Down-The-Hole Hammer And Pipe Drilling Technology

Technical Principle

DTH hammer and tube drilling technology is a drilling method that combines the speed advantage of air DTH hammer drilling and the advantage of casing wall protection that is conducive to the stability of the borehole wall. When drilling, the eccentric drill is thrown out when the eccentric block is rotated forward. The diameter of the thrown eccentric drill is larger than the diameter of the center drill. While drilling, the casing is driven by the pipe shoe to follow up synchronously, and the seamless steel pipe protects It is very important to stabilize the hole wall of the combined exploration and production well to prevent the hole wall from falling off and collapse. When the eccentric drill bit is drilled to the complete formation, after drilling 0.5~1 m, the eccentric block is retracted by reversing, and then the eccentric drill is retrieved from the protective wall casing, so that the quaternary system can be traversed more smoothly. Overburden and broken complex stratum.

Technical characteristics

1. The down-the-hole hammer and tube drilling technology makes full use of the advantages of the pneumatic down-the-hole hammer to quickly break the rock, which is conducive to the development and implementation of combined exploration and production wells in hydrogeological surveys.

2. Follow-up drilling technology can follow up the casing while drilling. It does not require water and drilling mud, especially in arid and water-deficient areas. It can double the effort with half the effort, avoid the difficulty of buying water to drill, and improve work efficiency. The improvement is very beneficial.

3. This type of drilling technology uses synchronous follow-up casing to protect the wall when drilling, making full use of the advantages of the air DTH hammer to quickly break the rock, while maintaining the hole wall of the fourth series of weak overburden on the upper part of the borehole stable. The broken cuttings are carried out of the hole by the high-speed air flow, and the suction effect is beneficial to the opening of the water outlet channel. The continuous washing of the hole wall by the high-speed air will also shorten the well washing time, which is beneficial to the improvement of hydrogeological drilling and well completion efficiency.

4. The down-the-hole hammer and pipe drilling technology is suitable for hard rock drilling. For clay formations or similar soft formations, it is easy to block the air passage and the discharged drill cuttings are easy to hang on the hole wall to form a mud plug, which is difficult to achieve the ideal drilling efficiency .

5. The casing drilled by the down-the-hole hammer with the pipe is pulled out by special equipment after completing the task of wall protection, which can be recycled within a certain period of time, reducing construction costs.