[1]Well Tech China Oilfield Services Ltd. COSL Sanhe Hebei;
[2]Tanggu Operating Company of Well Tech China Oilfield Services Ltd. COSL Tianjin;
[1]Well Tech China Oilfield Services Ltd. COSL Sanhe Hebei;
[2]Tanggu Operating Company of Well Tech China Oilfield Services Ltd. COSL Tianjin;
[2]Tanggu Operating Company of Well Tech China Oilfield Services Ltd. COSL Tianjin;