internal seal and an oppositely arranged external seal which serve to encapsulate the threaded surfaces of the connection and thereby isolate the encapsulated surfaces from corrosive attack and which also provide structural support for adjoining critical cross sections on the pin and box members for the purpose of decreasing stresses in said areas, whereby the entire connection has increased capacity to resist failure when in rotary fatigue service;
• and
• wherein the internal seal is a short, low angle seal of between 0.200″ and 0.400″ in engaged length and between 1° and 5° taper and the external seal is a long, low angle seal of at least 0.400″ in engaged length and between 1° and 5° taper.

A threaded pipe connection comprising:

• a box having internal threads with stab flanks and load flanks and flat roots and crests and a pin having external threads with stab flanks and load flanks and flat crests and roots for mating with the internal threads of the box to make up a pipe connection, the threads increasing in width in one direction on the box and in the other direction on the pin so that the roots, crests and flanks of the threads move together during make up;
• the pin thread having a complex profile stab flank made up of at least an inner wall portion and an intersecting outer wall portion which together form a double sloped flank for engaging a mating stab flank of the complimentary box member to provide an interfit between the stab flanks of the pin and box members, the interfit serving to limit the radial movement of the pin threads into the mating box member complimentary thread structure to control radial make up of the pipe connection;
• the threaded pipe connection further comprising a metal-to-metal seal formed between mating surfaces of the box and pin at opposite extents of the threaded surfaces thereof, the metal-to-metal seals forming an internal seal and an oppositely arranged external seal which serve to encapsulate the threaded surfaces of the connection and thereby isolate the encapsulated surfaces from corrosive attack;
• and
• wherein the internal seal is a short, low angle seal of between 0.200″ and 0.4001″ in engaged length and between 1° and 5° taper and the external seal is a long, low angle seal of at least 0.400″ in engaged length and between 1° and 5° taper.