Route planner for cost-optimal gas transport
KEMA has developed a decision support tool for Dutch gas transmission system operator,
Gasunie, to schedule its operational instruments. This will provide a cost-optimal solution to
the gas-dispatching problem on the basis of shipper nominations and day-ahead predictions
of the demand for natural gas.
Objectives
Gasunie is under regulatory pressure to reduce operational cost in a gas market where the gas-dispatching problem is getting increasingly complex due to liberalized market conditions. The objective of the client is to optimize the use of its compressor stations, gas quality conversion stations and gas balancing services provided by a third party. Additionally, they must maintain certain high standards of natural gas security of supply to more than 1000 exit points in the network. This leads to a highly complex and non-linear optimization problem that cannot be solved using standard simulation and optimization tools for the oil and gas industry.
Project
KEMA has developed an iterative method to tackle the non-linear optimization problem. The method utilizes successive linear programming on the basis of a reduced representation of the network, obtained from the original network model in an automated way. We approximate performance of the compressors and the non-linear behavior of the pipelines using empirical curves. These curves are based on actual field measurements of machine fuel consumption over the past twelve months and the observed loss of pressure in the network. Gasunie has implemented the route planner for gas transport in a computer-based decision support system connected to its existing simulator (GUS), and it is currently undergoing an extensive field test program.
Benefits
In order for the route planner to become a true decision support tool, we demonstrated that it is able to ‘think like a dispatcher’. The apparent intelligence of the tool was tested by confronting the route planner during normal operation with a number of additional dilemmas and observing the proposed escape routes. Based on the results of these tests, our tool earned its place on the dispatching team just as any junior dispatcher would have had to gain peer acceptance. The main benefit of the route planner is its ability to find a solution to the gas transport problem even if the conditions on the liberalized gas market are not typical, and human dispatchers don’t see an easy solution based on years of experience with monopolistic market conditions. This helps to avoid mistakes that risk endangering the security of gas supply in the Netherlands. Furthermore, based on the first test results, we believe that it will be possible to reduce the fuel cost of the compressor stations by a few percent. The exact numbers will have to be confirmed after full implementation of the tool as part of the regular gas dispatching process in 2010.
Client
> Gasunie, the Netherlands
Project coordinator
> KEMA, the Netherlands
Project details
> Duration: January 2007 – ongoing