同沉积压扭断层在柴达木盆地西部南区油气成藏中的意义

柴达木盆地西部南区逆断层断面产状呈上陡下缓的铲式特征,生长系数变化在1.3~2.5之间,断距纵向上向浅层逐渐变小和横向上向一个方向逐渐增大,总体表现为典型的同沉积压扭断层。指出该断层演化主要经历了同生冲断期、褶皱发育期、平静期及二次活动期4个阶段,长期活动的NWW向主干断层除控制构造带的展布格局外,还控制着烃源岩、储集层、盖层及其组合的空间发育,同时还有效地沟通着源岩与圈闭并成为有效输导体系的一部分,近N S向展布的次级断层决定着局部构造的发育特点,与NWW向断层联合控制着油气的局部富集。

SIGNIFICANCE FOR PETROLEUM ACCUMULATION OF SYNSEDIMENTARY COMPRESSIVE-SHEAR FAULTS IN SOUTH-WEST OF QAIDAM BASIN

The fault planes of reverse faults in south-west of Qaidam basin are shovel and the growth indexes are ranging from 1.3 to 2.5, the fault throws become smaller from bottom to top and more and more strong from one side to another laterally, and they are typical synsedimentary compressive-shear faults. The evolution process can he divided into four stages, synsedimentary faulting, folding, sleeping and activating. The active NWW mainly faults control the structural zones and the combination of source rock, reservoir and seal rock. Moreover, the NWW faults connect the source rock and traps effectively. The NS minor faults dominate the evolution of local traps, and determine the petroleum accumulation together with the NWW faults.