盐构造与深水重力流的相互作用及响应

在发育盐构造的被动大陆边缘盆地中，明确盐构造活动与深水重力流事件的沉积耦合特征是该类盆地相对优质储层和甜点区预测、评价的基础。通过综合钻井、岩心分析和三维地震精细解释，对墨西哥湾Sureste盆地中新统深水重力流沉积与盐构造之间的作用方式及响应进行研究，并探讨不同作用方式的成因及油气地质意义。研究表明，Sureste盆地陆坡区发育一系列与盐构造活动相关的微盆、地形坡折、局部凸起和弯曲通道等地貌单元；在这种复杂陆坡地貌背景下，早期和同沉积期盐构造既可以疏导或限制重力流，形成导向、限定、局限和侧向迁移等多种作用类型，也可以被重力流侵蚀形成不整合，后期盐构造活动对深水重力流沉积的改造表现为截切和变形两种样式；不同作用方式和匹配关系受重力流的性质、侵蚀能力与盐构造的规模、数量、走向以及活动时间和强度的控制，局限、侵蚀和截切对应了盐构造与深水重力流沉积相互作用的三个端元；早期和同沉积期盐构造活动影响深水碎屑岩储层的质量和分布，后期盐构造活动对构造、构造—岩性圈闭的形成至关重要。

Interactions and Responses Between Salt Structures and Deep Water Gravity Flow: A case study from the Miocene strata in the Sureste Basin,Gulf of Mexico

In passive continental margin basins with salt tectonics， the determination of sedimentary coupling characteristics between salt tectonic activity and deep-water gravity flow events is the basis for the prediction and evaluation of relatively high-quality reservoirs and “sweet spot” areas in such basins. In this paper， the interaction types and response characteristics between Miocene deep-water sediments and salt structures in the Sureste Basin in the Gulf of Mexico are analyzed by means of integrated drilling and core analysis and the detailed interpretation of high-resolution three-dimensional seismic data. In addition， the genesis of different action modes and the significance of hydrocarbon exploration are discussed. The results show that the lower continental slope of the Sureste Basin develops a series of geomorphic units related to salt tectonic activities， such as a mini-basin， topographic slope break， local uplift， and connected tortuous corridors， etc. For this topographically complex slope， deep-water gravity flow depositions and salt structures form a variety of interaction modes and matching relationships. The early and syndepositional active salt structures can not only direct or limit gravity flow， forming various interaction types， such as guidance， confinement， blocking， and lateral deflection， but also be eroded by gravity flows to form an unconformity. The reconstruction of deep water deposition by salt activities in the late period shows two styles of truncation and deformation. Different interactions are likely controlled by the nature and erosional power of the gravity flow， the size， quantity， and orientation of the salt structure， and the timing and intensity of the salt structure growth. Blocking， erosion， and truncation correspond to three end-member classes of interaction between the salt structure and deep water deposition. Early and syndepositional salt tectonic activities affect the quality and distribution of deep water clastic reservoirs， and late salt tectonic activities are crucial to the formation of structural and structure-lithologic traps.