00000nz a2200000n 4500 001 KSH2004029072 005 20040726164313 008 040726 n azknn|abn |a a|a | 150 ▼a유정 경량 시멘트[油井輕量--]▲ 450 ▼wr▼i영어▼aoil well lightweight cement▲ 550 ▼wg▼a유정 시멘트[油井--]▲