Exhibit 21
SUBSIDIARIES OF THE REGISTRANT Percentage of Voting Securities Owned By Immediate Parent as of December 31, 1999 -------------------- Consolidated subsidiaries of the Registrant (Jurisdiction of incorporation): Parker Drilling Company of South America, Inc. (Oklahoma) 100% Parker Drilling Company of Oklahoma, Inc. (Oklahoma) 100% Parker Technology, Inc. (Oklahoma) (1) 100% Parker-VSE, Inc. (formerly Vance Systems Engineering, Inc.) (Texas) (2) 100% Parker Drilling Company International Limited (Nevada) (3) 100% Parker Drilling Company of New Guinea, Inc. (Oklahoma) 100% Parker Drilling Company Limited (Nevada) 100% Parker North America Operations, Inc. (Nevada) (4) 100% Parker Drilling Offshore Corportion (formerly Hercules Offshore Corporation) (Texas) 100% Parker Drilling Company (Bolivia) S.A. (Bolivia) 100%
Certain subsidiaries have been omitted from the list since they would not, even if considered in the aggregate, constitute a significant subsidiary. All subsidiaries are included in the consolidated financial statements. - --------------------------------------------------------------------------- (1) Parker Technology, Inc. owns 100% of two subsidiary corporations, namely: Parco Masts and Substructures, Inc. (Oklahoma) Parker Valve Company (Texas) (2) Parker-VSE, Inc. (formerly Vance Systems Engineering, Inc.) owns 100% of Parker Drilling Company Limited (Bahamas) and 93% of Parker Drilling Company Eastern Hemisphere, Ltd. (Oklahoma). Parker Drilling Company Limited owns 7% of Parker Drilling Company Eastern Hemisphere, Ltd. (Oklahoma). (3) Parker Drilling Company International Limited owns 100% of four subsidiary corporations, namely: Parker Drilling International of New Zealand Limited (New Zealand) Choctaw International Rig Corp. (Nevada) (which owns 100% of the common stock of Parker Drilling Company of Indonesia, Inc. (Oklahoma)) Creek International Rig Corp. (Nevada) (which owns 100% of Perforadora Ecuatoriana (Ecuador)) Parker Drilling Company of Argentina, Inc., (Nevada). (4) Parker North America Operations, Inc. owns 100% of: Parker Drilling Company North America, Inc. (Nevada). Parker Drilling U.S.A. Ltd. (Nevada) which owns: Parker Drilling Offshore International, Inc. (Cayman Islands)-100% Mallard Bay Drilling Nigeria Limited (Nigeria) - 100% Mallard Drilling of South America, Inc. (Cayman Islands) - 100% Parker Drilling Offshore U.S.A., L.L.C. (formerly Mallard Bay Drilling L.L.C) (Oklahoma) - 99% Quail Tools, L.L.P. (Oklahoma) - 99% Parker Drilling Company Limited (Oklahoma) which owns 1% of: Parker Drilling Offshore U.S.A., L.L.C. (formerly Mallard Bay Drilling L.L.C.) (Oklahoma) Quail Tools, L.L.P. (Oklahoma) Parker Technology, L.L.C. (Louisiana)