Connection

A tubular connection comprising:

• a pin member having tapered external threads including full height threads and runout threads extending from a base to an end of said pin member;
• a box member having tapered internal threads including full height threads extending from a base to an end of said box member;
• said threads including grooves, said threads having crests and roots and stab and load flanks with said stab flanks having stab crest corner radiuses and stab root corner radiuses with flat flanks therebetween, said load flanks having a continuous radiuses forming an S-shape;
• said box end engaging said pin base to form a locking shoulder;
• said box member receiving said pin member until said corner radiuses engage;
• said comer radiuses guiding said threads into said accommodating grooves and said flat flanks guiding said stab flanks into engagement upon rotation of one of said pin or box members relative to the other member;
• and
• said stab flank engagement shifting to an engagement of said load flanks as said locking shoulder is formed.

A tubular drill string comprising:

• a first pipe and a second pipe having inner and outer diameters;
• a pin end on said first pipe having a first shoulder, first threads with negative load flanks and positive stab flanks, and a first radial end, said first shoulder having a first collar and a first groove with a first surface;
• a box end on said second pipe having a second radial end, second threads with negative load flanks and positive stab flanks for threadingly engaging said first threads, and a second shoulder, said second radial end having a second collar and a second protruding member with a second surface positioned on said box end of said second pipe to be received by said first groove on said pin end upon make-up of the connection;
• said first and second surfaces being radiused to increase surface contact between said pin and box ends as torque is applied upon make-up;
• and
• said first radial end abutting said second shoulder upon make-up.

A connection comprising:

• a pin connector having first threads with negative load flanks and positive stab flanks, a first terminal end and a first shoulder with a first radiused surface;
• a box connector having second threads with negative load flanks and positive stab flanks, a second terminal end with a second radiused surface, and a second shoulder;
• said first radiused surface extending across said first shoulder and said second radiused surface extending across said second terminal end;
• and
• said first and second radiused surfaces engaging upon make-up.

A connection comprising:

• a pin connector having first tapered threads with load flanks and stab flanks, a first terminal end, and a first shoulder with a first surface formed by a cross section, a portion of said cross section being curved;
• a box connector having second tapered threads with load flanks and stab flanks, a second shoulder, and a second terminal end with a second surface formed by a cross section, a portion of said cross section being curved;
• said first surface extending substantially across said first shoulder and said second surface extending substantially across said second terminal end;
• and
• said first and second surfaces engaging upon make-up.

A pin member for use in a connection comprising:

• a pin member body having external tapered threads extending from a pin end to a pin base, said pin end having a pin end shoulder and said pin base having a pin base shoulder;
• said external tapered threads of said pin member having crests and roots and having stab flanks with a positive flank angle and load flanks with a negative flank angle, said stab flanks having corner radiuses and said load flanks having continuous comer radiuses at said crests and roots;
• at least one of said pin end shoulder and pin base shoulder having a concave or convex radiused surface;
• wherein said pin member is suited to make a connection with a box member having internal tapered threads extending from a box end to a box base, said box end having a box end shoulder engaging said pila base shoulder and a box base shoulder engaging said pin end shoulder, said internal tapered threads having crests and roots and having stab flanks with a positive flank angle and load flanks with a negative flank angle, said stab flanks of said internal threads having corner radiuses that engage with said stab flanks of said external threads on said pin member;
• further wherein at least one of said box end shoulder and said box base shoulder has a concave or convex radiused surface that engages with said convex or concave radiused surface of said pin member upon connection of said pin member to said box member.

A box member for use in a connection comprising:

• a box member body having internal tapered threads extending from a box end to a box base, said box end having a box end shoulder and said box base having a box base shoulder;
• said internal tapered threads having crests and roots and having stab flanks with a positive flank angle and load flanks with a negative flank angle;
• said stab flanks having corner radiuses and said load flanks having continuous corner radiuses at said crests and roots;
• at least one of said box end shoulder and box base shoulder having a concave or concrete radiused surface;
• wherein said box member is suited to make a connection with a pin member having external tapered threads extending from a pin end to a pin base, said pin end having a pin end shoulder engaging said box base shoulder and a pin base shoulder engaging said box end shoulder, said external tapered threads having crests and roots and having stab flanks with a positive flank angle and load flanks with a negative flank angle, said stab flanks of said external threads having comer radiuses that engage with said stab flanks of said internal threads upon pin member being inserted into said box member;
• further wherein at least one of said pin end shoulder and said pin base shoulder has a concave or convex radiused surface that engages with said convex or concave radiused surface of said box member upon connection of said pin member to said box member.