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,t...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%e60%at the principal oil generation stage,and 50%e80%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 230.4×10^(12) m^(3) at the high evolution stage of occluded hydrocarbon of the Lower Cambrian Qiongzhusi Fm in this basin,and 12.3×10^(12) m^(3) 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 GaoshitieMoxi,Ziyang and Weiyuan,covering a favorable area of 4.3×10^(4) km^(2).展开更多
To understand the reservoir property and hydrocarbon accumulation conditions of the Middle and Upper Ordovician intraplatform shoal between ultra-deep main strike-slip faults in Fuman Oilfield of the Tarim Basin, Chin...To understand the reservoir property and hydrocarbon accumulation conditions of the Middle and Upper Ordovician intraplatform shoal between ultra-deep main strike-slip faults in Fuman Oilfield of the Tarim Basin, China, the main strike-slip faults in and around well FD1 in the basin were analyzed in terms of sedimentary facies, sequence stratigraphy, intraplatform shoal reservoir property, and oil and gas origins, based on drilling data. The Yingshan Formation intraplatform shoal between the main strike-slip faults is superimposed with low-order faults to form a new type of hydrocarbon play. Firstly, hydrocarbons generated from the Lower Cambrian Yuertusi Formation source rocks vertically migrated into the second member of Yingshan Formation through the main strike-slip faults, and then migrated laterally until they were accumulated. A small amount of oil from Well FD1 came from the Yuertusi Formation source rocks in the mature stage, and a large amount of gas originated from oil cracking in the ultra-deep reservoirs. Therefore, the secondary gas condensate reservoir in Well FD1 is characterized by high gas to oil ratio, dry gas (dryness coefficient being 0.970) and hybrid origin. This new type of hydrocarbon play characterized by intraplatform shoal and low-order fault suggests a prospect of continuous hydrocarbon-bearing area in Fuman Oilfield, which will expand the ultrap-deep oil and gas exploration in the oilfield.展开更多
The systematic experimental studies were performed on the hydrate formation kinetics and gas-hydrate equilibrium for a simulated catalytic cracking gas in the water-in-oil emulsion. The effect of temperature, pressure...The systematic experimental studies were performed on the hydrate formation kinetics and gas-hydrate equilibrium for a simulated catalytic cracking gas in the water-in-oil emulsion. The effect of temperature, pressure and initial gas-liquid ratio on the hydrate formation was studied, respectively. The data were obtained at pressures ranging from 3.5 to 5 MPa and temperatur.es from 274.15 to 277.15 K. The results showed that hydrogen and methane can be separated Irom the （~2＋ ti＇action by tOrming hydrate at around 273.15 K which is much higher temperature than that of the cryogenic separation method, and the hydrate formation rate can be enhanced in the wa- ter-in-oil emulsion compared to pure water. The experiments provided the basic data for designing the industrial process, and setting the suitable operational conditions. The measured data ot gas-hydrate equilibria were compared with the predictions by using the Chen-Guo hydrate thermodynamic model.展开更多
In this paper, simulated experiment device of coal and gas outburst was employed to perform the experiment on gas-containing coal extrusion. In the experiment, coal surface cracks were observed with a high-speed camer...In this paper, simulated experiment device of coal and gas outburst was employed to perform the experiment on gas-containing coal extrusion. In the experiment, coal surface cracks were observed with a high-speed camera and then the images were processed by sketch. Based on the above description, the paper studied the fractal dimension values from different positions of coal surface as well as their changing laws with time. The results show that there is a growing parabola trend of crack dimension value in the process of coal extrusion. Accordingly, we drew the conclusion that extruded coal crack evolution is a process of fractal dimension value increase. On the basis of fractal dimension values taken from different parts of coal masses, a fractal dimension of the contour map was drawn. Thus, it is clear that the contour map involves different crack fractal dimension values from different positions. To be specific, where there are complicated force and violent movement in coal mass, there are higher fractal dimension values, i.e., the further the middle of observation surface is from the exit of coal mass, and the lower the fractal dimension value is. In line with fractal geometry and energy theory of coal and gas outburst, this study presents the relation between fractal dimension and energy in the process of extruding. In conclusion, the evolution of crack fractal dimension value can signify that of energy, which has laid a solid foundation for the quantification research on the mechanism of gas-containing coal extrusion.展开更多
In recent years,much attention has been paid to the development environment,biogenetic compositions and hydrocarbon generation characteristics of ancient source rocks in the deep strata of the Sichuan Basin because oi...In recent years,much attention has been paid to the development environment,biogenetic compositions and hydrocarbon generation characteristics of ancient source rocks in the deep strata of the Sichuan Basin because oil and gas exploration extends continuously to the deep and ultra-deep strata and a giant gas field with the explored reserves of more than 1×10^(12)m^(3)was discovered in the Middle and Upper ProterozoiceLower Paleozoic strata in the stable inherited paleo-uplift of the central Sichuan Basin.Based on the previous geological research results,outcrop section of the Datangpo Fm,Nanhua System,at the southeastern margin of the Sichuan Basin was observed and the samples taken from the source rocks were tested and analyzed in terms of their organic geochemistry and organic petrology.It is shown that high-quality black shale source rocks of the Datangpo Fm are developed in the tensional background at the southeastern margin of the Sichuan Basin between two glacial ages,i.e.,Gucheng and Nantuo ages in the Nanhua Period.Their thickness is 16e180 m and mineral compositions are mainly clay minerals and clastic quartz.Besides,shale in the Datangpo Fm is of high-quality sapropel type source rock with high abundance at an overmature stage,and it is characterized by low pristane/phytane ratios(0.32-0.83),low gammacerane abundance,high-abundance tricyclic terpane and higher-content C_(27)and C_(29)gonane,indicating that biogenetic compositions are mainly algae and microbes in a strong reducing environment with low salinity.It is concluded that the Datangpo Fm source rocks may be developed in the rift of Nanhua System in central Sichuan Basin.Paleo-uplifts and paleo-slopes before the Caledonian are the favorable locations for the accumulation of dispersed liquid hydrocarbons and paleo-reservoirs derived from the Datangpo Fm source rocks.In addition,scale accumulation zones of dispersed organic matter cracking gas and paleo-reservoirs originated from the Datangpo Fm source rocks may be discovered in the stable area inside the Sichuan Basin.展开更多
Based on analyses of characteristics,hydrocarbon charging history and geological conditions for the formation of Sinian-Cambrian reservoirs in the north slope area of central Sichuan paleo-uplift,the natural gas origi...Based on analyses of characteristics,hydrocarbon charging history and geological conditions for the formation of Sinian-Cambrian reservoirs in the north slope area of central Sichuan paleo-uplift,the natural gas origin,accumulation evolution,accumulation pattern and formation conditions of large lithologic gas reservoirs have been investigated.Through comprehensive analyses of natural gas composition,carbon and hydrogen isotopic compositions,fluid inclusions,reservoir bitumen,and geological conditions such as lithofacies paleogeography and beach body characterization,it is concluded that:(1)The natural gas in the Sinian-Cambrian of the north slope area is mainly oil cracking gas,and different contribution ratios of multiple sets of source rocks lead to different geochemical characteristics of natural gas in different reservoirs.(2)Although the both Sinian and Cambrian gas reservoirs in this area are lithologic gas reservoirs under monocline background,the former has normal-pressure and the latter has high-pressure.There are three types of source-reservoir-caprock combinations:single source with lower generation and upper reservoir,double sources with lower generation and upper reservoir or with side source and lateral reservoir,double sources with lower generation and upper reservoir or with upper generation and lower reservoir.The Permian-Triassic is the main generation period of oil,Early-Middle Jurassic is the main generation period of oil cracking gas and wet gas,and Late Jurassic-Cretaceous is the main generation period of dry gas.(3)The Sinian-Cambrian system of the north slope area has two favorable conditions for formation of large lithologic gas reservoirs,one is that the large scale beach facies reservoirs are located in the range of ancient oil reservoirs or near the source rocks,which is conducive to the"in-situ"large-scale accumulation of cracked gas in the paleo-oil reservoirs,the other is that the large scale mound-beach complex reservoirs and sealing layers of inter beach tight zones match effectively to form large lithologic traps under the slope background.The research results confirm that the north slope area has large multi-layer lithologic gas reservoirs with more than one trillion cubic meters of natural gas resources and great exploration potential.展开更多
This paper presents experimental results of cocracking of straight-run gasoline (SRG) and light gaS oil (LGO) in an improved pulsed-micro-pyrolyzer. It is shown that there are negative opergistic effect on the yields ...This paper presents experimental results of cocracking of straight-run gasoline (SRG) and light gaS oil (LGO) in an improved pulsed-micro-pyrolyzer. It is shown that there are negative opergistic effect on the yields and selectivities of ethylene and propylene in cocracking. The difference in coking tendencies betWeen the cocracking and the separate cracking is compared as well.展开更多
Industrial purification processes for ethylene from steam pyrolysis or cracking gases generally employ multiple energy-intensive steps to remove C_(2)H_(2),C_(2)H_(6),CO_(2),and C_(3) hydrocarbons.Designing multifunct...Industrial purification processes for ethylene from steam pyrolysis or cracking gases generally employ multiple energy-intensive steps to remove C_(2)H_(2),C_(2)H_(6),CO_(2),and C_(3) hydrocarbons.Designing multifunctional molecular separators that integrate multiple structural characteristics capable of removing several impurities simultaneously is highly desired but not yet realized.Here,we address this challenge using a custom-designed multifunctional,and industry-compatible ultramicroporous crystalline physisorbent(CALF-20)to purify C_(2)H_(4) from a seven-component cracking gas mixture(C_(2)H_(4),C_(2)H_(2),C_(2)H_(6),CO_(2),C_(3)H_(4),C_(3)H_(6),and C_(3)H8)by one-step separation with remarkable performance.Verified by breakthrough experiments,C_(2)H_(4)(>99.99%)can be recovered not only from binary C_(2)H_(6)/C_(2)H_(4)(50/50),ternary C_(2)H_(2)/C_(2)H_(4)/C_(2)H_(6)(33/33/33),and quaternary C_(2)H_(2)/C_(2)H_(4)/C_(2)H_(6)/CO_(2)(25/25/25/25)mixtures,but also from a typical seven-component gas cracking mixture of C_(2)H_(2)/C_(2)H_(4)/C_(2)H_(6)/CO_(2)/C_(3)H_(4)/C_(3)H_(6)/C_(3)H8(0.6/62/10/0.3/0.6/26/0.5),even at the high humidity of 74%.Notably,CALF-20 can be easily produced on the kilogram scale,showing great commercial application potential.Together with its framework flexibility and appropriate pore geometry,CALF-20 exhibits a sorbent-sorbate induced-fit behavior strengthening multiple specific recognition sites for the corresponding vips,validated by single-crystal X-ray diffraction study and molecular modeling.This work is the first example of using a single physisorbent to purify C_(2)H_(4) from a seven-component cracking gas mixture and opens an avenue to address complicated hydrocarbon mixture separation challenges.展开更多
Using high pressure and geological condition simulation vessels, we conducted hydrous pyrolysis experiments of kerogen, solid bitumen and liquid hydrocarbons in southern China in order to study the processes of gas ge...Using high pressure and geological condition simulation vessels, we conducted hydrous pyrolysis experiments of kerogen, solid bitumen and liquid hydrocarbons in southern China in order to study the processes of gas generation and derive geo- chemical indicators of gas genesis under approximate pressure and temperature. The results indicate that gas generation productivity of different marine material decreased in the ganic matter （solid bitumen and heavy oil）, and kerogen. order of crude oil （light oil and condensate）, dispersed soluble or- Under identical temperature-pressure regimes, pyrolysates derived from kerogen and dispersed soluble organic matter display drastically different geochemical characteristics. For example, the δ13Cc02-δ13C1 values of gaseous products from dispersed soluble organic matter are greater than 20%o, whereas those from kerogen are less than 20%~. The 813C1 values of pyrolysates from different marine hydrocarbon sources generally increase with pyrolysis temperature, but are always lower than those of the source precursors. The δ13C values of ethane and propane in the pyrolysates also increase with increasing pyrolysis temperature, eventually approaching that of their sources, at peak hydro- carbon generation. At high-over mature stages, the δ13C values of ethane and propane are often greater than those of their sources but close to those of coal gases, and thus become ineffective as gas genetic indicators. Ln（CffC3） can clearly distin- guish kerogen degradation gas from oil cracking gas and Ln（CJC2）-（δ13C1-δ13C2） can be an effective indicator for distinguishing oil cracking gas from dispersed soluble organic matter cracking gas.展开更多
The composition characteristics of light hydrocarbons from crude oil,chloroform bitumen A,saturated hydrocarbon fraction,aromatic hydrocarbon fraction,and asphaltene fraction during cracking have been studied systemat...The composition characteristics of light hydrocarbons from crude oil,chloroform bitumen A,saturated hydrocarbon fraction,aromatic hydrocarbon fraction,and asphaltene fraction during cracking have been studied systematically.The results revealed that the content of n-alkanes,branched alkanes and cycloalkanes in light hydrocarbons from the samples gradually decreased as the simulation temperature increased,and finally almost depleted completely,while the abundance of methane,benzene and its homologues increased obviously and became the main products.The ratios of benzene/n-hexane and toluene/n-heptane can be used as measures for oil cracking levels.Variation characteristics of maturity parameters of light hydrocarbons,for example,iC4/nC4,iC5/nC5,isoheptane value,2,2-DMC4/nC6,and 2-MC6+3-MC6/nC7 for different samples with increasing pyrolysis temperature,are consistent with those in petroleum reservoirs,indicating that these parameters may be efficient maturity index.展开更多
Well Yingnan 2,an important exploratory well in the east of Tarim Basin,yields high commercial oil and gas flow in Jurassic.Natural gas components and carbon isotopic composition indicate that it belongs to sapropel t...Well Yingnan 2,an important exploratory well in the east of Tarim Basin,yields high commercial oil and gas flow in Jurassic.Natural gas components and carbon isotopic composition indicate that it belongs to sapropel type gas.Because this region presents many suits of hydrocarbon source rocks,there are some controversies that natural gases were generated from kerogen gas or crude oil cracking gas at present.By using the kinetics of hydrocarbon generation and carbon isotope,natural gas of Well Yingnan 2 is composed mainly of crude oil cracking gas,about 72%,it is generated from secondary kerogen gas of Cambrian-Lower Ordovician source rock and crude oil cracking gas of Mid-Upper Ordovician oil reservoir.The main oil and gas filling time is 65 Ma later in the Jurassic gas reservoir of Well Yingnan 2,so the gas reservoir belongs to late accumulation and continuous filling type.展开更多
The Sinian-Cambrian formations of the Sichuan Basin have favorable hydrocarbon accumulation conditions,but the exploration for large-scale gas fields is quite challenging due to old strata and multiple tectonic moveme...The Sinian-Cambrian formations of the Sichuan Basin have favorable hydrocarbon accumulation conditions,but the exploration for large-scale gas fields is quite challenging due to old strata and multiple tectonic movements.Since the Weiyuan Sinian large gas field was found in 1964,the largest monoblock gas field(Anyue Gasfield)was discovered in the Cambrian Longwangmiao Formation of the Moxi region in 2013 with proven gas reserves of 440.1×109 m3.Total proven,probable and possible reserves exceed one trillion cubic meters in the Sinian Dengying Formation and the Cambrian Longwangmiao Formation of the Gaoshiti-Moxi region.The natural gas components,light hydrocarbons,reservoir bitumen abundance and other evidences prove that the dry natural gas was mainly derived from oil-cracking,with methane(a content of 82.65%-97.35%),ethane(a content of 0.01%-0.29%),nitrogen(a content of 0.44%-6.13%),helium(a content of 0.01%-0.06%),and hydrogen sulphide(0.62-61.11 g/m^(3)).Gas reservoir pressure increases gradually from the Sinian normal pressure(a pressure coefficient of 1.07-1.13)to high pressure(a pressure coefficient of 1.53-1.70)in the Cambrian Longwangmiao Formation.The temperature of the gas reservoir is 137.5-163 ℃.Gas reservoir traps are divided into three categories:tectonic type,tectonic-formation type and tectonic-lithologic type.The large-scale enrichment of the Sinian-Cambrian natural gas results from effective configuration of the large stable inherited palaeo-uplift during the Tongwan tectonic movement,wide distribution of ancient source rocks,high-quality reservoirs with vast pore-cavity,crude oil cracking of large palaeo-reservoirs and favorable preservation conditions.According to the palaeo-structure pattern prior to crude oil cracking of the palaeo-reservoirs,and bitumen abundance as well as the distribution characteristics of current gas reservoirs,the accumulation patterns of the cracking gas reservoir can be classified into three types:accumulation type,semi-accumulation and semi-dispersion type,and dispersion type.This understanding will play an important role in guiding the exploration of the Sinian-Cambrian natural gas exploration in the Sichuan Basin.展开更多
Focusing on the two natural gas exploration geological problems with abundant source of oil cracking gas in the late stage and the sealing condition of the oil cracking gas reservoir,the kinetics of oil cracking gas a...Focusing on the two natural gas exploration geological problems with abundant source of oil cracking gas in the late stage and the sealing condition of the oil cracking gas reservoir,the kinetics of oil cracking gas and the evaluation parameters of gas cap rock are adopted to the study on the natural gas accumulation conditions in the Tadong area.Both the study on the kinetics of oil cracking gas and the statistical results of reservoir bitumen reveal that the geological formation of oil cracking gas in the Tadong area is located in the top of Cambrian.Two kinds of oil cracking gas geological models at least,namely well Mandong-1's early rapid generation model(Middle Ordovician-end Silurian)and peak cracking model(with the natural gas conversion rate>90%),namely well Yingnan-2's two-stage generation model of oil cracking gas,have been set up.The oil cracking gas of Yingnan-2 in the late stage is very significant in the evaluation of natural gas exploration in the Tadong area.The evaluation results of the cap rock show that the microscopic parameters of cap rock from the lower assemblage of Cambrian-Ordovician are better than those from the upper assemblage.The former has strong capillary sealing ability and higher cap rock breakthrough pressure than the upper assemblage,with strong sealing ability,so that natural gas dissipates mainly by diffusion.According to the above investigations,the lower assemblage Cambrian-Ordovician natural gas of Kongquehe slope,Tadong low uplift and Yingjisu depression in the Tadong area prospects well.展开更多
There are mainly 3 kinds of existing states of oil generating from source rocks,that is,dispersive liquid hydrocarbon inside of source rock,dispersive liquid hydrocarbon outside of source rock and concentrated liquid ...There are mainly 3 kinds of existing states of oil generating from source rocks,that is,dispersive liquid hydrocarbon inside of source rock,dispersive liquid hydrocarbon outside of source rock and concentrated liquid hydrocarbon outside of source rock.Because of the differences in thermal history and medium conditions around,and the interaction of organic and inorganic matter,the liquid hydrocarbon with 3 kinds of existing state has different cracking conditions.The gas generation dynamics experiments of crude oil matching different mediums indicate that the distribution of activation energy of methane changes a lot according to medium difference.The carbonate has a main influence on oil cracking conditions and can largely reduce its activation energy,which reflects the lower cracking temperature of crude oil.The mudstone takes a second place and the sandstone is the smallest.The catalytic cracking function to the oil of the carbonate,of the mudstone and of the sandstone changes weaken in turn.The corresponding Ro values of main gas generation period in different mediums are as follows:1.5%―3.8%with pure crude oil,1.2%―3.2%with dispersive crude oil in carbonate,1.3%~3.4%with dispersive crude oil in mudstone and 1.4%―3.6%with dispersive crude oil in sandstone.The influence of pressure to crude oil cracking is relatively complicated.In the low heating speed condition,pressure restrains the oil cracking and gas generation,but in the high heating speed condition,pressure has an indistinctive influence to the oil cracking and gas generation.Pressure also makes a different effort in different evolvement stage.Taking the middle and lower Cambrian source rocks in the Tarim Basin as an example,primary oil generating quantity is 2232.24×108 t,residual oil and oil cracking gas quantity is 806.21×108 t and 106.95×1012 m 3 respectively.展开更多
基金National Major S&T Project“Formation Conditions,Accumulation Regularity and Target Evaluation of Large Gas Fields”(Grant No.2011ZX05007).
文摘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%e60%at the principal oil generation stage,and 50%e80%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 230.4×10^(12) m^(3) at the high evolution stage of occluded hydrocarbon of the Lower Cambrian Qiongzhusi Fm in this basin,and 12.3×10^(12) m^(3) 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 GaoshitieMoxi,Ziyang and Weiyuan,covering a favorable area of 4.3×10^(4) km^(2).
基金Supported by the National Natural Science Foundation of China(42230816)PetroChina Science and Technology Project(2021DJ1501)Tarim Oilfield Technology Project(T202112).
文摘To understand the reservoir property and hydrocarbon accumulation conditions of the Middle and Upper Ordovician intraplatform shoal between ultra-deep main strike-slip faults in Fuman Oilfield of the Tarim Basin, China, the main strike-slip faults in and around well FD1 in the basin were analyzed in terms of sedimentary facies, sequence stratigraphy, intraplatform shoal reservoir property, and oil and gas origins, based on drilling data. The Yingshan Formation intraplatform shoal between the main strike-slip faults is superimposed with low-order faults to form a new type of hydrocarbon play. Firstly, hydrocarbons generated from the Lower Cambrian Yuertusi Formation source rocks vertically migrated into the second member of Yingshan Formation through the main strike-slip faults, and then migrated laterally until they were accumulated. A small amount of oil from Well FD1 came from the Yuertusi Formation source rocks in the mature stage, and a large amount of gas originated from oil cracking in the ultra-deep reservoirs. Therefore, the secondary gas condensate reservoir in Well FD1 is characterized by high gas to oil ratio, dry gas (dryness coefficient being 0.970) and hybrid origin. This new type of hydrocarbon play characterized by intraplatform shoal and low-order fault suggests a prospect of continuous hydrocarbon-bearing area in Fuman Oilfield, which will expand the ultrap-deep oil and gas exploration in the oilfield.
基金Supported by the National iqatural Science Foundation of China （20925623, U1162205）.
文摘The systematic experimental studies were performed on the hydrate formation kinetics and gas-hydrate equilibrium for a simulated catalytic cracking gas in the water-in-oil emulsion. The effect of temperature, pressure and initial gas-liquid ratio on the hydrate formation was studied, respectively. The data were obtained at pressures ranging from 3.5 to 5 MPa and temperatur.es from 274.15 to 277.15 K. The results showed that hydrogen and methane can be separated Irom the （~2＋ ti＇action by tOrming hydrate at around 273.15 K which is much higher temperature than that of the cryogenic separation method, and the hydrate formation rate can be enhanced in the wa- ter-in-oil emulsion compared to pure water. The experiments provided the basic data for designing the industrial process, and setting the suitable operational conditions. The measured data ot gas-hydrate equilibria were compared with the predictions by using the Chen-Guo hydrate thermodynamic model.
基金the National Natural Science Foundation of China (Nos. 50904067 and 51104156)the New Century Excellent Talents in University (No. NCET-10-0768) for their support of this project
文摘In this paper, simulated experiment device of coal and gas outburst was employed to perform the experiment on gas-containing coal extrusion. In the experiment, coal surface cracks were observed with a high-speed camera and then the images were processed by sketch. Based on the above description, the paper studied the fractal dimension values from different positions of coal surface as well as their changing laws with time. The results show that there is a growing parabola trend of crack dimension value in the process of coal extrusion. Accordingly, we drew the conclusion that extruded coal crack evolution is a process of fractal dimension value increase. On the basis of fractal dimension values taken from different parts of coal masses, a fractal dimension of the contour map was drawn. Thus, it is clear that the contour map involves different crack fractal dimension values from different positions. To be specific, where there are complicated force and violent movement in coal mass, there are higher fractal dimension values, i.e., the further the middle of observation surface is from the exit of coal mass, and the lower the fractal dimension value is. In line with fractal geometry and energy theory of coal and gas outburst, this study presents the relation between fractal dimension and energy in the process of extruding. In conclusion, the evolution of crack fractal dimension value can signify that of energy, which has laid a solid foundation for the quantification research on the mechanism of gas-containing coal extrusion.
文摘In recent years,much attention has been paid to the development environment,biogenetic compositions and hydrocarbon generation characteristics of ancient source rocks in the deep strata of the Sichuan Basin because oil and gas exploration extends continuously to the deep and ultra-deep strata and a giant gas field with the explored reserves of more than 1×10^(12)m^(3)was discovered in the Middle and Upper ProterozoiceLower Paleozoic strata in the stable inherited paleo-uplift of the central Sichuan Basin.Based on the previous geological research results,outcrop section of the Datangpo Fm,Nanhua System,at the southeastern margin of the Sichuan Basin was observed and the samples taken from the source rocks were tested and analyzed in terms of their organic geochemistry and organic petrology.It is shown that high-quality black shale source rocks of the Datangpo Fm are developed in the tensional background at the southeastern margin of the Sichuan Basin between two glacial ages,i.e.,Gucheng and Nantuo ages in the Nanhua Period.Their thickness is 16e180 m and mineral compositions are mainly clay minerals and clastic quartz.Besides,shale in the Datangpo Fm is of high-quality sapropel type source rock with high abundance at an overmature stage,and it is characterized by low pristane/phytane ratios(0.32-0.83),low gammacerane abundance,high-abundance tricyclic terpane and higher-content C_(27)and C_(29)gonane,indicating that biogenetic compositions are mainly algae and microbes in a strong reducing environment with low salinity.It is concluded that the Datangpo Fm source rocks may be developed in the rift of Nanhua System in central Sichuan Basin.Paleo-uplifts and paleo-slopes before the Caledonian are the favorable locations for the accumulation of dispersed liquid hydrocarbons and paleo-reservoirs derived from the Datangpo Fm source rocks.In addition,scale accumulation zones of dispersed organic matter cracking gas and paleo-reservoirs originated from the Datangpo Fm source rocks may be discovered in the stable area inside the Sichuan Basin.
基金Chinese Academy of Sciences Strategic Pilot Science and Technology Project(Class A)(XDA14010403)National Science and Technology Major Project(2016ZX05007)PetroChina Science and Technology Project(2021DJ0604,kt2020-01-03)。
文摘Based on analyses of characteristics,hydrocarbon charging history and geological conditions for the formation of Sinian-Cambrian reservoirs in the north slope area of central Sichuan paleo-uplift,the natural gas origin,accumulation evolution,accumulation pattern and formation conditions of large lithologic gas reservoirs have been investigated.Through comprehensive analyses of natural gas composition,carbon and hydrogen isotopic compositions,fluid inclusions,reservoir bitumen,and geological conditions such as lithofacies paleogeography and beach body characterization,it is concluded that:(1)The natural gas in the Sinian-Cambrian of the north slope area is mainly oil cracking gas,and different contribution ratios of multiple sets of source rocks lead to different geochemical characteristics of natural gas in different reservoirs.(2)Although the both Sinian and Cambrian gas reservoirs in this area are lithologic gas reservoirs under monocline background,the former has normal-pressure and the latter has high-pressure.There are three types of source-reservoir-caprock combinations:single source with lower generation and upper reservoir,double sources with lower generation and upper reservoir or with side source and lateral reservoir,double sources with lower generation and upper reservoir or with upper generation and lower reservoir.The Permian-Triassic is the main generation period of oil,Early-Middle Jurassic is the main generation period of oil cracking gas and wet gas,and Late Jurassic-Cretaceous is the main generation period of dry gas.(3)The Sinian-Cambrian system of the north slope area has two favorable conditions for formation of large lithologic gas reservoirs,one is that the large scale beach facies reservoirs are located in the range of ancient oil reservoirs or near the source rocks,which is conducive to the"in-situ"large-scale accumulation of cracked gas in the paleo-oil reservoirs,the other is that the large scale mound-beach complex reservoirs and sealing layers of inter beach tight zones match effectively to form large lithologic traps under the slope background.The research results confirm that the north slope area has large multi-layer lithologic gas reservoirs with more than one trillion cubic meters of natural gas resources and great exploration potential.
文摘This paper presents experimental results of cocracking of straight-run gasoline (SRG) and light gaS oil (LGO) in an improved pulsed-micro-pyrolyzer. It is shown that there are negative opergistic effect on the yields and selectivities of ethylene and propylene in cocracking. The difference in coking tendencies betWeen the cocracking and the separate cracking is compared as well.
基金supported by the National Natural Science Foundation of China(grant nos.22201304,22178378,and 22127812)the Science Foundation of China University of Petroleum-Beijing(grant nos.2462021QNXZ011 and 2462022YXZZ007).
文摘Industrial purification processes for ethylene from steam pyrolysis or cracking gases generally employ multiple energy-intensive steps to remove C_(2)H_(2),C_(2)H_(6),CO_(2),and C_(3) hydrocarbons.Designing multifunctional molecular separators that integrate multiple structural characteristics capable of removing several impurities simultaneously is highly desired but not yet realized.Here,we address this challenge using a custom-designed multifunctional,and industry-compatible ultramicroporous crystalline physisorbent(CALF-20)to purify C_(2)H_(4) from a seven-component cracking gas mixture(C_(2)H_(4),C_(2)H_(2),C_(2)H_(6),CO_(2),C_(3)H_(4),C_(3)H_(6),and C_(3)H8)by one-step separation with remarkable performance.Verified by breakthrough experiments,C_(2)H_(4)(>99.99%)can be recovered not only from binary C_(2)H_(6)/C_(2)H_(4)(50/50),ternary C_(2)H_(2)/C_(2)H_(4)/C_(2)H_(6)(33/33/33),and quaternary C_(2)H_(2)/C_(2)H_(4)/C_(2)H_(6)/CO_(2)(25/25/25/25)mixtures,but also from a typical seven-component gas cracking mixture of C_(2)H_(2)/C_(2)H_(4)/C_(2)H_(6)/CO_(2)/C_(3)H_(4)/C_(3)H_(6)/C_(3)H8(0.6/62/10/0.3/0.6/26/0.5),even at the high humidity of 74%.Notably,CALF-20 can be easily produced on the kilogram scale,showing great commercial application potential.Together with its framework flexibility and appropriate pore geometry,CALF-20 exhibits a sorbent-sorbate induced-fit behavior strengthening multiple specific recognition sites for the corresponding vips,validated by single-crystal X-ray diffraction study and molecular modeling.This work is the first example of using a single physisorbent to purify C_(2)H_(4) from a seven-component cracking gas mixture and opens an avenue to address complicated hydrocarbon mixture separation challenges.
基金supported by Petroleum & Chemical United Fund Project(Grant No. 40739902)
文摘Using high pressure and geological condition simulation vessels, we conducted hydrous pyrolysis experiments of kerogen, solid bitumen and liquid hydrocarbons in southern China in order to study the processes of gas generation and derive geo- chemical indicators of gas genesis under approximate pressure and temperature. The results indicate that gas generation productivity of different marine material decreased in the ganic matter （solid bitumen and heavy oil）, and kerogen. order of crude oil （light oil and condensate）, dispersed soluble or- Under identical temperature-pressure regimes, pyrolysates derived from kerogen and dispersed soluble organic matter display drastically different geochemical characteristics. For example, the δ13Cc02-δ13C1 values of gaseous products from dispersed soluble organic matter are greater than 20%o, whereas those from kerogen are less than 20%~. The 813C1 values of pyrolysates from different marine hydrocarbon sources generally increase with pyrolysis temperature, but are always lower than those of the source precursors. The δ13C values of ethane and propane in the pyrolysates also increase with increasing pyrolysis temperature, eventually approaching that of their sources, at peak hydro- carbon generation. At high-over mature stages, the δ13C values of ethane and propane are often greater than those of their sources but close to those of coal gases, and thus become ineffective as gas genetic indicators. Ln（CffC3） can clearly distin- guish kerogen degradation gas from oil cracking gas and Ln（CJC2）-（δ13C1-δ13C2） can be an effective indicator for distinguishing oil cracking gas from dispersed soluble organic matter cracking gas.
基金Supported by the National Natural Science Foundation of China (Grant No. 40573030)the National Key Science and Technology Program of China During the 10th Five-Year Plan Period (Grant No. 2004BA616A02-01-01-03)
文摘The composition characteristics of light hydrocarbons from crude oil,chloroform bitumen A,saturated hydrocarbon fraction,aromatic hydrocarbon fraction,and asphaltene fraction during cracking have been studied systematically.The results revealed that the content of n-alkanes,branched alkanes and cycloalkanes in light hydrocarbons from the samples gradually decreased as the simulation temperature increased,and finally almost depleted completely,while the abundance of methane,benzene and its homologues increased obviously and became the main products.The ratios of benzene/n-hexane and toluene/n-heptane can be used as measures for oil cracking levels.Variation characteristics of maturity parameters of light hydrocarbons,for example,iC4/nC4,iC5/nC5,isoheptane value,2,2-DMC4/nC6,and 2-MC6+3-MC6/nC7 for different samples with increasing pyrolysis temperature,are consistent with those in petroleum reservoirs,indicating that these parameters may be efficient maturity index.
文摘Well Yingnan 2,an important exploratory well in the east of Tarim Basin,yields high commercial oil and gas flow in Jurassic.Natural gas components and carbon isotopic composition indicate that it belongs to sapropel type gas.Because this region presents many suits of hydrocarbon source rocks,there are some controversies that natural gases were generated from kerogen gas or crude oil cracking gas at present.By using the kinetics of hydrocarbon generation and carbon isotope,natural gas of Well Yingnan 2 is composed mainly of crude oil cracking gas,about 72%,it is generated from secondary kerogen gas of Cambrian-Lower Ordovician source rock and crude oil cracking gas of Mid-Upper Ordovician oil reservoir.The main oil and gas filling time is 65 Ma later in the Jurassic gas reservoir of Well Yingnan 2,so the gas reservoir belongs to late accumulation and continuous filling type.
基金This work was funded by National Science and Technology Major Project of China(Grant No.2011ZX05007)PetroChina Exploration and Production Special Project“Evaluation and associated exploration technology research of Sinian hydrocarbon-bearing reservoir in Leshan-Longnvsi Paleo-uplift of the Sichuan Basin”.
文摘The Sinian-Cambrian formations of the Sichuan Basin have favorable hydrocarbon accumulation conditions,but the exploration for large-scale gas fields is quite challenging due to old strata and multiple tectonic movements.Since the Weiyuan Sinian large gas field was found in 1964,the largest monoblock gas field(Anyue Gasfield)was discovered in the Cambrian Longwangmiao Formation of the Moxi region in 2013 with proven gas reserves of 440.1×109 m3.Total proven,probable and possible reserves exceed one trillion cubic meters in the Sinian Dengying Formation and the Cambrian Longwangmiao Formation of the Gaoshiti-Moxi region.The natural gas components,light hydrocarbons,reservoir bitumen abundance and other evidences prove that the dry natural gas was mainly derived from oil-cracking,with methane(a content of 82.65%-97.35%),ethane(a content of 0.01%-0.29%),nitrogen(a content of 0.44%-6.13%),helium(a content of 0.01%-0.06%),and hydrogen sulphide(0.62-61.11 g/m^(3)).Gas reservoir pressure increases gradually from the Sinian normal pressure(a pressure coefficient of 1.07-1.13)to high pressure(a pressure coefficient of 1.53-1.70)in the Cambrian Longwangmiao Formation.The temperature of the gas reservoir is 137.5-163 ℃.Gas reservoir traps are divided into three categories:tectonic type,tectonic-formation type and tectonic-lithologic type.The large-scale enrichment of the Sinian-Cambrian natural gas results from effective configuration of the large stable inherited palaeo-uplift during the Tongwan tectonic movement,wide distribution of ancient source rocks,high-quality reservoirs with vast pore-cavity,crude oil cracking of large palaeo-reservoirs and favorable preservation conditions.According to the palaeo-structure pattern prior to crude oil cracking of the palaeo-reservoirs,and bitumen abundance as well as the distribution characteristics of current gas reservoirs,the accumulation patterns of the cracking gas reservoir can be classified into three types:accumulation type,semi-accumulation and semi-dispersion type,and dispersion type.This understanding will play an important role in guiding the exploration of the Sinian-Cambrian natural gas exploration in the Sichuan Basin.
基金Supported by PetroChina Foundation Project(Grant No.07-01C-01-07)Na-tional Basic Research Program of China(Grant No.2007CB209503)
文摘Focusing on the two natural gas exploration geological problems with abundant source of oil cracking gas in the late stage and the sealing condition of the oil cracking gas reservoir,the kinetics of oil cracking gas and the evaluation parameters of gas cap rock are adopted to the study on the natural gas accumulation conditions in the Tadong area.Both the study on the kinetics of oil cracking gas and the statistical results of reservoir bitumen reveal that the geological formation of oil cracking gas in the Tadong area is located in the top of Cambrian.Two kinds of oil cracking gas geological models at least,namely well Mandong-1's early rapid generation model(Middle Ordovician-end Silurian)and peak cracking model(with the natural gas conversion rate>90%),namely well Yingnan-2's two-stage generation model of oil cracking gas,have been set up.The oil cracking gas of Yingnan-2 in the late stage is very significant in the evaluation of natural gas exploration in the Tadong area.The evaluation results of the cap rock show that the microscopic parameters of cap rock from the lower assemblage of Cambrian-Ordovician are better than those from the upper assemblage.The former has strong capillary sealing ability and higher cap rock breakthrough pressure than the upper assemblage,with strong sealing ability,so that natural gas dissipates mainly by diffusion.According to the above investigations,the lower assemblage Cambrian-Ordovician natural gas of Kongquehe slope,Tadong low uplift and Yingjisu depression in the Tadong area prospects well.
基金the National Basic Research Program of China(Grant No.2007CB209500)the National Natural Science Foundation of China(Grant No.40672097)
文摘There are mainly 3 kinds of existing states of oil generating from source rocks,that is,dispersive liquid hydrocarbon inside of source rock,dispersive liquid hydrocarbon outside of source rock and concentrated liquid hydrocarbon outside of source rock.Because of the differences in thermal history and medium conditions around,and the interaction of organic and inorganic matter,the liquid hydrocarbon with 3 kinds of existing state has different cracking conditions.The gas generation dynamics experiments of crude oil matching different mediums indicate that the distribution of activation energy of methane changes a lot according to medium difference.The carbonate has a main influence on oil cracking conditions and can largely reduce its activation energy,which reflects the lower cracking temperature of crude oil.The mudstone takes a second place and the sandstone is the smallest.The catalytic cracking function to the oil of the carbonate,of the mudstone and of the sandstone changes weaken in turn.The corresponding Ro values of main gas generation period in different mediums are as follows:1.5%―3.8%with pure crude oil,1.2%―3.2%with dispersive crude oil in carbonate,1.3%~3.4%with dispersive crude oil in mudstone and 1.4%―3.6%with dispersive crude oil in sandstone.The influence of pressure to crude oil cracking is relatively complicated.In the low heating speed condition,pressure restrains the oil cracking and gas generation,but in the high heating speed condition,pressure has an indistinctive influence to the oil cracking and gas generation.Pressure also makes a different effort in different evolvement stage.Taking the middle and lower Cambrian source rocks in the Tarim Basin as an example,primary oil generating quantity is 2232.24×108 t,residual oil and oil cracking gas quantity is 806.21×108 t and 106.95×1012 m 3 respectively.
