Enviromental Monitoring

 

AUTOMATIC EARLY WARNING AND ALARM SYSTEM FOR THE DETECTION OF HYDROCARBONS
 

(LIQUID AND VAPOURS) IN THE SUBSOIL AND GROUNDWATER

The system is based on the properties of a special plastic filament that can melt in a few seconds when in contact with hydrocarbons. The filament is inserted into the groundwater by a small diameter piezometer and is connected to a weight. The small weight is linked by a longer and thin steel cable to a micro switch. When the hydrocarbons reach the filament it melts releasing the weight, this will determine the tension of the steel cable and the further activation of the micro switch and the related alarm procedure.
This system is not affected by the groundwater fluctuation, turbidity, chemical or physical variations, it does not need calibrations or maintenance. To control the perimeter of a large refinery EUREKOS prepared a system formed by 16 monitoring point and after 8 years they are still working perfectly without special maintenance, there are in fact no electronic parts or electric contacts in the sensors with the consequence that the possibilities of faults are very very limited. The type of alarm can be tailored according to the Customer’s requirement: Radio alarm to different type of receptors or transmission to a remote location with the code of the sensor for immediate location, or visual alarm with a red sign inside the coupling head (one minute is needed for the opening and closing of the inspection head) or sound alarm or combination of the different type.

Examples of Applications:
MONITORING OF LEAKS FROM FUEL STATIONS, OIL DEPOSITS, PIPELINES, HYDROCARBON STORAGE TANKS

Installation of boreholes in the proximity (downstream) of buried tanks or pipes, installation near the basement of above ground large tanks, or installation through inclined boreholes BELOW the basement

Installation in water wells or monitoring wells
Installation inside industrial sewer system

 

HIGH RESOLUTION MONITORING OF LEAKS FROM PIPELINES

The system was developed to have a high precision determination of the point of leak, it is applied in the beam of pipelines linking refineries to a pier or inside industrial or urban areas where high precision is needed in the pinpointing of a leak.

A series of piezoelectric sensors are set in contact with the pipe by a magnetic support; the sensors detect the vibration pattern of the pipe and send the analogical signal to a A/D interface. The sensors are spaced at intervals of 200 metres.

A computer located in the Control Room sends a query to the sensors and receives back the data in digital format.
The signals receive a complex processing based on AGC to optimise the gain according to the different noise level caused by the variation of pressure, T°, density, direction of flow etc.

After this treatment the software analyses and compares the acoustic spectra sent by two adjacent sensors.

By the application of a special algorithm the software analyses the frequency content, the power spectrum and some other characteristic of the spectra searching similarities between the data of the two sensors in a selected frequency window. If a "peak" with frequency and amplitude that could be related to a leak is detected, a second routine is activated to determine the distance of the source of the “peak” from the sensors.

After that, if a “coherence” between the two sensor is found, a third step based on signal stacking to remove the random noise is applied and new routine is activated ( involving the two further sensors) to identify the “peak” as a leak , and in this case the ALARM signal is activated. The actual process can be run in a few seconds and the ALARM provides the positioning of the possible leak.
The System is integrated with the Automatic Early Warning system for the groundwater control.


SYNOPTIC TABLE OF THE LEAK DETECTION AND GROUNDWATER CONTROL SYSTEMS

 

 


Geophysical     investigations


Water and soil de-      pollution


Detection of water and gas leaks


Environmental monitoring


Products

 
European and International projects

  Italian Version