下扬子上古生界油气富集条件探索

Exploration of Oil and Gas Enrichment Conditions of the Upper Paleozoic in Lower Yangtze

下扬子地区上古生界历经多年勘探,虽有优质的二叠系多套烃源岩的存在,但是一直未能实现大型商业规模的油气发现。结合多年来钻井以及野外地质情况,分析认为区内油气能否富集应该主要受到"二次生烃"强度以及储层的控制。目前重点研究的黄桥区域"二次生烃"强度最大,但是储集条件并不理想,需要天然二氧化碳驱动才能有稳定产量,句容地区则相反,储集条件良好,但是由于主力储层埋藏较浅、断裂发育,而且"二次生烃"强度偏弱,因此这两个地区均非上古生界油气富集的最好地区,下部还需梳理下扬子地区地质、地震情况,寻找出下扬子区域上古生界油气可以富集的地区。

Discovery of large scale of commercial oil and gas has not been achived in the upper Paleozoic of Lower Yangtze area after having being explored for many years, although there are many sets of high quality hydrocarbon source rocks in the Permian. Based on the drilling and geological investigating in the past few years, it is considered that the enrichment of oil and gas in the area should be mainly affected by the degre of “secondary hydrocarbon generation ＂ and the control of the reservoir. At present, Huangqiao block was carried on key research due to its high strength of secondary hydrocarbon generation, but the reservoir condition is not ideal, it need to adopt a stable yield of natural carbon dioxide as driving force for oil extraction. On the contrary, Jurong block has good reservoir, but due to the shallow burial of the main reservoirs and complicated faults system, also it has two weak strength of secondary hydrocarbon generation, so neither Huangqiao block nor Jurong block is the best place for oil explorating in the upper Paleozoic. In order to find the enrichment region of oil and gas in the upper Paleozoic in lower Yangtze region, geological and seismic conditions should be sort out on the next step.