The thermal regimes in sedimentary basins in the continental area of China are varied and reflect differences in geological settings. As a result of these variable thermal regimes, the history of hydrocarbon generatio...The thermal regimes in sedimentary basins in the continental area of China are varied and reflect differences in geological settings. As a result of these variable thermal regimes, the history of hydrocarbon generation in each basin is also different. An east-west profile of the thermal threshold across the continental basins of China, like the Liaohe Basin, the North China Basin, the Ordos Basin, the Qaidam Basin and the Tarim Basin, was constructed using large numbers of heat flow measurements, temperature data and rock thermophysical parameters. Isotherms, surface heat flow, mantle heat flow and Moho temperature beneath the basins are shown in the profile, which illustrates changes in some thermal characteristics between basins in east China and those in west China. Thermal evolution histories in basins were reconstructed using Easy%Ro method, apatite fission track annealing and other paleothermometers. Typical hydrocarbon generation histories of the primary source rocks were modeled by referring to the thermal evolution data. Thermal stages controlled source rocks maturation and oil and gas generation, and influenced the type of hydrocarbon (oil and gas) production in the basins.展开更多
The Lenghu tectonic belt is located at or near the northern margin in the Qaidam Basin,which is an intracontinental composite basin evolved during the Mesozoic and Cenozoic epochs.The Lower Jurassic is considered a go...The Lenghu tectonic belt is located at or near the northern margin in the Qaidam Basin,which is an intracontinental composite basin evolved during the Mesozoic and Cenozoic epochs.The Lower Jurassic is considered a good source rock with a wide distribution.Since the deposit of the Lower Jurassic hydrocarbon source rock,the basin has undergone many tectonic events of subsidence and uplift.The source rocks in the Lengke-1 well,have experienced a complicated tectonic-burial history during which different hydrocarbon generation(HG) evolutions have taken place.We have investigated the history of burying,heating and hydrocarbon generation of the Lower Jurassic source rocks,not just on the basis of tectonic disturbance and deep burial,but also from new studies in fluid inclusion measurements and the application of numerical simulation with EASY%Ro.Our study reveals the evolution process,tectonic episodes and the strength of the HG of the Jurassic source rock.We conclude that twice HG processes have taken place since the Lower Jurassic formation and infer from that the important conclusion that more HG of the Lower Jurassic source rock took place during the Eocene-Miocene epochs.Finally,we discuss the oil and gas tarp formation and destruction in the Lenghu tectonic belt and point out that more attention should be paid to the thrust faults,which formed during the late Himalayan epoch.展开更多
Pre-existing models for thermal history modelling have shown deficiency in explicit algorithms to establish the quantitative relationship between maturity indices and thermal gradients in some sedimentary basins that ...Pre-existing models for thermal history modelling have shown deficiency in explicit algorithms to establish the quantitative relationship between maturity indices and thermal gradients in some sedimentary basins that experienced multi-episodic rifting evolution. In this study, a forward and inverse combination model（FICM） is proposed to estimate the vitrinite reflectance（Ro） and thermal gradients. The forward module is used to calculate Ro values. It couples the EASY%Ro model with burial history reconstruction with consideration of thermal gradient variations during basin evolution. The inverse module reconstructs histoical thermal gradients by calibrating cmputed Ro against measured Ro data. The time-temperature series is a necessary input for both forward and inverse modules. Sample density is a profound factor influencing the accuracy of modelling results. In order to obtain satisfying outputs, a sufficient sample density is required. Thermal gradients are assumed to vary linearly between two given samples. Modelling results of case studies indicate that the sensitivity of heating time to Ro evlution is differnt with thermal gradients depending on geolgoical setting. Three difffernt districts, which include the time-sensitive area, the temperature-sensitive area and the non-sensitive area, can be recognized on the the relationship map among Ro variations, heating time and geothermal gradients. This model can be applied to reconstruct the thermal history and maturation evolution in a basin that has undergone complex multi-episodic rifting.展开更多
The Dongpu （东濮） depression is a Mesozoic subsidence and Cenozoic fault basin developed within the North China eraton. Since the deposition of Permo--Carboniferous hydrocarbon source rock, the depression has underg...The Dongpu （东濮） depression is a Mesozoic subsidence and Cenozoic fault basin developed within the North China eraton. Since the deposition of Permo--Carboniferous hydrocarbon source rock, the depression has undergone many tectonic disturbances and uplifts. The source rocks have un- dergone nonuniform uplift, deformation, deep burying, and magmatism, and those led to an inter- rupted or stepwise evolution of the hydrocarbon source rocks in Qinggu （庆古）-2 well. We have investigated the history of burying, heating, and hydrocarbon generation of the Permo-Carboniferous hy- drocarbon source rocks not just on the basis of tectonic disturbance and deep burying, but also with new studies in apatite fission track analysis, fluid inclusion measurements, and the application of the numerical simulation of EASY%Ro. The heating temperature of the source rocks pulsated upward from Indosinian to Himalayan stages and reached a maximum during early Himalayan. This led to the stepwise increases of organic maturation and multiple stages of hydrocarbon generation. This study delineated the tectonic stages, maturity evolved ranges, and the intensity of hydrocarbon generation of Permo-Carboniferous source rocks in Qinggu-2 well. The hydrocarbon gen- eration mainly occurred during Indosinian and early Himalayan. The early Himalayan stage hydrocarbon generation is the larger one, but the Dongying （东营） movement, which happened at the end of early Himalayan, may destroy the trapped oil and gas. Thereby, future exploration will need to pay more attention to the Dongying movement effect in Qinggu-2 well area, and it may get new breakthrough in Permo-Carboniferous oil and gas.展开更多
文摘The thermal regimes in sedimentary basins in the continental area of China are varied and reflect differences in geological settings. As a result of these variable thermal regimes, the history of hydrocarbon generation in each basin is also different. An east-west profile of the thermal threshold across the continental basins of China, like the Liaohe Basin, the North China Basin, the Ordos Basin, the Qaidam Basin and the Tarim Basin, was constructed using large numbers of heat flow measurements, temperature data and rock thermophysical parameters. Isotherms, surface heat flow, mantle heat flow and Moho temperature beneath the basins are shown in the profile, which illustrates changes in some thermal characteristics between basins in east China and those in west China. Thermal evolution histories in basins were reconstructed using Easy%Ro method, apatite fission track annealing and other paleothermometers. Typical hydrocarbon generation histories of the primary source rocks were modeled by referring to the thermal evolution data. Thermal stages controlled source rocks maturation and oil and gas generation, and influenced the type of hydrocarbon (oil and gas) production in the basins.
基金supported by the Natural Oil & Gas Stratagem Tap of China
文摘The Lenghu tectonic belt is located at or near the northern margin in the Qaidam Basin,which is an intracontinental composite basin evolved during the Mesozoic and Cenozoic epochs.The Lower Jurassic is considered a good source rock with a wide distribution.Since the deposit of the Lower Jurassic hydrocarbon source rock,the basin has undergone many tectonic events of subsidence and uplift.The source rocks in the Lengke-1 well,have experienced a complicated tectonic-burial history during which different hydrocarbon generation(HG) evolutions have taken place.We have investigated the history of burying,heating and hydrocarbon generation of the Lower Jurassic source rocks,not just on the basis of tectonic disturbance and deep burial,but also from new studies in fluid inclusion measurements and the application of numerical simulation with EASY%Ro.Our study reveals the evolution process,tectonic episodes and the strength of the HG of the Jurassic source rock.We conclude that twice HG processes have taken place since the Lower Jurassic formation and infer from that the important conclusion that more HG of the Lower Jurassic source rock took place during the Eocene-Miocene epochs.Finally,we discuss the oil and gas tarp formation and destruction in the Lenghu tectonic belt and point out that more attention should be paid to the thrust faults,which formed during the late Himalayan epoch.
基金the National Natural Science Foundation of China (Nos. 91028009 and 41372112)the Key Project of Hubei Natural Science Foundation (No. 2008CDA095)the Funding of Key Laboratory of Tectonics and Petroleum Resources of the Ministry of Education (No. TPR-2012-02)
文摘Pre-existing models for thermal history modelling have shown deficiency in explicit algorithms to establish the quantitative relationship between maturity indices and thermal gradients in some sedimentary basins that experienced multi-episodic rifting evolution. In this study, a forward and inverse combination model（FICM） is proposed to estimate the vitrinite reflectance（Ro） and thermal gradients. The forward module is used to calculate Ro values. It couples the EASY%Ro model with burial history reconstruction with consideration of thermal gradient variations during basin evolution. The inverse module reconstructs histoical thermal gradients by calibrating cmputed Ro against measured Ro data. The time-temperature series is a necessary input for both forward and inverse modules. Sample density is a profound factor influencing the accuracy of modelling results. In order to obtain satisfying outputs, a sufficient sample density is required. Thermal gradients are assumed to vary linearly between two given samples. Modelling results of case studies indicate that the sensitivity of heating time to Ro evlution is differnt with thermal gradients depending on geolgoical setting. Three difffernt districts, which include the time-sensitive area, the temperature-sensitive area and the non-sensitive area, can be recognized on the the relationship map among Ro variations, heating time and geothermal gradients. This model can be applied to reconstruct the thermal history and maturation evolution in a basin that has undergone complex multi-episodic rifting.
基金supported by the Science and Technology Key Item of China National Petroleum Corporation (No. 970206)the Natural Oil & Gas Stratagem Tap of China (No. XQ-2004-03)and the National Natural Science Foundation of China (No. 40730422)
文摘The Dongpu （东濮） depression is a Mesozoic subsidence and Cenozoic fault basin developed within the North China eraton. Since the deposition of Permo--Carboniferous hydrocarbon source rock, the depression has undergone many tectonic disturbances and uplifts. The source rocks have un- dergone nonuniform uplift, deformation, deep burying, and magmatism, and those led to an inter- rupted or stepwise evolution of the hydrocarbon source rocks in Qinggu （庆古）-2 well. We have investigated the history of burying, heating, and hydrocarbon generation of the Permo-Carboniferous hy- drocarbon source rocks not just on the basis of tectonic disturbance and deep burying, but also with new studies in apatite fission track analysis, fluid inclusion measurements, and the application of the numerical simulation of EASY%Ro. The heating temperature of the source rocks pulsated upward from Indosinian to Himalayan stages and reached a maximum during early Himalayan. This led to the stepwise increases of organic maturation and multiple stages of hydrocarbon generation. This study delineated the tectonic stages, maturity evolved ranges, and the intensity of hydrocarbon generation of Permo-Carboniferous source rocks in Qinggu-2 well. The hydrocarbon gen- eration mainly occurred during Indosinian and early Himalayan. The early Himalayan stage hydrocarbon generation is the larger one, but the Dongying （东营） movement, which happened at the end of early Himalayan, may destroy the trapped oil and gas. Thereby, future exploration will need to pay more attention to the Dongying movement effect in Qinggu-2 well area, and it may get new breakthrough in Permo-Carboniferous oil and gas.
