Research on Key Technology of Rotary Drilling Rig in Complex Formation Construction

In the construction of modern infrastructure, various complex geological conditions bring great challenges to the construction of rotary drilling RIGS. From the karst cave in karst area, to the unstable structure of sand and gravel layer, and to the high strength obstacle of hard rock formation, the construction technology of rotary drilling rig is put forward strict requirements. In order to ensure the smooth progress of construction and overcome these problems, the following introduces the key technologies of rotary drilling rig in complex formation construction.

1. Formation investigation and construction planning: geological drilling, geophysical exploration and other methods are used before construction to comprehensively understand the lithology, structure and hydrology information of the strata. According to the survey results, make a detailed construction plan, select suitable equipment and technology.

2. Bit selection and improvement: Select bits according to different formation characteristics, such as double-bottom sand hopper for soft soil layer and rock-socketed barrel drill for hard rock formation. The drill bit can also be improved to improve drilling efficiency.

3. Mud preparation and management: Allocate mud according to the formation conditions, such as loose porous strata, to improve the viscosity and specific gravity of mud. Real-time monitoring of mud performance during construction, timely adjustment to ensure the stability of the hole wall.

4. Optimization of drilling parameters: During drilling, drilling speed, pressure and rotational speed are dynamically adjusted according to formation changes. The soft formation increases the speed appropriately, while the hard formation decreases the speed and increases the pressure.

5. Hole collapse and diameter reduction prevention: hole collapse, immediately stop drilling, analyze the reasons and take corresponding measures, such as increasing the proportion of mud. In order to reduce the diameter, the method of repeatedly sweeping the hole is used to enlarge the aperture.

6. Determination of pile end bearing layer: When approaching the design elevation of pile end, determine whether the bearing layer is reached through cuttings analysis and drilling parameter changes. If necessary, advance drilling and other means are used to ensure the quality of pile end.

In the complex formation construction of rotary drilling rig, the key technologies mentioned above are interlinked from pre-construction preparation to process control and then to quality control. Only by comprehensive application of these technologies can we effectively deal with the challenges of complex strata, ensure the quality and safety of pile foundation construction, and promote the construction of infrastructure to a new height.