The field-proven OneSubsea subsea modular injection system (SMIS) was the first of its kind to complete riserless hydraulic access intervention in Malaysia.

SMIS is a hydraulic intervention package that combines an injection conduit of openwater coiled tubing with a subsea injection skid or barrier package, complete with dual-barrier valves, integral fail-safe control system, and weak-link connector.

The subsea injection skid can interface with any subsea interface via the MARS multiple application reinjection system or a dedicated interface. A flexible jumper between the subsea injection skid and the subsea interface minimizes risk to the host structure.

The single, large-diameter coiled tubing conduit design is simple to manage and enables an increased flow rate. The use of larger-diameter coiled tubing in this application is made possible by the addition of several proprietary technologies that facilitate safe fatigue management while in service. A secondary circulation line is used in applications where required.

Broad range of applications

The system can be used for a variety of chemical injections, such as scale squeezes, acid stimulation, flushing applications, hydrate remediation, and well kill. It can be deployed on short notice as a rental service from a vessel of opportunity, delivering solutions efficiently and with lower intervention costs.

Efficiency-optimizing features

  • Rigless fluid injection
  • Modular system architecture
  • Highly flexible conduit design to suit a broad range of operating depths and dynamic conditions
  • Various available subsea interfaces, including MARS system choke access technology, which can be installed using standard running tools and procedures
  • Mudmat-landable subsea barrier package to reduce risk to the subsea architecture


Working pressure

10,000 psi [68.9 MPa]

Water depth

<6,560 ft [2,000 m]

Injection flow rate

16 bbl/min [2,900 L/min] at 10,000 psi

Technical features

  • 2-in through-flow diameter
  • Passive pressure-balanced weak link
  • Active disconnection and barrier control function
  • Fail-safe control system
  • Riser circulation line, where required
  • Proprietary fatigue management technology
  • Proprietary MARS system interface technology
  • ROV operation

Interface architecture

  • MARS system choke technology
  • Dedicated intervention connector
  • Tree cap

Installation and deployment

  • Monohull vessel (moonpool or overboard)
  • Rig