窟窿山逆掩推覆带速度建场及其特征
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摘要
采用层位控制法,对区内窟窿山、金海子两块三维探区进行了精细速度建场及成图,对地震速度在纵向、横向上的分布特征进行了初步探讨。分析结果表明,本区速度纵向上成层性较明显,在表层-浅层段及中-深层段存在速度倒转现象;推覆体速度在横向上呈清晰的块状特征;平面速度变化总体趋势由北向南逐渐增大,变化梯度北小南大;速度等值线大体呈北西向分布;两个三维探区均存在速度异常区。深浅层岩性、厚度以及压实程度的差异,是造成速度异常的基本原因。
By horizon-controlled method, the velocity fields of Kulongshan and Jinhaizi 3-D areas are mapped, the characteristics of vertical and transversial distribution of velocity are discussed. The analyzed result shows that distinct velocity layering feature occurs in vertical direction, and velocity reversion is found in near surface-shallow zone and mid-deep zone; the velocity of overthrust nappe is of clear block feature in lateral direction; the variation of lateral velocity tends to growing from north to south, with gradient of north-low and south-high; the contour of velocity assumes distributing along the north-west direction roughly, and there are abnormal-velocity regions for these two 3-D areas. It is shown that differences in deep-shallow lithology, thickness and compaction degrees are the essential causes for the velocity anomaly in these areas.
By horizon-controlled method, the velocity fields of Kulongshan and Jinhaizi 3-D areas are mapped, the characteristics of vertical and transversial distribution of velocity are discussed. The analyzed result shows that distinct velocity layering feature occurs in vertical direction, and velocity reversion is found in near surface-shallow zone and mid-deep zone; the velocity of overthrust nappe is of clear block feature in lateral direction; the variation of lateral velocity tends to growing from north to south, with gradient of north-low and south-high; the contour of velocity assumes distributing along the north-west direction roughly, and there are abnormal-velocity regions for these two 3-D areas. It is shown that differences in deep-shallow lithology, thickness and compaction degrees are the essential causes for the velocity anomaly in these areas.
引文
[1]中国石油天然气股份有限公司编.地震资料解释新技术培训教材[M].北京:石油工业出版社,2001.
[2]中国石油勘探与生产分公司编.中国中西部前陆盆地冲断带油气勘探文集[C].北京:石油工业出版社,2002.
[3]肖文华,魏军.祁连山北缘逆掩推覆带构造及成藏特征[J].新疆石油地质,2003,24(5):533-535.
[2]中国石油勘探与生产分公司编.中国中西部前陆盆地冲断带油气勘探文集[C].北京:石油工业出版社,2002.
[3]肖文华,魏军.祁连山北缘逆掩推覆带构造及成藏特征[J].新疆石油地质,2003,24(5):533-535.