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Evaluation criteria for gas source rocks of marine carbonate in China
Hydrocarbon generating and expulsion simulation experiments are carried out using samples artifically matched between the acid-dissolved residue of relatively low-maturity limestone and the original sample. This work makes up for the insufficiency of source rock samples with high abundance of organic matters and low maturity in China. The organic carbon content of the 10 prepared samples varies between 0.15 % and 0.74 %. Pyrolysis data and simulation experiment results of hydrocarbon generating and expulsion, which were obtained by a high-temperature and high-pressure open system, indicate that the lower limit of organic carbon content for marine carbonate rock to generate and expel hydrocarbons is 0.23 %-0.31%. In combination with the numerical analysis of organic carbon in marine carbonate rocks from Tarim Basin, Sichuan Basin, Ordos Basin and North China, as well as the contribution of these gas source rocks to the discovered gas pools, we think that the organic carbon criterion for carbonate gas source rocks should be 0.3%....
2020-09-13 23:35:02浏览：66
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Determination of the solubility parameter of cellulose acrylate using inverse gas chromatography
The solubility parameters of cellulose acrylate substituted degree 2.12 (CEA) have been calculated from the measured retention data by inverse gas chromatography at various temperatures. The weight fraction activity coefficients of the solvents at infinite dilution (Ω∞1), the Flory-Huggins thermodynamic interaction parameters between CEA and solvents (X∞12), the excess molar heats of mixing (△Hs1), the partial molar heats of mixing at infinite dilution (△H∞1), the solubility parameters of solvent (δ1), and the solubility parameters of CEA (δ2), were calculated at various temperatures. The δ2 of the CEA was 17.32, 18.00, 18.13, 18.54, 19.39 at 55, 60, 65, 70 and 75℃, respectively....
2020-09-15 12:28:59浏览：70
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Geological constraints of giant and medium-sized gas fields in Kuqa Depression
There is a gas-rich and well-charged petroleum system in the Kuqa Depression where Triassic and Jurassic source rocks play important roles. Distributed in an area of more than 10000 km2 and with a thickness of up to 1000 m, they are composed of dark mudstones, carbonaceous mudstones and coal seams containing 6%, 40% and 90% of TOC, respectively, and are mainly the humic organic matter. As high-quality regional cap rocks, the Neogene and Eogene gypsum rocks and gypseous mudstones matched well with the underlying Neogene and Cretaceous-Eogene sandstones. They have formed the most favorable reservoir-seal assemblages in the Kuqa Depression. Also the Jurassic sandstones and mudstones formed another favorable reservoir-seal assemblage. The traps are shaped late in the fold-thrust belt, mainly fixed in the Tertiary-Quaternary, where ten structure styles have been distinguished. These traps spread as a zone in N-S, are scattered like a segmental line in W-E and show tier-styled vertically. The best traps are gypsum-salt covered fault-bend anticlines related to the passive roof duplex. This petroleum system is characterized by late accumulation. In the early Himalayan Movement, mainly gas condensate and oil accumulated and were distributed in the outer circular region of the kitchen; whereas in the middle and late Himalayan the gas accumulations mainly formed and were distributed in the inner circular region near the kitchen. The overpressure of gas pools is common and is formed by seal capacity of thick gypsum layers, extensive tectonic compression and large uplift. The well-preserved anticline traps underlying the high-quality regional cap rocks of the Tertiary gypsum rocks and gypseous mudstones are the main targets for the discovery of giant and medium-sized gas fields. Above conclusions are important for the petroleum geology theory and the exploration of the fold-thrust belt in foreland basins in central and western China....
2020-09-13 23:35:02浏览：65
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Research on Geological Structure Mark of Coal and Gas Outbursts in Pingdingshan Mining Area
Based on the study of regional displaying rules of coal and gas outburst controlled by geological structure in Pingdingshan mining area, the geological structure features in outburst sites were investigated emphatically. The combination type, orientation and least seam thickness in outburst sites were put forward. This research provides a geological mark for forecasting gas outbursts in deep mining....
2020-09-13 23:35:02浏览：58
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An experimental study of shear strength of gas-hydrate-bearing core samples
The shear strength of gas-hydrate-bearing reservoirs is one of the most important parameters used to study mechanical properties of gas-hydrate-bearing reservoirs. The shear strength of gas-hydratebearing reservoirs changes with filling and cementation of gas hydrates, which will affect the wellbore and reservoir stability. Traditional shear tests could not be conducted on gas-hydrate-bearing core samples because the gas hydrates exist under a limited range of temperature and pressure conditions. This paper describes a novel shear apparatus for studying shear strength of gas-hydrate-bearing core samples under original reservoir conditions. The preparation of gas-hydrate-bearing core samples and subsequent shear tests are done in the same cell. Cohesion and internal friction angle of the core samples with different saturations of gas hydrates were measured with the apparatus. The effect of gas hydrates on the shear strength of reservoirs was quantitatively analyzed. This provides a foundation for studying wellbore and reservoir stability of gas-hydrate-bearing reservoirs....
2020-09-13 23:35:02浏览：37
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Activation of Rejected Fly Ash Using Flue Gas Desulphurization (FGD) Sludge
Low-grade fly ash ( rejected fly ash, rFA ), a significant portion of the pulverized fuel ash ( PFA ) produced from coal-fired power plauts and rejected from the ash classifying process, remains unused due to its high carbon content and large particle size ( ＞ 45μm ). But it is thonght that the rejected ash may have potential uses in chemical stabilization/solidification ( S/S ) processes which need relatively lower strengths and a lower chemical reactivity. Flue Gas Desulphurisation ( FGD ) sludge is a by-product of air pollution control equipment in coal fired power plants whose chemical composition is mainly gypsum. As there is no effective usage of both of these two ntaterials , it is of interest to research on the possible octtivation of rFA using FGD . This paper presents experimental results of a study on the properties of rFA activated by the FGD in rFA-cement pastes. Different percetages of FGD were added into the mix to study the effects of the FGD on the reaction of the rFA blended cement pastes.The results show that FGD takes effect as an activator only at late curing ages. Adding Ca ( OH)2 enhances the effect of FGD on activating the hytration of rFA. Also, 10% FGD by weight of rFA is the optimal addition in the rFA-cement pastes. The results of the compressive strength measurements correlate well with the porosity results....
2020-09-13 23:35:02浏览：49
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Distributions of crystals and gas bubbles in reservoir ice during growth period
In order to understand the dominant factors of the physical properties of ice in ice thermodynamics and mechanics, in-situ observations of ice growth and decay processes were carried out. Two samplings were conducted in the fast and steady ice growth stages. Ice pieces were used to observe ice crystals and gas bubbles in ice, and to measure the ice density. Vertical profiles of the type and size of ice crystals, shape and size of gas bubbles, and gas bubble content, as well as the ice density, were obtained. The results show that the upper layer of the ice pieces is granular ice and the lower layer is columnar ice; the average crystal size increases with the ice depth and remains steady in the fast and steady ice growth stages; the shape of gas bubbles in the upper layer of ice pieces is spherical with higher total content, and the shape in the middle and lower layers is cylinder with lower total content; the gas bubble size and content vary with the ice growth stage; and the ice density decreases with the increase of the gas bubble content....
2020-09-13 23:35:02浏览：52
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Research on On-line detection system for natural gas pipeline
Four methods for testing the thickness and defect of pipeline are compared and analyzed in this paper. The testing principle of magnetic leakage flux based on electromagnetism is discussed in detail. From the experiments of sensor character, the effects caused by some factors are found, which give some important information for sensor design, and this method is proved reasonable and effective. The mechanical and electrical structures of inspection equipment, as well as its working principle and technical features are introduced. In this paper, control flow and software design are discussed, too. This detection system has been successfully developed. Experiments show that this detection system has high resolution and can be put into practice....
2020-09-13 23:35:02浏览：69
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GAS流量温压补偿在DCS中的设计与应用
GAS流量的温度压力补偿是工业流量检测中经常遇到的问题.本文着重阐述了GAS流量测量在横河DCS系统中的应用及其流量温压补偿的计算校正与设计....
2020-09-13 23:35:02浏览：39
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Spatial coupling relationships of gas hydrate formation in the Tibetan Plateau
At present, gas hydrates are known to occur in continental high latitude permafrost regions and deep sea sediments. For middle latitude permafrost regions of the Tibetan Plateau, further research is required to ascertain its potential development of gas hydrates. This paper reviewed pertinent literature on gas hydrates in the Tibetan Plateau. Both geological and ge-ographical data are synthesized to reveal the relationship between gas hydrate formation and petroleum geological evo-lution, Plateau uplift, formation of permafrost, and glacial processes. Previous studies indicate that numerous residual basins in the Plateau have been formed by original sedimentary basins accompanied by rapid uplift of the Plateau. Ex-tensive marine Mesozoic hydrocarbon source rocks in these basins could provide rich sources of materials forming gas hydrates in permafrost. Primary hydrocarbon-generating period in the Plateau is from late Jurassic to early Cretaceous, while secondary hydrocarbon generation, regionally or locally, occurs mainly in the Paleogene. Before rapid uplift of the Plateau, oil-gas reservoirs were continuously destroyed and assembled to form new reservoirs due to structural and thermal dynamics, forcing hydrocarbon migration. Since 3.4 Ma B.P., the Plateau has undergone strong uplift and extensive gla-ciation, periglacier processes prevailed, hydrocarbon gas again migrated, and free gas beneath ice sheets within sedi-mentary materials interacted with water, generating gas hydrates which were finally preserved under a cap formed by frozen layers through rapid cooling in the Plateau. Taken as a whole, it can be safely concluded that there is great temporal and spatial coupling relationships between evolution of the Tibetan Plateau and generation of gas hydrates....
2020-09-13 23:35:02浏览：67
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Origin of Natural Gas in Kekeya Field, Tarim Basin, China
This paper is mainly concentrated on the geochemical characteristics and origin of gas of Kekeya field in the Tarim basin, NW China. This study shows that Permian mudstone is the main source rock of oil and gas. Based on the carbon isotopes of C1-C4, the carbon isotope of gas in Kekeya field is a little heavier than that in the typical marine-derived gas. The relationship between carbon isotopes of methane and ethane is coincident with Faber equation of gas derived from organic matter Ⅰ/Ⅱ. The majority of gas maturity is estimated, based on the formula, at 1.8 %-2.2 % besides K2 and K18 wells. In addition, the gas derived from 0.9 %-1.2 % Ro source rocks may also be mixture. 40Ar/36Ar and 3He/4He ratios from the gas samples also support the mixing process. Moreover, the gas in this region is mainly generated from more mature source rocks although the low mature gas exists....
2020-09-13 23:35:02浏览：40
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Source-Contacting Gas:Accumulation Mechanism and Distribution in China
Source-contacting gas, which is also called basin-center gas, deep basin gas, is the tight-sand gas accumulation contacting closely to its source rocks. Having different accumulation mechanisms from conventional gas reservoirs that are formed by replacement way, the typical source-contacting gas reservoirs are formed by piston-typed migration forward way. Source-contacting gas accumulations exhibit a series of distinctly mechanic characteristics. According to the valid combination of these characteristics, the estimation for the type of discovered gas reservoirs or distributions of source-contacting gas reservoirs can be forecasted. The source-contacting gas is special for having no edge water or bottom water for gas and complicated gas-water relationships, which emphasizes the intimate association of reservoir rocks with source rocks, which is called the root of the gas reservoir. There are many basins having the mechanic conditions for source-contacting gas accumulations in China, which can be divided into three regions. Most of the basins with favorable accumulation conditions are located mainly in the central and western China. According to the present data, basins having source-contacting gas accumulations in China can be divided into three types, accumulation conditions and configuration relationships are the best in type A basins and they are the larger basins in central China. Type B basins with plain accumulation conditions exist primarily in eastern China and also the basins in western China. Accumulation conditions and exploration futures are worse in type C basins, which refer mainly to the small basins in southern China and China Sea basins. Main source-contacting gas basins in China are thoroughly discussed in this paper and the distribution patterns of source-contacting gas in five huge basins are discussed and forecasted....
2020-09-13 23:35:02浏览：83
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Temperature distribution and control in liquefied petroleum gas fluidized beds
Temperature distribution and control have been investigated in a liquefied petroleum gas (LPG) fluidized bed with hollow corundum spheres (A12O3) of 0.867-1.212 mm in diameter at moderately high temperatures (800-1100℃). Experiments were carried out for the air consumption coefficient α in the range of 0.3 to 1.0 and the fluidization number N in the range of 1.3 to 3.0. Particle properties, initial bed height, α and N all affect temperature distribution in the bed. Bed temperature can be adjusted about 200℃ by combined the adjusting of α and N....
2020-09-13 23:35:02浏览：53
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Research and Application of New Methods to Oil-Gas Geochemical Exploration
Based on the results of researches and applications for many years, it has been discovered that new methods and techniques for geochemical exploration of oil and gas such as D C, altered carbonate, Hg in absorption phase, Ks, Fe2+, d 13C, fluorescence in two and three dimensions, and N2 and O2 in heat release can give full play in the following five fields: (1) optimization of the favourable target or hollow zones and structural zones in a region; (2) evaluation of oil traps and delineation of prospective oil and gas areas; (3) prediction of deep-seated oil-bearing horizons; (4) evaluation of the genesis of oil and gas geochemical anomalies and determination of the types of oil and gas accumulations; (5) forecast of the burial depths of oil and gas pools....
2020-09-13 23:35:02浏览：37
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Distribution and Chain Pattern of Liquefied Natural Gas Industry in China
The production and consumption of natural gas in China has been developing rapidly in recent years. It is expected that the annual growth rate of the demand for natural gas will reach 12% in the next 15 years, and the gas consumption in the primary energy will increase from 0.3% to 10% or more by 2020. However, since the supply of natural gas cannot satisfy the requirements, China has begun to build liquefied natural gas (LNG) terminals in the coastal regions such as Guangdong and Fujian, and solve this problem by importing LNG from foreign countries. LNG needs to be transported by LNG ships from abroad. With the rapid growth of global gas production, the volume of LNG trade also increases, and the interregional production increased from 0.3% in 1970 to 26.2% in 2004. So, we need LNG ships more than before. This article puts forward the distribution of LNG ships and the speculation of the future of LNG transportation based on the studies on foreign LNG production, the LNG trade, the building of LNG ships, the LNG transportation, the chain model of LNG distribution, etc....
2020-09-13 23:35:02浏览：60
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