SOS (Special Oilfield Services) is a company that provides oil and gas services. It offers completion equipment and liner hangers, machine protection systems, vibration monitors, wireless triaxial sensors, electrical heaters, pressure relief valves, orifice plates, and other products. The company also provides reliability engineering and asset management, tubular maintenance, pipeline integrity services, and more. SOS is a joint venture of Mohsin Haider Darwish.