The Great Man-Made River Phase II pipeline system supplies the northern parts of Libya with water. The pipeline system is fed by 4 well fields with 598 wells feeding the huge 4.0 meter in diameter pipeline. The pipeline is approximately 1000 kilometers in length, with a number of enormous reservoirs, pumping stations and valve stations strategically placed along the pipeline.
The project was at one stage regarded one of the largest building projects in the world, and was in 2005 nominated water project of the world – because of the size of the project and because of the unique use of modeling software to reduce the capital cost.
The pipeline has a capacity to supply up to 2.5 million m3 of water per day from the Sahara desert to the large city of Tripoli. The pipeline has a number of off-takes along the way supplying smaller cities and agricultural production.
The reservoirs along the pipeline are literally lakes. Soil conditions in the desert makes foundation of the reservoirs problematic – and therefore one of the very capital demanding items in the system.
To minimize the reservoir sizes and hence reduce one of the very capital heavy items in the project, it was at a very early stage of the project decided to use real-time modeling of the pipeline, to minimize the required reservoir capacity by optimizing the planning and operation of the pipeline.
The real-time modeling embedded in the computer control system makes it possible to plan the operation of the pipeline in a manner so that the reservoir fluctuation is minimized – hence that the reservoirs could be built a lot smaller than what would normally be regarded good engineering practice.
This paper describes the use of the computer control system as a mean to reduce reservoir sizes, and thereby reduce capital expenditure on a pipeline system.