Wiktionary
tube well
n. A well in which a a stainless steel tube is bored directly down into an aquifer
WordNet
tube well
n. a well made by driving a tube into the earth to a stratum that bears water [syn: driven well]
Wikipedia
Tube well
A tube well is a type of water well in which a long wide stainless steel tube or pipe is bored into an underground aquifer. The lower end is fitted with a strainer, and a pump lifts water for irrigation. The required depth of the well depends on the depth of the water table.