Natural Gas In China Research Articles

Environmental benefits analysis based on life cycle assessment of rice straw-based synthetic natural gas in China

A cradle-to-gate life cycle assessment of rice straw-based synthetic natural gas (R-SNG) production was carried out in this study, and the inventories of rice straw cultivating and harvesting, feedstock transportation, R-SNG facility construction and dismantling, and power consumption (i.e. purchased electricity (PE) scheme and self-supply power (SP) scheme) stages were analyzed. Then, the inventory data was characterized and normalized. The results showed that the SP scheme can significantly reduce the environmental impacts of R-SNG product. A comparison of R-SNG, natural gas (NG) and coal-based synthetic natural gas (C-SNG) was conducted from the perspective of environmental impacts. The results showed that the amount of CO2 emission from C-SNG was the largest, followed by that from NG, while the amount of CO2 emission from R-SNG was negative. A sensitivity analysis about allocation principles of the rice straw and rough rice was carried out to evaluate the allocation principles on the environmental impacts. In conclusion, R-SNG showed great environmental benefits in the abiotic resources saving and greenhouse gases emission reduction.

Evaluating Design of Increasing Block Tariffs for Residential Natural Gas in China: A Case Study of Henan Province

Solving the problem of residential cross-subsidies for natural gas is a key and difficult point of further phasing out the fossil fuel subsidies in China. The government implemented the increasing block tariffs for residential natural gas to settle this issue. However, the relevant researches are still very limited. In this paper, we apply the price-gap approach and welfare evaluation methods to analyze the subsidies and increasing block tariffs for residential natural gas in Henan province in 2013 and find that the subsidies mainly benefited the high-income group, as they accounted for only 20% of the total population but received 32.36% of the total subsidies. The low-income group accounted for 20% of the total population, but obtained only 11.95% of the total subsidies. Residential natural gas subsidies lack fairness and efficiency, which mainly resulted in the excessive gas volume in the first block in Henan province. In addition, we design some schemes of increasing block tariffs for residential natural gas and find that more blocks and larger gap of gas price among different blocks can optimize the subsidy redistribution and improve its fairness and efficiency. The local governments should design proper volume in the first block, enlarge gap of gas price when implementing the increasing block tariffs; they should also enhance the awareness on energy conservation among the high income group.

Natural gas and energy revolution: A case study of Sichuan–Chongqing gas province

For a full and accurate understanding of the position and role of natural gas in China's energy revolution and providing a decision-making reference for the scientific establishment of natural gas development strategies and the deepening of the energy revolution, this paper analyzed the role of natural gas in guiding the energy revolution in China and points out the main direction of natural gas utilization in the Sichuan–Chongqing gas province which takes the lead in China's natural gas industry. The study provides the following findings. First, with a huge space for development, natural gas will play an important role in China's third energy revolution. Second, natural gas resources are abundant and have a huge potential for development in China. Third, natural gas can be used for a large range of purposes in the Sichuan–Chongqing gas province. In addition to be used as city gas, natural gas can also be used for industrial fuel mainly as a substitute for coal, transportation, distributed energy, peak-shaving power generation, and high-end natural gas chemical raw materials. Some conclusions are made. First, as the cleanest fossil energy and the best fuel, natural gas will play an irreplaceable role in China's third energy revolution in the 21st century. Second, the Sichuan–Chongqing gas province is rich in natural gas, hydropower and other renewable resources. By 2020, it will become the largest gas production province in China, with natural gas production over 550 × 108 m3. By 2030, driven by the rapid development of shale gas, gas production in the province is expected to exceed 800 × 108 m3. Third, the Sichuan–Chongqing gas province is likely to become the leader in China's third energy revolution.

Modelling an optimal foreign natural gas import scheme for China

Following China's pledge to mitigate GHG emissions, natural gas has become an important choice for promoting low-carbon development in the country. China has introduced natural gas-friendly policies to increase the penetration of natural gas into its total energy consumption, causing an increase in the demand for foreign natural gas in China. This study attempts to devise a foreign natural gas import scheme for China by constructing a mathematical programming model. Various aspects of energy security, such as diversification, lower dependency, supplier export capacity, minimizing the import cost, transport distance and political instability associated with each of the foreign natural gas suppliers, were incorporated in the decision-making model for a foreign natural gas import scheme for the years 2015–2020. The proposed model optimizes China's strategy by utilizing the existing capacity of the piped natural gas (PNG) infrastructure and gradually increasing the liquefied natural gas (LNG) supply from the top six suppliers in the world, i.e. Qatar, Malaysia, Australia, Nigeria, Indonesia, Trinidad & Tobago and Algeria. Furthermore, the analysis of the existing and planned LNG and PNG import infrastructure suggests that China will have more than enough import capacity to fulfil the demand for foreign natural gas in the country until 2020.

Natural gas price effects in China based on the CGE model

Natural gas is a clean energy source with many benefits and its proportion in the energy consumption structure in China has been gradually increasing over the recent years. Since the price of natural gas in China has been controlled and maintained at a relatively low level by the government, reforming the natural gas industry in China has been the matter of much attention in light of its macroeconomic effects on the overall economy. Using the Computable General Equilibrium model and the 2012 Social Accounting Matrix, the results show increases in natural gas prices lead to an increase in the consumer price index (CPI) and lead to reductions in GDP. The chemical industry sector is strongly influenced by a natural gas price increase. Furthermore, chemical fertilizer manufacturing industry and chemical products’ manufacturing have very significant effects in China. Therefore the government may gradually establish and improve the management of natural gas price to avoid negative effects, and implement a differential price as the industries exhibit different levels of resistance in response to natural gas price changes.

Forecasting the relation of supply and demand of natural gas in China during 2015-2020 using a novel grey model

Forecasting the relation of supply and demand of natural gas in China during 2015-2020 using a novel grey model

China’s Cap on Coal and the Efficiency of Local Interventions: A Benefit-Cost Analysis of Phasing out Coal in Power Plants and in Households in Beijing

China’s Cap on Coal Consumption (CCC) Policy serves as a key strategy to address the serious air pollution in China, and it helps to address coal’s climate, environment and health damages. Current implementation of it focuses on substituting coal used in power plants and boilers with natural gas, whereas phasing out household coal use is less emphasized. This study estimates the benefits and costs of interventions for phasing out coal used in power plants and in households in Beijing. The results suggest that the phasing out of household coal use can result in net social benefits. However, coal-to-gas projects for power plants actually bring net social losses, a result largely attributable to the relative high price of natural gas in China. In addition to the actual policy evaluations of phasing out coal, this study outlines how to conduct economic analysis of air pollution policies in China taking into account uncertainty and correlations of key parameters. With the importance at a national and global level to reduce the negative effects of coal consumption, together with the trend of scaling up coal reduction interventions in China from local pioneers to the national level, this study provides implications on how to achieve more socially beneficial results for such interventions.

Impacts of low oil price on China and the world natural gas industry chain

Since the second half of 2014, the crude oil price has been in rapid decline, which poses profound impacts on the global natural gas industry chain. The issue started to surface in the oil and gas sector on how to survive in such a situation. In this paper, an overview was first made on the world natural gas industry chain experiencing from the high-oil-price period to the low-oil-price period, then the influences of low oil price on natural gas production patterns, prices and development prospects, etc., and finally discussion focus was put on the challenges and opportunities brought about by the sustained low oil price to the natural gas industry chain in present China. The results are concluded as follows. First, under such low oil price situation, oil and gas companies at present have to cut capital expenditure to such a degree that the oil and gas output will be both of particular concern in the future. Second, low oil price will compel the falls of global natural gas prices to different degrees, so natural gas economy will drop greatly compared with crude oil prices. Third, such a low oil price will exert more severe impact on the high-cost unconventional natural gas sector; as a result, many unconventional oil and gas companies have suffered frequent bankruptcy at abroad, while such companies in China are holding different attitudes towards unconventional natural gas. Fourth, the oil and gas M&A market remains a laggard due to many other reasons. Fifth, this drop in oil prices is just occurring at the time when natural gas is developing so rapidly in China, which will bring both challenges and opportunities to the industrial structural reform of natural gas in China.

Forecasting the natural gas demand in China using a self-adapting intelligent grey model

Reasonably forecasting demands of natural gas in China is of significance as it could aid Chinese government in formulating energy policies and adjusting industrial structures. To this end, a self-adapting intelligent grey prediction model is proposed in this paper. Compared with conventional grey models which have the inherent drawbacks of fixed structure and poor adaptability, the proposed new model can automatically optimize model parameters according to the real data characteristics of modeling sequence. In this study, the proposed new model, discrete grey model, even difference grey model and classical grey model were employed, respectively, to simulate China's natural gas demands during 2002–2010 and forecast demands during 2011–2014. The results show the new model has the best simulative and predictive precision. Finally, the new model is used to forecast China's natural gas demand during 2015–2020. The forecast shows the demand will grow rapidly over the next six years. Therefore, in order to maintain the balance between the supplies and the demands for the natural gas in the future, Chinese government needs to take some measures, such as importing huge amounts of natural gas from abroad, increasing the domestic yield, using more alternative energy, and reducing the industrial reliance on natural gas.

Coal-based synthetic natural gas vs. imported natural gas in China: a net energy perspective

China has two choices to meet the gap between its gas demand and supply in the short term: coal-based synthetic natural gas and imported natural gas. China currently faces the following question: between coal-based synthetic natural gas and imported natural gas, which is the better choice for China? To provide a reference for policy makers and investors, this paper compares the energy efficiency of the Datang coal gasification project, which is the first demonstration project in China, with that of imported natural gas by an energy return on investment analysis. The results show that when the environmental inputs are not considered, the energy return on investment values of coal-based synthetic natural gas with different boundaries range from 1.7:1 to 6.9:1. The values of the total imported natural gas decreased from 14.5:1 in 2009 to 7.5:1 in 2014 and then increased to 9.2:1 in 2015. When the environmental inputs are considered, the energy return on investment values of coal-based synthetic natural gas and that of imported natural gas decrease to 1.4:1–3.4:1 and 5.9:1–9.6:1, respectively. Regardless of whether the environmental inputs are considered, imported natural gas generally has a better energy return on investment than coal-based synthetic natural gas. These results suggest that from a net energy perspective, policy makers and investors should encourage to import more natural gas and be prudent about developing the coal gasification industry.

Water Availability for Shale Gas Development in Sichuan Basin, China.

Unconventional shale gas development holds promise for reducing the predominant consumption of coal and increasing the utilization of natural gas in China. While China possesses some of the most abundant technically recoverable shale gas resources in the world, water availability could still be a limiting factor for hydraulic fracturing operations, in addition to geological, infrastructural, and technological barriers. Here, we project the baseline water availability for the next 15 years in Sichuan Basin, one of the most promising shale gas basins in China. Our projection shows that continued water demand for the domestic sector in Sichuan Basin could result in high to extremely high water stress in certain areas. By simulating shale gas development and using information from current water use for hydraulic fracturing in Sichuan Basin (20,000-30,000 m(3) per well), we project that during the next decade water use for shale gas development could reach 20-30 million m(3)/year, when shale gas well development is projected to be most active. While this volume is negligible relative to the projected overall domestic water use of ∼36 billion m(3)/year, we posit that intensification of hydraulic fracturing and water use might compete with other water utilization in local water-stress areas in Sichuan Basin.

Природный газ в энергопотреблении Китая: основные тенденции развития

Природный газ в энергопотреблении Китая: основные тенденции развития

Evaluation on occluded hydrocarbon in deep–ultra deep ancient source rocks and its cracked gas resources

Oil-cracked gas, as the main type of high-over mature marine natural gas in China, is mainly derived from occluded hydrocarbon. So it is significant to carry out quantitative study on occluded hydrocarbon. In this paper, the occluded hydrocarbon volume of the main basins in China was calculated depending on their types, abundances and evolution stages by means of the forward method (experimental simulation) and the inversion method (geologic profile dissection). And then, occluded hydrocarbon evolution models were established for five types of source rocks (sapropelic, sapropelic prone hybrid, humic prone hybrid, humic and coal). It is shown that the hydrocarbon expulsion efficiency of sapropelic and sapropelic prone hybrid excellent source rocks is lower than 30% at the low-maturity stage, 30%–60% at the principal oil generation stage, and 50%–80% at the high-maturity stage, which are all about 10% higher than that of humic prone hybrid and humic source rocks at the corresponding stages. The resource distribution and cracked gas expulsion of occluded hydrocarbon since the high-maturity stage of marine source rocks in the Sichuan Basin were preliminarily calculated on the basis of the evolution models. The cracked gas expulsion is 230.4 × 1012 m3 at the high evolution stage of occluded hydrocarbon of the Lower Cambrian Qiongzhusi Fm in this basin, and 12.3 × 1012 m3 from the source rocks of Sinian Doushantuo Fm, indicating good potential for natural gas resources. It is indicated that the favorable areas of occluded hydrocarbon cracked gas in the Qiongzhusi Fm source rocks in the Sichuan Basin include Gaoshiti–Moxi, Ziyang and Weiyuan, covering a favorable area of 4.3 × 104 km2.

Contribution and significance of dispersed liquid hydrocarbons to reservoir formation

Abstract Oil expulsion rate of different types of source rock in geologic settings are estimated by modeling hydrocarbon generation and expulsion and examining the geological sections of different source-reservoir combinations. The major gas generation peak of oil-cracked gas kitchen is determined by study on the gas generation timing of dispersed liquid hydrocarbon inside and outside source rock and ancient oil reservoirs, and the factors affecting the gas generation timing. A “five-step method” based on the origin method is set up to quantitatively evaluate the cracked gas generated by dispersed liquid hydrocarbons. The hydrocarbon generation and expulsion experiment of different types of source rock, the study on oil expulsion rate of different source-reservoir combinations, analysis of rock pyrolysis parameters of reservoir rock all show that there is a large amount of liquid hydrocarbons retained in the source rock, and the feature on the whole is the oil expulsion rate decreases with the reducing of total organic carbon (TOC). The expulsion rate of source rock with TOC of less than 2% is below 50% in general during the liquid-window stage, while that of alternating sandstone and mudstone and of thick mudstone, with TOC of 2%−4%, are 60% and 30% respectively. Affected by the ancient landform, the expelled liquid hydrocarbons accumulated in different abundance in formations, with dispersed or semi-dispersed and semi-gathered form, and they are called dispersed liquid hydrocarbons outside source rock. When buried deeper, both dispersed liquid hydrocarbons inside and outside the source can be cracked into natural gas to form conventional and unconventional gas accumulations. Exploration practices in the Sichuan and Tarim basins have proven that the cracked gas generated by dispersed, semi-dispersed and semi-accumulated, and accumulated liquid hydrocarbons is an important source of deep natural gas in China, and takes an important position in gas exploration.

Natural gas pricing reform in China: Getting closer to a market system?

Recent policy in China targets an increase in the contribution of natural gas to the nation's energy supply. Historically, China's natural gas prices have been highly regulated with a goal to protect consumers. The old pricing regime failed to provide enough incentives for natural gas suppliers, which often resulted in natural gas shortage. A new gas pricing reform was tested in Guangdong and Guangxi provinces in 2011, and introduced nationwide in 2013. The reform is aimed at creating a more market-based pricing mechanism. We show that a substantial progress toward a better predictability and transparency of prices has been made. The prices are now more connected with the international fuel oil and liquid petroleum gas prices. The government's approach for a temporary two-tier pricing when some volumes are still traded at old prices reduced a potential opposition during the new regime implementation. Some limitations of the natural gas pricing remain as it created biased incentives for producers and favors large natural gas suppliers. The pricing reform at its current stage falls short of establishing a complete market mechanism driven by an interaction of supply and demand of natural gas in China.

Discovery of hiatus in Feixianguan Formation and its geological implications,Sichuan Basin, SW China

The lower Triassic Feixianguan Formation of the Sichuan Basin is an important exploration target for marine natural gas in China. It is widely believed that a certain interval from Fei 1 to Fei 4 displays conformable contacts rather than long-term wide-ranging hiatus. However, 2 denudational interfaces on the top of Member Fei 1 and Fei 2 respectively were found in the present work, which relies on the delicate core observation of 4 cored wells in Puguang Gas Field, microscopic observations of microsamples in terms of thin sections, scanning electron microscopy and cathodoluminescence, and geochemical testing. Evidence indicates that on the top of the first and second Member of Feixianguan Formation there existed karst unconformities, which is in distinguished contrast to previous interpretations of conformable contacts. According to those geological and geochemical investigations, a new classification is proposed for the interior Feixianguan Formation. The tectonic episode division of Indosinian movement consequently may be modified from the previous conception of a first-order episode to 3 sub-first-order episodes that correspond to the impact of 2 uplifting processes during the early Indosinian orogeny. These uplifting processes are the cause in interpreting the pervasive exposure and unconformable interfaces in Fei 1 and Fei 2 karstifications. Thus, we suggest another appropriate division of 3 third-order sequences that may suit the Feixianguan Formation, which correspond to Fei 1, Fei 2, and Fei 3-Fei 4. Regional reservoir formation was also largely affected by penecontemporaneous karstification. Massive dissolution pores fill with seepage sediments but generally remain effective reservoir spaces.

Future of Shale Gas in China and its Influence on the Global Markets for Natural Gas

The goal of this paper is to evaluate the perspectives of China to become less dependent on gas imports in future. This paper tries to forecast the future production of natural gas in China and demand for imports. The key problem is to what extent China can become the second country after the USA with shale gas revolution and whether it will be able to do that in the next 20 years. We find several obstacles preventing the scenario of China becoming net gas exporter; among them lack of conventional gas reserves and water scarcity in the location of shale gas deposits. However, there is huge uncertainty in the volume of future gas imports from China resulting not only from the uncertainty of its demand but also of supply. Results show that China's energy strategy will lead to an increase in the speed of shale gas extraction.

Reservoir characteristics and productivity analysis of tight sand gas in Upper Paleozoic Ordos Basin China

Abundant tight sands rich in natural gas, as a kind of unconventional energy source, have been discovered in the Ordos Basin, Central-North China, which can contribute greatly to the sustainable supply of natural gas in China. In this paper, the geological and petrophysical characteristics of a typical tight sand gas reservoir in the Upper Paleozoic of the Ordos Basin were investigated and correlated to the productivity of gas wells. Several important petrophysical relationships were revealed based on data from drill cuttings, core, and well logging, including porosity versus permeability, stress sensitivity to permeability, and rock density versus porosity. Their effects on well's productivity were discussed. The productivity of the targeted reservoir was analyzed and classified using a formation capacity method (K·H factor), and was compared with the production data of similar tight sand and low permeability blocks in the region, which can provide good reference for the field development.

Analysis of rationality of coal-based synthetic natural gas (SNG) production in China

To alleviate the problem of the insufficient reserves of natural gas in China, coal-based synthetic natural gas (SNG) is considered to be a promising option as a source of clean energy, especially for urban use. However, recent study showed that SNG will not accomplish the task of simultaneous energy conservation and CO2 reduction. In this paper, life cycle costing is made for SNG use in three main applications in residential sector: heating, household use, and public transport. Comparisons are conducted between SNG and coal, natural gas, liquefied petroleum gas (LPG), diesel, and methanol. The results show that SNG is a competitive option only for household use. The use of SNG for heating boilers or city buses is not as cost-effective as expected. The biggest shortcoming of SNG is the large amount of pollutants generated in the production stage. At the moment, the use of SNG is promoted by the government. However, as shown in this paper, one can expect a transfer of pollution from the urban areas to the regions where SNG is produced. Therefore, it is suggested that well-balanced set of environmental damage-compensating policies should be introduced to compensate the environmental losses in the SNG-producing regions.

Evaluation research on performance of permeability and fracture in Sulige gas field by new method

Tight gas is the most available alternative unconventional natural gas in China. Its potential is huge and the Sulige gas field is the biggest one. However, there are many urgent development problems to be solved, and evaluating well performance is of one of them. Low permeability, strong stress sensitivity and hydraulic fracturing make it difficult to predict well performance. Evaluating the performance of permeability and fracture is important for production. Although well-testing is the most effective to assess the reservoir, it takes a long time because of low permeability, so it cannot be implemented repeatedly. Fortunately production can provide continuous long-time data for performance assessment. The method presented in this paper combines well-testing and production data analysis. We assess 206 vertical wells and 102 multi-stage fractured horizontal wells in the Sulige gas field. The exponential equation is applied and pressure sensitivity coefficient of permeability and fracture is regressed.