CAJ | 학술논문

从烃源岩、储层、盖层等基本地质条件,沥青的地球化学特征,以及地层后期抬升的低温年代学等方面系统解剖了四川盆地东南缘习水吼滩志留系古油藏的成藏特征.习水吼滩古油藏的主要储层是下志留统石牛栏组亮晶生屑灰岩,储层沥青主要分布在生物碎屑颗粒之间和粒内溶孔中,该储层沥青来自志留系自身的烃源岩.志留系源岩生成于还原沉积环境中,有机质主要来自于低等水生生物.志留系储层中与油气包裹体共生的盐水包裹体均一温度平均为97.2℃,结合研究区地层沉积埋藏史,可以确定油气充注的时间大约为距今200Ma.邻近志留系古油藏的下奥陶统湄潭组粉砂岩样品的磷灰石裂变径迹表明,研究区在距今29Ma左右隆升到退火带之内,距今4.5Ma之后经受了加速隆升,约有2100～2450m厚的地层受到剥蚀,最终造成了古油藏的破坏.
종경원암、저층、개층등기본지질조건,력청적지구화학특정,이급지층후기태승적저온년대학등방면계통해부료사천분지동남연습수후탄지류계고유장적성장특정.습수후탄고유장적주요저층시하지류통석우란조량정생설회암,저층력청주요분포재생물쇄설과립지간화립내용공중,해저층력청래자지류계자신적경원암.지류계원암생성우환원침적배경중,유궤질주요래자우저등수생생물.지류계저층중여유기포과체공생적염수포과체균일온도평균위97.2℃,결합연구구지층침적매장사,가이학정유기충주적시간대약위거금200Ma.린근지류계고유장적하오도통미담조분사암양품적린회석렬변경적표명,연구구재거금29Ma좌우륭승도퇴화대지내,거금4.5Ma지후경수료가속륭승,약유2100～2450m후적지층수도박식,최종조성료고유장적파배.
The forming characteristics of the Silurian destroyed reservoir in the Houtan section in the southeastern margin of Sichuan Basin were studied according to the basic geologic conditions of source rocks, reservoir rocks and cap rocks,as well as the geochemis-try characteristics of bitumen and the thermochronology of detritus minerals. The main reservoir rock of the destroyed oil reservoir is sparite with bioclastic. The bitumen distributed in the inter-grain pores of biological detritus and their solution inner-grain pores. The content and distribution of isoprenoid, steranes and terpanes from bitumen in Silurian illustrated that the source rocks were de-posited in the reduced environment, and the organic source mainly came from the low-grade hydrobiosm. The stable carbon isotope showed that the bitumen came from source rock of the Silurian. The mean homogenization temperature of saline inclusions coexisting with hydrocarbon inclusions is 97. 2℃. Combined with the burial history of the studied area, the hydrocarbon infilling time was de-termined to be about 200 Ma before present. The fission track age of apatite in the Ordovician Meitan Formation near the destroyed oil reservoir showed that the formation uplifted in anneal zone at about 29 Ma before present and accelerated uplifted at 4. 5 Ma before present. The denudation thickness was about 2100-2450 m in the studied area, which finally destroyed oil reservoir.