DIAGRAMM OF THE ENTIRE EXTRACTION PLANT.

The technological choice selected is that of off-shore extraction with transportation of the methane to the shore by gas pipeline from the barge.

This installation has a number of advantages over the on-shore solution currently used at Cape Rubona :

• The vertical position of the column will favour a homogenous flow of diphasic liquid by avoiding systematic blockages. In addition, in a vertical position the total length of the column will be reduced from the present 850 m to 330-340 m, which will reduce charge loss and the cost of equipment.
• The suspended column will not be subjected to scraping due to movement of the lake any more and can be easily hoisted to the surface for adjustment or repair.

Of course maintenance is more difficult on a floating structure and the construction of a barge able to carry all the installations involves a not inconsiderable increase in costs. But in spite of this, at the present moment the off-shore solution seems to offer the best compromise for the extraction of gas.

The installation which we are suggesting is thus made up of an off-shore extraction barge supporting the entire separation and washing equipment. Recuperated gas is then carried by submerged gas pipeline to the consumption unit on shore.