The authors quantify the impacts of sulfate and nitrate aerosol formation on surface-layer 03 concentrations over China using the one-way nested-grid capa- bility of the global three-dimensional Goddard Earth Ob- serv...The authors quantify the impacts of sulfate and nitrate aerosol formation on surface-layer 03 concentrations over China using the one-way nested-grid capa- bility of the global three-dimensional Goddard Earth Ob- serving System chemical transport model （GEOS-Chem）. Chemical reactions associated with sulfate formation are simulated to generally increase 03 concentrations in China. Over the North China Plain （NCP） and the Si- chuan Basin （SCB）, where simulated sulfate concentra- tions are the largest, ozone concentrations show maximum increases in spring by 1.8 ppbv （3.2%） in the NCP and by 2.6 ppbv （3.7%） in the SCB. On the contrary, nitrate formation is simulated to reduce 03 concentrations by up to 1.0 ppbv in eastern China, with the largest reduc- tions of 1.0 ppbv （1.4%） in summer over the NCE Ac- counting for the formation of both sulfate and nitrate, the surface-layer O3 concentrations over a large fraction of eastern China are simulated to increase in winter, spring, and autumn, dominated by the impact of sulfate forma- tion, but to decrease in summer because of the dominant contribution from nitrate formation.展开更多
Acid gas injection into saline aquifers is one of promising ways to reduce greenhouse gas emissions and to dispose hazardous waste simultaneously. On the basis of Level Set method, an improved mathematical model that ...Acid gas injection into saline aquifers is one of promising ways to reduce greenhouse gas emissions and to dispose hazardous waste simultaneously. On the basis of Level Set method, an improved mathematical model that described interfacial dynamics of acid gas-brine system in a deep confined saline aquifer was proposed for predicting the propagation of the acid gas plume, which was featured by using Peng-Robinson equation and modified Lucas equation to describe variations of the density and viscosity of acid gas in saline aquifers. The evolutional characte^stics of acid gas plume were obtained through numerical simulations using COMSOL Multiphysics 3.5a. The results showed that under intrinsic characteristics of aquifers and operational conditions given, the variation of acid gas density was the major factor that influences the patterns and shapes of the plume. The leading edge position of acid gas plume was intensively dependent on the acid gas composition. Under the scheme of fixed mass flow rate injection, as the molar fraction of H2S increased, the position of leading edge advanced gradually towards the injection well. Moreover, the estimation of the storage efficiency of acid gas in saline aquifers was clarified and discussed. The proposed approach and the simulation results will provide insights into the determination of optimal operational strategies and rapid identification of the consequences of acid gas injection into deep confined saline aquifers.展开更多
The study area is located in a Mediterranean region, so the effects of the climate variations are very important. The authors contribution to this subject is based on the compilation of many results obtained from diss...The study area is located in a Mediterranean region, so the effects of the climate variations are very important. The authors contribution to this subject is based on the compilation of many results obtained from dissertations and theses that are carried out under their supervision. The main tool used, in addition to other methods, is the water hydrochemistry as it is proved very useful in obtaining good results and helpful in getting objective interpretations regarding the presence and absence of salinity. Several factors are undertaken to show the presence of salts in waters in the plain, the lithology of the geological formations shows that they are composed of alluvium sediments where the permeability is quite high, and this enables hydraulic communication between the fresh water of the aquifer and saline water of the sea. The study of climate shows a decrease of precipitation which favors an important decrease of recharge rate to the aquifer, and hence a decrease of water resource. The strontium which is a good indicator for the origin of salinity shows a variation that indicates a variation in the distribution of the salinity, and therefore diverse origins of salinity all over the studied area. This can infer the presence of marine invasion in the down-stream part of the aquifer, whereas elsewhere salinity is caused by the presence of evaporitic formation, mainly by the argillaceous matrix in the bottom of the lake. in the up-stream part of the aquifer. In the lake, salinity is explained展开更多
The total organic carbon （TOC） in the marine source rock of the Ordos Basin mostly ranges from 0.2% to 0.5%. The industrial standard commonly states that the TOC value has to be no less than 0.5% （0.4% for high mat...The total organic carbon （TOC） in the marine source rock of the Ordos Basin mostly ranges from 0.2% to 0.5%. The industrial standard commonly states that the TOC value has to be no less than 0.5% （0.4% for high mature or over-mature source rock） to form large petroleum reservoirs. However, gas source correlation indicates that the natural gas in the Jingbian gas field does receive contribution from marine source rocks. In order to determine the effect of Carboxylate salts （or called as organic acid salts） on TOC in highly mature source rocks with low TOC value, we sampled the Ordovician marine source rock and the Permian transitional facies source rock in one drilled well in the southern Ordos Basin and performed infrared and GC-MS analysis. It is found that both kerogen-derived organic acids and carboxylate salt-conversed organic acids exist in both marine and transitional facies source rocks. The carboxylate salt-conversed organic acids mainly come from the complete acidification of carboxylate salts, which confirms the presence of carboxylate salts in the marine source rocks. Although the C16：o peak is the main peak for the organic acids both before and after acidification, the carboxylate salt-conversed organic acids have much less relative abundance ahead of C^6：o compared with that of the kerogen-based and free organic acids. This observation suggests that the kerogen-based and free organic acids mainly decarboxylate to form lower carboxylic acids, whereas the carboxylate salt-conversed organic acids mainly break down into paraffins. By using calcium hexadecanoate as the reference to quantify the kerogen-derived and carboxylate salt-conversed organic acids, the high TOC （〉2.0%） marine source rocks have low carboxylate salt content and the low TOC （0.2%-0.5%） marine source rocks contain high content of carboxylate salt. Therefore, for the marine source rocks with 0.2%-0.5% TOC, the carboxylate salts may be a potential gas source at high maturity stage.展开更多
The CO2 contents of natural gas from the eastern Sichuan Basin were mainly less than 2%, and they were generally large when the H2S contents were over 5%. The natural gas in the eastern Sichuan Basin showed high δ13C...The CO2 contents of natural gas from the eastern Sichuan Basin were mainly less than 2%, and they were generally large when the H2S contents were over 5%. The natural gas in the eastern Sichuan Basin showed high δ13C1 values uncorrelated with H2S contents, and the oil-associated gas generally displayed carbon isotopic reversal between methane and ethane, whereas the coal-derived gas samples displayed positive series. The δ13c values of CO2 in the natural gas could be divided into two types, one with low values （-24‰-12‰） and the other with high values （-8‰-4‰）. The natural gas had low R/Ra values and broad COj3He values distinct from the mantle-derived gas, and the CO2 was typical of crustal origin. Natural gas with high δ3Cco2 values is distributed in the north region of the eastern Sichuan Basin, and CO2 in H2S-poor and H2S-free reservoirs was mainly derived from the thermal decomposition of carbonate rocks under Permian magmatism and high heat flow, whereas CO2 in the gas reservoirs with high TSR extent was derived mainly from the dedolomitization of carbonate reservoirs under acidic formation water, and the CO2 of TSR origin generally entered into the secondary calcite. The CO2 in natural gas in the south-central region of the eastern Sichuan Basin, which had been rarely affected by the Emeishan mantle plume, displayed low δ13C values and was of organic origin. Though the natural gas in Wolonghe gas field had experienced TSR, the low reac- tion extent and weak acidity of formation water could hardly have resulted in the dedolomitization, and therefore CO2 in the natural gas was mainly of TSR origin with low δ13C values.展开更多
The failure of pillars between bedded salt cavern gas storages can be seen as processes that the deformations of pillars convert from continuous gradual change system to catastrophe state,which are typical nonlinear c...The failure of pillars between bedded salt cavern gas storages can be seen as processes that the deformations of pillars convert from continuous gradual change system to catastrophe state,which are typical nonlinear catastrophe problems.In the paper,the cusp catastrophe model is proposed to obtain the stability factors of pillars.It can overcome the shortages of traditional strength reduction finite element method(SR FEM) and greatly improve the accuracy of stability factors obtained by numerical simulations.The influences of cavern depth,gas pressure,pillar width,and time on the stability factors are studied.Y-1 and Y-2 salt cavern gas storages,located at Jiangsu province of China,were simulated as examples.The stability factors of pillars between Y-1 and Y-2 were evaluated,and the running parameters were recommended to ensure the pillars stability.The results showed that the cusp catastrophe model has high practicability and can precisely predict the stability factors.The stability factors are equidirectional with the increase of gas pressure and pillar width,but reverse to the increase of cavern depth and time.The stability factors of pillars between Y-1 and Y-2 are small for narrow widths,which are influenced greatly by gas pressure,time,pressure difference,and gas production rate.In order to ensure the safety of pillars,the lowest gas pressure,safe running time,max.pressure difference and max.gas production rate of Y-1 and Y-2 were recommended as 7 MPa,5 years,3 MPa,and 0.50 MPa/d,respectively.展开更多
基金supported by the National Basic Research Program of China (973 program, Grant No. 2014CB441202)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA05100503)
文摘The authors quantify the impacts of sulfate and nitrate aerosol formation on surface-layer 03 concentrations over China using the one-way nested-grid capa- bility of the global three-dimensional Goddard Earth Ob- serving System chemical transport model （GEOS-Chem）. Chemical reactions associated with sulfate formation are simulated to generally increase 03 concentrations in China. Over the North China Plain （NCP） and the Si- chuan Basin （SCB）, where simulated sulfate concentra- tions are the largest, ozone concentrations show maximum increases in spring by 1.8 ppbv （3.2%） in the NCP and by 2.6 ppbv （3.7%） in the SCB. On the contrary, nitrate formation is simulated to reduce 03 concentrations by up to 1.0 ppbv in eastern China, with the largest reduc- tions of 1.0 ppbv （1.4%） in summer over the NCE Ac- counting for the formation of both sulfate and nitrate, the surface-layer O3 concentrations over a large fraction of eastern China are simulated to increase in winter, spring, and autumn, dominated by the impact of sulfate forma- tion, but to decrease in summer because of the dominant contribution from nitrate formation.
基金Supported by the National Natural Science Foundation of China （21176198）, and the Research Fund for the Doctoral Program of Higher Education of China （2012021110071）.
文摘Acid gas injection into saline aquifers is one of promising ways to reduce greenhouse gas emissions and to dispose hazardous waste simultaneously. On the basis of Level Set method, an improved mathematical model that described interfacial dynamics of acid gas-brine system in a deep confined saline aquifer was proposed for predicting the propagation of the acid gas plume, which was featured by using Peng-Robinson equation and modified Lucas equation to describe variations of the density and viscosity of acid gas in saline aquifers. The evolutional characte^stics of acid gas plume were obtained through numerical simulations using COMSOL Multiphysics 3.5a. The results showed that under intrinsic characteristics of aquifers and operational conditions given, the variation of acid gas density was the major factor that influences the patterns and shapes of the plume. The leading edge position of acid gas plume was intensively dependent on the acid gas composition. Under the scheme of fixed mass flow rate injection, as the molar fraction of H2S increased, the position of leading edge advanced gradually towards the injection well. Moreover, the estimation of the storage efficiency of acid gas in saline aquifers was clarified and discussed. The proposed approach and the simulation results will provide insights into the determination of optimal operational strategies and rapid identification of the consequences of acid gas injection into deep confined saline aquifers.
文摘The study area is located in a Mediterranean region, so the effects of the climate variations are very important. The authors contribution to this subject is based on the compilation of many results obtained from dissertations and theses that are carried out under their supervision. The main tool used, in addition to other methods, is the water hydrochemistry as it is proved very useful in obtaining good results and helpful in getting objective interpretations regarding the presence and absence of salinity. Several factors are undertaken to show the presence of salts in waters in the plain, the lithology of the geological formations shows that they are composed of alluvium sediments where the permeability is quite high, and this enables hydraulic communication between the fresh water of the aquifer and saline water of the sea. The study of climate shows a decrease of precipitation which favors an important decrease of recharge rate to the aquifer, and hence a decrease of water resource. The strontium which is a good indicator for the origin of salinity shows a variation that indicates a variation in the distribution of the salinity, and therefore diverse origins of salinity all over the studied area. This can infer the presence of marine invasion in the down-stream part of the aquifer, whereas elsewhere salinity is caused by the presence of evaporitic formation, mainly by the argillaceous matrix in the bottom of the lake. in the up-stream part of the aquifer. In the lake, salinity is explained
基金supported by National Natural Science Foundation of China(Grant Nos.41173035&41322016)National Key Foundational Research and Development Project(Grant No.2012CB214800)the National Science & Technology Special Project(Grant No.2011ZX05005-004-004)
文摘The total organic carbon （TOC） in the marine source rock of the Ordos Basin mostly ranges from 0.2% to 0.5%. The industrial standard commonly states that the TOC value has to be no less than 0.5% （0.4% for high mature or over-mature source rock） to form large petroleum reservoirs. However, gas source correlation indicates that the natural gas in the Jingbian gas field does receive contribution from marine source rocks. In order to determine the effect of Carboxylate salts （or called as organic acid salts） on TOC in highly mature source rocks with low TOC value, we sampled the Ordovician marine source rock and the Permian transitional facies source rock in one drilled well in the southern Ordos Basin and performed infrared and GC-MS analysis. It is found that both kerogen-derived organic acids and carboxylate salt-conversed organic acids exist in both marine and transitional facies source rocks. The carboxylate salt-conversed organic acids mainly come from the complete acidification of carboxylate salts, which confirms the presence of carboxylate salts in the marine source rocks. Although the C16：o peak is the main peak for the organic acids both before and after acidification, the carboxylate salt-conversed organic acids have much less relative abundance ahead of C^6：o compared with that of the kerogen-based and free organic acids. This observation suggests that the kerogen-based and free organic acids mainly decarboxylate to form lower carboxylic acids, whereas the carboxylate salt-conversed organic acids mainly break down into paraffins. By using calcium hexadecanoate as the reference to quantify the kerogen-derived and carboxylate salt-conversed organic acids, the high TOC （〉2.0%） marine source rocks have low carboxylate salt content and the low TOC （0.2%-0.5%） marine source rocks contain high content of carboxylate salt. Therefore, for the marine source rocks with 0.2%-0.5% TOC, the carboxylate salts may be a potential gas source at high maturity stage.
基金supported by National Natural Science Foundation of China (Grant No. 40972134)RIPED Young Professional Innovation Fund (Grant No. 2010-B-16-04)
文摘The CO2 contents of natural gas from the eastern Sichuan Basin were mainly less than 2%, and they were generally large when the H2S contents were over 5%. The natural gas in the eastern Sichuan Basin showed high δ13C1 values uncorrelated with H2S contents, and the oil-associated gas generally displayed carbon isotopic reversal between methane and ethane, whereas the coal-derived gas samples displayed positive series. The δ13c values of CO2 in the natural gas could be divided into two types, one with low values （-24‰-12‰） and the other with high values （-8‰-4‰）. The natural gas had low R/Ra values and broad COj3He values distinct from the mantle-derived gas, and the CO2 was typical of crustal origin. Natural gas with high δ3Cco2 values is distributed in the north region of the eastern Sichuan Basin, and CO2 in H2S-poor and H2S-free reservoirs was mainly derived from the thermal decomposition of carbonate rocks under Permian magmatism and high heat flow, whereas CO2 in the gas reservoirs with high TSR extent was derived mainly from the dedolomitization of carbonate reservoirs under acidic formation water, and the CO2 of TSR origin generally entered into the secondary calcite. The CO2 in natural gas in the south-central region of the eastern Sichuan Basin, which had been rarely affected by the Emeishan mantle plume, displayed low δ13C values and was of organic origin. Though the natural gas in Wolonghe gas field had experienced TSR, the low reac- tion extent and weak acidity of formation water could hardly have resulted in the dedolomitization, and therefore CO2 in the natural gas was mainly of TSR origin with low δ13C values.
基金supported by the National Science and Technology Major Project of China (Grant Nos 2008ZX05017, 2008ZX05036)the Ex-cellent Doctor Degree Dissertation Training Program of China University of Petroleum (Grant No Z10-10)
文摘The failure of pillars between bedded salt cavern gas storages can be seen as processes that the deformations of pillars convert from continuous gradual change system to catastrophe state,which are typical nonlinear catastrophe problems.In the paper,the cusp catastrophe model is proposed to obtain the stability factors of pillars.It can overcome the shortages of traditional strength reduction finite element method(SR FEM) and greatly improve the accuracy of stability factors obtained by numerical simulations.The influences of cavern depth,gas pressure,pillar width,and time on the stability factors are studied.Y-1 and Y-2 salt cavern gas storages,located at Jiangsu province of China,were simulated as examples.The stability factors of pillars between Y-1 and Y-2 were evaluated,and the running parameters were recommended to ensure the pillars stability.The results showed that the cusp catastrophe model has high practicability and can precisely predict the stability factors.The stability factors are equidirectional with the increase of gas pressure and pillar width,but reverse to the increase of cavern depth and time.The stability factors of pillars between Y-1 and Y-2 are small for narrow widths,which are influenced greatly by gas pressure,time,pressure difference,and gas production rate.In order to ensure the safety of pillars,the lowest gas pressure,safe running time,max.pressure difference and max.gas production rate of Y-1 and Y-2 were recommended as 7 MPa,5 years,3 MPa,and 0.50 MPa/d,respectively.
