How to drill a well to get water?

In order to exploit deep groundwater, tube wells with small diameter (several centimeters to tens of centimeters) and considerable depth (several tens to hundreds of meters) have been developed. Pipeline drilling requires special drilling machinery and complex technology. As early as 250 BC, in China's present Sichuan Province, a large number of wells tens of meters or even 100 meters deep were dug in hard rocks to exploit underground brine to cook salt. After drilling a well to expose the confined aquifer containing salt water, the groundwater flows out of the well by itself. This kind of well is artesian well. China Sichuan Ziliujing (now Zigong City) got its name from this. In modern countries, tube wells are mainly used to mine groundwater, power rigs are used to drill wells, and various pumps are used as water lifting tools. Before 1949, only a few cities in China had a small number of tube wells, and only a few wells were used for power pumping; By 1980, the number of wells used for electric water pumping increased to 200,000, which were widely used for water supply in industrial and mining towns and agricultural irrigation.