An optimization model for managing compressors in salt cavern gas storage

Abstract

The article presents issues related to technical and economic optimization of filling underground gas storage in salt cavern (CUGS) on the example of Mogilno. Operation practice suggests that the first step is to inject the caverns with a high convergence, then with smaller and at the end caverns with the smallest convergence. In the withdraw process, the situation is reversed. On the other hand, the gas injection into the deepest caverns requires more compressor power. Optimization that takes into account only the speed of storage caverns convergence is not ideal. While injecting gas into storage caverns, compressors typically use about 1–3% of the transported gas, depending on the management of compressors operation. Taking into account the amount of gas supplied to the CUGS Mogilno, the cost of fuel gas that is used can be significant. In the liberalized gas market an underground gas storage operator will have to account carefully and buy fuel gas at market prices. These facts raise an important question: how to manage the operation, in a free gas market in the most efficient way which affects the profitability service storage provision in underground gas storage in salt caverns. This paper presents the optimization model, developed by the authors, that minimizes the consumption of fuel gas, while preventing overdependence loss of underground salt caverns volume, during the gas injecting process into storage caverns.