西湖凹陷天台西地区火成岩的识别及其在勘探中的应用

Identification of Igneous Rocks and Its Application in Exploration in the west of Tiantai Area of Xihu Sag

周静毅 段文豪 刘明阳 全心怡

ZHOU Jingyi DUAN Wenhao LIU Mingyang QUAN Xinyi

中国石油化工股份有限公司上海海洋油气分公司勘探开发研究院, 上海 200120

Institute of Exploration and Development, SINOPEC Shanghai Offshore Oil & Gas Company, Shanghai 200120, China

西湖凹陷天台西地区火成岩发育比较丰富，在测井曲线上一般表现为高速、高自然伽玛和高密度的特征，而在地震剖面上表现为强振幅的特征。利用地震几何属性可以较好地刻画火成岩的空间的展布情况：相干切片可以大致显示火成岩的分布范围；最大相似度倾角属性可以清楚地揭示出火山口的位置并刻画出火成岩横向侵入的边界范围。通过对火成岩的精细刻画及与断层的切割关系研究，认为该区的圈闭类型以火成岩与断块联合形成的圈闭为主，并且圈闭定型时间略晚于烃源岩排烃高峰期。由于火成岩的活动，对圈闭有一定的改造作用，使得该区形成了多期充注，后期调整、晚期成藏的油藏模式。

There are lots of igneous rocks developed in the west of Tiantai, Xihu Sag.They are generally characterized by high speed, high natural gamma and high density on the logging curves, and strong amplitude on the seismic sections. Some seismic technologies can be used to identify igneous rock, such as the seismic geometric attributes to depict the spatial distribution, coherent slice to roughly delineate the distribution range, the maximum similarity inclination attributes to locate the crater position and depict the lateral boundary of igneous intrusion. Based on the fine depiction of igneous rocks and the study of the relationship between igneous rocks and faults, the authors think that most of the traps in the study area are related with the igneous rocks and fault block.The forming time of traps was slightly later than the peak time of hydrocarbon expulsion.The activity of igneous rocks made changs to the traps, which resulted in the hydrocarbon accumulation in this area with the characteristics of multi stage charging and being adjusted in later period.

https://doi.org/10.3969/j.issn.1008-2336.2017.04.035