南华北盆地谭庄凹陷巴1井原油地球化学特征及成藏条件

摘要

The analysis of the biomarker compositional characteristics of crude oils from the Lower Cretaceous of the Tanzhuang Sag in the Southern North China Basin indicated for the Lower Cretaceous origin, and the reservoir was indigenously generated and accumulated. According to the simulation of burial and thermal evolution histories, there were at least two stages of hydrocarbon charging in the study area. The early stage was the Early Cretaceous and the late stage was from the Late Tertiary to Quaternary. The studies of accumulation conditions revealed that the Lower Cretaceous source rocks in the Tanzhuang Sag had good quality, strong sealing capacity and nice allocation of generation-migration-accumulation; however, the Lower Cretaceous sandstones with low porosity and permeability restricted petroleum exploration. High resolution sequence stratigraphy and sedimentary facies studies were advised to predict favorable sandbodies.%通过对南华北盆地谭庄凹陷巴1井下白垩统原油的地球化学特征分析,认为该原油来自于下白垩统烃源岩,为自生自储型油藏.结合埋藏史—热演化史模拟结果分析,推测该原油经历了至少早(K1)、晚(N+Q)2期充注过程.油气成藏条件综合研究表明,谭庄凹陷下白垩统烃源岩品质较好、盖层封闭能力强、局部圈闭发育、匹配关系良好,但由于下白垩统砂岩为低孔低渗储层,物性整体差,制约了油气勘探的突破.建议开展高精度层序地层学研究和沉积相精细刻画,预测相对有利的储层砂体.