The prediction and analysis of natural gas demand can provide help for reasonable production scheduling and resource allocation, and then bring economic benefits to the network companies. This paper discusses the current research progress of natural gas demand prediction and other energy demand prediction, analyzes the research status and development direction in this field at home and abroad, and introduces the characteristics and development trend of the models used specially. The problems in current study and future research direction are pointed out, and the research results and the research results that can be used for reference are summarized, which can provide reference for future research on the further development of natural gas demand.

In view of the characteristics of coalbed methane "multi-point intervening, flexible gathering" and the complex flow pattern of the gas-water two-phase flow in the pipe, under the complicated terrain, the pipeline network pressure fluctuates frequently, seriously affecting the gas gathering and transportation system efficiency and operational safety. In order to more accurately calculate the pressure of the pipe network, based on the multiphase hydraulic and thermodynamic calculation method, the steady-state calculation model of coal-bed gas pipeline network is established by using the pipe network node method. A method of steady-state simulation of segmented pipe network considering terrain fluctuation is put forward. Through the calculation and analysis of the pipe network, it can be seen that the pressure calculation results of the pipe network calculation model under the terrain fluctuation are more accurate and reliable, which provide a reference for rational design and operation of coalbed gas pipeline network in complex terrain.

In order to measure the concentration of mixed oil transported in pipeline more precisely, the conductivity probe is modified and applied to determin concentration of mix oil in the pipeline based on the principle of the conductance measurement of gas-liquid two-phase flow's liquid holdup. The experimental apparatus can be used to calibrate the probe by measuring the different concentration of brine to obtain the corresponding output signal. The calibrated experimental apparatus can easily measure the concentration of mixed oil at different times and different positions of the pipeline cross section.

        In recent years, a series of pipeline leakage accidents frequently occur due to aging, corrosion and manmade damage. At present, most of related software focuses on the qualitative accidental assessment and localization of the leaking point while the study correlated with practical calculation of leakage volume is rare. An efficient quantitative calculation of the volume of leakage is essential to provide guidance for subsequent accidental management, environmental evaluation and division of the hazardous area. Connected with the alarm system and the online calculation module, a software with the function of online and offline calculation is developed on the basis of transient flow model coupled with hydraulic and thermal factors. A real case study is presented to demonstrate the relative error which is less than 5% and the results prove that it is of practical value and able to offer reference and guidance for engineers.