The Sichuan Basin is a superimposition basin composed of terrestrial and marine sediments that is well known for its abundant petroleum resources. Thermal history reconstruction using paleogeothermal indicators, inclu...The Sichuan Basin is a superimposition basin composed of terrestrial and marine sediments that is well known for its abundant petroleum resources. Thermal history reconstruction using paleogeothermal indicators, including vitrinite reflectahoe and thermochronological data, shows that different structural subsections of the Sichuan Basin have experienced various paleogeothermal episodes since the Paleozoic. The lower structural subsection comprising the Lower Paleozoic to Middle Permian （Pz-P2） successions experienced a high paleogeothermal gradient （23.0-42.6℃/km） at the end of the Middle Permian （P2）, whereas the upper structural subsection comprising Late Permian to Mesozoic strata underwent a relatively lower paleogeothermal gradient （13.2-26.9℃/km） at the beginning of the denudation （Late Cretaceous or Paleocene in the different regions）. During the denudation period, the Sichuan Basin experienced a successive cooling episode. The high paleogeothermal gradient resulted from an intensive thermal event correlated to the Emeishan mantle plume. The heat flow value reached 124.0 mW/m2 in the southwestern basin near the center of the Emeishan large igneous province. The low geothermal gradient episode with heat flow ranging from 31.2 to 70.0 mW/m2 may be related to the foreland basin evolution. The cooling event is a result of the continuous uplift and denudation of the basin.展开更多
A comprehensive study on geothermal history of the Turpan-HamiBasin by vitrinite reflectance, fluid inclusion geothermometry, apatite fission track and 40Ar-39Ar dating displays that the main effects influencing geote...A comprehensive study on geothermal history of the Turpan-HamiBasin by vitrinite reflectance, fluid inclusion geothermometry, apatite fission track and 40Ar-39Ar dating displays that the main effects influencing geotemperature distribution are burial depth of the basement, heat flow, magmatic activities, as well as tectonic movement, having a rugulation to be higher in the east and north, lower in the west and south, as well as higher in the past and lower at the present. The heat of the mantle source and the Indo-China tectonic thermal event have extremely influenced matura-tion of source rocks of the upper Lower Permian and the Middle and Upper Triassic in the lndo-China epoch. While, the geothermal gradient and the weak tectonic geothermal event of the Early Yanshan Movement provided necessary heat for the maturation of source rock in coal-bearing strata of the Middle and Lower Jurassic.展开更多
The present geothermal gradient and terrestrial heat flow was calculated of 18 wells in the Jianghan Basin.Thermal gradient distribution of the Jianghan Basin was obtained based on data of systematical steady-state te...The present geothermal gradient and terrestrial heat flow was calculated of 18 wells in the Jianghan Basin.Thermal gradient distribution of the Jianghan Basin was obtained based on data of systematical steady-state temperature and oil-test temperature.The basin-wide average thermal gradient in depth interval of 0-4000 m is 33.59℃/km.We report nine measured terrestrial heat flow values based on the data of detailed thermal conductivity and systematical steady-state temperature.These values vary from 41.9 to 60.9 mW/m 2 with a mean of 52.3±6.3 mW/m 2.However,thermal history analyses based on vitrinite reflectance(VR) and apatite fission track(AFT) data indicate that thermal gradient in the northern and southern Qianbei Fault reached its peak of ～36 and ～39℃/km respectively in the Middle Jurassic and the Oligocene,and it descended during the early Miocene to the present-time value.Furthermore,tectonic subsidence analysis reveals that the tectonic subsidence of the Jianghan Basin in the Cretaceous to early Miocene was characterized by synrift initial subsidence followed by the subsequent thermal subsidence.The thermal history and tectonic subsidence history of Jianghan Basin are of great significance to petroleum exploration and hydrocarbon source assessment,because they bear directly on issues of petroleum source rock maturation.Based on the thermal history and tectonic subsidence history,with the combination of geochemical and thermal parameters,the maturation and the hydrocarbon generation intensity evolution history of the P2d source rocks are modeled.The results show that the P2d source rocks are in a higher degree of maturation at present,and the Yuan'an and Herong sags are the two most important kitchens in the Late Jurassic,Xiaoban Sag is another most important kitchen during the Late Cretaceous to late Paleogene,and the Zhijiang and Mianyang sags are other two important hydrocarbon kitchens in the Late Cretaceous.The Mianyang Sag and Yichang Ramp are the favorable exploration targets in the future.This study may provide new insight for the understanding of the oil and gas exploration potential for the Jianghan Basin.展开更多
基金the National Natural Science Foundation of China(Grant No.41102152)the PetroChina Innovation Foundation(Grant No.2013D-5006-0102)+1 种基金the National Basic Research Program of China(Grant No.2012CB214703)the Science Foundation of China University of Petroleum,Beijing(Grant No.YJRC2013-002)
文摘The Sichuan Basin is a superimposition basin composed of terrestrial and marine sediments that is well known for its abundant petroleum resources. Thermal history reconstruction using paleogeothermal indicators, including vitrinite reflectahoe and thermochronological data, shows that different structural subsections of the Sichuan Basin have experienced various paleogeothermal episodes since the Paleozoic. The lower structural subsection comprising the Lower Paleozoic to Middle Permian （Pz-P2） successions experienced a high paleogeothermal gradient （23.0-42.6℃/km） at the end of the Middle Permian （P2）, whereas the upper structural subsection comprising Late Permian to Mesozoic strata underwent a relatively lower paleogeothermal gradient （13.2-26.9℃/km） at the beginning of the denudation （Late Cretaceous or Paleocene in the different regions）. During the denudation period, the Sichuan Basin experienced a successive cooling episode. The high paleogeothermal gradient resulted from an intensive thermal event correlated to the Emeishan mantle plume. The heat flow value reached 124.0 mW/m2 in the southwestern basin near the center of the Emeishan large igneous province. The low geothermal gradient episode with heat flow ranging from 31.2 to 70.0 mW/m2 may be related to the foreland basin evolution. The cooling event is a result of the continuous uplift and denudation of the basin.
文摘A comprehensive study on geothermal history of the Turpan-HamiBasin by vitrinite reflectance, fluid inclusion geothermometry, apatite fission track and 40Ar-39Ar dating displays that the main effects influencing geotemperature distribution are burial depth of the basement, heat flow, magmatic activities, as well as tectonic movement, having a rugulation to be higher in the east and north, lower in the west and south, as well as higher in the past and lower at the present. The heat of the mantle source and the Indo-China tectonic thermal event have extremely influenced matura-tion of source rocks of the upper Lower Permian and the Middle and Upper Triassic in the lndo-China epoch. While, the geothermal gradient and the weak tectonic geothermal event of the Early Yanshan Movement provided necessary heat for the maturation of source rock in coal-bearing strata of the Middle and Lower Jurassic.
基金supported by National Natural Science Foundation of China(Grant No.41102152)Sinopec Marine Prospective Study Program(Grant No.2007CB411704)
文摘The present geothermal gradient and terrestrial heat flow was calculated of 18 wells in the Jianghan Basin.Thermal gradient distribution of the Jianghan Basin was obtained based on data of systematical steady-state temperature and oil-test temperature.The basin-wide average thermal gradient in depth interval of 0-4000 m is 33.59℃/km.We report nine measured terrestrial heat flow values based on the data of detailed thermal conductivity and systematical steady-state temperature.These values vary from 41.9 to 60.9 mW/m 2 with a mean of 52.3±6.3 mW/m 2.However,thermal history analyses based on vitrinite reflectance(VR) and apatite fission track(AFT) data indicate that thermal gradient in the northern and southern Qianbei Fault reached its peak of ～36 and ～39℃/km respectively in the Middle Jurassic and the Oligocene,and it descended during the early Miocene to the present-time value.Furthermore,tectonic subsidence analysis reveals that the tectonic subsidence of the Jianghan Basin in the Cretaceous to early Miocene was characterized by synrift initial subsidence followed by the subsequent thermal subsidence.The thermal history and tectonic subsidence history of Jianghan Basin are of great significance to petroleum exploration and hydrocarbon source assessment,because they bear directly on issues of petroleum source rock maturation.Based on the thermal history and tectonic subsidence history,with the combination of geochemical and thermal parameters,the maturation and the hydrocarbon generation intensity evolution history of the P2d source rocks are modeled.The results show that the P2d source rocks are in a higher degree of maturation at present,and the Yuan'an and Herong sags are the two most important kitchens in the Late Jurassic,Xiaoban Sag is another most important kitchen during the Late Cretaceous to late Paleogene,and the Zhijiang and Mianyang sags are other two important hydrocarbon kitchens in the Late Cretaceous.The Mianyang Sag and Yichang Ramp are the favorable exploration targets in the future.This study may provide new insight for the understanding of the oil and gas exploration potential for the Jianghan Basin.
