陆相坳陷湖盆浅水三角洲地震沉积学模型

Seismic sedimentology is the use of seismic data to study sedimentary rocks and the processes by which they form. It is a front subject after seismic stratigraphy and sequence stratigraphy. Recently, the detailed exploration of complex reservoir (thin layer, deep layer, unconventional hydrocarbon reservoirs, etc.) gets more and more attention. The difficulty of the recognition of thin-layer reservoirs(the thickness of sandbody is less than 10m, even equal to 1m) by using the conventional theory and methods is obvious. By comprehensive analysis of seismic lithology and seismic geomorphology, seismic sedimentology that mainly uses the horizontal character of seismic data, provides an effectual method for sedimental lithology study, thin-layer sandbody recognition, sedimental type and evolution determination. Seismic sedimentology originates from the research of thick sandbody in marine basin. In China, there are some scientific and technical difficulties such as thin-layer sandstone reservoirs, complex relationship of lithology-velocity, low seismic resolution, etc. in the detailed exploration of thin layer sandstone reservoirs. Shallow water delta of non-marine lacustrine basin is a hotspot in detailed oil and gas exploration of China. This research will select Cretaceous shallow water delta in Songliao Basin as a target. Through establishing high-frequency sequence stratigraphy framework and analyzing rock-physical relationship of thin-layer sandbody and seismic geomorphology, seismic sedimentology model of shallow water delta in non-marine depression-type lacustrine basin will be established. The seismic sedimentology theory and technical system will be improved by this study which also can be used as a reference for seismic sedimentology study in non-marine basins, especially in postrift depression-type basin in China.

地震沉积学是继地震地层学和层序地层学之后出现的一个国际关注的前沿学科。近年来，人们关注复杂油气藏（薄层、深层、非常规油气藏等）的精细勘探。对于薄层油气藏（砂体厚度小于10m，甚至厚度为1m）的识别，采用常规地质学理论和方法是困难的，而当今地震沉积学却能通过地震岩性学和地震地貌学的综合分析，研究沉积岩性、识别薄层砂体，确定沉积类型及其演化。但地震沉积学起源于海相盆地较为厚层的砂体研究，在当今中国薄层砂体油气精细勘探中还存在砂体储层薄、岩性-速度关系复杂、地震分辨薄层砂体难等需要解决的科学和技术难题。陆相湖盆浅水三角洲是中国油气精细勘探的热点，故本项目选择松辽盆地白垩系浅水三角洲为研究对象，在建立高分辨层序地层格架的基础上，开展薄层砂体岩石物理关系和地震地貌学分析，建立陆相坳陷湖盆浅水三角洲地震沉积学模型，完善地震沉积学的理论和技术体系，并为其他陆相盆地相关研究提供科学依据。

地震沉积学是继地震地层学和层序地层学之后出现的一个国际关注的前沿学科。本项目针对当今中国路线坳陷湖盆油气精细勘探中还存在砂体储层薄、岩性-速度关系复杂、地震分辨薄层砂体难等科学和技术难题，以松辽盆地白垩系浅水三角洲为研究对象，通过地震岩性学与地震地貌学综合研究，在建立白垩系青山口组高分辨层序地层格架的基础上，开展了薄层砂体岩石物理关系和地震地貌学分析，获得了清晰反映浅水三角洲分布和发育特点的地层切片，通过岩心刻度标定，建立了陆相坳陷湖盆浅水三角洲地震沉积学模型。地震沉积学主要应用地震资料的水平分辨率，提供了确定沉积岩性、薄层砂体、沉积类型与演化的有效方法。围绕地震沉积学方法技术和实例分析，在国内外学术刊物上发表多篇具有积极推动作用的学术文章，为陆相盆地（特别是中国裂后盆地）开展地震沉积学以及浅水三角洲相关研究提供了科学参考依据。