南华北地区主要层系热演化特征及其油气地质意义

THERMAL EVOLUTION DEGREE AND ITS HYDROCARBON GEOLOGICAL IMPLICATIONS OF THE MAIN STRATA SERIES IN THE SOUTHERN NORTH CHINA CRATON

赵俊峰 刘池洋 何争光 刘永涛

Zhao Junfeng Liu Chiyang He Zhengguang Liu Yongtao

西北大学大陆动力学国家重点实验室, 西安 710069 2. 西北大学地质学系, 西安 710069 3. 东方地球物理公司研究院, 河北 涿州 072751

State Key Laboratory of Continental Dynamics(Northwest University), Xi'an, Shaanxi 710069, China 2. Department of Geology, Northwest University, Xi'an, Shaanxi 710069, China 3. Geophysical Research Institute of Bureau of Geophysical Prospecting, CNPC, Zhuozhou, Hebei 072751, China

南华北是我国油气勘探久攻未克的地区之一,客观评价烃源岩的热演化程度及其作用过程,是该地区勘探面临的关键问题。通过对600余组有机质镜质体反射率数据并结合其它古温标的分析,较全面评价了该地区古近系、中生界及上古生界烃源岩的热演化特征并探讨了其油气地质意义。古近系热演化多处于未成熟—低成熟阶段,平面上呈南低北高的格局;济源凹陷有机质热演化相对较高,达成熟阶段。中生界热演化程度普遍高于古近系,谭庄—沈丘凹陷中部下白垩统、济源凹陷三叠系烃源岩多数处于液态窗范围。上古生界热演化程度空间上极不均一,总体呈南低北高的格局。从热演化与保存条件分析认为,太康隆起及相邻鹿邑凹陷北部的部分地区,可作为古生界常规天然气或煤层气勘探的远景区;周口坳陷倪丘集凹陷中南部、谭庄—沈丘凹陷东部及襄城凹陷南部等具有新生代二次生烃的潜力。

The southern North China Craton is one of the area in China experienced decades of exploration while no industrial reservoir has been found.To objectively evaluate the thermal status and its evolution processes is one of the key in this area.Based on more than 600 suits of Ro data and other geothermometer data,the thermal evolution characteristics and its hydrocarbon geological implications of the Paleogene,Mesozoic and Upper Paleozoic are discussed in this paper.The values of Ro from the Paleogene System are higher in the north and lower in the south.Most of the organic matter in Zhoukou Depression is immature and low mature,in contrast with the mature status in Jiyuan and Zhongmou Sags of Kaifeng Depression.Thermal evolution degree of the Mesozoic is higher than the one of the Paleogene in general.The Lower Cretaceous in Tanzhuang-Shenqiu Sags and the Trassic in Jiyuan sag are now in the peak liquid hydrocarbon-generating stage.The thermal evolution degree of the Upper Paleozoic shows strong heterogeneity in space,ranging from immature to overmature,and decreased from north to south.Taikang Uplift and adjacent northern Luyi Sag are inferred to well prospective area for normal nature gas or coal bed methane exploration.Some areas such as the mid-south part of Niqiuji Sag,the east part of Tanzhuang-Shenqiu Sags and the south of Xiangcheng Sag in Zhoukou Depression have the potential of secondary hydrocarbon generation.

国家自然科学基金(重大研究计划)重点项目(90814005);西北大学大陆动力学国家重点实验室科技部专项经费项目(BJ091354);陕西省教育厅自然科学专项(09JK794);西北大学科研启动基金项目资助

https://doi.org/10.11781/sysydz201002101