Until recently it was not possible to detect hydrocarbons directly in a subsea environment, however, new technology has advanced and now a Hydrocarbon Detector is now available. The Hydrocarbon Detector can detect oil and gas in water and display data in real time. It is primarily a Methane detector but will detect all gaseous hydrocarbons. A new version of the Hydrocarbon Detector has recently been developed that will detect mono ethylene glycol (MEG).
"If it leaks... SNIFFIT "
The system uses two types of sensor depending on requirement. For methane and similar an underwater gas sensor is used. A prime application for the technology is detecting leaks from subsea gas pipelines and installations.
For crude oil pipeline leaks, lubricating oils, hydrocarbon based control fluids etc. a Long Range fluorometer is used (see PLD Fluorescent Leak Detection (FPLD)
SNIFFIT is a unique, real-time system for the detection of gaseous and liquid hydrocarbons. In the offshore oil & gas environment, SNIFFIT is an essential tool for detection of leaks from pipelines and other sub-sea installations. The simple to operate system is designed for easy fitting aboard ROVs, AUVs and other underwater vehicles. Measurements are made directly by the SNIFFIT system and results are displayed in real-time via the user friendly software package.
Features and Benefits of SNIFFIT Real-time data presentation:
- Simple integration to host ROV etc
- High sensitivity
- Compact and robust
- Proven track record
- Rapid availability
- Direct sensing of fluid - no tracer additives
- Rated to 2000m for gas 3000m for oil (deeper versions available as a special)
- Non invasive
- Immediate reaction to events
- No consumables
- No specialist training
- Offshore pipeline and sub-sea installation monitoring
- Environmental monitoring of outfalls and waste
- Seabed dredging safety monitoring
- Methane hydrate exploration
- Additional data for route surveys - gas vents etc.
- Marine accident searches and forensics
For the offshore oil and gas industry, hydrocarbons fall loosely into three areas: oil, gas and mixtures of both (multi-phase) and therefore the method used for Hydrocarbon Detection will depend on which of the three is prevalent.
Methods of Hydrocarbon Detection also fall into three modes: for oil we use long range fluorescence, for gas we use the Methane sensor and for multiphase we can use both sensors together where data are displayed for both sensors simultaneously.
Leak detection is an integral part of subsea Pipeline Repair and is used during commissioning of new pipeline installations and for existing operational pipelines. Leak detection methods are used to locate leakage points so that Pipeline Repair work can be carried out efficiently.
I've just looked through the 'Close Out Report' for the BP job in which we made use of the Sniffit. Unfortunately there are few comments, probably due to the tool's success, but in the 'De-brief Report' and as part of the ROV's performance assessment, the tool was marked 9/10 ('Excellent performance and meeting all contractual requirements').
Kevin Samphier", Technip