华北区古生界原生油气藏勘探前景

从油气系统角度分析了华北区古生界的石油地质条件。下古生界是一套以海相碳酸盐岩为主的沉积，在开阔海台地相的台凹环境下形成的源岩生烃潜力最大，纵向上表现为寒武系的府君山组、张夏组，奥陶系的马家沟组、峰峰组。平面上以黄骅—临清复向斜带为最有利区。上古生界是一套海陆交互相的煤系地层，煤层及暗色泥岩厚，热演化程度大多处于成熟—高熟阶段，生烃潜力大。从源岩的生烃演化史及油气的运聚和圈闭关系指出古生界具有形成原生油气藏的条件，原生油气藏勘探研究的难点及关键问题在于烃源岩的二次生烃潜力、范围及油气保存条件。在系统分析总结前人勘探研究工作的基础上，研究了渤海湾、南华北及沁水地区古生界油气生成、保存条件，指出渤海湾地区是二次生烃的最有利地区，油气保存条件好，古生界原生油气藏勘探前景广阔；南华北地区油气生成及保存条件好，但源岩演化程度较高，是天然气的有利勘探区；沁水地区亦具有二次生烃条件，但盖层及油气保存条件差、水动力条件强，北部地区古生界原生油气藏的勘探前景尚好。

tEXPLORATION PROSPECT OF PALEOZOIC PRIMARY OIL AND GAS POOLS IN HUABEI AREA

The Palaeozoic petroleum geological condition of Huabei area had been analyzed in detail from the petroliferous system angle.The Lower Palaeozoic is mainly a set of marine carbonate rocks,and the soruce rocks located in the sag region has large potential,such as the Cambrian Fujunshan and Zhangxia formations and the Ordovician Majiagou and Fengfeng formations in the section.The Huanghua Linqing structural belt is the favorable exploration region.The Upper Palaeozoic is mainly a set of coal measure sediments with the characteristics of large thickness of coal and dark mud bed with mature overmature evolutionary degree,so that,the upper Palaeozoic has large potential as well.Based on the hydrocarbon generation history of Palaeozoic source rocks and the interrelations between the migration and accumulation of oil and gas,it has been identified that the Palaeozoic has the condition of forming the primary oil and gas pools.The key problems of the Palaeozoic prospect are the potential of secondary hydrocarbon generation,distribution range of source rocks and preserve condition of oil and gas.The Palaeozoic petroliferous property had been studied based on a large amount of basic geological informations and the conclusions had been obtained that the Bohaiwan area is a favorable Palaeozoic oil and gas prospect place with good secondary hydrocarbon generation and petroleum preserve conditions. The southern Nanbei area is a good Palaeozoic gas prospect place with good hydrocarbon generation and petroleum preserve condition,but high evolutionany degree of source rocks,and the Qinshui area is not an ideal place for the Palaeozoic petroleum prospect because of the strong hydrodynamic and poor petroleum preserve condition.