INSERTION METHOD OF WELL STRAINER CASING

PURPOSE:To prevent the loading and to secure the stability of a well by supporting strainer casing pipes having an outside diameter smaller by a specific % than that of the well with casing spacers to form a fluid channel between hole walls. CONSTITUTION:An upper casing 2' is provided to the inside of a large well 1', well hoes 3' are excavated in the lower part thereof, and a large number of hole strainer holes 4' are bored to provide strainer casings 5' having an outside diameter smaller 15%-40% than that of the well hole 3'. After that, casing spacers 6 having legs to be radially projected are mounted to the strainer casings 5 at proper intervals, and the strainer casings 5' are supported on the central part in the holes 3'. A sufficient interval space is formed between walls of the well holes 3' to secure a fluid channel. According to the constitution, the loading variation with the lapse of time bearing relation to the strainer cashings 5' is hard to occur, and the stability of the well can be promoted.