致密砂岩压实效应影响因素分析综述

Influence Factor Analysis about Compaction in Tight Sandstone

摘要: 压实作用存在于成岩史的任何阶段，在致密砂岩的成岩过程中扮演着重要的角色。本文从砂岩内因(沉积)和外因(地层条件)两大方面多种因素分析砂岩压实效应的差异性，沉积作用造成砂岩颗粒大小、颗粒强度、脆韧性等差异，砂岩孔隙度随颗粒、强度增大而增大；地层压力是砂岩致密化主要原因，但随压力增加孔隙度存在早期速变阶段和中晚期的缓变阶段；在压实过程中，孔隙压力、地下流体、温度、时间等都对压实效应有不同程度的影响。

Abstract: There is compaction in any diagenesis stage; compaction is necessary in diagenesis process for tight sandstone. Analyzing compaction difference of sandstone from intrinsic factors (sedimentation), extrinsic factors (formation condition) and so on in this paper, sedimentation causes the difference in particle size, particle strength, particle brittleness and toughness in sandstone; sandstone porosity increases with particle size and particle strength increasing. And formation pressure is a significant factor to cause densification in sandstone; however, porosity changes fast in early diagenesis stage and changes slowly in medium and late diagenesis stage with pressure increasing; pore pressure, underground fluid, temperature, time and so on influence compaction in various degrees in compaction process.