川西拗陷压实规律研究

利用川西拗陷各井声波测井资料分别制作了泥岩、砂岩的压实曲线，统计了部分井压力系数与层位的关系，通过这些资料的综合分析，总结出了川西拗陷的压实规律。研究认为，川西拗陷在纵向上存在四个压实阶段，即快速压实阶段、正常压实阶段、过渡阶段、欠压实阶段；川西拗陷从北向南，各压实层段顶界深度有逐渐增大趋势；上三叠统的砂岩与泥岩存在类似的异常高压现象；不同压实阶段，油气分布特征不同，但气藏主要存在于过渡带和欠压实带。

RESEARCH ON THE COMPACTION LAW OF THE WEST SICHUAN DEPRESSION

On the basis of the acoustic well logging data from west Sichuan depression, the compaction curves of the sandstone and mudstone are depicted, and the relation between pressure coefficient and formation location in some wells are collected by the comprehensive analyses of these data, compaction law of the west Sichuan depression is summarized . It is revealed that there are four stages of compaction vertically, which are the fast compaction stage, the normal compaction stage, the transition compaction stage and the undercompaction stage. There is a trend gradually deepening to the up boundary of each compacted layer from north to south. The sand and mudstone of upper Triassic (T3) have the similar phenomenon of abnormal pressure. The distributing characteristic of oil and gas is different in different compaction stage. but natural gas mainly exists in the transition stage and the undercompaction stage.