西湖凹陷平湖组深层岩性圈闭刻画方法研究——以孔南地区为例

Study on the Method of Deep Lithologic Traps in Pinghu Formation of Xihu Sag: Taking the Kongnan Area as An Example

刘婷婷 蒋涔

LIU Tingting JIANG Cen

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

西湖凹陷保俶斜坡带主要勘探目的层中上始新统平湖组系有障壁海岸浅水近岸沉积体系。该套地层由潮控三角洲沉积体系、泻湖/潮道体系交互构成受海平面升降控制的垂向演化沉积序列，并进一步被同生断层复杂化，形成一系列纵向叠合、横向受断层切割连片的复合圈闭群。目的层断块化严重、埋深大、物性差，给储层刻画造成困难。此次研究以孔南地区平湖组为例，在优化和岩石物理分析的基础上，运用确定性叠前同时反演、波形结构特征变化开展储层研究，并结合钻井沉积层序沉积相特征，采用地质-物探相结合的方法进行岩性圈闭刻画。实现了储层预测与实钻厚度平均误差小、岩性边界可靠的技术目标。

The main exploration target layer of Baochu Slope in Xihu Sag is a shallow-water sedimentary system with barrier coast in Pinghu Formation of the Middle and Upper Eocene. This set of strata is composed of a tidal-controlled delta sedimentary system and a lagoon/ tidal channel system that interacts to form a sedimentary sequence controlled by sea level rise and fall. And it is further complicated by contemporaneous faults, forming a series of traps which are vertically superimposed and laterally separated by faults. The target layer has characteristics of serious fault block, large burial depth and poor physical properties, which makes it difficult to characterize the reservoir. In this study, taking Pinghu Formation in the Kongnan area as an example, on the basis of basic data optimization and petrophysical analysis, deterministic pre-stack simultaneous inversion and changes in waveform structure characteristics are used to carry out reservoir research, and combined with drilling sedimentary sequence characteristics, lithologic traps are characterized by a combination of geological and geophysical methods. The technical goal of small average error between reservoir prediction and actual drilling thickness and reliable lithologic boundary is achieved.

https://doi.org/10.3969/j.issn.1008-2336.2022.02.007