The Majiang paleo-reservoir is a typical destroyed hydrocarbon reservoir, buried in carbonate strata of China＇s southern marine-facies. Field geological explorations, interpretations of seismic profiles and balanced ...The Majiang paleo-reservoir is a typical destroyed hydrocarbon reservoir, buried in carbonate strata of China＇s southern marine-facies. Field geological explorations, interpretations of seismic profiles and balanced cross-section restorations around this paleo-reservoir reveal that its formation and evolution have been restricted by multiphase tectonic movements of different intensities. A regional tectonic mechanism and model have been suggested for the formation and evolution of the Majiang paleo- reservoir. Geological field exploration has been carried out along three typical Silurian cross-sections and rock samples were tested in combination with water-rock interaction. Based on the result of cap tests, the planar distribution, the residual thickness, the erosion thickness and the preservation conditions, the Silurian mudstone cap is discussed around the Majiang paleo-reservoir. Combining the hydrodynamic conditions of its formation and evolution and its tectonic movements, we determined the fact that the thicker the cap is, the more resistant it is to hydrodynamic destruction. The multi-phase formation and destructive geological model of the paleo-reservoir is established through an overall analysis of multi- phase tectonic evolutions, cap developments, hydrodynamic conditions and solid mineral metallogenic ages measured by Rb-Sr, Pb and Sm-Nd isotope techniques.展开更多
The discovery of many Proterozoic primary oil and gas reservoirs around the world testifies that the Meso-Neoproterozoic petroleum is an energy resources realm worthy of attention.This paper firstly reports the occurr...The discovery of many Proterozoic primary oil and gas reservoirs around the world testifies that the Meso-Neoproterozoic petroleum is an energy resources realm worthy of attention.This paper firstly reports the occurrence of hydrocarbon accumulations in the Neoproterozoic Luotuoling Formation in the Jianchang Sag,the Yanliao Faulted-Depression Zone.Petrography observation shows that the lower sandstone member of the Luotuoling Formation contains yellow fluorescent liquid hydrocarbons,while the upper sandstone member is rich in solid bitumen.Further analysis of the biomarkers and isotopic compositions reveals that the upper and lower reservoirs have different oil sources.The bitumen in the lower reservoir is rich in C_(19)-C_(20)tricyclic terpanes(TTs),13α(n-alkyl)-tricyclic terpanes and rearranged hopanes,but lacks gammacerane and steranes and depletes ^(13)C isotope(-33.4‰to-30.6‰).This is consistent with the properties of the Hongshuizhuang Formation source rocks.The upper reservoir bitumen has C_(23)TT as the major peak among C_(19)-C_(23)TTs,lacks 13α(n-alkyl)-tricyclic terpanes,has a low abundance of rearranged hopanes,obvious distribution of gammacerane and steranes,and depletion of the^(13)C isotope;essentially the same as the Gaoyuzhuang Formation source rocks.The discovery of oil seepage in the Luotuoling Formation of the Han-1 well is a promising indicator of the Precambrian oil and gas exploration potential of the Jianchang Sag.展开更多
The exact determination of isotopic ages of hydrocarbon accumulation,reconstruction and destruction periods using traditional isotopic dating methods is complex because of the small numbers of minerals that correlate ...The exact determination of isotopic ages of hydrocarbon accumulation,reconstruction and destruction periods using traditional isotopic dating methods is complex because of the small numbers of minerals that correlate with hydrocarbons.The quantitative and direct study of hydrocarbon geochronology is therefore an important scientific problem for isotope geochronology and petroleum geology.This study obtains two isotopic ages from a quartz vein sample associated with bitumen in a reverse fault located in the Bankeng paleo-reservoir on the southern margin of the middle Yangtze block (the northern margin of the JiangnanXuefeng uplift) by inclusion 40Ar/39Ar stepwise crushing in a vacuum.Two different and good linear inverse isochrons that correspond to two age plateaus were determined.The two ages correspond to primary inclusions of about 228 Ma and secondary inclusions of about 149 Ma.These inclusion groups represent two distinct kinds of fluids.Quartz veins associated with bitumen in faulted paleo-reservoirs,which have a strict response relationship with tectonization and hydrocarbon accumulation,are the unified products of tectonic processes,hydrocarbon accumulation and reconstruction.Therefore,they can be used to constrain the hydrocarbon accumulation,reconstruction and destruction periods that are controlled by multiphase and complicated tectonic actions.The evolutionary processes of hydrocarbon accumulation can be divided into two periods consisting of a primary oil and gas reservoir formation period in the late Indosinian epoch (about 228 Ma) and a period of oil and gas reservoir reconstruction in the early Yanshan epoch (about 149 Ma).This study quantitatively reconstructs the hydrocarbon accumulation and destruction chronological framework of a giant hydrocarbon accumulation belt along the southern margin of the middle Yangtze block (the northern margin of the Jiangnan-Xuefeng uplift) controlled by multiphase and complicated tectonism.The two ages associated with hydrocarbons here correspond to the special controlling actions of continental tectonics in the Jiangnan-Xuefeng uplift that affected the timeline of reconstruction and destruction in this giant marine hydrocarbon accumulation.This study shows the feasibility and usefulness of dating inclusions with the 40Ar/39Ar technique for hydrocarbon geochronology,especially in the marine hydrocarbon accumulation region of southern China within a geological setting of old strata,high thermal evolution hydrocarbons,and complex,multiphase and multicycle tectonization.展开更多
基金support from the National Natural Science Foundation of China(Grant Nos.40972090,40672143 and 40172076)the National Major Fundamental Research and Development Project(Grant Nos.2005CB422107 and G1999043305)the National Science and Technology Project(Grant Nos.2008ZX05005-002-04-02)
文摘The Majiang paleo-reservoir is a typical destroyed hydrocarbon reservoir, buried in carbonate strata of China＇s southern marine-facies. Field geological explorations, interpretations of seismic profiles and balanced cross-section restorations around this paleo-reservoir reveal that its formation and evolution have been restricted by multiphase tectonic movements of different intensities. A regional tectonic mechanism and model have been suggested for the formation and evolution of the Majiang paleo- reservoir. Geological field exploration has been carried out along three typical Silurian cross-sections and rock samples were tested in combination with water-rock interaction. Based on the result of cap tests, the planar distribution, the residual thickness, the erosion thickness and the preservation conditions, the Silurian mudstone cap is discussed around the Majiang paleo-reservoir. Combining the hydrodynamic conditions of its formation and evolution and its tectonic movements, we determined the fact that the thicker the cap is, the more resistant it is to hydrodynamic destruction. The multi-phase formation and destructive geological model of the paleo-reservoir is established through an overall analysis of multi- phase tectonic evolutions, cap developments, hydrodynamic conditions and solid mineral metallogenic ages measured by Rb-Sr, Pb and Sm-Nd isotope techniques.
基金supported by the National Key Research and Development Program of China(No.2017YFC0603102)the Liaohe Oilfield Company,CNPC(Oil Accumulation Mechanism of Meso-Neoproterozoic Oil Reservoir in the Liaoxi Depression,NE China)(No.LHYT-KTKFYJY-2018-JS9798)。
文摘The discovery of many Proterozoic primary oil and gas reservoirs around the world testifies that the Meso-Neoproterozoic petroleum is an energy resources realm worthy of attention.This paper firstly reports the occurrence of hydrocarbon accumulations in the Neoproterozoic Luotuoling Formation in the Jianchang Sag,the Yanliao Faulted-Depression Zone.Petrography observation shows that the lower sandstone member of the Luotuoling Formation contains yellow fluorescent liquid hydrocarbons,while the upper sandstone member is rich in solid bitumen.Further analysis of the biomarkers and isotopic compositions reveals that the upper and lower reservoirs have different oil sources.The bitumen in the lower reservoir is rich in C_(19)-C_(20)tricyclic terpanes(TTs),13α(n-alkyl)-tricyclic terpanes and rearranged hopanes,but lacks gammacerane and steranes and depletes ^(13)C isotope(-33.4‰to-30.6‰).This is consistent with the properties of the Hongshuizhuang Formation source rocks.The upper reservoir bitumen has C_(23)TT as the major peak among C_(19)-C_(23)TTs,lacks 13α(n-alkyl)-tricyclic terpanes,has a low abundance of rearranged hopanes,obvious distribution of gammacerane and steranes,and depletion of the^(13)C isotope;essentially the same as the Gaoyuzhuang Formation source rocks.The discovery of oil seepage in the Luotuoling Formation of the Han-1 well is a promising indicator of the Precambrian oil and gas exploration potential of the Jianchang Sag.
基金Basin-range tectonics,composite structural system,hydrocarbon accumu-lation and reconstruction in middle Yangtze block (YPH08002)Research Fund of Key Laboratory of Tectonics and Petroleum Resources (China University of Geosciences Wuhan)+2 种基金Ministry of Education (TPR-2009-06)the National Natural Science Foundation of China (40902038)the Natural Science Foundation of Hubei Province (2009CDB217)
文摘The exact determination of isotopic ages of hydrocarbon accumulation,reconstruction and destruction periods using traditional isotopic dating methods is complex because of the small numbers of minerals that correlate with hydrocarbons.The quantitative and direct study of hydrocarbon geochronology is therefore an important scientific problem for isotope geochronology and petroleum geology.This study obtains two isotopic ages from a quartz vein sample associated with bitumen in a reverse fault located in the Bankeng paleo-reservoir on the southern margin of the middle Yangtze block (the northern margin of the JiangnanXuefeng uplift) by inclusion 40Ar/39Ar stepwise crushing in a vacuum.Two different and good linear inverse isochrons that correspond to two age plateaus were determined.The two ages correspond to primary inclusions of about 228 Ma and secondary inclusions of about 149 Ma.These inclusion groups represent two distinct kinds of fluids.Quartz veins associated with bitumen in faulted paleo-reservoirs,which have a strict response relationship with tectonization and hydrocarbon accumulation,are the unified products of tectonic processes,hydrocarbon accumulation and reconstruction.Therefore,they can be used to constrain the hydrocarbon accumulation,reconstruction and destruction periods that are controlled by multiphase and complicated tectonic actions.The evolutionary processes of hydrocarbon accumulation can be divided into two periods consisting of a primary oil and gas reservoir formation period in the late Indosinian epoch (about 228 Ma) and a period of oil and gas reservoir reconstruction in the early Yanshan epoch (about 149 Ma).This study quantitatively reconstructs the hydrocarbon accumulation and destruction chronological framework of a giant hydrocarbon accumulation belt along the southern margin of the middle Yangtze block (the northern margin of the Jiangnan-Xuefeng uplift) controlled by multiphase and complicated tectonism.The two ages associated with hydrocarbons here correspond to the special controlling actions of continental tectonics in the Jiangnan-Xuefeng uplift that affected the timeline of reconstruction and destruction in this giant marine hydrocarbon accumulation.This study shows the feasibility and usefulness of dating inclusions with the 40Ar/39Ar technique for hydrocarbon geochronology,especially in the marine hydrocarbon accumulation region of southern China within a geological setting of old strata,high thermal evolution hydrocarbons,and complex,multiphase and multicycle tectonization.
