Applicability and Selection Recommendations for Different Drilling Equipment

Applicability and Selection Recommendations for Different Drilling Equipment

When choosing drilling equipment, the primary principle is to "match the tool to the task," meaning selecting the most effective machine based on the main type of geological formation you intend to drill. Underground soil and rock vary greatly, from soft sand to hard granite, and no single drilling rig can perfectly handle all situations. Therefore, understanding the strengths of mainstream models and the types of formations they are best suited for is fundamental to making the right choice.

Rotary drilling rigs are the most widely used type, particularly effective in soft to medium-hard formations such as soil, sand, clay, and partially weathered rock. They work by rotating a drill bit to cut through the soil, while circulating mud or water to carry the cuttings out of the hole. This method offers fast drilling speeds, regular boreholes, and smooth operation, making it ideal for drilling agricultural irrigation wells, domestic water wells, and engineering exploration holes ranging from tens to hundreds of meters deep. If your target formation is primarily of this type, a rotary drilling rig is usually the most efficient and economical choice.

When encountering hard rock layers, large boulders, or very dense formations, the cutting efficiency of rotary drilling rigs becomes very low. In this case, impact drilling rigs become a more suitable tool. Their working principle is similar to a heavy hammer, relying on the repeated lifting and free fall of a heavy drill string to crush the rock with immense impact force. Although its drilling speed in hard rock may not be as fast as a rotary drill in soft soil, its ability to break hard rock is irreplaceable. Therefore, in mountainous areas dominated by bedrock such as granite and hard sandstone, or when needing to penetrate thick layers of gravel, impact drilling rigs should be prioritized. Their drawback is that they produce relatively more vibration and noise during operation.

However, underground conditions are often complex and variable, with alternating soft and hard layers or unknown geological conditions being common challenges. To address this uncertainty, multi-functional drilling rigs (also known as combination drilling rigs) are an ideal choice. These devices typically integrate both rotary and impact functions, allowing operators to flexibly switch between working modes based on the geological formation encountered in real-time: using rotary drilling for fast penetration in soft soil and immediately switching to impact drilling when encountering hard rock. This "multi-functional" characteristic significantly reduces the trouble and cost of changing equipment midway due to geological changes. Although the initial investment in the equipment itself may be higher, the overall benefits are significant in complex geological formations.

Our selection advice is as follows: First, collect as much local geological data as possible or consult experienced well drillers to determine the main geological formations you will be drilling through. If it's confirmed to be soft soil, choose a rotary drill; if it's hard rock, choose an impact drill; if you are unsure or the formations may be a mix of soft and hard, a composite drilling rig is a safer and more adaptable option. Second, consider your budget and long-term needs: if you only need to drill one shallow well, renting or choosing a small basic model might be more cost-effective; if you plan to engage in well drilling business long-term or need to handle various geological conditions, investing in a more powerful composite drilling rig might be more worthwhile. Finally, tell a reliable equipment supplier about your geological assessment, well depth requirements, budget, and site conditions. Their professional recommendations will help you make the most practical decision.