Drilling Schemes for Different Well Types: Equipment Selection Guide

Drilling Schemes for Different Well Types: Equipment Selection Guide

The purpose of drilling a water well directly affects the required well depth, water volume, water quality, and technical requirements, thus determining the differences in equipment and processes. The following are key points for drilling schemes and equipment selection for three main well types: drinking water, agricultural irrigation, and industrial water.

Drinking Water Wells: The core requirements are safe water quality, stable water volume, and long-term reliability. Well depths are typically tens to two hundred meters to obtain stable deep groundwater. Extremely high hygiene requirements are necessary, and any contamination is strictly prohibited. For equipment selection, truck-mounted rotary drilling rigs or small multi-functional drilling rigs are suitable, as they are mobile and flexible, allowing operation near residential areas. During drilling, clean, environmentally friendly, high-quality mud must be used to protect the well wall and isolate contaminants. The well casing must be made of food-grade stainless steel or high-quality PVC pipe, and the filter pipe section must be finely designed to prevent fine sand from entering. After drilling, thorough disinfection and prolonged pumping and flushing of the well are essential until the water quality fully meets standards.

Agricultural Irrigation Wells: The core objective is to obtain a sufficiently large and stable water volume, while also considering economic efficiency. Well depths vary greatly, ranging from shallow wells of tens of meters to deep wells of two to three hundred meters, depending on local hydrological conditions. Due to the large water consumption, well diameters are typically large. Medium to large drilling rigs are the mainstream choice, such as rotary drilling rigs or truck-mounted deep well drilling rigs, to ensure drilling efficiency and well diameter. Percussion drilling tools may be used when dealing with gravel layers. Well casing can be welded steel pipes or compliant plastic pipes, requiring robustness, durability, and high water output. Water quality requirements are relatively relaxed, but sand content must be controlled to protect the water pump.

Industrial deep wells: Primarily used for industrial cooling, process water, or geothermal extraction, characterized by extremely deep wells, complex operating conditions, and high technical standards. Depths often reach hundreds to thousands of meters, potentially encountering high-temperature rock formations or corrosive water. Equipment selection must utilize large deep well drilling rigs or oil drilling rigs with powerful power and torque. Drilling must address hard rock, high temperatures, and complex geology, potentially employing multi-stage casing, air down-the-hole hammers, or advanced mud systems. High-strength, corrosion-resistant oil casing must be selected for the well. Well completion processes are extremely rigorous, requiring long-term stability and exceptionally high structural integrity.

Before selecting equipment, professional geological and hydrological surveys are essential. A fundamental principle is to select the most reliable, efficient, and site-appropriate equipment, while meeting technical requirements, rather than blindly pursuing "large and comprehensive" options. Successful drilling is a combination of scientific planning, suitable equipment, and mature processes.