The drilling speed of Construction engineering multi-head drilling rig is a complex indicator affected by many factors.
1. Influence of geological conditions
Different geological conditions have a fundamental impact on the drilling speed of multi-head drilling rigs. In soft soil areas, such as silty soil or silty clay, multi-head drilling rigs can drill relatively quickly. Due to the low shear strength of this type of soil, the drill bit is easy to cut into and break up the soil. Under such geological conditions, the drilling speed of a multi-head drilling rig may reach several meters per hour. In hard rock formations, however, the situation is quite different. If it is hard rock such as granite and basalt, the drilling speed will be significantly reduced. The hardness, integrity and development of joints and fissures of the rock will all affect the drilling speed. For intact, hard rock, a multi-head drill may only be able to drill a few centimeters per hour or even less. In the sand layer, although the cohesion between sand grains is small, the stability of the sand layer is poor, and hole collapse is prone to occur during drilling. This requires controlling the drilling speed to ensure the stability of the hole wall. The drilling speed is between soft soil and rock, ranging from a few tenths of a meter to several meters per hour.
2. Drill bit type and performance
The type of drill bit used in a multi-head drilling rig is directly related to the drilling speed. For example, for soil drilling, a spiral drill bit can effectively cut the soil and bring it out of the hole. This drill bit can drill faster under suitable soil conditions. When drilling into rock layers, roller cone drill bits or diamond drill bits are more suitable. A roller cone drill bit breaks rock through the rolling of cones. Its drilling speed depends on factors such as the size and number of cones, the shape and material of the teeth, and other factors. Diamond drill bits use the hardness of diamond to cut rocks, and their drilling speed is related to the particle size and distribution density of diamond and the structure of the drill bit. A high-quality drill bit can break up the formation more efficiently, thereby increasing the penetration rate, while a drill bit that is severely worn or not suitable for a specific formation will cause the penetration rate to decrease.
3. Power and torque of drilling rig
The power and torque provided by the power system of the multi-head drilling rig are also important factors affecting the drilling speed. Greater power and torque enable the drill bit to cut into the formation with greater force, thereby speeding up drilling. If the power is insufficient, the drill bit may have difficulty drilling or even be unable to drill when facing harder formations. For example, the power of an electric multi-head drill determines its cutting ability during drilling, and the system pressure and flow of a hydraulic multi-head drill affect the torque output, which will all affect the drilling speed.
4. Setting of operating parameters
Reasonable setting of operating parameters such as drilling pressure, rotation speed, etc. is crucial to drilling speed. Appropriate drilling pressure can maintain good contact between the drill bit and the formation and effectively break the formation, but if the pressure is too high, it may lead to increased wear of the drill bit or overloading of the drill rig. The rotational speed also needs to be adjusted according to the drill bit type and geological conditions. Too high or too low a rotational speed is not conducive to increasing the drilling speed. In actual operation, operators need to continuously optimize operating parameters according to specific construction conditions to achieve the best drilling speed.
