松辽盆地基底石炭-二叠系热演化史  

Restoration of thermal history of the Permo-Carboniferous basement in the Songliao Basin

作　　者：任战利[1] 萧德铭[2] 迟元林[2] 任延广[2] 梁宇[1,2] 

机构地区：[1]西北大学大陆动力学国家重点实验室,陕西西安710069 [2]中国石油大庆油田有限责任公司,黑龙江大庆163453

出　　处：《石油与天然气地质》2011年第3期430-439,共10页Oil & Gas Geology

基　　金：高等学校全国优秀博士学位论文作者专项资金资助项目(200347)

摘　　要：松辽盆地北部石炭-二叠系镜质体反射率值普遍较高,普遍大于3.0%,不同构造单元石炭-二叠系镜质体反射率值差异较大。松辽盆地深层石炭-二叠系基底镜质体反射率-深度关系曲线分为两种类型,表明松辽盆地深层石炭-二叠系基底有不同的热演化过程。一种是两段型,镜质体反射率-深度曲线在石炭-二叠系顶部不整合面上、下镜质体反射率值发生突变,不整合面之下石炭-二叠系镜质体反射率值及古地温明显高于上覆地层,表明石炭-二叠系最大古地温是在早白垩世登娄库组沉积之前达到的,白垩纪以来沉积地层厚度对石炭-二叠系古地温提高及热演化程度没有影响。另一种为似线型,石炭-二叠系顶部不整合面上、下镜质体反射率值及古地温连续变化,表明石炭-二叠系最大古地温是在晚白垩世—渐新世之前达到的,白垩纪以来沉积的地层厚度对石炭-二叠系古地温及热演化程度的提高有贡献。在综合分析有机质镜质体反射率、包裹体测温、裂变径迹年龄等多种参数的基础上,对松辽盆地基底石炭-二叠系热演化史进行了恢复,并分析了热演化史与油气生成的关系。Vitrinite reflectance of the Permo-Carboniferous in the north of Songliao Basin is generally high,usually more than 3.0%,and varies greatly in different tectonic units.The curve of vitrinite reflectance（Ro）-depth（H）of the Permo-Carboniferous basement in Songliao Basin has two types,which means that they have different thermal history.One is a two-section type.Vitrinite reflectance values change abruptly across the unconformity on top of the Permo-Carboniferous.The Ro values and paleotemperature of the Permo-Carboniferous strata under the unconformity are obviously higher than that of the overlying strata,indicating that the maximum paleotemperature of Permo-Carboniferous strata had been reached before the deposition of the Early Cretaceous Denglouku Formation.The sedimentary strata deposited since the Cretaceous have no influences on the improvement of the Permo-Carboniferous paleotemperature and thermal maturity.The other is a pseudo-linear type.The Ro values and paleotemperature vary successively across the unconformity on top of the Permo-Carboniferous strata,which shows that maximum paleotemperature of the Permo-Carboniferous strata had been reached betwen the Late Cretaceous and Oligocene.The sedimentary strata since the Cretaceous contribute to the improvement of Permo-Carboniferous paleotemperature and thermal maturity.Based on comprehensive analysis on vitrinite reflectance,fluid inclusion,fission-track age and so on,paleotemperature and thermal history of Songliao Basin is restored,and the relation between basin thermal history and hydrocarbon generation is analyzed.

关 键 词：裂变径迹 古地温 构造-热事件 热演化史 石炭-二叠系 松辽盆地 

分 类 号：TE121.1[石油与天然气工程—油气勘探]