Abstract: A method is described for supply of liquid from a liquid storage to a casing string (10,12, 14..) which from a deck (16) on an installation is conveyed down in a well with the help of a pipe handler comprising an elevator, where the liquid is supplied via an uppermost casing (10) which is added to the casing string, and the liquid is supplied through a filling pipe (30) via an outlet nozzle (36) to the top of the casing (10) already during the pipe's (10) screwing into the casing string (10, 12, 14..) where the filling pipe is extended during the liquid supply until the casing string is being lowered down to a position where it is securely locked to the deck (16), and liquid is added to a suitable level in the casing string.