扇三角洲沉积体系及其油气聚集关系

orey

提要 扇三角洲沉积体系是断陷盆地中极为发育的一种沉积体系，主要由扇三角洲平原组合，扇三角洲前缘组合和前三角洲沉积构成，可识别出9种成因相。

Abstract Fan deltaic depositional systems arewell developed in rift basins, and usually consist of fan delta plainassociation, fan delta-front association and prodelta association. Nine geneticfacies can be distinguished in fan deltaic depositional system.

受沉积物供给速率、可容空间增长速率及盆缘断裂产状等因素控制可划分出退积型、加积型、前积型、陡坡型和缓坡型五种扇三角洲类型。Controlled by sediment flux rate, available accommodation expansionrate and basin-bounded fault, fan deltaic depositional system style can begenerally divided into five types , i.e. degrading, aggrading , prograding ,steep slope and slow slope fan deltas .

位于扇三角洲平原的辫状分流河道砂体及其位于扇三角洲前缘的与之有成因联系的水下分流河口坝、洪水型重力流沙等物性好，可以构成优质储层。

Thebraided distributary channel sand-bodies developed in fan delta plains andtheir related subaqueous distributary mouth bar and flood gravity currentsand-bodied deposited in fan delta-front zones are high quality reservoirs .

含油勘探成果亦证实各主力油层段平面上主要分布于扇三角洲前缘及分流间湾区，小部分位于扇三角洲平原区。

Oilexploration results have shown that principal oil reservoirs are distributeddominantly in fan delta-front zones and interdistributary bays , and somereservoirs are developed in fan delta plain areas.

受埋藏深度和成岩场的影响，不同地区、不同层位主力油层段的物性与岩性相关性各异。

Influencedby burial-depth and diagenesis , principal oil-bearing beds in different areasand different horizons are different because of the various relationshipsbetween physical properties and lithologies .

因此，应用沉积体系分布与油气聚集规律挖掘剩余油层及进行远景区预测是有效的与可行的。

Therefore,the relationship of depositional system distribution to oil and gasaccumulation can be applied to search for residual oil-bearing beds and topredict prospect areas.

关键词 扇三角洲沉积体系  油气聚集

Key Words fan deltaic depositional system  oil and gas accumulation