Abstract: With the deepening exploration from conventional to unconventional hydrocarbon, and shallow to deep reservoirs, a batch of new fields of tight oil and gas reservoirs are gradually emerging in southern Songliao Basin. Based on geological theory innovation and key technological breakthroughs, significant breakthroughs and progress have been made in exploration of tight oil and gas in southern Songliao Basin in recent years. By summarizing progress in three major fields of tight oil in Fuyu oil reservoir, deep tight gas in basin, and coalbed methane in fault depression, the paper analyzes the geological conditions, exploration progress, accumulation mechanism and resource potential in southern Songliao Basin, and also proposes the next research and development direction. (1) The study clarifies the coupling accumulation mechanism of "three in one" for Fuyu tight oil reservoir, involving overpressure drive of high-quality source rocks in Qingshankou Formation, transport of intensive interlayer faults, and hydrocarbon accumulation in the thick sand bodies of main channel of Member 4 of Quantou Formation. The tight oil resources in Fuyu oil reservoir amount to 9.72×10⁸t, and the undiscovered resources are estimated to be 4.91×10⁸t. Three favorable areas are selected, namely Xinbei, Gudian, and Yuzijing-Tahucheng. Moreover, it is pointed out that Fuyu tight oil reservoir plays a key role in increasing reserves and production in Jilin oilfield (PetraChina Jilin Oilfield Company), and efforts should be made to sustainably promote the integration of reserve increase and productivity construction. (2) The study reveals the source-reservoir integrated accumulation mechanism of deep tight gas based on the coupling of high-maturity coal-bearing source rock and volcanic material-rich reservoir. The deep tight gas resources amount to 7.67×10¹²m³, and five favorable zones that can be effectively utilized have been identified, including Wukeshu, Huajia-Guojia, Xiaochengzi, Shenzijing, and Hashituo areas. It is clarified that deep tight gas is an important replacement resource in Jilin oilfield. (3) Based on the parameters of coal rock, coal quality, coal reservoir characteristics, and gas content, the coal bed methane resources are estimated to be 1.11×10¹²m³. Three favorable areas for coalbed methane exploration have been identified, i.e., Wangfu fault depression, Dehui fault depression, and Fulongquan fault depression, with a favorable exploration area of 19 370 km². In conclusion, the three favorable areas for tight oil and gas exploration provide important resource foundations for stable production in Jilin oilfield, and will provide replacement resources for high-quality development of Jilin oilfield. Relevant exploration experience and understandings are expected to provide reference and inspiration for neighboring areas and similar basins.

Key words: southern Songliao Basin, tight oil, tight gas, coalbed methane, new field, resource potential

摘要： 随着松辽盆地南部油气勘探由常规到非常规、由浅层到深层不断深入,松辽盆地南部逐渐展现出一批致密油气新领域。近年来,基于地质理论创新和关键技术攻关,松辽盆地南部在致密油气勘探新领域取得了重要突破和重大进展。通过梳理扶余油层致密油、盆地深层致密气和断陷层煤层气3大领域,分析了松辽盆地南部的地质条件、勘探进展、成藏机制和资源潜力,明确了下一步的攻关方向。研究成果主要包括:①明确了扶余油层致密油"三位一体"(青山口组优质烃源岩超压驱动、密集层间断裂输导和油气在泉头组四段主河道厚层砂体中聚集)的耦合成藏机制;扶余油层致密油的资源量为9.72×10⁸t、待发现资源量为4.91×10⁸t;优选了新北地区、孤店地区和余字井—塔虎城地区3个有利区,并指出扶余油层致密油是中国石油吉林油田公司(吉林油田)增储上产的重中之重,可持续推进一体化增储建产工作。②揭示了深层致密气具有高成熟含煤层系烃源岩与富含火山物质储层耦合的源-储一体成藏机制;深层致密气资源量为7.67×10¹²m³;梳理出5个可效益动用的有利区带(五棵树地区、华家—郭家地区、小城子地区、神字井地区和哈什坨地区),明确了深层致密气是吉林油田重要的资源接替领域。③基于煤岩的煤质、煤储特征以及含气量等参数,估算煤层气资源量为1.11×10¹²m³,并落实了王府断陷、德惠断陷和伏龙泉断陷3个断陷的煤层气勘探有利区,有利区面积达19 370 km²。致密油气勘探的3大领域是吉林油田稳产的重要资源基础,将为吉林油田的高质量发展提供接替资源,相关勘探经验和认识可为邻区和类似盆地提供借鉴和启示。

关键词: 松辽盆地南部, 致密油, 致密气, 煤层气, 新领域, 资源潜力