库车前陆褶皱冲断带中段第三系盐枕构造

本文旨在探讨库车前陆褶皱冲断带盐枕构造的类型、分布、成因机制及其与油气聚集的关系。通过地震反射剖面的解释和石油地质条件综合分析,认为库车前陆褶皱冲断带由北而南依次发育残留盐枕、非稳态盐枕和稳态盐枕等 3类盐枕构造,沿克拉苏构造带和西秋立塔克构造带呈长条形带状分布,其成因受重力滑动、重力扩展、区域挤压和塑性流动作用的联合控制。从盐枕构造的演化序列和分布特征看,该区盐枕构造的主要特点表现为:北部盐枕形成较早,稳定性差,出现残留盐枕,盐枕规模较小;南部盐枕形成较晚,稳定性较强,形态相对完整,规模较大。库车前陆褶皱冲断带盐枕构造与油气聚集密切相关,伴随盐枕构造的形成,发育大量盐相关油气圈闭构造,沿盐枕构造成带状分布,同时盐枕构造巨厚的盐岩层为油气聚集提供了良好的封闭条件。

TERTIARY SALT PILLOW STRUCTURES IN THE CENTRAL SECTOR OF THE KUQA FORELAND FOLD-AND-THRUST BELT,TARIM BASIN, NORTHWEST CHINA

The paper aimed to analyze the type, distribution, mechanism and relation to the oil gas accumulation of the salt pillows in the Kuqa foreland fold and thrust belt, Tarim Basin, northwest China. Based on the interpretation of seismic profiles and integrated analysis of petroleum geology, the residual salt pillows, unstable salt pillows and stable ones developed from the north to the south in the area. The salt pillows distributed along the Klash and West Qiulitag structural belts, their developing being controlled by gravitational sliding and spreading, regional compression and plastic flow of the salt beds. The salt pillows formed earlier, with poor stability, smaller size and relict ones occurring in the northern part; and in the southern part, the salt pillows formed later, with more stable, larger size and relatively complete salt pillows. Accompanied with creation of the salt pillows, a large number of salt related petroleum traps developed, and the salt bed itself could be served as excellent seals for oil gas accumulation.