6 Advantages of Reverse Circulation Vs Direct Circulation On ...

In last article 8 Points on How to Select Water Well Drilling Rig, the Drilling method are mentioned, here we will give some further introduction on reverse circulation drilling system. The RC is widely used in borehole drilling area especially in water well drilling and foundation drilling for big diameter hole.

With competitive price and timely delivery, JK Drilling sincerely hope to be your supplier and partner.

Reverse Circulation(RC) Working Principle

• The drilling theory of air reverse circulation is similar with the theory of drawing water with air compressor.
• The air flows down the annulus between inner tube and outer tube and go inside single wall pipe right at air water mixer, where produces countless tiny bubbles. These bubbles going up along the pipe and expanding simultaneously. Due to the air continuing going inside the fluid, it formed lower density mixture of air and water upper the mixer. It leads the higher density fluid in the well go up with cuttings because of the pressure difference. In this way the cuttings are brought out of the well hole very fast.

Configuration of Reverse Circulation Borehole Drilling System

Want more information on Crawler Mounted Drilling Rigs? Feel free to contact us.

Here are the main advantages of RC(reverse circulation) drilling compared to DC(direct circulation) drilling:

1. High Drilling Efficiency

• The Velocity of cuttings flowing up is 10 &#; 50 times faster than

  direct circulation drilling

• According to the historical data, for clay layer the drilling speed achieves 12 m/h maximum
• For sand it is 20 m/h
• For gravel cobble it is 1 &#; 1.5 m/h.
• For f 4 &#; f 6 level rock condition it is 1 &#; 3 m/h.
• In general, drilling speed is 1.2 &#; 3 times faster than direct circulation drilling.

2. Giving sampling faster and more accurate

• The direction of flushing air flowing is same with direction of core going inside tube, which cuttings are not contaminated by sloughing formation off the hole walls.
• It helps to get integrated core and giving an accurate formation log

3. High ratio of actual drilling time/ preparing time

• For rock formation, when drilling with tricone bit, the actual drilling time/whole rig working time is around 80 &#; 90%

4. High quality well hole achieved

• Less deviation on hole diameter from top to bottom.
• Clean on well bottom and less slope of well. All of these can lead to higher water yield.
• In average, it is 2 times less than direct circulation for time spent for washing well, meanwhile one third higher water yield compared to direct circulation

5. Lower drilling cost

• The reverse circulation drilling has higher drilling efficiency, and can get better quality well hole and longer life time for drill bit.
• The total cost is lower &#;  compared to direct circulation drilling

6. Larger diameter hole can be drilled

• Drillers usually use it to drill large diameter hole due to it is easier and faster to clean the hole, especially for softer formation.

Above is all about the comparison or difference between Reverse circulation and Direct circulation regarding bore hole drilling . For most of our water well drilling rig, it can work with both reverse circulation and direct circulation drilling tools, such as our  DTH crawler mounted drilling rig, trailer mounted as well as truck mounted drilling rig etc.

In next blog we will give introduction on how to select or design the high level reverse circulation drilling system.

More Articles:

Excavator can be divided into many types, such as crawler excavator, wheeled excavator and towed and rail excavator, etc. But they all consist of a boom, dipper, bucket and cab. The crawler excavator is a tracked vehicle that moves upon crawler tracks. On contrast, wheeled excavator is moved upon wheels. They both can be used in many working conditions, such as digging of the trenches, holes; material handling, forestry work, demolition.

The advantage of a crawler excavator is that it can dig or excavate without much set-up. It can realize 360°free rotation. The crawler crane&#;s dynamic property and trafficability is better than wheeled crane. It is capable of working in mining project or muddy area with stronger gradeability. Wheeled excavator features high flexibility, which can travel rapidly among different jobsites with the speed up to 40-50KM/H. It is suitable for firm ground operation without harm to the road surface. On the other hand, the tyre&#;s low heat resistance and high flexibility undercut its stability and safety.

Therefore, nowadays more and more people prefer crawler excavator. Even though crawler excavator is not good at mobility, the specific transport cart will provide the transport service. Besides, the crawler excavator&#;s comprehensive performance is better than the wheeled crane, which can be used in various jobsites. 

The company is the world’s best Crawler Mounted Pneumatic Tophammer Drill Rig supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.