... coal, oil shale, tarsands, and shallow oil and gas.PDC bit : 56, 60, 76, 96, 113, 123, 133 and 153mm outer diameters. PDC core ... , NQ3, HQ, HQ3, PQ, PQ3, T2 76, T2 86, T6 101, T6 116, T2 131 and so on.China Drilling Geological Equipment ltd., is ... the main manufacturer of drilling tool in china, and specializing in the design and manufacture ...