Abstract: The global unconventional oil and gas resources have huge potential, and now have become an important target for hydrocarbon exploration and exploitation and also a key field for increasing oil and gas reserves and production in the future. The continental tight sandstone gas in the Triassic Xujiahe Formation and Jurassic reservoirs, as well as the Jurassic tight oil and shale oil are new fields for oil and gas exploration and exploitation in Sichuan Basin, which play a crucial role in petroleum resources composition of the basin. Sichuan Basin experienced the tectonic evolution of Longmenshan foreland basin and intracontinental depression basin in the Late Indosinian-Yanshanian period, and the evolution of three second-order sequences in the Late Indosinian period has a controlling effect on the interstratified source-reservoir superposition in Xujiahe Formation, thus determining the formation of in-source and near-source gas reservoirs. The lacustrine transgression and delta-river depositional systems developed in Yanshanian period evolved into the Lower Jurassic source rocks and the high-quality sand bodies of Shaximiao Formation, respectively, and the source rocks of Xujiahe Formation were connected with large-scale faults, which laid the foundation for the formation of tight gas reservoirs in Shaximiao Formation. Indosinian foreland basin and Yanshanian depression basin are the key areas for tight oil and gas exploration in Sichuan Basin in the future. The delta sand bodies developed at the periphery of lake basin in Member 3 to 5 of Xujiahe Formation in the western-central Sichuan Basin and the shallow-water delta-channel sand bodies in the east of central Sichuan Basin are favorable exploration fields for tight gas, of which the estimated resources exceed 3.0×10¹²m³ and 0.5×10¹²m³ respectively. In addition, the Lower Jurassic tight oil and shale oil also have a certain resource potential.

Key words: tight oil and gas, new exploration field, resource potential, continental strata, Sichuan Basin

摘要： 全球非常规油气资源潜力巨大。非常规油气已成为目前油气勘探开发的重要组成,也是未来油气增储上产的关键领域。三叠系须家河组与侏罗系陆相致密砂岩气以及侏罗系致密油、页岩油是四川盆地油气勘探开发的新领域,在盆地油气资源构成中占据重要地位。四川盆地在印支晚期和燕山期先后经历了龙门山前陆盆地与陆内坳陷盆地的构造演化。印支晚期3个二级沉积层序的演化控制着须家河组的源-储呈互层交错的叠置关系,决定了其源内/近源型气藏的形成;燕山期的湖侵沉积体系和三角洲—河流沉积体系分别形成下侏罗统烃源岩和沙溪庙组优质砂体,加之有规模断层沟通下伏须家河组烃源岩,为沙溪庙组致密气藏的形成奠定了基础。印支期前陆盆地与燕山期坳陷盆地是今后四川盆地致密油气的关键勘探领域。川西—川中地区须家河组三段—须家河组五段沉积期湖盆周缘发育的三角洲砂体以及川中地区东部沙溪庙组浅水三角洲—河道砂体是致密气的有利勘探区,估算其资源量分别超过3.0×10¹²m³和0.5×10¹²m³。此外,四川盆地下侏罗统致密油也具备一定的资源潜力。

关键词: 致密油气, 勘探新领域, 资源潜力, 陆相层系, 四川盆地