Construction of Natural Gas Energy-measuring System in China: A Discussion

During the 13th Five-Year Plan, China's natural gas industry developed rapidly, and a diversified supply and marketing pattern was formed, including domestic conventional gas, unconventional gas (shale gas, tight sandstone gas, coalbed methane, etc.), coal-based synthetic natural gas, imported LNG and imported pipeline gas. The gross calorific value of gas sources ranged from 34 MJ/m3 to 43 MJ/m3 , and the maximum difference of calorific value between different gas sources exceeded 20%. On May 24th, 2019, the National Development and Reform Commission and other three ministries/commissions jointly issued the Supervision Regulation on the Fair Access of Oil and Gas Pipeline Network Facilities and required that a natural gas energy measuring and pricing system shall be established within 24 months from the implementation date of this Regulation. In order to speed up the construction of China's natural gas energy measuring system, this paper summarizes domestic achievements in the construction of natural gas energy measuring system from the aspects of value traceability and energy measurement standard, and analyzes natural gas flowrate measurement technology, calorific value determination technology, value traceability, localization, intelligentization and application technology of key energy measurement equipment, natural gas pipeline network energy balancing technology based on big data analysis, multi-source quality tracking and monitoring technology, and energy measurement standard system, the need of new energy detection and measurement technology, and put forward strategy for the development of natural gas measuring in China. And the following research results are obtained. First, China's natural gas energy measuring system can basically meet the requirements of implementing natural gas energy measurement, but it still falls behind the international leading level in terms of calibration and application of high-level flowmeter (such as 0.5 class), high-accuracy gas reference material, level of calorific value reference equipment, and measurement standard system, and needs to be further improved. Second, it is necessary for China to speed up the research and application of the localization and intelligentization technologies of key energy measurement equipment. Third, natural gas pipeline network shall be equipped with measurement check method, energy balancing system based on big data analysis, and multi-source quality tracking and monitoring system, so that the energy transmission loss index of natural gas pipeline network can be superior to the international leading level (0.10%). Fourth, to realize the large-scale application of hydrogen energy and bio-energy and the mixed transportation of hydrogen, bio-methane and natural gas, it is necessary to carry out research on new technology and standardization of hydrogen/bio-methane blended natural gas detection and measurement.