Author(s)

S. Kravanja & B. Žlender

Abstract

This paper presents the cost optimization of an underground gas storage (UGS), designed from lined rock caverns (LRCs). The optimization is performed by the non-linear programming (NLP) approach. For this purpose, the NLP optimization model OPTUGS was developed. The model comprises the cost objective function, which is subjected to geomechanical and design constraints. It is proposed that the geotechnical problem will be solved simultaneously. In such a way, the optimization enables not only that the solution is optimal, but also that the rock mass achieves enough strength, stability and safety. It is proposed that the optimization will be performed for the phase of the conceptual design. The numerical example at the end of the paper demonstrates the efficiency of the introduced optimization approach. Keywords: underground gas storage, UGS, lined rock cavern, LRC, optimization, non-linear programming, NLP. 1 Introduction The paper deals with the optimization of the investment and operational costs of an underground gas storage (UGS), designed from lined rock caverns (LRCs) [1-3]. The optimization is performed by the non-linear programming (NLP) approach. For this purpose, the NLP optimization model is developed. Since the optimization is proposed to be performed for the phase of the conceptual design, only some basic conditions are defined in the optimization model in order to assure enough strength safety of the rock mass and impermeability of the cavern wall and steel lining. The latter is achieved by the limitation of steel lining and concrete wall stains. The considered UGS is performed by the construction of one or more LRCs. The structure of the LRC is simple: its reservoir wall is designed from a concrete wall and a steel lining. Although the concrete wall is reinforced, it just transports

Keywords

underground gas storage, UGS, lined rock cavern, LRC, optimization, non-linear programming, NLP