Rotary Drilling Rig Clear Water Construction Process

The clear water construction process is a widely used method in specific geological conditions for rotary drilling rigs. By using clear water as the circulating medium, this method ensures borehole cleanliness and stability while maintaining high construction quality. It is commonly employed in soft soil, silt, and gravel layers. This article provides a detailed overview of the clear water construction process, focusing on its principles, operation steps, advantages, and precautions.

1. Principles of Clear Water Construction

The core of the clear water construction process is to pump clear water into the borehole, utilizing its circulation to remove slurry and rock debris generated during drilling. This keeps the borehole clean and contributes to maintaining wall stability. During this process, clear water serves as the drilling medium, reducing friction between the drilling tool and the ground layers and minimizing efficiency loss caused by sediment clogging at the bottom of the hole.

2. Operation Steps for Clear Water Construction

1. Preparation

• Level the construction site, remove surface obstacles, and set up water and slurry tanks.

• Check the rotary drilling rig equipment, including the rotary head, slurry pump system, and drill rods, ensuring all are in working condition.

• Select appropriate drill bits and rods based on geological reports and ensure a sufficient supply of clear water.

2. Drilling Operations

• Use the rotary drilling rig to advance drilling while pumping clear water into the borehole through the slurry pump.

• The clear water circulates to the borehole bottom, carrying slurry and rock debris back to the surface and into the slurry tank for sedimentation.

• Adjust the clear water flow rate based on borehole depth to maintain cleanliness and stability during the drilling process.

3. Maintaining Borehole Stability

• In easily collapsible formations, supplement clear water with slurry or stabilizers to enhance borehole wall stability.

• Monitor borehole conditions during drilling, stopping immediately to address any signs of wall seepage or collapse.

4. Borehole Cleaning

• After drilling, continue using the clear water circulation system to clean sediment at the bottom of the hole until it is free of debris.

• Use depth-measuring equipment to check sediment thickness and ensure it meets design requirements.

3. Advantages of Clear Water Construction

1. Environmental Friendliness
   Compared to slurry construction, clear water construction requires fewer chemical additives, generating less waste and aligning with environmental standards.

2. Simplicity
   The equipment requirements for clear water construction are relatively simple, as it does not require a complex slurry preparation system, making the process easy to operate.

3. Cost-Effective
   Clear water as a circulating medium reduces the need for large quantities of slurry materials, lowering construction costs.

4. Versatility
   Particularly effective in soft soil and silt formations, clear water construction enables quick and efficient drilling operations.

4. Precautions for Clear Water Construction

1. Geological Suitability
   In hard rock or complex formations, clear water construction may not provide sufficient wall stability. The choice of construction method should align with geological conditions.

2. Water Resource Management
   Clear water construction consumes significant amounts of water. Evaluate site water availability beforehand to avoid project delays due to insufficient supply.

3. Slurry Handling
   The debris and sediment carried by clear water must be properly treated to prevent site pollution or drainage system blockages.

4. Equipment Maintenance
   Slurry pumps and drainage equipment are frequently used during clear water construction. Clean and maintain the equipment after operations to ensure proper functionality.

5. Conclusion

The clear water construction process is an efficient, safe, and environmentally friendly method for rotary drilling rigs in specific formations. By carefully planning the construction process, managing water resources, and maintaining equipment, the method’s advantages can be fully realized. As technology advances, the clear water construction process will continue to evolve, offering even more efficient solutions for foundation engineering projects.