The difference between water circulation pile driver (forward circulation rig and reverse circulation rig)

Difference between positive circulation rig and reverse circulation rig

The process of drilling into holes is the same. The difference is the circulation method of drilling fluid (mud). The drilling fluid (mud) is circulated to protect the well wall and slag, that is, the drilling fluid (mud) ) Cycle to bring out the slag in the borehole ...

The drilling fluid (mud) of the positive circulation drilling rig is pumped from the mud pool to the drill pipe by a mud pump, and is continuously transported to the well through the drill pipe, and then naturally discharged from the wellhead while taking the slag out.

It comes to the ground. Because it slags out by natural circulation of drilling fluid (mud), the circulation capacity and slag removal capacity are relatively weak. Positive circulation is suitable for silt, clay, gravel layer, weathered shale, sand layer.

The circulation method of the drilling fluid (mud) of the reverse circulation drilling rig is just the opposite.Its drilling fluid is transported from the wellhead (outside the drill pipe) to the drilling by a mud pump, and then compressed air or mud pump is used to remove the drilling fluid.

The middle of the stick is drawn out, so the circulation ability and slag discharge ability are relatively strong, not only the slag discharge is relatively clean, but the slag with relatively large particles can also be discharged, and the slag like large eggs can be discharged. So it is more suitable.

It is used to drill holes in relatively large-grained formations such as pebble layers. Reverse circulation is suitable for soil layers, gravel layers, rubber layers, and more suitable for gravel layers.

Comparison of the two, the slag discharge capacity of the positive circulation drilling rig is relatively weak, but the process is relatively simple and easy to operate, and the price of the positive circulation drilling rig is relatively cheap; the slag discharging ability of the reverse circulation drilling rig is relatively strong, but the process is more complicated.

Improper operation can easily lead to hole sinking and buried drilling. The positive circulation drilling rig only needs one mud pump, while the reverse circulation drilling rig needs two mud pumps, or one mud pump and one air compression.