| 2TD                                                             |    | UK                 |
|-----------------------------------------------------------------|--------------|--------------------|
| Altesco Drilling Technology EURL                                |    | Algeria            |
| Casing Drilling Holdings Ltd.                                   |    | Barbados           |
| Casing Drilling International Ltd.                              |    | Barbados           |
| Drilling Innovation de Mexico, SA de CV                         |    | Mexico             |
| Drilling Innovation M.E. Ltd.                                   |    | Cyprus             |
| OCSET (Beijing) Trading Co. Ltd.                                |         | PRC (China)        |
| OCSET, LLC                                                      |    | Russian Federation |
| Personal Tecnico Para Servicios Petroleros SA de CV             |    | Mexico             |
| PT. Tesco Indonesia                                             |    | Indonesia          |
| TDT (Beijing) Commerce Co. Ltd.                                 |         | PRC (China)        |
| Tesco Argentina S.A.                                            |    | Argentina          |
| Tesco Canada International (Middle East) FZE                    |    | UAE                |
| Tesco Canada International (Middle East) FZE—Qatar Branch |    | Qatar              |
| Tesco Canada International Inc.                                 |    | CAN - Alberta      |
| Tesco Colombia S.A.                                             |         | Panama             |
| Tesco Colombia S.A. – Sucursal Colombia                   |         | Colombia           |
| Tesco Corporation—US Branch                               |    | US - Texas         |
| Tesco Corporation (Norway) AS                                   |    | Norway             |
| Tesco Corporation (UK) Limited                                  |    | UK                 |
| Tesco Corporation (US)                                          |    | US - Delaware      |
| Tesco Corporation Sucursal Argentina                            |    | Argentina          |
| Tesco Corporation Sucursal Ecuador                              |    | Ecuador            |
| Tesco Corporation Sucursal Mexico                               |    | Mexico             |
| Tesco Corporation Sucursal Peru                                 |    | Peru               |
| Tesco Corporation Sucursal Venezuela                            |    | Venezuela          |
| Tesco de Bolivia S.R.L.                                         |    | Bolivia            |
| Tesco do Brasil Servicios Petroleo                              |    | Brazil             |
| TESCODRILLING Ecuador S.A.                                      |         | Ecuador            |
| Tesco Drilling Australia Pty Limited                            |    | Australia          |
| Tesco Drilling LLC                                              |         | Oman               |
| Tesco Drilling Technology Inc.                                  |    | CAN - Alberta      |
| Tesco Drilling Technology Limited                               |    | CAN - Alberta      |
| Tesco Drilling Venezuela, CA                                    |    | Venezuela          |
| Tesco Latin America Limited                                     |    | Barbados           |
| Tesco Offshore Services Inc.                                    |         | US - Nevada        |
| Tesco Peru S.A.                                                 |         | Peru               |
| Tesco Products Ltd.                                             |    | CAN - Alberta      |
| Tesco R.F. Company Limited                                      |    | Cyprus             |
| Tesco R.F. Company Limited—Russia Branch                  |    | Russian Federation |
| Tesco Saudi Arabia Ltd. (LLC)                                   |    | Saudi Arabia       |
| Tesco Saudi Holding Limited                                     |    | Cyprus             |
| Tesco Services International Inc.                               |    | CAN - Alberta      |
| Tesco Singapore PTE. Ltd.                                       |    | Singapore          |
| Tesco Singapore PTE Ltd – Brunei Branch                   |         | Brunei             |
| Tesco Singapore PTE Ltd – India Project Office            |         | India              |
| Tesco Singapore PTE Ltd – NZ Branch                       |    | New Zealand        |
| Tesco Singapore PTE Ltd. – PNG Branch                     |         | Papua New Guinea   |
| Tesco US Holding LP                                             |    | US - Nevada        |

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