西湖凹陷G构造深部次生溶蚀带成岩相分析

Analysis of Diagenetic Facies in Deep Secondary Denudation Zone of G Structure,Xihu Sag

东海陆架盆地西湖凹陷深部勘探正面临着储层优选与预测问题,如何在特低孔特低渗背景中寻找有利储层已成为勘探成败之关键。此文以西湖凹陷G构造深层次生溶蚀带为例,在沉积演化、碎屑组分、孔渗特征分析基础上,提出压实、溶蚀作用决定成岩相的观点,探讨了次生溶蚀带内部构成、垂向演变、空间规律,深化理解了深部酸性次生溶蚀作用的石油地质意义及其发生发展条件,不仅在深部储层认识上为G构造成藏认识提供了有力佐证,也为整个凹陷的深层勘探开拓了思路。

The hydrocarbon exploration in deep zone of Xihu sag is facing great challenge in reservoir optimization and forecasting. How to find favorable reservoirs in extremely low porosity and permeability formation has become the key to the success of exploration. In this article, taking the deep secondary denudation zone in G structure as an example, the idea that diagenetic facies is determined by compaction and denudation in the study area has been put forward based on analysis on sedimentary evolution, detrital components, porosity and permeability characteristics. In addition, the internal structure, vertical evolution, and spacial distribution of secondary denudation zone were also discussed in this article. Moreover, deep understanding about the petroleum geological significance of deep acid secondary dissolution and the development conditions have been made, which not only provides a powerful evidence for understanding the geologic conditions for hydrocarbon accumulation in deep reservoirs in G structure, but also provides new ideas on the deep hydrocarbon exploration in the whole Xihu depression.