The Significance and Development of Toothed Rock Reamer Hole Opener

The significance of developing a toothed rock reamer hole opener:

• The workload of horizontally crossing rock layers is increasing.

• Having a high-quality rock reamer hole opener can improve the capabilities of horizontal rock drilling and secure a place in the competitive market.
  

The development of toothed under reamers hole openers:

1. Select the teeth of a tricone roller bit used for oil drilling as the cutting edge for cutting rocks, and use a single tooth + tooth holder as a cutting edge assembly.

The teeth roll and impact to break rocks. Tungsten carbide inlaid teeth are chosen, which have high hardness, good wear resistance, and long service life. The disadvantage is that inlaid teeth are brittle and easy to break or fall off due to poor adhesion.

For strata with a hardness between 8000 psi and 12000 psi, such as soft rocks to hard rocks, tungsten carbide alloy teeth with chisel shapes should be selected, and the tooth height and tooth spacing can be appropriately enlarged to improve drilling efficiency. For strata with a hardness above 12000 psi, conical tungsten carbide alloy teeth should be chosen, and the tooth height and tooth spacing should be reduced accordingly. Of course, the selected tooth shape of the hole opener drill bit should also be determined based on the length to be drilled.

2. Determine the size of the under reamers hole openers according to the hardness of the rock and the type of drilling rig. For small rigs drilling soft rocks, each level can extend by 100mm, and for large rigs drilling soft rocks, each level can extend by 100mm-200mm. For large rigs drilling hard rocks, each level can extend by 100mm-150mm.

3. Toothed reamers usually have toothed holder models of 8.5 inches, 9.5 inches, and 12.5 inches. A drill pipe used for oil drilling is selected as the core shaft of the rock reamer. The diameter of the core shaft is determined according to the size of the reamer and the connecting type. The main reinforcement plate welded to the core shaft is 30-32mm thick and made of 45 steel or 16Mn. The mud hole on the core shaft has 4 holes per mud chamber, with hole diameters of 16-20mm. The teeth are evenly distributed and welded on a circular base to ensure that all teeth are on a concentric circle.

The difficulties encountered during construction are:

• The core shaft of the rock reamer hole opener is prone to cracks or even breakages at the joint with the cylinder head.

• Easy to get stuck.
  

• The teeth of the rock reamer hole opener are prone to breakage.
  

• The back of the tooth holder of the rock reamer hole opener is prone to wear.
  

Our brand, GREAT, specializes in the processing and research of steel and diamond materials, and is involved in research and development, design, production, and sales of No-Dig petroleum equipment. So far, we aim to become the top material supplier for CNPC, Sinopec, and CNOOC. Please feel free to contact us for any inquiries.