Abstract: The starting depth of steady mudstone sonic log was used to evaluate the structural compression stress in Kuqa Depression.The maximum contribution of the structural compression to overpressure in Kuqa Depression was calculated using the starting depth of steady mudstone sonic log.The analysis on the origin of overpressure shows that the contribution of structural compression to overpressure is different in the different area of Kuqa Depression.The maximum contribution of structural compression to the overpressure is from 55% to 80% in the Ke-Yi structural zone and is from 22% to 39% in Ku1 Well.The structural compression is the main factor of contribution to overpressure only in the Ke-Yi structural zone.The distributions of overpressure in Kela-2 Well and Ku-1 Well are characterized by the allogenic overpressure.

Key words: Kuqa Depression, foreland basin, structural compression, quantitative evaluation, origin of overpressure

摘要： 根据泥岩声波时差平直段开始深度点的特殊性,运用库车坳陷内各井的泥岩声波时差平直段开始的深度点估算了构造挤压应力的大小、构造挤压应力转化为超压的比例以及构造挤压对超压的最大贡献率,分析了库车坳陷的超压成因。结果表明,在库车坳陷不同的构造带,构造挤压对超压的贡献率不同。在克—依构造带,构造挤压对超压的最大贡献率为55%~80%,成为该构造带超压的主要控制因素;而在构造挤压不是很强烈的阳霞凹陷,以库1井资料估算的构造挤压对超压的最大贡献率只有22%~39%。克拉2井与库1井的压力分布都具有他源超压的特征,他源超压的成因及其地质意义应该引起足够的重视。

关键词: 库车坳陷, 前陆盆地, 构造挤压, 定量评价, 超压成因