CAJ | 학술논문

下刚果盆地深水区的油气显示出了海相原油的特征，盐上海相烃源岩开始受到关注。通过对下刚果盆地海相烃源岩地球化学资料分析，综合评价了盐上4套海相烃源岩的地球化学特征和生烃潜力，研究了其成因并划分了成因类型，同时探讨了不同成因类型烃源岩发育的主控因素。结果表明：下刚果盆地盐岩层之上发育海相烃源岩，有机质丰度中等—好，干酪根类型为Ⅱ、Ⅲ型，成因上以海相内源型和海相混合生源型为主；盆地海相烃源岩整体在3500 m左右深度进入生油窗，成熟的海相烃源岩是下刚果盆地深水区油气的重要来源之一；由于上升洋流、缺氧环境(大洋缺氧事件)和古河流的作用，以及海洋、河流两种地质营力此消彼长的关系，自晚白垩世至中新世，盆地沉积环境从海湾变迁到受河流作用逐渐加强的开阔海洋，有机质来源从以海洋有机质为主过渡到河流携带来的陆源有机质比例加重，直到以陆源有机质为主；海陆二元有机质输入量的相对变化和海洋沉积环境的变迁从根本上决定了海相烃源岩的特征。
하강과분지심수구적유기현시출료해상원유적특정，염상해상경원암개시수도관주。통과대하강과분지해상경원암지구화학자료분석，종합평개료염상4투해상경원암적지구화학특정화생경잠력，연구료기성인병화분료성인류형，동시탐토료불동성인류형경원암발육적주공인소。결과표명：하강과분지염암층지상발육해상경원암，유궤질봉도중등—호，간락근류형위Ⅱ、Ⅲ형，성인상이해상내원형화해상혼합생원형위주；분지해상경원암정체재3500 m좌우심도진입생유창，성숙적해상경원암시하강과분지심수구유기적중요래원지일；유우상승양류、결양배경(대양결양사건)화고하류적작용，이급해양、하류량충지질영력차소피장적관계，자만백성세지중신세，분지침적배경종해만변천도수하류작용축점가강적개활해양，유궤질래원종이해양유궤질위주과도도하류휴대래적륙원유궤질비례가중，직도이륙원유궤질위주；해륙이원유궤질수입량적상대변화화해양침적배경적변천종근본상결정료해상경원암적특정。
The characteristic of petroleum in the deepwater area of Lower Conga Basin is marine,so that the marine source rock above the salt is a concern.According to the geochemical analysis data and geological information of marine source rock in Lower Congo Basin,the geochemical characteristics, hydrocarbon potential, origin and genetic types for the four sets of marine source rocks were comprehensively discussed,and the main controlling factors for the different genetic types of marine source rocks were analyzed.The results show that the marine source rocks develop above the salt rock of Lower Congo Basin,and the abundances of organic matters of them are moderate-good with typesⅡand Ⅲof kerogens,and the source rocks are consist primarily of the marine endogenous type and marine mixed type;marine source rocks in Lower Congo Basin enter the oil-generating window at the depth of about 3 500 m,and mature marine source rocks are important sources of petroleum in the deepwater area of Lower Congo Basin;because of the ascending current,anoxic environments (oceanic anoxic events), palae-fluvial action and the shift relationship between the geologic agents of ocean and river, the sedimentary environments in Lower Congo Basin change from the gulf to the open ocean strengthened gradually by fluvial action, and organic matter inputs vary gradually from marine-dominated to terrigenous-dominated from Late Cretaceous to Miocene;the changes of relative marine-terrigenous organic matter input and ocean sedimentary environment fundamentally determine the characteristics of marine source rocks.