US Patent 11346165 Horizontal stand builder and catwalk

A system and method for horizontally building stands of tubulars and transferring them to a rig floor. The system has a horizontal stand builder which assembles double or triple stands of tubulars. A catwalk and V-door are positioned alongside the horizontal stand builder. A skate is able to push either single, double, or triple stands along the catwalk and up the V-door to a position whereby an elevator on the rig can grip the stand and move it onto the rig. For transferring single stands of tubular, there is a carrier at the upper end of the V-door which can grip the single stand and lift it to the position for the elevator to grip it and move it onto the rig.