论文部分内容阅读
因为与油气成藏作用相关的矿物种类较少,传统同位素测年法很难在油气成藏期方面展开应用,油气成藏年代的直接、定量研究是同位素年代学和石油地质研究面临的重大科学问题.本次研究对中扬子地块南缘(江南-雪峰隆起北缘)半坑古油藏断裂带内沥青伴生石英脉进行的包裹体40Ar/39Ar同位素真空击碎法测年实验,获得了两条截然不同的、线性相关均良好的反等时线,对应两个年龄坪,两期年龄分别对应228Ma左右的原生包裹体和149Ma左右的次生包裹体,代表了两期不同性质的流体行为.古油藏断裂带内沥青及伴生的石英脉体是构造作用和成藏及改造作用过程中的一体化产物,与构造作用和烃类运聚具有着非常严格的响应关系,可以约束多期复杂构造作用下油气成藏、改造和破坏的时间,据此将半坑古油藏成藏演化过程划分为晚印支期(228Ma左右)原生油气藏形成阶段和早燕山期(149Ma左右)油气藏改造阶段.本次研究重建了多期复杂构造作用控制下的中扬子地块南缘(江南-雪峰隆起北缘)巨型油气成藏带内油气聚集与改造/破坏的年代学格架,是江南-雪峰隆起北缘特殊大陆构造属性对海相油气巨量富集与改造/破坏的控制作用在时间链条上的体现.展示了流体包裹体40Ar/39Ar定年技术在油气成藏年代学方面,特别是在中国南方地层时代老、烃类演化程度高、多旋回构造作用背景下的海相油气成藏地区应用的可行性与良好前景.
Because of the few types of minerals related to hydrocarbon accumulation, the traditional isotope dating method is very difficult to be applied in the hydrocarbon accumulation period. The direct and quantitative study of hydrocarbon accumulation age is a major science in isotopic geochronology and petroleum geology research Problem.The 40Ar / 39Ar isotope fragmentation dating of the inclusions in the bitumen-bearing quartz vein in the Miankeng ancient reservoir fault zone on the southern margin of the middle Yangtze block (southern margin of the Xuefeng uplift) Two distinct anti-isochronous linear correlations are good, corresponding to the two age Ping, two age corresponding to about 228Ma primary inclusions and 149Ma secondary inclusions, representing two different nature Fluid behavior The bitumen and associated quartz veins in the paleo-oil reservoir fracture zone are the integrated products of tectonism and reservoir forming and remolding processes, and have very strict response to the tectonic action and hydrocarbon migration. They can be constrained The time of hydrocarbon accumulation, alteration and destruction under the complex and multi-period complex structure is divided into the formation phase of the primary reservoirs of Late Indosinian (about 228 Ma) Early Yanshanian (about 149 Ma) reservoir reconstruction stage This study reconstructed the accumulation and reformation of hydrocarbons in the giant hydrocarbon accumulation zone under the control of multi-period complex tectonics in the southern margin of the middle Yangtze block (southern margin of the Jiangnan-Xuefeng uplift) / Devastating chronological framework is a reflection of the controlling role of the special continental tectonics in the southern margin of the Xuepeng uplift on the enrichment and transformation / destruction of massive marine oil and gas over the time chain. It is shown that the fluid inclusions 40Ar / 39Ar The dating technology is feasible and promising for application of hydrocarbon accumulation geochronology, especially in the age of the stratigraphic age in southern China, the high degree of hydrocarbon evolution, and the multi-cycle tectonic setting.