Applicable Scenarios for Different Well Drilling Equipment

Applicable Scenarios for Different Well Drilling Equipment

Well drilling is not a one-size-fits-all task. The varied properties of underground rock and soil mean that no single drilling rig can perfectly handle all situations. Therefore, understanding the principles of mainstream well drilling equipment and the geological formations they excel at is key to making the right choice and achieving efficient construction. We can broadly categorize common well drilling equipment into several main types, each performing best in its specific application.

First, in soft formations, rotary drilling rigs are undoubtedly the mainstay. The working principle of this type of rig is similar to manually screwing a screw into wood. It drives the drill rod and drill bit to rotate at high speed, cutting and grinding soil, sand, and general clay layers, while simultaneously relying on circulating mud or water to carry the debris out of the hole. This "drilling and flushing simultaneously" method results in fast drilling speeds, good hole quality, and relatively smooth and continuous operation in soft formations. It is very suitable for drilling wells at depths of tens to hundreds of meters for agricultural irrigation or domestic water supply, and is one of the most widely used models.

However, when encountering hard rocks, large pebbles, or dense weathered layers, the efficiency of rotary cutting decreases significantly, and the drill bit wears out extremely quickly. In these situations, impact drilling rigs become necessary. Their working principle is more direct; one can imagine repeatedly and violently striking downwards with a heavy hammer. The drill bit is lifted by a winch and allowed to fall freely, relying on the immense impact force to break the rock. Although its drilling speed may not be as fast as rotary drilling rigs in soft layers, it has irreplaceable advantages for hard rock formations. In mountainous areas dominated by hard bedrock, or when penetrating gravel layers to find deep water sources, impact drilling is often a more reliable choice.

With technological advancements, to cope with complex and varied geological formations (such as alternating layers of soft and hard rock, or situations where the upper layer is soil and the lower layer is rock), multi-functional drilling rigs have emerged. These devices typically combine rotary and impact functions, and some can even achieve high-frequency vibration. Operators can flexibly switch working modes according to the geological formations encountered: using rotation for soft soil and initiating impact when encountering hard rock. This significantly improves the adaptability and construction efficiency of the equipment, avoiding the predicament of having to replace the entire system due to sudden hardening of the ground. Of course, functional integration also means more complex equipment and higher investment. Therefore, the choice of equipment ultimately depends on the prediction of the geological conditions of the target area, the required well depth, and the cost budget. The wisest approach is often to refer to existing successful well drilling experience in the area and describe the requirements in detail to a professional equipment service provider to obtain the most suitable recommendation for the actual scenario.