01 Geological and Drilling Strategy Selection
◉ Operating Instructions and Drilling Methods
An excellent operator must constantly understand the type and strength of the geological formation being drilled, and be familiar with the appropriate drill rods and tools, as well as the most suitable drilling method. Only in this way can precise control be achieved, resulting in minimal load, minimal wear, and the fastest drilling progress. For different geological conditions, rotary drilling rigs mainly employ four drilling methods: cutting, breaking, churning, and grinding.#square drilling machine#
◉ Cutting Drilling
Cutting drilling primarily relies on bucket teeth, combined with a double-bottom sand-collecting bucket and friction-type drill rods. It is suitable for drilling into stable formations with low resistance. These formations typically have low geological strength, such as mud, silt, and sand layers, with a strength generally not exceeding 400 kPa. Through the rotation and cutting action of the bucket teeth, drilling resistance can be effectively reduced, thereby increasing the drilling speed of the rig.
◉ **Brewing Drilling:** Breaking drilling primarily uses cutting teeth for drilling, typically equipped with a double-bottom rock-feeding bucket. Depending on the geological strength of the formation, friction-resistance or mechanically locked drill pipes can be selected. This drilling method is suitable for formations with strengths between 500 kPa and 1000 kPa, such as gravel, mudstone, sandstone, shale, and moderately weathered rock. By increasing pressure, force is transferred to the alloy points on the cutting teeth, thus achieving effective breaking drilling.
◉ **Pulling Drilling:** Pulling drilling is mainly suitable for geological conditions with irregularly arranged pebbles. Because pebbles are hard and cannot be cut or broken, a pulling method is required. During operation, the main reel suspends the drill pipe, and the tips of the drill bit teeth gently pulverize the pebbles to loosen them. Subsequently, the drill bit is lowered in a floating state, thus avoiding the strength and vibration of the pebbles and achieving effective drilling. This drilling method requires operators with certain skills and experience to ensure drilling efficiency and safety.
◉ Grinding Drilling#square drilling machine#
Grinding drilling is primarily suitable for rock formations with a single-circumference compressive strength ranging from several megapascals to tens of megapascals, and is commonly used in drilling end-bearing piles. By using a rock-cutting drill and a toothed drill, along with mechanically locked drill rods, the drill bit can drill in a circumferential or grinding manner. Depending on the characteristics of the rock formation, such as its type, strength, brittleness, and fracture conditions, fracturing operations may also be performed during drilling. This drilling method requires operators to possess a high level of technical skill and extensive experience to ensure drilling efficiency and safety.#square drilling machine#
