The technical water supply (TWS) pipeline between Kulsary and Tengiz is the sole source of the technical water to the Tengiz facilities. The pipeline was put into operation in 1985 and is owned by Tengizchevroil (TCO). The pipeline is lying underground, where soil is characterised by corrosion aggressiveness, and its original design life is over. Due to the weakened pipe wall the pipeline is vulnerable to pressure surges. Therefore the operation pressure of the pipeline has degraded several times.
In phase 1 of the TWS project, Witteveen+Bos Kazakhstan prepared a minimum and maximum alternative for the repair or replacement of the pipeline. Based on this business case TCO gave approval to continue with phase 2 of the project in which six alternatives will be worked out and evaluated. Besides the cost, reliability is the major selection criterion for the alternatives. A RAM (Reliability, Availability and Maintainability) analysis has a prominent part in the phase 2 activities. As the system reliability not only depends on the pipeline itself but also on water storage on the plant this will was taken into account as well. The water consumption on the plant and the water supply in Kulsary form the boundary conditions for the project. Future developments like fire water project and water recycling project are also taken into account on this stage. Phase 2 of the project was finalised in January 2011.