Mpd-capable flow spools

A riser segment assembly comprising:

• a main tube defining a primary lumen;
• a collar defining a lateral opening in fluid communication with the primary lumen;
• two flanges each coupled to a different end of the main tube, each flange comprising:
• a mating face configured to mate with a flange of an adjacent riser segment;
• and
• a central flange lumen configured to be in fluid communication with the primary lumen of the main tube;
• a fitting coupled to the collar, the fitting defining a fitting lumen in fluid communication with the lateral opening;
• a retainer coupled to the main tube, the retainer comprising a body having a top, a bottom, and an opening extending between the top and bottom of the body;
• a first connector configured to be removably received within the opening of the retainer to secure the first connector to the main tube, the first connector defining a lumen having an inlet through which fluid can enter the first connector in a first direction, and an outlet through which fluid can exit the first connector in a second direction that is different than the first direction, wherein the lumen of the first connector is configured to be in fluid communication with the fitting lumen;
• and
• wherein the retainer includes one or more members coupled to the body and movable between a first position in which the first connector is permitted to enter or exit the opening of the body, and a second position in which the one or more members prevent the first connector from entering or exiting the opening of the body.

A method comprising:

• lowering a riser segment assembly through a rotary of a drilling rig, wherein the riser segment assembly includes:
• a main tube defining a primary lumen;
• a collar defining a lateral opening in fluid communication with the primary lumen;
• two flanges each coupled to a different end of the main tube, each flange comprising:
• a mating face configured to mate with a flange of an adjacent riser segment;
• and
• a central flange lumen configured to be in fluid communication with the primary lumen of the main tube;
• a fitting coupled to the collar, the fitting defining a fitting lumen in fluid communication with the lateral opening;
• a retainer coupled to the main tube, the retainer comprising:
• a body having a top, a bottom, and an opening extending between the top and bottom of the body;
• and
• one or more members coupled to the body and movable between a first position and a second position;
• connecting, below the rotary, a first connector to the retainer by:
• moving the first connector into the opening of the retainer, the first connector defining a lumen having an inlet through which fluid can enter the first connector in a first direction, and an outlet through which fluid can exit the first connector in a second direction that is different than the first direction, wherein the lumen of the first connector is configured to be in fluid communication with the fitting lumen;
• and
• moving the one or more members between the first position, in which the one or more members permit the first connector to enter or exit the opening of the body, and the second position, in which the one or more members prevent the first connector from entering or exiting the opening of the body.