基于正演模拟的碳酸盐岩缝洞体系连通性分析

Connectivity analysis of carbonate fracture-cave system based on forward modeling

塔里木盆地奥陶系碳酸盐岩储层发育,由洞、孔、缝之间的不同组合所形成的缝洞型油藏是主要研究目标。缝洞连通性是油田勘探开发实践中高效井优选的重要依据,对于缝洞型油藏的解剖认识与开发均具有重要意义。本文通过模型正演技术,建立相对简单的缝洞地质模型并获取炮集资料,采用GeoEast处理解释系统,分析采集参数与资料处理参数对缝洞体之间的连通性分析的影响,进而认识地震波通过连通缝洞体时可能的地震反射特征,指导缝洞连通性的解释。通过对地震瞬时振幅解释等方法的探索及应用,可以在一定程度上区分缝洞体之间的地震波场差异。该方法可推广应用于地质特征相似的区域。

The Ordovician carbonate reservoirs in Tarim Basin are well developed. Fractured-vuggy reservoirs formed by different combinations of caves, holes and fractures are the main research targets. Fracture-cave connectivity is an important basis for optimizing high-efficiency wells in oilfield exploration and development practice, and is of great significance to the understanding and development of fracture-cave reservoirs. In this paper, a relatively simple geological model of fracture and cave is established by forward modeling technology, and gun-gathering data are obtained. GeoEast processing and interpretation system is used to analyze the influence of acquisition parameters and data processing parameters on the connectivity analysis between fracture and cave bodies. Then, the possible seismic reflection characteristics of seismic waves passing through the connected fracture and cave bodies are recognized, to guide the interpretation of fracture-cave connectivity.By exploring and applying the methods of seismic instantaneous amplitude interpretation, the difference of seismic wave between fracture and cave bodies can be distinguished to some extent. This method can be extended to areas with similar geological characteristics.