Product Details

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API specification 8 1/2in tricone drill bit

Product Description

Cutting Structure

In response to the characteristics that inserts in different areas on the cone have different cutting actions,conical inserts are placed in permanent contact area and wedge inserts are placed in alternative contact area so that the drilling efficiency is greatly improved.Wear resistance of cutting structure is enhanced by setting diamond inserts in the permanent contact area of the cone where inserts are severely worn.Tungsten carbide inserts are placed on cone top face to protect cone body from abrasive erosion.

Gauge Structure

With active cutting gauge protection inserts on bit body,the bit has good gauge protection and updrill capability.

Bearing Structure

High precision journal bearing.Balls lock the cone.Hardfaced head bearing surface.Cone bearing inlaid with friction-reducing alloy.Abrasion resistance and seizure resistance of the bearing are improved .Compared with three cone bit,the leg bearing is bigger,so it can receive higher WOB and high reliability.

Hydraulic Design

Small angled watercourse design increased the shirttail thickness and can effectively prevent the watercourse erosion.Opitmized hydraulics structure improves the cleaning capability and increase ROP.

IADC	WOB(KN/mm)	RPM(r/min)	Applicable Formations
417/427	0.3-0.9	150-70	very Soft formation with low compressive strength and high drillability,such as clay,soft mudstone,shale,salt,loose sands,etc.
437/447	0.35-0.9	150-70	very Soft formation with low compressive strength and high drillability,such as clay,soft mudstone,shale,salt,loose sands,etc.
515/525	0.35-0.9	180-60	very Soft formation with low compressive strength and high drillability,such as mudstone,salt,soft limestone, sands,etc.
517/527	0.35-1.0	140-50	Soft formation with low compressive strength and high drillability,such as mudstone,salt,soft limestone,sands,etc
535/545	0.35-1.0	150-60	medium soft with harder formation, more abrasive streaks,such as hard shale,mudstone,soft limestone,etc.
537/547	0.4-1.0	120-40	medium soft with harder formation, more abrasive streaks,such as hard shale,mudstone,soft limestone,etc.
617/627	0.45-1.1	90-50	medium hard with higher compressive strength as well as thick and hard streaks,such as hard shale,sands,limestone,dolomite,etc.
637	0.5-1.2	80-40	hard with higher compressive strength as well as thick and hard streaks,such as hard shale,sands,limestone,dolomite,etc.
737	0.7-1.2	70-40	Hard with high abrasiveness such as hard limestone,dolomite,firm sands,etc
827/837	0.7-1.2	70-40	very hard with high abrasiveness,such as quartzite,quaruzite sand,chert,basalt,granite,etc.