When is the use of a casing pipe necessary in drilling?

The use of casing pipe in drilling is necessary primarily when the borehole needs support and to prevent contamination. In drilling operations, casing serves several important functions that are critical for the integrity of the well and the surrounding environment.

Casing provides structural support to the borehole, preventing it from collapsing, particularly in unstable soil or rock formations. This support is essential for the overall stability of the well and ensures that the drilling process can continue safely. Additionally, casing helps isolate different aquifer layers to avoid cross-contamination between them. This is especially important in drinking water wells where the protection of groundwater quality is paramount. By preventing the mingling of water from various strata, casing aids in maintaining the integrity of the water supply.

In contrast, using casing is not limited to shallow wells or specific types of geological conditions like hard rock. It is a fundamental practice in various drilling scenarios where the risks associated with borehole collapse or contamination are present. While there may be cost considerations related to the use of casing, these are often outweighed by the necessity to ensure safe and compliant drilling practices.