Introduction  Pipeline hydraulic calculation is an important component of the natural gas transmission and distribution system. Applying this theory allows for the analysis of relationships between the pipeline diameter, the flow velocity, the pressure drop, and the gas density. It plays a crucial role throughout the entire lifecycle of natural gas pipeline construction and operation. Pipeline hydraulic calculation has an important impact on the design optimization and operation scheduling of pipeline transmission and distribution. This article aims to simulate and analyze the hydraulic calculation of a long-distance natural gas main pipeline in a certain region to provide reference data for practical works such as the construction and operation optimization of the main pipeline in that region.

  Method  In the existing regional pipeline network, the PIPELINE STUDIO software model was used to calculate and simulate the operation status of the main pipeline in the region under different working conditions. The focus was on extreme working conditions, such as "peak demand in summer " and "supply guarantee in winter", aiming to identify potential issues in pipeline operation and analyze the main gas transmission bottlenecks.

  Result  The research has shown that whether the working condition is of "peak demand in summer" or " supply guarantee in winter", the current pipeline system in the region has gas transmission bottlenecks, and it is necessary to optimize and adjust the pipeline operation scheduling, the gas flow direction, and the hydraulic pressure to further maximize the gas transmission capacity of the regional pipeline network.

  Conclusion  By analyzing the gas transmission capacity under different extreme working conditions, it is possible to propose plans in optimized operations, interconnections, and technological improvements, which can eliminate pipeline bottlenecks, ensure the safe and efficient operation of regional pipeline networks, and meet the changing gas consumption requirements of market users.