Research On China's Natural Gas Supply And Demand And Its Security From The Perspective Of Energy Transition

Energy is an important material basis for economic and social development,and energy security is an important part of national resources and economic security.With the rapid development of China's economy and the acceleration of energy transition,the proportion of natural gas in China's energy consumption structure has continued to rise.Since China began to become a country of net import of natural gas in 2007,it took only about ten years,and China's natural gas dependence has risen to 37.9%.In 2018,China further surpassed Japan to become the world's largest natural gas importer,and China's natural gas import dependence reached 45.3%.Rapidly rising import dependence and frequent natural gas security incidents have attracted widespread attention from the government,enterprises and academia.Natural gas security has become another major security issue affecting China's economic and social sustainable development after oil security.Since the oil crisis broke out in the 1970 s,energy security has been the focus of academic research.The early concept of energy security mainly focused on ensuring oil supply and price stability.With the increasing proportion of natural gas in the world energy consumption structure,the issue of natural gas security has attracted more and more attention.In recent years,the research on natural gas security has gradually increased,mainly from the perspective of natural gas development itself,to study the future supply and demand situation,natural gas price fluctuation,natural gas security evaluation and other issues,but the literature on natural gas security from the theoretical perspective of energy transition is rare.There are substitutability and complementarity among different energy sources.It is possible to neglect the systematic adjustment and mutual adaptation caused by the change of energy supply and demand pattern and price if we only study the development trend of one energy source.Taking energy transition as the breakthrough point,this paper analyses the internal relationship between economic growth,energy transition and natural gas security from a more systematic perspective,and analyses the changing trend of natural gas proportion in China's energy consumption structure since the founding of the People's Republic of China,as well as the security problems of natural gas caused by the expanding gap between supply and demand.Relevant analysis and empirical research broaden the perspective of natural gas supply and demand security research,and provide theoretical reference for energy transition and optimization and adjustment of natural gas security policy.The main research,innovations and features include the following:(1)This paper has introduced Hidden Markov Model(HMM)into the field of economic analysis to simulate the complementary and alternative relationships between different energy types in the process of energy transition.From the principle analysis,the advantage of Hidden Markov Model is to introduce GDP growth rate as the observed variable of energy structure adjustment,and based on historical data to establish a self-learning mechanism between GDP growth rate and energy structure adjustment.It is closer to the reality of the interaction between economic and energy development.In order to compare the consistency and difference of different models and scenarios,three scenarios of hidden Markov model,Markov model with planning constraint and Markov model with natural evolution are set to predict.The empirical results show that China's natural gas proportion of consumption accounts for primary energy in 2035 is 16.5%,17.3% and 13.6%,respectively,equivalent to 697.5?731.6 and 574.8billion cubic meters.Compared with the historical data,the prediction model has a high fitting degree and is close to the prediction results of the relevant literature.It shows that the structured model can better simulate the process of energy substitution and complementation in the process of energy transition under the condition of relatively stable economic and social development.Among them,the predicted results of Hidden Markov Model is between the natural evolution scenario and the planning constraint scenario,and the predicted result is close to the planning constraint scenario,which verifies that the two models have good consistency and rationality.Therefore,the Hidden Markov Model can be used not only for energy structure prediction,but also for structured prediction of similar problems such as mineral resources and agricultural products.(2)Based on the oil and gas peak theory,the peak production and peak time of natural gas in China were predicted.Differences with existing research include: First,the key variable was discriminated,Ultimate Recoverable Reserves(URR)is the key variable affecting the peak production and peak time of natural gas.Different literatures have different understandings and assumptions about URR.Based on the relevant literature,the author analyzes the connotation of URR.This paper considers that the idea of estimating URR based on the estimated detection rate is more reasonable,and the peak production and peak time of natural gas were predicted under different URR scenarios.Second,use the longest sample data as far as possible(1957-2017).Third,the internal mechanism between resource scarcity,peak gas and energy transition was further analyzed from the perspective of energy return of investment(EROI).The empirical results show that the predicted results have a high fitting degree with the historical yield,and the overall trend conforms to the "bell curve" rule of Hubbert model.Under the condition that the ultimate recoverable natural gas resources remain unchanged at the current level,the peak output of overall natural gas is 1967 billion cubic meters,and the peak year is about 2032.(3)In view of the rapidly rising dependence on imported natural gas,a natural gas supply and demand security indexes was constructed,and the key factors affecting natural gas security were identified by principal component analysis method..Based on the forecast of supply and demand,China's natural gas dependence will reach 53%,61%,68% and 72% in 2020,2025,2030 and 2035 respectively.It should be noted that dependence of imported natural gas is only an important indicator reflecting the security status of natural gas supply and demand,and it is difficult to comprehensively and accurately reflect the security level of natural gas supply and demand.This paper selects 15 indicators from the three aspects of supply,demand and import to measure the security status of natural gas supply and demand.From the perspective of Sino-US comparison,the principal component analysis method is used to identify the main factors affecting the security of natural gas supply and demand and to measure the comprehensive evaluation score.The empirical results show that since 1992,China's natural gas supply and demand security risks have slowly declined until 2005,and then the reversal began to rise.While the US natural gas supply and demand security risks have remained at a low level,there has been a slight fluctuation in the slow rise.Overall,China's natural gas supply and demand security risks are greater than the United States.This paper proposes that natural gas supply and demand security should have two connotations.One is that the natural gas demand and supply system realize the stability of long-term development trend under the condition of relatively stable fluctuation of natural gas price The other is that natural gas demand and supply system can respond quickly and in a timely manner to short-term demand and supply shocks.Combining annual data with monthly data,this paper measures the long-term risks and short-term risks of natural gas supply and demand security,and expands the theoretical perspective of natural gas supply and demand security research.(4)This paper studied different types of unconventional natural gas as a whole from the perspective of qualitative analysis and quantitative research.TOPSIS method was used to construct the investment evaluation model of unconventional natural gas industry,which filled the gap in the empirical research field of the comprehensive evaluation of unconventional natural gas investment through the analysis of the current situation and theoretical research.Increasing the utilization of unconventional natural gas will help to curb the rise trend of dependence on natural gas imported and reduce the risk of natural gas supply and demand.By comprehensively comparing various factors affecting the prospects of unconventional natural gas investment,it can be found that under different perspectives,government and enterprises have slightly different evaluations of unconventional natural gas investment development priorities.The priority of industrial investment is tight gas,coalbed methane,shale gas and natural gas hydrate.In general,On the background of China's economic transitions and energy transition,facing the trend of rapid growth in natural gas demand and weak growth in output,the continuous increase in natural gas dependence is a high probability event.For a country like China with the second largest economy and the highest natural gas import volume,over-reliance on imported natural gas to meet domestic demand is clearly a long-term “hidden danger”.Natural gas is not only a basic resources for economic and social development,but also a global commodity pursued by speculative capital.Under the complex and changeable situation of global geo-economic and political situation,China should formulate policies to encourage and support enterprises to strengthen investment in natural gas exploration and development at home and abroad,so as to postpone the trend of rapid increase in imported natural gas dependence as far as possible.Strive for time and space to enhance the self assurance ability of natural gas in the process of energy transition.