Hydraulic Modelling and Compression Design for High-Pressure Natural Gas Transmission: A Case Study of the Calabar–Ajaokuta Gas Pipeline System

Abstract

Natural gas is one of the most critical components of the global energy mix and plays a central role in the ongoing energy transition It is regarded as one of the cleanest and most versatile fossil fuels due to its lower carbon emissions compared to coal and oil..   Global natural gas consumption is projected to increase steadily, particularly in developing economies where industrialization and power generation demand are expanding.Nigeria’s economy relies heavily on oil revenue, which has historically limited diversification into gas-based industrial development, including petrochemical and fertilizer production. For Nigeria, possessing abundant reserves of natural gas with most of it wastefully flared off, channelling this gas to supply energy to these industries becomes inevitable. The current demand capacity of CAPS that proposed to be 2000 MMSCFD has been found to be insufficient for the future demand capacity. Process simulation using PIPESIM software package showed that the required capacity could not be achieved without the use of compressors along the pipeline.  This study presents a detailed hydraulic and steady-state process simulation analysis using PIPESIM software to evaluate the suitability of 48-inch and 565-inch pipeline diameters for delivering 2000 MMSCFD and 3200 MMSCFD under specified pressure constraints. Applying the hydraulic and steady state process simulations enable the compression requirements, pressure and velocity profiles to be evaluated. Two operational scenarios representing current (2000 MMSCFD) and projected future (3200 MMSCFD) demand capacities were evaluated. Results indicate that one compressor station is required to deliver 2000 MMSCFD, while four compressor stations are necessary to sustain 3200 MMSCFD at the minimum arrival pressure of 68 barg. The findings provide a technical basis for optimal pipeline sizing, compressor configuration, and long-term gas transmission reliability within Nigeria’s expanding energy infrastructure..