滨里海盆地东缘巨厚盐岩区盐下构造的解释方法研究

滨里海盆地东缘隆起带下二叠统是一套巨厚的膏盐层,局部发育多个巨厚盐丘,厚度从200～3500m不等。由于盐丘与围岩(上二叠统碎屑岩)之间存在巨大速度差异,造成盐下石炭系目的层地震反射层在盐丘部位出现构造上拉的现象。如何通过盐下构造地震解释方法研究来准确恢复盐下构造形态,成为制约研究区勘探突破和增储上产的关键。经过多年对盐下构造解释方法的研究,本文总结出了一套适合于盐丘发育区及类似地质特征地区进行精细解释的方法,包括速度分析技术、模型正反演技术、古构造恢复技术等。这些技术对于恢复盐下地层相对真实的构造形态具有重要意义,应用效果十分显著。

Interpretation method of subsalt structures in significant thickness of salt beds, east merging of littoral Caspian Sea basin.

The Lower Permian of uplifts in east merging of littoral Caspian Sea basin is a set of giant thickness of salt beds and multiple salt domes with significant thickness developed locally, in which the thickness is from 200m to 3500m. The significant difference in velocities between salt domes and surrounding beds made the reflection horizons at subsalt Lower Carboniferous target pull-up. How to restore the subsalt structural feature correctly by studying seismic interpretation methods of subsalt structures becomes the key factor constraining exploration breakthrough, increasing reserves and productions in studied region. The paper summarized a set of methods suitable for fine interpretation in the salt-dome-developed areas and the regions having similar geologic feature after many years' studies of interpretation methods of subsalt structures, including velocity analysis technique, forward modeling and inversion technique and paleostructural restoration technique. These techniques have important meaning of restoring relatively true structural feature of subsalt beds and visible application effects.