WorldWide Drilling Resource

Understanding Tricone Rock Bit Codes Adapted from Information by Bit Brokers International and the International Association of Drilling Contractors Since 1940, the International Association of Drilling Contractors (IADC) has represented the worldwide gas and oil drilling industry with a goal of establishing high standards of safety, environmental stewardship, and operational efficiency. IADC Codes make it easier for drill operators to describe what kind of rock bit they are looking for. Bit Brokers International follows the IADC bit classification system in which the first three digits classify the bit according to the formation it is designed to drill and the bearing/seal design used. First Digit: 1, 2, 3 - Indicate steel-tooth bits with 1 for soft, 2 for medium, and 3 for hard formations. 4, 5, 6, 7, 8 - Are used for tungsten carbide insert bits for varying formation hardness with 4 being the softest and 8 the hardest. Second Digit: 1, 2, 3, 4 - Represent a further breakdown of formation with 1 being the softest and 4 the hardest. Third Digit: This classifies the bit according to bearing/seal type and special gauge wear protection as follows: 1 Standard open-bearing roller bit 2 Standard open-bearing roller bit, air-cooled 3 Standard open-bearing roller bit with gauge protection which is defined as carbide inserts in the heel of the cone 4 Sealed roller-bearing bit 5 Sealed roller-bearing bit with gauge protection 6 Journal sealed-bearing bit 7 Journal sealed-bearing bit with gauge protection Bearing Types: There are primarily four types of bearing designs used in tricone drilling bits: - Standard open-bearing roller bit - With these bits, the cones will spin freely since this bit has a front row of ball bearings and a back row of roller bearings. - Standard open-bearing roller bit for air drilling - Although similar to standard open- bearing roller bits, they have air flows di- rectly into the cone through the passage- ways inside the pin to cool the bearings. These bits are not used for mud drilling. - Sealed-bearing roller bits - These bits contain an O-Ring seal with a grease reser- voir for bearing cooling. The seal 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. Fourth Digit: The following letter codes are used in the fourth digit posi- tion to indicate additional features: A - Air Application R - Reinforced Welds C - Center Jet S - Standard Steel Tooth D - Deviation Control X - Chisel Insert E - Extended Jet Y - Conical Insert G - Extra Gauge Protection Z - Other Insert Shape J - Jet Deflection Unde r s t and i ng t he I ADC B i t Classification System can help you make more informed choices in bit selection. 19 WorldWide Drilling Resource ® NOVEMBER 2018 Standard open-bearing roller bit. Journal-bearing roller bit. G&O