Natural gas consumption forecasting model based on coal-to-gas project in China

Natural gas is widely used because it is environmentally friendly,particularly in reducing carbon emission and improving the Air Quality Index(AQI)around densely populated cities.China has initiated a coal-to-gas project(CGP)to improve the air quality in northern China.As a subcompany of China National Petroleum Corporation,PetroChina Natural Gas Marketing North Company has been focusing on natural gas resource allocation while considering numerous issues such as ensuring the bottom line of livelihood requirements in winter and the performance of economic indicators for an entire calendar year in the northern part of China.Therefore,the accurate prediction of natural gas consumption is important to PetroChina Natural Gas Marketing North Company.It has become a challenge to forecast natural gas consumption because the natural gas market has changed considerably because of the CGP.Natural gas consumption cannot be forecasted using conventional models.This study analyzes the characteristics of the CGP based on the data obtained from rural individual users and company users.Based on the analysis,the gas consumption in winter is predicted using two different forecasting approaches.The methods presented in this paper provide a basis for formulating effective measures for natural gas scheduling in the northern part of China.

Underground coal gasification and its strategic significance to the development of natural gas industry in China

Based on the present situation and trend of underground coal gasification in China and overseas, this article puts forward the basic concept, mechanism and mode of underground coal gasification, and presents the challenges, development potential and development path now faced. In China, underground coal gasification which is in accord with the clean utilization of coal can produce "artificial gas", which provides a new strategic approach to supply methane and hydrogen with Chinese characteristics before new energy sources offer large-scale supply. Coal measure strata in oil-bearing basins are developed in China, with 3.77 trillion tons coal reserves for the buried depth of 1000-3 000 m. It is initially expected that the amount of natural gas resources from underground coal gasification to be 272-332 trillion cubic meters, which are about triple the sum of conventional natural gas, or equivalent to the total unconventional natural gas resources. According to the differences of coal reaction mechanism and product composition of underground coal gasification, the underground coal gasification can be divided into three development modes, hydrogen-rich in shallow, methane-rich in medium and deep,supercritical hydrogen-rich in deep. Beyond the scope of underground mining of coal enterprises, petroleum and petrochemical enterprises can take their own integration advantages of technologies, pipeline, market and so on, to develop underground coal gasification business based on their different needs and technical maturity, to effectively exploit a large amount of coal resources cleanly and to alleviate the tight supply of natural gas. It can also be combined with using the produced hydrogen in nearby area and the CO_2 flooding and storage in adjacent oil areas to create a demonstration zone for net zero emissions of petroleum and petrochemical recycling economy. It is significant for reserving resources and technologies for the coming "hydrogen economy" era, and opening up a new path for China's "clean, low carbon, safe and efficient" modern energy system construction.

Mechanisms of carbon isotopic fractionation in the process of natural gas generation: Geochemical evidence from thermal simulation experiment

Low maturity coal samples were taken from the Ordos Basin to conduct gold tube thermal simulation experiment in a closed system,and the characteristics of the products were analyzed to find out the fractionation mechanism of carbon isotopes and the causes of abnormal carbon isotopic compositions of natural gas.At the heating rates of 2℃/h(slow)and 20℃/h(rapid),the low maturity coal samples of the Ordos Basin had the maximum yields of alkane gas of 302.74 mL/g and 230.16 mL/g,theδ13C1 ranges of-34.8‰to-23.6‰and-35.5‰to-24.0‰;δ13C2 ranges of-28.0‰to-9.0‰and-28.9‰to-8.3‰;andδ13C3 ranges of-25.8‰to-14.7‰and-26.4‰to-13.2‰,respectively.Alkane gas in the thermal simulation products of rapid temperature rise process showed obvious partial reversal of carbon isotope series at 550℃,and at other temperatures showed positive carbon isotope series.In the two heating processes,theδ13C1 turned lighter first and then heavier,and the non-monotonic variation of theδ13C1 values is because the early CH4 is from different parent materials resulted from heterogeneity of organic matter or the carbon isotope fractionation formed by activation energy difference of early enriched 12CH4 and late enriched 13CH4.The reversal of carbon isotope values of heavy hydrocarbon gas can occur not only in high to over mature shale gas(oil-type gas),but also in coal-derived gas.Through thermal simulation experiment of toluene,it is confirmed that the carbon isotope value of heavy hydrocarbon gas can be reversed and inversed at high to over mature stage.The isotope fractionation effect caused by demethylation and methyl linkage of aromatic hydrocarbons may be an important reason for carbon isotope inversion and reversal of alkane gas at the high to over mature stage.

Distribution Characteristics and Accumulation Model for the Coal-formed Gas Generated from Permo-Carboniferous Coal Measures in Bohai Bay Basin, China: A Review

Coal-formed gas generated from the Permo-Carboniferous coal measures has become one of the most important targets for deep hydrocarbon exploration in the Bohai Bay Basin,offshore eastern China.However,the proven gas reserves from this source rock remain low to date,and the distribution characteristics and accumulation model for the coal-formed gas are not clear.Here we review the coal-formed gas deposits formed from the Permo-Carboniferous coal measures in the Bohai Bay Basin.The accumulations are scattered,and dominated by middle-small sized gas fields,of which the proven reserves ranging from 0.002 to 149.4×108 m3 with an average of 44.30×108 m3 and a mid-point of 8.16×108 m3.The commercially valuable gas fields are mainly found in the central and southern parts of the basin.Vertically,the coal-formed gas is accumulated at multiple stratigraphic levels from Paleogene to Archaeozoic,among which the Paleogene and PermoCarboniferous are the main reservoir strata.According to the transporting pathway,filling mechanism and the relationship between source rocks and reservoir,the coal-formed gas accumulation model can be defined into three types:"Upward migrated,fault transported gas"accumulation model,"Laterally migrated,sandbody transported gas"accumulation model,and"Downward migrated,sub-source,fracture transported gas"accumulation model.Source rock distribution,thermal evolution and hydrocarbon generation capacity are the fundamental controlling factors for the macro distribution and enrichment of the coal-formed gas.The fault activity and the configuration of fault and caprock control the vertical enrichment pattern.

Numerical Simulation of NO_x Formation in Coal Combustion with Inlet Natural Gas Burning

A full two-fluid model of reacting gas-particle flows and coal combustion is used to simulate coal combustion with and without inlet natural gas added in the inlet. The simulation results for the case without natural gas burning is in fair agreement with the experimental results reported in references. The simulation results of different natural gas adding positions indicate that the natural gas burning can form lean oxygen combustion enviroment at the combustor inlet region and the NOx concentration is reduced. The same result can be obtained from chemical equilibrium analysis.

Safety appraisement on building natural gas pipeline over coal mining subsidence area

The target of the text is to scientifically appraise dynamic development of surface deformation in subsidence area and its influence on groundwork stability of natural pipe and then adopt some technological measures to ensure safe circulation of natural pipeline. Analysed the influence on natural pipeline from coal mining subsidence in the way of pipeline grade variation, vertical curve variation, transverse deformation, horizontal pull and compression deformation and pipe stress variation etc., and described detailed surface subsidence product and its used time among initial phase, active phase and decline phase in the course of surface movement deformation time. In the context of considering surface subsidence that doesn＇t reach basic latter end and residual subsidence quantity, the text confirmed the calculation method of residual deformation in surface subsidence area, and gave the technological measures about building natural gas pipeline in subsidence area finally.

Analysis of the Strategies of the 'Replacement of Coal and Oil' with Natural Gas in Sichuan Province

Sichuan Province boasts rich clean energy such as natural gas and hydroelectricity. In order to realize the blueprint of a beautiful China, it is both necessary and feasible for Sichuan Province to ＂replace coal and oil＂ with natural gas. Based on the actual situation of Sichuan Province, through research and investigation, rational thinking and summarization, this paper analyzes the current demand for energy supply in Sichuan, defines the development goals and ideas concerning Sichuan＇s ＇replacement of coal and oil＂ with natural gas, examines the action plan related to such replacement and puts forward relevant policies and suggestions.

A Comparative Environmental Evaluation of the Coal and Natural Gas Life Cycle

Natural gas and coal are the main primary energy resources used in the Romanian energy sector, 73.7% in 2011, taking into account the fuel imports. The objective of the article consists in analyzing all the processes along the coal and the natural gas life cycle in order to assess their overall environmental impact. Two energy technologies were analyzed, for each resource: the pulverized coal combustion with supra-critical parameters and CO2 capture unit and the natural gas combined cycle. Considering the functional unit of electricity production for 1 year, it was found that the natural gas combined cycle remains the more interesting energy technology from an environmental point of view. However, the pulverized coal with supra-critical parameters equipped with a CO2 capture unit has the lowest environmental impact on the climate change. The weakest point of the coal technology is its low efficiency.

Advances of nanotechnologies for hydraulic fracturing of coal seam gas reservoirs:potential applications and some limitations in Australia

Some of the most promising potential applications of nanotechnology to hydraulic fracturing of coal seam gas(CSG)are reviewed with a focus on Australian CSG wells.Three propitious applications were identifed:(1)Nanoparticle enhanced viscoelastic surfactants(VES)fracturing fuids to prevent fuid loss by up to 30%,made possible by the formation of pseudo-flter cakes and reducing the viscosity of the VES fuids.Besides,there is no requirement of clay control additives or biocides.(2)Nano-proppants to extend fracture networks and reduce proppant embedment by introducing them prior to the emplacement of larger proppants.Fly Ash nanoparticles can be particularly efective because of their high sphericity and mechanical strength.(3)Nanoparticle-coated proppants,to mitigate the migration of particle fnes by restricting them close to their source by adsorption,with MgO being the most efective.The use of nanotechnology in hydraulic fracturing applications is currently hindered due to a discordant regulatory environment compounded by the cost of the nanoparticles themselves,as well as,a lack of feld data to validate the technology under real downhole conditions.Although the necessary feld tests are unlikely to be conducted for as long as abundant natural gas is available,exploratory studies could pave the way for future applications.

The Future of Gas to Liquids as a Gas Monetisation Option

The paper introduces gas to liquids (GTL) as a monetising option from a technology, marketing and project perspective. GTL is complementary to LNG and pipelines. At the same time, using natural gas as a source for fuels in the form of GTL helps countries around the world to diversify their energy supplies. Furthermore, gas-based products are inherently cleaner than oil products. Shell's proprietary GTL technology or SMDS (Shell Middle Distillates Synthesis), is discussed in some detail. The paper also covers the challenges for successful implementation of GTL projects and why Shell is well positioned to take a lead in the industry on the basis of its long standing and broad experience in GTL research, plant operations, marketing and excellent track record in mega projects in the last thirty years. Shell's commitment to GTL is best demonstrated by the recent signing of a Heads of Agreement with Qatar Petroleum for the construction of the world's largest GTL plant. A key success factor is Shell's experience with marketing quantities of high quality GTL products from its 12,500 barrels per day plant at Bintulu, Malaysia since 1993. Further marketing opportunities will arise when new GTL capacity comes on-stream in the middle east when more quantities will become available to bulk users. Amongst the most interesting market will be automotive transportation, where clean GTL fuels can be positioned as an 'alternative fuel beyond oil' providing energy security to host countries. Shell is actively engaging with a number of regulators, automotive companies and governments worldwide including China, to demonstrate the performance of GTL and its cost effectiveness in reducing local emissions. An added benefit is that GTL can use existing infrastructure and requires no investment. Finally, the paper briefly discusses the coal to liquids (CTL) process as an alternative route to produce high quality GTL products and the key issues relating to the process.

Genetic type and source of natural gas in the southern margin of Junggar Basin, NW China

Natural gas has been discovered in many anticlines in the southern margin of the Junggar Basin. However, the geochemical characteristics of natural gas in different anticlines haven’t been compared systematically, particularly, the type and source of natural gas discovered recently in Well Gaotan-1 at the Gaoquan anticline remain unclear. The gas composition characteristics and carbon and hydrogen isotope compositions in different anticlines were compared and sorted systematically to identify genetic types and source of the natural gas. The results show that most of the gas samples are wet gas, and a few are dry gas;the gas samples from the western and middle parts have relatively heavier carbon isotope composition and lighter hydrogen isotope composition, while the gas samples from the eastern part of southern basin have lighter carbon and hydrogen isotope compositions. The natural gas in the southern margin is thermogenic gas generated by freshwater-brackish water sedimentary organic matter, which can be divided into three types, coal-derived gas, mixed gas and oil-associated gas, in which coal-derived gas and mixed gas take dominance. The Jurassic coal measures is the main natural gas source rock in the southern margin, and the Permian lacustrine and the Upper Triassic lacustrine-limnetic facies source rocks are also important natural gas source rocks. The natural gas in the western part of the southern margin is derived from the Jurassic coal measures and the Permian lacustrine source rock, while the natural gas in the middle part of the southern margin is mainly derived from the Jurassic coal measures, partly from the Permian and/or the Upper Triassic source rocks, and the natural gas in the eastern part of the southern margin is originated from the Permian lacustrine source rock. The natural gas in the Qingshuihe oil and gas reservoir of Well Gaotan-1 is a mixture of coal-derived gas and oil-associated gas, of which the Jurassic and Permian source rocks contribute about half each.

Natural gas hydrates in the Qinghai-Tibet Plateau: Characteristics, formation, and evolution

The Qinghai-Tibet Plateau(also referred to as the Plateau)is the largest area bearing alpine permafrost region in the world and thus is endowed with great formation conditions and prospecting potential of natural gas hydrates(NGH).Up to now,one NGH accumulation,two inferred NGH accumulations,and a series of NGH-related anomalous indicators have been discovered in the Plateau,with NGH resources predicted to be up to 8.88×10^(12) m^(3).The NGH in the Qinghai-Tibet Plateau have complex gas components and are dominated by deep thermogenic gas.They occur in the Permian-Jurassic strata and are subject to thin permafrost and sensitive to environment.Furthermore,they are distinctly different from the NGH in the high-latitude permafrost in the arctic regions and are more different from marine NGH.The formation of the NGH in the Plateau obviously couples with the uplift and permafrost evolution of the Plateau in spatial-temporal terms.The permafrost and NGH in the Qilian Mountains and the main body of the Qinghai-Tibet Plateau possibly formed during 2.0–1.28 Ma BP and about 0.8 Ma BP,respectively.Under the context of global warming,the permafrost in the Qinghai-Tibet Plateau is continually degrading,which will lead to the changes in the stability of NGH.Therefore,The NGH of the Qinghai-Tibet Plateau can not be ignored in the study of the global climate change and ecological environment.

Development Status and Prospects of the Natural Gas Industry in China

The year 2017 saw explosive growth in China's natural gas market, and the apparent consumption was 235.7 billion cubic meters, up 18.2% over the same period of 2016. In 2017, China's domestic production growth picked up significantly, reaching 145.3 billion cubic meters, an increase of 9%.Natural gas imports grew rapidly, and imported pipeline gas and imported LNG totaled 91.6 billion cubic meters. The trade volume of LNG surpassed that of pipeline gas for the first time since 2012. In 2018, the macro-economy is expected to maintain growth at a moderate-to-high rate. However, driven by favorable factors such as environmental policies, China's demand for natural gas is expected to continue to grow rapidly, and natural gas consumption will maintain double-digit growth, roughly at 12%. Nevertheless, the seasonable imbalance between natural gas supply and demand will remain conspicuous.

HEALTH IMPACT ASSESSMENTS A Tool for Designing Climate Change Resilience into Green Building and Planning Projects

INTRODUCTION Historical records have documented considerable changes to the global climate,with significant health,economic,and environmental consequences.Climate projections predict more intense hurricanes;increased sea level rise;and more frequent and more intense natural disasters such as heat waves,heavy rainfall,and drought in the future(1;2).The coast along the Gulf of Mexico is particularly vulnerable to many of these environmental hazards and at particular risk when several strike simultaneously-such as a hurricane disrupting electricity transmission during a heat wave.

Factors controlling the enrichment of natural gas in Kuche depression,Tarim Basin,NW China:Molecular geochemical evidence from sedimentary organic matter

Using molecular geochemical data from infrared spectrometer and pyrolysis gas chromatography-mass spectrometry, this paper investigates the petroleum generation characteristics of Jurassic coal measures from Kuche depression, Tarim Basin, NW China. The results showed that the Jurassic coaly rocks with medium maturity (R0%: 0.8-1.1) were enriched in gas-prone functionalities (-CH3) and low molecular weight pyrolysates (【nC21), indicating that the coaly rocks from Kuche depression were gas/condensate prone at the stages of middle to high maturation, and it was further supported by the oil/source correlation from well Yinan 2 in this region.

Life cycle assessment and economic analysis of HFC-134a production from natural gas compared with oil-based and coal-based production

China is the largest producer and consumer of HFC-134a(1,1,1,2-tetrafluoroethane)in the world.Coal-based route is mainly adopted to produce HFC-134a,which suffers from large waste and CO_(2) emissions.Natural gas is a low-carbon and clean energy resource,and no research has been found on the environment and economy of producing HFC-134a from natural gas.In this study,CML 2001 method was used to carry out the life cycle assessment of natural gas(partial oxidation)-based and natural gas(plasma cracking)-based routes(abbreviated as gas(O)-based and gas(P)-based routes,respectively),and their environmental performances were compared with coal-based and oil-based routes.Meanwhile,considering that China is vigorously promoting the transformation of energy structure,and the application of electric heating equipment to replace fossil-based heating equipment in industrial field,which has a great impact on the environmental performance of the production processes,the authors conducted a scenario analysis.The results showed that the gas(O)-based route had the most favourable environmental benefits.However,the gas(P)-based route had the highest potential for reducing environmental burdens,and its environmental benefit was the most favourable in scenario 2050.Additionally,the economic performance of the gas(P)-based route was significantly better than that of gas(O)-based and coal-based routes.

Formation and distribution of coal measure source rocks in the Eocene Pinghu Formation in the Pinghu Slope of the Xihu Depression,East China Sea Shelf Basin

The Xihu Depression in the East China Sea Shelf Basin is a large petroliferous sedimentary depression,in which oil and gas reservoirs were mainly discovered in the Pinghu Slope and the central inversion zone.The oil-gas source correlation in the Xihu Depression was analyzed by hydrocarbon generating thermal simulation data via gold-tube pyrolysis experiments.The results indicated that the oil and gas in the Xihu Depression were mainly derived from coal measure source rocks of the Eocene Pinghu Formation.Therefore,the identification of coal seams is extremely crucial for evaluating coal measure source rocks in the Pinghu Formation in the Xihu Depression.Geochemical and petrological characterization pointed to input of terrigenous organic matter and redox conditions of the depositional environment as factors that govern the ability of the coal measure source rocks in hydrocarbon generation in the Xihu Depression.In this regard,the sedimentary organic facies in the Pinghu Formation were classified into four predominantly terrigenous and one mixed-source subfacies,which all varied in carbon and hydrogen content.The coal measure source rocks in the carbon-and hydrogen-rich tidal flat-lagoon exhibited the highest hydrocarbon generation potential,whereas the mudstone in the neritic facies was the poorest in its hydrocarbon yield.These results suggested that the coal measure source rocks in the Pinghu Formation likely developed in the Hangzhou Slope and the Tiantai Slope,both representing promising sources for oil and gas exploration.

Economics of Coalbed Methane in North West Spain

Coal during its carbonization process produces a gas. This gas, mainly formed by methane, can be used. The use of CBM (Coal bed methane) as an energetic resource is not much known in Spain. This work is the first step to enhance the development of this resource in Castilla y León. A theoretical review and a state of the art description have been carried out, taking into account all the factors that can influence in the development of a CBM project. Then CBM resources have been quantified by Castilla y León accurately for every coal bed. After that, technical feasibility has been used to evaluate total amount of gas that can be recovered. The last step was to evaluate economic feasibility to know how much gas could be economically profitable. This paper covers the economic factor and exploitation options of CBM in Castilla y León, considering technical parameters together with costs and economic requirements for the tow most promising areas in north-west Spain. The main findings include that a CBM system would be feasible in Guardo-Barruelo, however, the economic feasibility will be limited to long operation time of the wells and an increase of the prices of natural gas. In North Leon, the results show a high profitability even under low natural gas prices.

Novel Simplified Method for Coalbed Methane Feasibility Evaluation

Coal during its carbonization process produces a gas. This gas, mainly formed by methane, can be used. This gas, coalbed methane (CBM), is usually mainly formed by methane and can be considered similar to natural gas as energy source. The evaluation of the techno-economic feasibility of the extraction of this gas depends on a large number of complex different factors. The work carried out covers the different aspects to simplify the first approach for CBM feasibility quantification considering a short number of indicators. A theoretical review and a state of the art description have been carried out, taking into account all the factors that can influence in the development of a CBM project. After that, technical feasibility has been used to evaluate total amount of gas that can be recovered. The last step was to evaluate economic feasibility to know how much gas could be economically profitable. Conclusions got have been used to develop a simple method for evaluating CBM economic feasibility considering just four easy known parameters of coal beds. These are: the rank, the thickness, the gas concentration, and the permeability.

Powder River Basin Coal: Powering America

Powder River Basin (PRB) coal in Wyoming and Montana is used to produce 18 percent of the electricity consumed in the United States. Coal production from the PRB more than doubled between 1994 and 2009. PRB coal companies produced greater amounts of coal at declining real prices over much of this period through investment in equipment and production systems that achieved massive economies of scale. The bulk of PRB coal is shipped to the middle part of America from Texas in the south to Michigan in the north and New York in the east. States that consume significant amounts of PRB coal have electricity rates well below the national average. The largest industrial users of electricity are in these regions. Replacing PRB coal would require almost 5.5 trillion cubic feet of natural gas per year, representing a 26 percent increase in demand. Such an increase in gas consumption would increase prices for natural gas by roughly 76 percent. In such a world, U.S. energy users would pay $107 billion more each year for electricity and natural gas. Hence, by using PRB coal, the U.S. economy avoids $107 billion per year in higher energy costs. Estimates reported in the literature indicate that the gross environmental damages from PRB coal production are $27 billion. Hence, the net social benefits of PRB coal are $80 billion per year. Given the large size and low cost of these reserves, PRB coal will likely supply societal energy needs well into the future as long as the public and their elected officials are willing to accept the environmental impacts in return for the substantial economic benefits from using PRB coal.