苏北盆地与南黄海盆地中——新生界成烃对比浅析

COMPARISON ANALYSIS OF MESO-CENOZOIC HYDROCARBON GENERATION BETWEEN THE NORTH JIANGSU BASIN AND THE SOUTH YELLOW SEA BASIN

刘玉瑞

Liu Yurui

中国石油化工股份有限公司, 江苏油田分公司, 地质科学研究院, 江苏, 扬州, 225009

Geological Scientific Research Institute of Jiangsu Oilfield Company, SINOPEC, Yangzhou, Jiangsu 225009, China

苏北与南黄海盆地是统一的中—新生代盆地。苏北盆地勘探成果丰富,地化甄别7套暗色泥岩仅4套对成藏有贡献,3套属拗陷广湖灰泥岩,分布广、质量稳定,岩电特征突出;1套属断陷湖的纯泥岩。重新厘定南黄海盆地烃源岩,确认南坳有5套烃源岩,套数比苏北多、厚度略大,北坳仅有1套;各套形成环境、岩电特征与苏北相似,但品质和稳定性略差。两盆地烃源岩都处低熟—成熟阶段,南黄海总体低于苏北,成熟可排烃源岩范围较苏北小。烃源岩质量、成熟度和排烃畅通度决定苏北各凹陷油气资源丰度,成熟度高、排烃畅通资源丰度高,相反则低;断陷沉积埋藏越发展,烃源岩越成熟,三垛期末为烃源岩成熟定型期。综合看,南黄海资源潜力不如苏北,南坳优于北坳。

The North Jiangsu Basin and the South Yellow Sea Basin are a unified Mesozoic-Cenozoic basin.The North Jiangsu Basin has seen fruitful exploration. Four out of seven sets of dark mudstone only contribute to hydrocarbon accumulation by geochemical analysis, in which three are wide lacustrine lime mudstones in depression which is characterized with wide distribution, high quality and significant in lithology-electricity, the other one is pure mudstone in rift lake. It can conclude that there are 5 sets of source rocks in the Southern Depression which are more in numbers and slightly larger in thickness than in the North Jiangsu Basin, and only one in the Northern Depression of the South Yellow Sea Basin. The source rocks of the South Yellow Sea Basin are similar in original environment and lithology-electricity with the North Jiangsu Basin, but less in quality and continuity. Source rocks develop at the low mature-mature stage in two basins, of which the South Yellow Sea Basin is lower in maturity than the North Jiangsu Basin resulting to narrow distribution of expulsive petroleum source rock. Quality, maturity and degree of expulsion of source rocks dominate abundance of hydrocarbon resources in sags of the North Jiangsu Basin, higher maturity and hydrocarbon expulsion of source rock, higher abundance of resources, otherwise it is low. Deeper sediments are buried in rift sag, more mature in source rocks. The end of the Sanduo stage is time for complete maturity of source rocks. In general, the South Yellow Sea Basin is not larger than the North Jiangsu Basin in resource potential where the Southern Depression is better than the Northern Depression.

中国石油化工股份有限公司科技项目(P02067)

https://doi.org/10.11781/sysydz201006541