成熟探区三维地震勘探的必要性──徐家围子油田勘探实例

NECESSITY OF 3D SEISMIC EXPLORATION IN MATURE EXPLORATION AREA──AN EXAMPLE OF XUJIAWEIZI OILFIELD

徐家围子油田的三维地震勘探取得了显著的地质效果，发现存在大面积构造圈闭，砂岩分布广泛，从而明确油藏以构造（包括断层）为主要控制因素，修正了以前认为是受构造、断层、岩性多种因素控制的复合型油藏的认识，重新确定的含油面积较以前扩大１／３以上。实践证明，即使在具有良好的地震地质条件的成熟探区，三维地震勘探仍是必要的。

good result of exploration has been obtained by 3D seismic in Xujiaweizi oilfield,A large area of structural traps with a great distribution of sandstones was found,by which the major controlling factors are determined to be structural ones(including faults),and the previous recognition that the reservoir was controlled by multi factors such as structure, faults and lithology has been corrected,and the redetermined oil-bearing area is 1/3 larger than old one, The practice shows 3D seismic exploration is still necessary even in mature exploration area with favorable seismic-geological conditions.