Andrew Wedgner, Gian Ganjar Zatnika, Sudi Mulyono
Papers # 2016 Berlin
The Star Energy Wayang Windu geothermal plant in Java, Indonesia, generates up to 227MW of electricity using the natural steam from deep beneath the earth. Once the steam has cooled and condensed it is returned to the underground reservoir through condensate pipelines and injection wells. By 2012 the existing steel pipeline was badly corroded due to the aggressive nature of the condensate and Star Energy identified PE100 as the best replacement material. This paper provides a background to the project and describes the materials selection, design and installation processes which Star Energy, their contractors and suppliers went through before concluding with some of the lessons that they learnt whilst undertaking the project.
The Star Energy Wayang Windu geothermal plant in Java, Indonesia, was completed in 1999 and today generates up to 227MW of electricity using steam from natural hot fluids deep beneath the earth. Once the steam has generated electricity using steam turbines it is cooled and condensed before being returned to the underground reservoir through a condensate pipeline and injection wells. Unfortunately, the condensate is very corrosive and its temperature can reach 50oC. In addition, the pipeline is laid in a hilly region and sections flow under gravity, which makes them prone to erosion.
After nearly 15 years of operation the condensate pipeline at Wayang Windu had been extensively repaired and was ready to be replaced. Rather than replacing it with another steel pipeline, the Star Energy decided to examine other materials that did not suffer from corrosion. When the power plant was originally constructed, engineers had no option but to use steel, but over the last decade the availability of alternative pipe systems has greatly increased across South East Asia.
Having reviewed the options the Star Energy team decided to install a single 400mm OD SDR 11 PE100 above ground pipeline in order to evaluate the performance of this material in a new application, together with identifying the practical challenges in constructing a pipeline in what, to them, was a new material.
The paper describes the above in detail, together with the design and installation process which Star Energy, their contractors and suppliers went through. It also discusses some of the lessons that they learnt through undertaking the project.