  Natural gas transmission pipelines are complex systems whose flow
characteristics are governed by challenging non-linear physical behavior. These
pipelines extend over hundreds and even thousands of miles. Gas is typically
injected into the system at a constant rate, and a series of compressors are
distributed along the pipeline to boost the gas pressure to maintain system
pressure and throughput. These compressors consume a portion of the gas, and
one goal of the operator is to control the compressor operation to minimize
this consumption while satisfying pressure constraints at the gas load points.
The optimization of these operations is computationally challenging. Many
pipelines simply rely on the intuition and prior experience of operators to
make these decisions. Here, we present a new geometric programming approach for
optimizing compressor operation in natural gas pipelines. Using models of real
natural gas pipelines, we show that the geometric programming algorithm
consistently outperforms approaches that mimic existing state of practice.
