摘要
沉积盆地热体制对理解盆地的成因演化过程以及油气和地热能源资源评估等具有关键作用,备受学术界和工业界关注。库车前陆盆地是中国重要的天然气产区,其热体制的准确厘定对于该区油气潜力评估具有重要意义。文章利用系统连续测温与试油温度数据,结合地层热物性数据,详细研究了库车前陆盆地的现今热状态特征。库车前陆盆地的现今地温梯度介于17.3~25.7℃/km之间,平均值为21.5±2.6℃/km;大地热流范围为27.4~57.9 mW/m^(2)之间,平均值为40.9±7.2 mW/m^(2)。区域内1000~6000 m埋深处的估算温度范围及均值分别为26~49℃(36±4.6℃)、42~82℃(59±7.5℃)、64~113℃(82±10.3℃)、85~127℃(102±11.6℃)、98~140℃(119±12.8℃)与110~155℃(133±13.9℃)。库车前陆盆地现今热状态整体偏低,分布上表现出“北高南低、东高西低”的空间格局。盆地西部沉积物厚度大,沉积层因其低热导率形成热屏蔽效应,阻碍深部热量向地表运输。同时,盆地东部新构造变形强度更大,断层运动生热效应明显。盆地沉积物厚度差异以及印度—欧亚大陆碰撞远距离效应作用下活动构造的强度差异联合造就了观测到的区域地热格局。
Geothermal regime of the sedimentary basins is key for understanding the formation and evolution of the basins and assessing hydrocarbon and geothermal energy,and has attracted much attention from the academia and industrial circles.Kuqa Foreland Basin,located between the Tarim Basin and Southern Tianshan Mountain,is one of major hydrocarbon exploration targets in China,and accurate knowledge of geothermal regime of this basin is beneficial for hydrocarbon potential assessment.Here we integrate updated steady-state temperature logs and oil testing temperature,with thermal properties data,to decipher the thermal characterization of the Kuqa Foreland Basin.The geothermal gradient of the basin ranges from 17.3 to 25.7℃/km,with an average of 21.5±2.6℃/km;while the heat flow varies from 27.4 to 57.9 mW/m^(2),with a mean of 40.9±7.2 mW/m^(2).The range and average of estimated formation temperatures at 1000-6000 m in the basin are 26-49℃(36±4.6℃),42-82℃(59±7.5℃),64-113℃(82±10.3℃),85-127℃(102±11.6℃),98-140℃(119±12.8℃)and 110-155℃(133±13.9℃),respectively.Generally,the present-day thermal state of the Kuqa Foreland Basin is relatively low and the thermal pattern is characterized by hot in the north and east,cold in the south and west,which is attributed to the east-west differences in the thickness of the Cenozoic sediments and the lateral variations in the intensity of active deformation associated with the far field effects of the Indo-Asian continental collision.The large thickness of the sediments in the western part of the basin,which forms the thermal blanketing effects owing to their low thermal conductivities,preventing the transport of heat from the deep to the surface.In addition,the active deformation in the eastern part of the basin is more intense,and the friction heating effect of fault movements is obvious.These two factors are combined to account for the observed present-day geothermal field pattern of Kuqa Foreland Basin.
作者
冯冠中
刘绍文
朱传庆
李香兰
FENG Guanzhong;LIU Shaowen;ZHU Chuangqing;LI Xianglan(Key Laboratory of Coast and Island Development,School of Geography and Ocean Science of Nanjing University,Nanjing 210023,China;Collaborative Innovation Center for South China Sea Studies,Nanjing 210093,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China)
出处
《高校地质学报》
CAS
CSCD
北大核心
2024年第4期460-475,共16页
Geological Journal of China Universities
基金
国家自然科学基金(4207020139)
中国石油科技创新基金研究项目(2020D-5007-0104)联合资助。
关键词
大地热流
地温梯度
岩石热物性
热体制
库车前陆盆地
Heat flow
geothermal gradient
thermal properties
thermal regime
Kuqa Foreland Basin
