... case, stop ring, stabilizer, landing ring, landing shoulder, locking couplng,adaptor coupling China Drilling Geological Equipment ltd., is the main professional ... wide range of drilling tool including drill rod, wireline core barrel (AQ-PQ) and assemblies, synthetic diamond core bits, natural ... casing tube: BW, NW, HW, HWT2.Core barrel: BQ,NQ,HQ,PQ , head assembly and assembly 3.AQ,BQ,NQ,HQ,PQ, T2 ...