EU Trademark Classification EU01 Chemicals 油井钻井中用于稳定井壁的化学添加剂（1671） Class 01 油井钻井中用于稳定井壁的化学添加剂 1671 Chinese 油井钻井中用于稳定井壁的化学添加剂 English Chemical additives for borehole stabilisation in oil well drilling Site ref. 1671 Class 01 Included in Harmonised Database (HDB)