渤海蓬莱9-1花岗岩潜山地震反射特征分析与储层解释

正确理解地震反射特征的地质意义是潜山储层预测的基础和关键之一。针对蓬莱9-1花岗岩潜山平缓的顶面外形和内部倾斜反射结构特征，利用三维地震、钻井等资料，通过正演模拟，从潜山风化壳特征入手，开展花岗岩潜山地震反射特征分析与储层解释研究。结果表明，花岗岩潜山遭受强烈的风化淋滤作用，垂向具有分带性，储层主要发育于砂砾质风化带；花岗岩内部倾斜反射结构为裂缝带的响应，受花岗岩岩性、构造作用的控制；裂缝带是风化壳储层发育的基础，只有倾斜反射结构发育区才能发育有利的风化壳储层；潜山顶面反射波振幅强度与风化壳储层发育程度呈负相关，综合潜山顶面振幅强弱和内部倾斜反射的发育程度，可以预测有利储层的分布；潜山顶面弱振幅、内部密集倾斜反射结构区主要位于花岗岩体东侧边界大断层附近，是最有利的储层发育区。该方法可为蓬莱9-1油田花岗岩潜山油藏后续开发和类似潜山的油气勘探提供参考。

Seismic reflection characteristic analysis and reservoir interpretation of Penglai 9-1 granite buried hill in Bohai Sea

Correctly understanding the geological significance of seismic reflection characteristics is the basis and key point of reservoir prediction in buried hills. Given the gentle top shape and internal inclined reflection structure of the Penglai 9-1 granite buried hill, this study starts with the characteristics of the weathered crust of this buried hill and presents a seismic reflection characteristic analysis and reservoir interpretation of the granite buried hill with 3D seismic, drilling, and other data through forward modeling. The research shows that the granite buried hill, subjected to strong weathering and leaching, exhibits vertical zoning. The reservoir is mainly developed in the sandy gravel weathering zone. The inclined reflection from inside the granite is the response of the fracture zone, and it is controlled by granite lithology and tectogenesis. The fracture zone is the basis for the development of the weathered crust reservoir. Only the inclined reflection development area allows the development of a favorable weathered crust reservoir. The magnitude of the amplitude of the reflected wave from the top of the buried hill is negatively correlated with the development degree of the weathered crust reservoir. The distribution of the favorable reservoir can be predicted by combining the magnitude of the amplitude from the top of the buried hill and the development degree of the inclined reflection from the inside. The area cha-racterized by a low amplitude from the top of the buried hill and dense inclined reflection from the inside is mainly located near the large fault on the east boundary of the granite body, and it is the most favorable area for reservoir development. The proposed method can provide a reference for the subsequent development of the granite buried-hill reservoir in Penglai 9-1 Oilfield and the exploration of similar buried hills.