周口残留盆地油气勘探前景分析

ANALYSES ON OIL AND GAS EXPLORATION PROSPECTS IN THE ZHOUKOU RESIDUAL BASIN

袁政文 何明喜 宋建华 古哲 杜建波

YUAN Zheng-wen HE Ming-xi SONG Jian-hua GU Zhe DU Jian-bo

西北大学, 陕西, 西安, 710069 2. 中国科学院, 地质与地地球物理研究所, 北京, 100029 3. 中国石化, 河南油田分公司, 河南, 南阳, 473132

Northwest University, Xi'an, Shaanxi 710069, China 2. Institute of geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 3. Henan Oilfield, SINOPEC, Nanyang, Henan 473132

该文首先分析了周口坳陷原型沉积盆地先后遭受的3期挤压和2期张性改造特征;然后通过油源对比,确定了残留盆地两套主要烃源岩:即下白垩统和石炭—二叠系;并按照"建造与改造"、"破坏与保存"的关系,划分了残留盆地4种油气成藏单元,分析了残留盆地油气系统的演化,预测了残留盆地自生自储、下生上储和古潜山等3种油气聚集类型.作者强调,残留盆地热演化的不均衡性为二次成烃创造了一定条件,二次成烃的强度和范围受上覆层早第三纪断陷构造控制.因此,二次成烃和晚期成藏是残留盆地勘探的主攻方向.深入研究下生上储(古生新储和中生新储)的必要条件和晚期成藏的有利场所,才能找准残留盆地油气勘探的突破口.

The reformation characteristics of three-period compression and two-period extension suffered by the prototype depositional basin of the Zhoukou Depression were analyzed in this paper at first.Then two groups of major residual oil source rocks in the Lower Cretaceous and the Carboniferous-Permian were determined through oil-source correlation.According to the relations of "construction to reformation" and "destruction to preservation",four kinds of pool-forming units were identified,the thermal evolution history of petroleum systems in the residual basin was analyzed,and three types of hydrocarbon accumulation patterns such as "self-generation and self-preservation","generation in lower zones and preservation in upper zones" and "fossil buried hills"were predicted.The authors emphasized that the inhomogeneity of thermal evolution created certain conditions for secondary oil generation,and the strength and range of secon-dary oil generation were controlled by the Early Tertiary fault structures in overlying formations.So the secondary oil generation and the pool-formation in late periods were determined as main research directions for further exploration.To study the necessary conditions of "oil generation in lower zones and preservation in upper zones" and the favorable occurrences for pool formation in later periods can help us to exactly find the breakthrough points of hydrocarbon exploration in residual basins.

https://doi.org/10.11781/sysydz200306679