关家堡滩海区近岸水下扇体研究及勘探意义

关家堡滩海区位于渤海湾盆地歧口凹陷向埕宁隆起过渡的斜坡区，沙河街组为该区主要勘探层系之一。沙河街组主要为湖盆边缘相沉积，近岸水下扇发育。该区沙河阶组沉积体系以海岸线为界分为：东部海域为长石及火成岩颗粒含量高的水下扇体沉积；西部陆地为碳酸盐岩颗粒含量高的水下扇体沉积。东部扇体储层物性好，西部扇体储层物性差。本文通过地震相识别、地震属性预测、测井约束反演、微相分析、分频解释等手段精细刻画了扇体的空间展布特征。结合成藏条件分析，认为该区近岸水下扇体具备形成构造一岩性、岩性油气藏的条件，储层的分布对油气富集具明显控制作用，沿形成扇体的主水道应成为扩展勘探领域的有利地带。

Study of near-shore underwater fans in Guanjiapu beach area and its exploration meaning.

Guanjiapu beach area is located in slope zone that is transient zone from Qikou sag of Bohai Bay basin to Chengning uplift, where the Es is one of major exploration strata in the area. The Es is mainly lake basin margin facies deposition and developed near-shore underwater fans. Taking the coastline as a boundary,the Es sedimentary system in the area can be divided into following parts:the east sea area is underwater fans deposition with high content of feldspar and igneous grains; the west continent is underwater fans deposition with high content of carbonate grains. The east fans are characteristic of good reservoir quality and the west are bad. The paper finely described the spatial spreading feature of fans by identification of seismic facies, seismic attributes prediction, logging-constrained inversion,micro-facies analysis, and frequency-division interpretation etc. It considered in combination with the analysis of reservoir-formed conditions that the near-shore underwater fans have the condition forming structural-lithologic reservoir and lithologic reservoir, the distribution of reservoirs has obviously controlling role to oil/gas accumulation and the favorable zones of expanded exploration areas should be along the main water channel where the fans were formed.