DTH Drilling Of 8.5inch TCI Tricone Bit With IADC Code 645

1 . Descriptions:

Tungsten Carbide Insert (TCI) bits are are used middle to hard rock formation which offers a variety of carbide inserts such as spherically shaped inserts for very hard rock or conically shaped inserts for softer rock. The number of rows of inserts is directly related to the type of application and the size of hole to be drilled. here are also open and sealed bearings available as well as three types of shirttail protection to choose from. TCI stands for Tungsten Carbide Insert.

2. Specification:

3 . Bit profile

4 . Bearing Types

There are primarily three types of bearing designs used in tricone drilling bits:

• STANDARD OPEN BEARING ROLLER BIT:

On these bits the cones will spin freely. This type of bit has a front row of ball bearings and a back row of roller bearings.

• SEALED BEARING ROLLERS BITS

These bits have an O-Ring seal with a grease reservoir for bearing cooling. The seals acts as a barrier against mud and cuttings to protect the bearings

• JOURNAL BEARING ROLLER BITS

These bits are strictly oil/grease cooled with nose bearings, O-Ring seal and a race for maximum performance.

5. Question :

What we should be pay attention on choosing the tricone drill bit ?

• IADC code passport
• TCI & Steel tooth options
• Additional tungsten carbide inserts on heel rows
• Tungsten carbide coating on cone bodies
• Diamond coated tungsten carbide inserts on the gauge of the cones
• Tungsten carbide inserts on the shirttail of the legs
• Additional central nozzle for cleaning cones

The tricone feature is that they come with their own passport as below :

• The specification of the cones
• The quality stamp signed by the person who made and checked the bit
• The recommended drilling parameters to get the best performance out of the bit:
• Bit weight
• Rotation speed
• Flushing volume

Which type of tricone you should choose ?

It depends on the geology you are drilling in and the diameters of the borehole you are drilling. The International Association of Drilling Contractors (IADC) have developed an easy use step system to choose the right tricone for your geology with additional features such as bit protection for longer production life.