湖盆滩坝砂体地质定量预测研究 -以青海湖、鄱阳湖、东营凹陷古近系湖盆为例

At present, domestic and foreign scholars have a certain understanding on the deposition mechanism and characteristics of lacustrine beach bar. But limited to the beach bar sand body thickness is thin, it is difficult to break through the limitations of the geophysical data resolution.There is an urgent need for geological prediction based on the sedimentary theory. Beach bar deposits are controlled by various factors, there is still no deposition simulation and geological prediction method is perfect.This study will be based on the particularity of the beach bar sedimentation, try to introduce new ideas. " Sedimentary black box " simulation. First of all,Geological unit with a similar background is seen as limited research unit.Only the input and output to be considered instead to explore the role of internal elements repeatedly process in detail. Input parameter of "black box"is the source supply,paleobathymetry,terrain conditions;The output parameter is the final record of the deposition.The "saturated deposition",not change over time, will be formed with full source supply.After the the saturated deposition is predicted,the non-saturated sedimentary beach bar will be forecast according to the analogy of the deposition conditions.The beach bar geological quantitative prediction is realized.Then geophysical inversion will be constrained by geological quantitative prediction. Accurate identification of the type of sand body is ultimately achieved.

受限于湖相滩坝薄互层砂体的层厚较薄，很难突破地球物理资料分辨率的限制，迫切需要从沉积理论出发进行地质定量预测，指导这种薄层砂体的精确识别。由于滩坝沉积受多因素控制，目前仍无成熟的模拟和地质预测方法。本次研究将尝试引入新的思路，即“沉积黑盒子”模拟进行地质预测。首先借鉴软件工程中的“黑盒子”思想，把不可分的、成因或环境相似的基本地质单元视为有限研究单元。其次，引入海岸动力学的经典原理并作适用性调整，推导滩坝的形成过程。然后，在现代滩坝沉积解剖和水槽模拟的基础上，确定滩坝“沉积黑盒子”的沉积参数输入和沉积记录输出的关系。重点分析水体参数，风浪参数，沉积前地形条件和物源供给参数和滩坝砂体建造之间的关系。并通过“沉积黑盒子”输出饱和沉积、欠饱和沉积、无沉积多种模式，最终形成湖相滩坝砂体的地质定量预测。

受限于湖相滩坝薄互层砂体的层厚较薄，很难突破地球物理资料分辨率的限制，迫切需要从沉积理论出发进行地质定量预测，指导这种薄层砂体的精确识别。由于滩坝沉积受多因素控制，目前仍无成熟的模拟和地质预测方法。.2016年以来，在国家自然科学基金的持续支持下，通过室内水槽（自行设计）模拟、青海湖、鄱阳湖现代沉积观测、油田生产实践，提出了针对湖相滩坝砂体的“风源盆”沉积模式，通过古地貌、古水深、古风场、古物源定量恢复，建立区域风源盆沉积动力学模型，划分出迎风体系、背风体系、侧风体系和深盆体系四种体系模式。根据体系内部各要素的相互关系，定量预测了滩坝类优质储集体的展布，形成了不同风场条件下的优质储集体预测方法和技术。解决了传统相模式在非主力物源区和物源通道无法解释和评价储集体的难题，为滩坝优质储集体的进一步勘探提供了新的方法。.围绕该技术发明授权国家发明专利5项，发表标注资助论文7篇，其中SCI检索论文3篇，获得教育部科技进步二等奖1项（第二完成人），已形成了一套集理论方法和技术应用为一体的技术成果。该方法技术在胜利油田、辽河油田等多个单位得到了现场应用，有效指导了滩坝类储集体的勘探与开发。具有广阔的应用和推广前景。