Abstract: Through deep exploration, light crude oil reservoirs dominated by condensate oil and gas have been discovered in the deep paleogene formation of Jiyang depression, indicating the huge exploration potential in deep reservoirs. The potential of light crude oil reservoirs in Jiyang depression is determined by analyzing the oil and gas source, reservoir space and reservoir-forming process of light crude oil reservoirs. The results suggest that the light crude oil reservoirs in Jiyang depression are characterized by low density, low viscosity, low freezing point and high gas-oil ratio, the crude oil is yellow or colorless, and the oil reservoirs are usually characterized by large buried depth, high stratum pressure and high sigle-well deliverability. A comprehensive analysis confirms that the light crude oil mainly originates from highly mature source rock in deep lower member of Es₄^x and Ek, which has a relatively strong resource base. The effective reservoir development model under the co-control of acid and base in deep stratum has broken through the understanding that the effective porosity is underdeveloped at the high ground temperature in deep stratum, proving that high-quality reservoirs are still developed at the depth below 4 km, which enhances the value of deep exploration. By analyzing the reservoir-forming process of light crude oil reservoirs, this paper puts forward two reservoiring models based on self source and other sources in deep stratum, pointing out the exploration direction of light crude oil reservoirs. Moreover, the comprehensive research has determined the exploration direction of light crude oil reservoirs such as sandstone rock in steep slope belt, deep red-bed reservoir body in gentle slope belt, low buried hill in slope belt and highly evolved shale oil in depression belt, providing a scientific basis for deep exploration in Jiyang depression.

Key words: Jiyang depression, light crude oil, condensate oil and gas, co-control of acid and base, reservoiring model, exploration potential

摘要： 随着深层勘探工作推进，济阳坳陷古近系深层发现了以凝析油气为主的轻质原油油藏，展示了深层巨大的勘探潜力。通过对轻质原油油藏油气来源、储集空间、成藏过程解剖，明确了济阳坳陷轻质原油油藏勘探潜力。研究结果表明，济阳坳陷轻质原油油藏具有低密度、低黏度、低凝固点、高气油比的特征，原油呈黄色—无色，油藏一般呈埋深大、地层压力大、单井产能高的特点。综合分析证实轻质原油主要来自于深部沙河街组四段下亚段—孔店组高成熟烃源岩，具有较雄厚的资源基础；深层酸碱共控有效储层发育模式突破了深层高地温背景下有效孔隙欠发育的认识，证实4 000 m以下依然发育优质储层，提升了深层勘探价值；通过对轻质原油油藏成藏过程进行解剖，提出了深层自源型、他源型两种成藏模式，指明了轻质原油油藏的勘探方向。综合研究落实了陡坡带砂砾岩体、缓坡带深层红层储集体、斜坡带低位潜山、洼陷带高演化页岩油等轻质原油油藏勘探方向，为济阳坳陷向深层勘探提供了科学依据。

关键词: 济阳坳陷, 轻质原油, 凝析油气, 酸碱共控, 成藏模式, 勘探潜力