| Subsidiary                                  |   | Jurisdiction of Incorporation |   | Principal Activities                       |   | % Owned |
|---------------------------------------------|--------|-------------------------------|--------|--------------------------------------------|--------|---------|
| Allis-Chalmers Energy Inc.                  |   | United States                 |   | Holding company                            |   | 100     |
| Archer Management (US) LLC                  |   | United States                 |   | Management company                         |   | 100     |
| Seawell Management AS                       |   | Norway                        |   | Management company                         |   | 100     |
| Seawell Management Ltd                      |   | United Kingdom                |   | Management company                         |   | 100     |
| Seawell Management (Bermuda) Ltd            |   | Bermuda                       |   | Management company                         |   | 100     |
| Seawell Management (Hong Kong) Limited      |   | Hong Kong                     |   | Management company                         |   | 100     |
| Seawell Norge AS                            |   | Norway                        |   | Onshore administration and holding company |   | 100     |
| Seawell AS                                  |   | Norway                        |   | Drilling, engineering and well services    |   | 100     |
| Seawell Offshore Denmark AS                 |   | Denmark                       |   | Well services                              |   | 100     |
| Seawell Services Ltd.                       |   | Hong Kong                     |   | Drilling services                          |   | 100     |
| Seawell Overseas Contracting Ltd.           |   | Hong Kong                     |   | Drilling services                          |   | 100     |
| Seawell Ltd. (UK)                           |   | United Kingdom                |   | Drilling, engineering and well services    |   | 100     |
| Seawell Consulting  Services Ltd. |   | United Kingdom                |   | Onshore administration and management      |   | 100     |
| Archer Assets UK Limited                    |   | United Kingdom                |   | Holding company                            |   | 100     |
| Seawell Drilling Ltd.                       |   | United Kingdom                |   | Drilling services                          |   | 100     |
| Archer Well Company Inc.                    |   | United States                 |   | Drilling, engineering and well services    |   | 100     |
| Seawell Emerald Ltd.                        |   | Bermuda                       |   | Owner of modular rig                       |   | 100     |
| Seawell Oil Tools Ltd.                      |   | Bermuda                       |   | Rental services                            |   | 100     |
| Seawell do Brasil Servicos de Petroleo Ltda |   | Brazil                        |   | Drilling and engineering services          |   | 100     |
| Seawell Oil Tools AS                        |   | Norway                        |   | Well services                              |   | 100     |
| Peak Well Solutions AS                      |   | Norway                        |   | Well services                              |   | 100     |
| TecWel AS                                   |   | Norway                        |   | Well services                              |   | 100     |
| TecWel Telemetri AS                         |   | Norway                        |   | Well services                              |   | 100     |
| TecWel Inc.                                 |   | United States                 |   | Well services                              |   | 100     |
| TecWel Ltd.                                 |   | United Kingdom                |   | Well services                              |   | 100     |
| C6 Technologies AS                          |   | Norway                        |   | Oilfield equipment                         |   | 50      |
| Viking Intervention Technology AS           |   | Norway                        |   | Oilfield equipment                         |   | 501     |
| Wellbore Solutions AS                       |   | Norway                        |   | Oilfield equipment                         |   | 42.6    |
| Rig Inspection Services Pte. Ltd            |   | Singapore                     |   | Inspection Services                        |   | 100     |
| Romeg Holdings Pty. Ltd.                    |   | Australia                     |   | Inspection Services                        |   | 100     |
| Gray Holdco, Inc.                           |   | United States                 |   | Holding company                            |   | 100     |
| Gray Parent Inc.                            |   | United States                 |   | Holding company                            |   | 100     |
| Gray Wireline Service Inc.                  |   | United States                 |   | Well services                              |   | 100     |
| Universal Wireline, Inc.                    |   | United States                 |   | Well services                              |   | 100     |