【摘要】 东濮凹陷下第三系沙河街组富含石膏及岩盐,为典型的盐湖相沉积,其有机碳、氯仿沥青A及总烃含量分别为0.74％、0.11％及800ppm,与渤海湾其它盆地比较都较低。这是由于该凹陷干酪根属混合型,埋藏较深、成熟度较高、排烃较完全之故。因此东濮凹陷下第三系有机碳等含量较低并不说明有机质丰度低,而恰恰证明其生油条件优越。 东濮凹陷不同地段因地质发育史不同,成油起始温度或埋藏深度都不一致,这是因为同一生油层在不同地区其有机质所经受的热变质均不一样,因而采用洛巴丁时-温指数来研究有机质成熟度是更为合理的。盐湖相沉积不但可富含有机质,而且天然气形成时间较晚,加上膏盐层渗透性极小,可作为良好盖层,防止气体逸散,这就是造成东濮凹陷天然气特别富集的原因。更多还原

【Abstract】 The lower Tertiary formation of Dongpu Depression is rich in gypsum and salt,being a typical saline deposition. The average contents of organic carbon, bitumen "A" and hydrocarbon are 0.74%, 0.11%, 800ppm respectively, much lower than those in other depressions in Bohai Bay area. In Dongpu depression the kerogen found in lower Tertiary formation is of mixed type with a high potential for petroleum generation, deeper burial depth, higher degree of maturation and complete expelling of hydrocarbon generated.The threshold temperatures or buried depths are different in different parts of Dongpu depression because of different sedimentary development. The use of Lopatin’s Time-Temperature Index for studing organic matter maturity is more reasonable. The generation of natural gas was later in gypsum-saline deposit and the low permeability saline deposit serves as a perfect cap rock, which is conducive to enrichment of natural gas in this area.更多还原