| OILTECH USA LIMITED | Private company limited by shares | Live |
| DALLAS OIL-TEX COMPANY LIMITED | Private company limited by shares | Dissolved |
| Oiltique International Limited | Private company limited by shares | Live |
| OILTON LIMITED | Private company limited by shares | Dissolved |
| OILTON INDUSTRIAL LIMITED | Private company limited by shares | Dissolved |
| DRAGON OILTOOLS LIMITED | Private company limited by shares | Live |
| OILTOWN INVESTMENTS LIMITED | Private company limited by shares | Live |
| OilTrans Limited | Private company limited by shares | Live |
| OILTREK LIMITED | Private company limited by shares | Live |