济阳坳陷古近系烃源岩分子成熟度参数的异常分布  

Anomalies of molecular indicators in Jiyang Eogene source rocks

作　　者：王广利[1] 王铁冠[1] 张林晔[2] 张学军[2] 

机构地区：[1]中国石油大学教育部油气成藏机理重点实验室,北京102249 [2]胜利油田有限公司地质科学研究院,山东东营257015

出　　处：《地球化学》2006年第5期560-566,共7页Geochimica

基　　金：国家自然科学基金(40003002)

摘　　要：济阳坳陷古近系湖相烃源岩的自然演化剖面结果表明,分子标志化合物的演化是一个受沉积环境、矿物组成、有机质赋存状态和温度等多种因素共同影响的复杂过程,其演化具有阶段性,随着埋藏深度增加,大多呈现出“先增大,后减小”的模式。形成于半咸水—微咸水的沙三段下部烃源岩分子标志化合物的演化较为剧烈,温度的影响是主要的,但随着深度的增加,碳酸盐矿物含量逐渐升高对分子标志化合物的演化起到了抑制作用;而形成于咸水—半咸水的沙四段烃源岩分子标志化合物变化平缓,平衡值降低,高盐沉积环境和丰富的碳酸盐矿物在一定程度上延缓了异构化进程。这个结果对于我们正确理解和应用分子成熟度参数具有重要启示,对于咸化湖泊条件下形成的第三系盆地深部地层的勘探具有指导意义。The natural maturation of molecular parameters in Eogene lacustrine deposition of Jiyang superdepression was studied using Gas Chromatography-Mass Spectrometry. The results show that the evolution of molecular markers was a complicated process influenced by matrix, mineral compositions, depositional environment and temperature in the source rocks. The molecular indices of maturation originally increased with maturity, and then decreased when getting maxima. As a whole, it couldn＇t be simply regarded as a first order reaction model, while two or more stages may be divided. The molecular parameters of Es3 Member which was formed under brackish water at first varied greatly with depth showing temperature dependently, and then got smaller because of the higher carbonate minerals in the deeper strata. Differently, the molecular parameters of Es4 Member which was formed under saline to brackish water varied more smoothly and showed lower equilibrium values, indicating the high carbonate minerals retarted the progress of the isomerization. This result is helpful to understanding and applying the molecular maturity parameters in the saline lacustrine petroleum basin.

关 键 词：自然演化剖面 分子成熟度参数 沉积环境 演化模式 碳酸盐矿物 济阳坳陷 

分 类 号：P593[天文地球—地球化学]