A tectono-thermal perspective on the petroleum generation,accumulation and preservation in the southern Ordos Basin, North China  

作　　者：Peng Yang Zhan-Li Ren Jin-Hua Fu Hong-Ping Bao Hui Xiao Zheng Shi Kun Wang Yuan-Yuan Zhang Wen-Hui Liu Wen-Hou Li 

机构地区：[1]State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi'an,710069,Shanxi,China [2]National Engineering Laboratory for Exploration and Development of Low-Permeability Oil and Gas Fields,Exploration and Development Research Institute of PetroChina Changqing Oilfield Company,Xi'an,710018,Shaanxi,China [3]Shaanxi Key Lab of Petroleum Accumulation Geology,School of Earth Science and Engineering,Xi'an Shiyou University,Xian,710065,Shaanxi,China [4]Wuxi Research Institute of Petroleum Geology,Petroleum Exploration and Production Research Institute,SINOPEC,Wuxi,214126,Jiangsu,China

出　　处：《Petroleum Science》2024年第3期1459-1473,共15页石油科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.42102164,42241204,41630312and 42272174);the Petro China Changqing Oilfield Company Science and Technology Major Project(ZDZX 2021-01)。

摘　　要：The southern Ordos Basin has excellent petroleum exploration prospects.However,the tectono-thermal history and the controls on petroleum generation,accumulation and preservation conditions in southern basin are unclear.In this study,we analyzed the present geothermal field,paleo-geothermal gradient,maturity of the hydrocarbon source rocks,uplift and cooling process and tectono-thermal evolution history.In the study area,for the Ordovician,Permain and the Triassic strata,the present temperature is low(3070℃)in the southeastern area but high(80140℃)in the northwestern area.The paleogeothermal gradient varied from 24℃/km to 30℃/km with a heat flow of 58—69 m W/m^(2)(i.e.,a medium-temperature basin).The paleo-temperatures are higher than the present temperatures and the maximum paleo-temperatures controlled the thermal maturity of the source rocks.The vitrinite reflectance(Ro)values of the Triassic strata are>0.7%and the thermal maturity reached the middlemature oil generation stage.The Rovalues of the Permian-Ordovician strata are>1.8%and the thermal maturity reached the over-mature gas generation stage.The southern Ordos Basin has experienced the multiple tectonic events at the Late Ordovician Caledonian(452 Ma),Late Triassic(215 Ma),Late Jurassic(165160 Ma),End-Early Cretaceous(110100 Ma)and Cenozoic(since 40 Ma).A large-scale tectonothermal event occurred at the End-Early Cretaceous(110100 Ma),which was controlled by lithospheric extension,destruction and thinning.This event led to the highest paleo-temperatures and thermal maturities and coeval with the peak period of petroleum generation and accumulation.The southern Ordos Basin has undergone rapid and large-scale uplift since the Late Cretaceous due to expansion of the northeastern margin of the Tibetan Plateau,uplift of the Qinling orogenic belt and thrust faulting in the Liupanshan tectonic belt.The southern Ordos Basin experienced tectonic overprinting that was strong in the south and weak in the north.The strongest overprinting occurred in the so

关 键 词：Fission-track dating Vitrinitereflectance Geothermal field Tectono-thermal evolution Petroleum geology Ordos Basin 

分 类 号：P618.13[天文地球—矿床学]