四川盆地德阳—武胜拉张槽西段构造—沉积特征及勘探领域

Tectonic-sedimentary characteristics and exploration plays in the western section of Deyang-Wusheng Intracratonic Sag, Sichuan Basin

罗开平 曹清古 彭金宁 李龙龙 曾华盛 张宏

LUO Kaiping CAO Qinggu PENG Jinning LI Longlong ZENG Huasheng ZHANG Hong

中国石化 石油勘探开发研究院 无锡石油地质研究所, 江苏 无锡 214126 中国石化 石油勘探开发研究院, 北京 100083

Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214126, China SINOPEC Petroleum Exploration&Production Research Institute, Beijing 100083, China

基于前人的认识和勘探成果，结合川西地区地球物理及地表地质资料，研究分析了四川盆地德阳—武胜拉张槽（西段）的结构及沉积充填特征，探讨了有利勘探领域及方向。德阳—武胜拉张槽是四川盆地晚二叠世长兴期在弱伸展背景下形成的北西向张性构造单元，具有两侧地层厚、中间地层薄的槽状结构特征。德阳—武胜拉张槽两侧边缘（台缘带）发育生物礁、生屑滩等高能相带沉积，有利于储层发育；槽中央发育较深水—深水环境下的微晶灰岩、硅质泥岩、碳质泥岩、页岩等岩性组合，是有利的烃源岩；其西段龙宝梁三维工区内沿着北西向台缘带发育带状生物礁，与下伏龙潭组等烃源岩及槽内长兴组泥页岩构成“下生上储”、“旁生侧储”源—储组合。该拉张槽边缘相带是油气的潜在勘探领域，龙宝梁地区是近期勘探的有利目标。

The tectonic-sedimentary characteristics and exploration plays in the western section of the Deyang-Wusheng Intracratonic Sag in the Sichuan Basin were studied by combining geophysical and surface geological data and exploration results. The Deyang-Wusheng Intracratonic Sag is a northwest trending tectonic unit formed in the Changxing period of the Late Paleozoic under a weak extension stress background. It has a trough-like structure, and is thick on both sides and thin in the middle. High energy facies such as biological reefs and bioclastic beaches are developed at the edges (platform margins) on both sides, which is conducive to reservoir development. Lithological combinations of microcrystalline limestone, siliceous mudstone, carbonaceous mudstone and shale developed under deep water in the center of the trough are favorable source rocks. A strip-shaped biological reef developed along the northwest platform margin in the Longbaoliang 3D work zone in the western section of the Deyang-Wusheng Intracratonic Sag. Combined with underlying source rocks such as the Longtan Formation, it forms "lower source and upper reservoir" and "side by side" source-reservoir combinations. The marginal facies of the intracratonic sag is a potential exploration area, and the Longbaoliang area is a favorable target for exploration.

中国石化科技部项目“川西二叠系成藏条件及勘探潜力分析” P18069-2

https://doi.org/10.11781/sysydz202002163