Reverse Circulation Drill Rig

Reverse circulation drilling is a geotechnical drilling technology where the flushing fluid flows down through the annulus between the drill pipe and the borehole wall to the bottom, then returns through the inner tube of the drill pipe to form a reverse circulation. The circulating medium can be water, mud, or air. Compared to traditional forward circulation drilling (where the flushing fluid is introduced into the drill pipe and returned through the annulus), reverse circulation drilling has a higher fluid (or air) flow velocity, a stronger ability to carry rock cuttings, and allows broken rock from the bottom of the borehole to be discharged promptly and quickly returned to the surface.

This ingenious "reverse circulation" design brings several significant advantages: First, the flushing medium rises at a high speed in the central hole of the drill pipe, resulting in a very strong ability to remove drill cuttings. The drill cuttings have a large particle size, less repeated breakage, and can significantly improve drilling efficiency, especially in large-diameter drilling. Second, sampling can be performed in real time without stopping drilling, and its advantages of high construction efficiency and low cost have been verified in exploration areas such as the Karatag region of Xinjiang. Third, when air is used as the circulating medium, water-saving drilling can be achieved, which is particularly advantageous in arid and water-scarce areas.

1. Extremely Fast Drilling Speed, 50%–300% Efficiency Improvement. The RC drilling rig utilises down-the-hole hammer impact crushing and continuous cuttings removal, achieving an average efficiency 2–5 times that of a full hydraulic core drilling rig. It can reach 8–15 m/hour in hard rock formations and 15–30 m/hour in loose formations, significantly shortening the construction period.
2. 100% Pure and Highly Representative Samples. Rock cuttings are directly returned through a sealed inner tube, preventing mixing with the wellbore soil, resulting in high sample purity and clear stratification. Compared to traditional coring, the sampling rate is consistently 95%–100%, providing accurate data for mineral grade assessment.
3. Adaptable to Complex Formations, No Borehole Collapse or Drill Bit Jam. Double-walled drill pipe + reverse airflow circulation ensures uninterrupted circulation even when encountering caves, fissures, and quicksand layers. No mud slurry is needed for borehole wall protection, reducing the risk of borehole collapse and stuck drill bits, offering significant advantages in sand and gravel layers, fractured zones, and water-scarce areas.
4. Lower overall cost, far exceeding the cost-effectiveness of traditional drilling rigs.

• Lower fuel consumption: 30%+ more fuel-efficient than comparable full hydraulic core drilling rigs.
• Less manpower required: 1-2 operators, high degree of automation.
• Even more consumables: Longer down-the-hole hammer life, less drill pipe wear, and simpler maintenance.

1. More drilling footage: Significantly increased drilling depth and coverage within the same budget.

 5. Multifunctional and Versatile. Quickly switches between air reverse circulation, mud reverse circulation, and air lift reverse circulation. Suitable for various scenarios, including mineral exploration, water wells, geothermal wells, engineering pile foundations, and blasting holes.