Method of forming and heat treating coiled tubing

A method of forming and heat treating a coiled tube, the method comprising:

• welding a plurality of steel strips together end-to-end to form a plurality of end-to-end welded strips and longitudinally welding the plurality of end-to-end welded strips to form a tube with a substantially constant inner diameter, outer diameter, and wall thickness along at least a first portion, a second portion, and a third portion, the third portion being disposed between the first portion and the second portion, said tube having one or more microstructures;
• and
• after forming the tube, performing a continuous and dynamic heat treatment (CDHT) process comprising a continuous quench and temper heat treatment along the first portion, the second portion, and the third portion, thereby modifying the one or more microstructures of the tube and thereby resulting in a post heat treatment (PHT) tube with a second microstructure comprising a uniformity of microstructure across (a) the plurality of steel strips, (b) a plurality of end-to-end welds joining the steel strips, and (c) a plurality of longitudinal welds joining the plurality of steel strips, and wherein the PHT tube after the continuous quench and temper process has at least 80% tempered martensite in the first, second, and third portions of the PHT tube;
• and
• coiling the PHT tube to form a coiled tube.