TMT now has a very large target on its back, page-297

see https://www.theprojectestimate.com/pipe-installation-man-hours for guidelines. assuming 6" pipe in 10m joints, 3 hours for handling and welding per joint.

To lay 100 joints of pipe (your 1km) per day takes 300 hours so 12 welders over 24 hours. so yeah, easily doable.

Or, they could lay reeled fiberglass pipe (up to 2.7km per reel depending on the size) with equivalent pressure ratings and get it done even faster https://www.nov.com/products/fiberspar-spoolable-fiberglass-pipe

my 2 cents, ymmv, dyor etc etc