河流辫曲转换与废弃特征及沉积构型响应

Characteristics of meander-braided transition, abandoned channel and corresponding sedimentary architecture are scientific problems need to study urgently in reservoir sedimentology. Taking ancient and modern fluvial deposits as the study object, we will carry out four major study items as follows: geological conditions and sedimentary architectures of fluvial meander-braided transition, geologic genetic types and architectural patterns of abandoned channel, fluvial sand body correlation methods and superposition patterns, and qualitative and quantitative characterization of barriers and baffles in fluvial channels. And 4 critical scientific problems will be focused on and be solved. The first one is the key geological conditions of meander-braided transition and sedimentary-architecture characteristics; the second is the geological genetic types and internal sedimentary architectural sequence of different abandoned channels; the third is suitable correlation methods and sand-body superimposed patterns to fluvial sand bodies integrating static geologic data and production performance information; and the forth is the of qualitative and quantitative characterization methods on the fluvial sand-body barriers and baffles. This project will be conducted though integrating the fluvial outcrops, modern deposits, and subsurface fluvial geo-bodies, combining with static geologic data and production performance information. Qualitative description and quantitative characterization methods will also be adopted. Finally, a set of sedimentological characterization methods of fluvial meander-braided transition, abandoned channel characteristics, and sedimentary architecture responses will be formed as the results of the whole study.

河流的辫曲转换、河道废弃特征及相应的沉积构型特征是储层沉积学中急需深入研究的科学问题。本项目拟以古、现代河流相沉积为研究对象，开展河流辫曲转换地质条件与沉积构型、废弃河道成因类型与内部构型模式、河流砂体对比方法与砂体叠置模式、河道砂体的隔夹层定性与定量表征等4项研究；力求解决河流辫曲转换的关键地质条件与沉积构型特点、废弃河道的地质成因类型与内部构型序、动静结合河流砂体对比适用方法与砂体叠置模式、河道砂体隔夹层定性与定量表征方法等4个关键科学问题。本项目拟采用地上描述与地下表征相结合、动静信息相结合、定性与定量相结合的研究思路，最终形成“河流辫曲转换与废弃特征及其沉积构型响应”的储层沉积学表征方法。

目前国内外学者主要解剖的是曲流河与辫状河储层的构型特征；而对辫曲转换型河、废弃河道的河型特征与构型特点方面的研究深度相对不足。河流储层沉积构型表征的核心研究内容是不同构型单元砂体的规模、砂体叠置方式以及隔夹层的分布特点，从而深入研究河流储层沉积构型对油气储层剩余油分布的控制作用。本项目以古代野外露头、现代河流沉积及古地下河道沉积为研究对象，开展了河流辫曲转换地质条件与沉积构型、废弃河道成因类型与内部构型模式、河流砂体对比方法与砂体叠置模式、河道砂体的隔夹层定性与定量表征等研究；探索解决了河流辫曲转换的关键地质条件与沉积构型特点、废弃河道的地质成因类型与内部构型序、动静结合河流砂体对比适用方法与砂体叠置模式、河道砂体隔夹层定性与定量表征方法等关键科学问题，最终形成了“河流辫曲转换与废弃特征及其沉积构型响应”的储层沉积学表征方法。项目研究成果预计可在实际油气田生产过程的储层砂体展布与对比中进行应用，可为提高油气勘探开发效果提供一定的理论与技术支持。