Natural gas refers to all gases naturally occurring in nature, including those formed by various natural processes in the atmosphere, hydrosphere, and lithosphere (including oil field gas, gas field gas, mud volcanic gas, coal bed gas, and biogenic gas, etc.).
Natural gas is buried underground
Natural gas is stored
1.Natural gas exists under the ground
Natural gas is one of the safer gas. It does not contain carbon monoxide and is lighter than air. Once leaked, it will spread upward immediately, and it is not easy to accumulate to form explosive gas. The safety is relatively higher than other combustors.
Using natural gas as an energy source can reduce
The genesis of natural gas is diverse, and the formation of natural gas runs through diagenesis, deep formation, post-formation, and metamorphism.
In 2005, the world's total proven natural gas reserves were 179.53 trillion cubic meters.
At the beginning of the 21st century, the world's major natural gas producing countries (unit: 100 million cubic meters)
country
Reserves
Annual output
Natural gas can suffocate when it reaches a certain level in the air. Natural gas is not as toxic as carbon monoxide, it is essentially harmless to the human body. However, if natural gas is in a high concentration state and the oxygen in the air is not enough to sustain life, it will still cause death. After all, natural gas cannot be used for human breathing. As fuel, natural gas can also cause casualties due to explosions.
Although natural gas is lighter and easier to diverge than air, when natural gas accumulates in a closed environment such as a house or tent, it will trigger a powerful explosion when it reaches a certain proportion. The explosion could level the entire house and even hit nearby buildings. The lower limit of the explosive limit of methane in air is 5% and the upper limit is 15%.
The explosion of compressed natural gas to be used in the engine of natural gas vehicles is basically unavailable under spontaneous conditions due to the volatile nature of the gas. Therefore, external forces are required to maintain the concentration of natural gas between 5% and 15% to trigger the explosion.
Natural gas is widely distributed in nature, with various types of genesis and different degrees of thermal evolution, and its geochemical characteristics are also diverse, so it is difficult to identify with a unified index. Practice has shown that it is more reliable to use a combination of multiple indicators than a single indicator. According to the projects involved in the determination of natural gas genesis, there are mainly isotopes, gas components, light hydrocarbons, and
Natural gas is an important energy source and is widely used as city gas and industrial fuel; however, natural gas is generally referred to only as a hydrocarbon-rich combustible gas stored in deeper formations, and natural gas that coexists with oil is often called for
Industrial fuel
Use natural gas instead of coal for factory heating, production boilers and thermal power plants
China
Natural gas is also buried in underground geological structures like crude oil. Some are stored in the same layer as crude oil, and some exist separately. For natural gas stored in the same horizon as crude oil, it will be produced along with crude oil.
As for the single-phase gas, we call it a gas reservoir. Its extraction method is very similar to that of crude oil, but also has its special features. due to
Natural gas accounted for about 18% to 19% of world energy consumption in the 1970s.
From 2006 to 2010, China's remaining technologically recoverable natural gas reserves increased from 3.0 trillion cubic meters to 3.8 trillion cubic meters, an increase of 25.90%; natural gas production increased from 58.6 billion cubic meters to 96.8 billion cubic meters, an increase of 65%.
From January to October 2011, China's natural gas output reached 82.6 billion cubic meters, a year-on-year increase of 6.60%. Although both reserves and production have increased significantly, they still cannot meet the domestic gas market consumer demand.
The growth of natural gas supply is not as fast as the growth of consumption, and the imbalance between domestic natural gas supply and demand has led to the continuous increase in China's natural gas imports. From January to October 2011, China imported about 25 billion cubic meters of natural gas, which has nearly doubled year-on-year.
During the Twelfth Five-Year Plan period, 44,000 kilometers of new natural gas pipelines (including branch lines) will be newly built, and the main pipeline capacity will be increased by about 150 billion cubic meters per year; the working gas volume of the new gas storages will be about 22 billion cubic meters, accounting for about 2015 natural gas consumption. 9% of the total; urban emergency and peak gas storage capacity reached 1.5 billion cubic meters.
By the end of the Twelfth Five-Year Plan period, a national main trunk with the West-East Gas Transmission, Sichuan-East Gas Transmission, Shaanxi-Beijing Line and coastal trunk roads as main arteries will be formed, connecting the four major strategic import channels, major production areas, consumption areas and gas storage Pipe network, forming a multi-gas supply, multi-modal peak regulation, stable and safe gas supply pattern. [4]
A research report issued by the China Petroleum and Chemical Industry Federation in January 2015 entitled "Uncertainty in the Development of Natural Gas in China" (hereinafter referred to as the "Report") shows that the apparent consumption of natural gas in China in 2014 was 180 billion cubic meters, a year-on-year increase of 7.4%, of which 58 billion cubic meters were imported natural gas, with an external dependence of 32.2%.
According to the Energy Development Strategy Action Plan (2014-2020) issued by the State Council [6]
On September 10, 2018, the State Council "Several Opinions on Promoting the Coordinated and Stable Development of Natural Gas" (hereinafter referred to as "Opinions"). It is proposed to increase domestic exploration and development efforts. Strive to achieve domestic natural gas output of more than 200 billion cubic meters by the end of 2020.
Data show that China's natural gas output increased by more than 10 billion cubic meters in 2017, reaching 148.03 billion cubic meters, a year-on-year increase of 8.2%. From January to July this year, China s apparent natural gas consumption has accumulated 157.56 billion cubic meters, a year-on-year increase of 16.47%; China s natural gas production has reached 90.49 billion cubic meters, a year-on-year increase of 5.5%, which is 3.3% lower than the growth rate of January to June 2017 percentage point.
The "Opinions" proposed that the construction of the production, supply, storage and marketing system should be strengthened to promote the dynamic balance of natural gas supply and demand. First, increase domestic exploration and development efforts. Strictly implement the block withdrawal mechanism for oil and gas exploration, comprehensively implement block competitive transfers, encourage market-oriented transfer of mining rights, accelerate the use of proven unused reserves, and strengthen the energy security assessment of state-owned oil and gas companies. The second is to improve the diversified overseas supply system for natural gas. Accelerate the diversification of importing countries (regions), transportation methods, import channels, contract models, and participating entities. The third is to build a multi-level reserve system. Promote the construction of gas storage capacity of local governments and urban gas enterprises in a coordinated manner, realize the intensive and large-scale operation of gas storage facilities, avoid blooming everywhere, and encourage various investment entities to establish joint ventures to build gas storage facilities. The fourth is to strengthen natural gas infrastructure construction and interconnection. Quickly introduce the reform plan of the oil and gas pipeline network system, promote the fair opening of infrastructure to third-party market entities; deepen the reform of "decentralization of service", and shorten the period of project construction procedures and approval.
The "Opinions" emphasizes the need to deepen the reform of the natural gas sector and establish and improve a coordinated and stable development mechanism. The first is to establish a forecast and early warning mechanism for natural gas supply and demand. The second is to establish a comprehensive coordination mechanism for natural gas development. "Coal to gas" adheres to "determining gas to reform" and gradually promotes the protection of gas demand in key areas such as Beijing, Tianjin, Hebei, the surrounding areas, and the Fenwei plain. The third is to establish and improve the natural gas demand side management and peak regulation mechanism. The fourth is to establish and improve the emergency system for natural gas supply guarantee. Implement the main responsibility of local people's governments at all levels for the people's livelihood gas protection and supply, and do a good job in pre-planning for grading protection and supply and user peak regulation. Fifth, rationalize the natural gas price mechanism. Ensure the steady implementation of the price reform plan for gas valve stations for residents, speed up the establishment of upstream and downstream natural gas price linkage mechanisms, and implement differentiated price policies such as seasonal spreads and interruptible gas prices. Sixth, strengthen the safe operation mechanism of the natural gas industry chain. [10]
The upper limit of sulfur content for civil natural gas is: Class I gas is 100mg / m3 or less, Class II gas is 200mg / m3 or less, and Class III gas is 460mg / m3 or less. Therefore, the maximum sulfur dioxide released after 1 cubic meter of natural gas is (460mg / 32) * 64 = 920mg.
GB / T 21446-2008 Measurement of natural gas flow with standard orifice flow meter GB / T 18975.2-2008 Industrial automation systems and integrated process plants (including oil and gas production facilities) Life cycle data integration Part 2: Data model GB / T 11060.2 -2008 Determination of sulfur compounds in natural gas-Part 2: Determination of hydrogen sulfide content by methylene blue method
GB / T 22634-2008 Conversion between natural gas water content and water dew point
GB / T 16781.1-2008 Determination of mercury content in natural gas. Part 1: Iodine chemical adsorption sampling method
GB / T 22724-2008 Design of LNG equipment and onshore installation
GB / T 19205-2008 standard reference conditions for natural gas
GB / T 22723-2008 Determination of natural gas energy
GB / T 18437.1-2009 Technical requirements for conversion of gas vehicles Part 1: Compressed natural gas vehicles
GB / T 23335-2009 Natural Gas Vehicle Type Test Regulations
GB 24162-2009 Periodic inspection and evaluation of compressed natural gas metal fiber ring wound cylinders for automobiles GB 17926-2009 Valves for compressed natural gas cylinders for automobiles
GB 24163-2009 Regular inspection and evaluation of compressed natural gas cylinders for stations
GB 24160-2009 Compressed Natural Gas Steel Liner Circular Wound Gas Cylinder
GB / T 24964-2010 Cryogenic light hydrocarbon fluid liquefied natural gas on board trade transfer procedure GB / T 24963-2010 LNG equipment and ship-shore interface
GB / T 11060.4-2010 Determination of sulfur compounds in natural gas. Part 4: Determination of total sulfur content by oxidation micro-coulometry
GB / T 11060.5-2010 Determination of sulfur compounds in natural gas. Part 5: Determination of total sulfur content by hydrogenolysis-rate meter colorimetry
GB / T 11060.1-2010 Determination of sulfur compounds in natural gas. Part 1: Determination of hydrogen sulfide content by iodometric method
GB / T 11060.3-2010 Determination of sulfur compounds in natural gas. Part 3: Determination of hydrogen sulfide content by the dual optical path detection method using lead acetate reaction rate
GB / T 16781.2-2010 Determination of mercury content in natural gas. Part 2: Sampling method for amalgamation of gold-platinum alloy
GB / T 14099.5-2010 Gas turbine procurement Part 5: Application in the oil and gas industry GB / T 25360-2010 Reciprocating piston natural gas compressors for automobile filling stations
GB / T 25986-2010 LNG bunkering device for automobiles GB / T 26780-2011 Compressed natural gas automobile fuel system collision safety requirements GB / T 26978.1-2011 Design and construction of vertical cylindrical flat-bottom steel LNG storage tanks assembled on site Part 1: General
GB / T 26978.2-2011 Design and construction of vertical cylindrical flat-bottom steel liquefied natural gas storage tanks assembled on site. Part 2: Metal components
Table 1 Common flow meters for natural gas measurement
