Ring Out PDC Drilling bit...

[dejavuoil]

Hello,

I would like the main reasons that cause a PDC Drilling bit get Ring Out?

Thanks in advance

DEJAVUOIL

[willbe]

Dejavuoil,

Could be many reasons... but mainly when cutters wear down and worn full, you get a ring out (were matrix body starts to drill). Teeth in that row could have been damaged while drilling shoe, bad practice of bedding the bit in hard formation, stringer drilling or chert or whatever. If in this section it happens often, go for other type of bit (more blades, smaller cutters) or a more rugged but with special abrasive / impact resistant cutters (generally I would much prefer Smith or Hughes bit over any of the others, but I guess other people like different flavours). If it really get's tough these are the bits I would rely on. Simple clays / shales all of them can drill at reasonable ROP.