The deformation structure of soft sediments has always been a research hotspot, which is of great significance for analyzing the tectonic and sedimentary evolution background of a basin, as well as the physical properties of reservoirs. Previous studies have reported that a large number of soft sediment deformation structures are developed in the western part of Liaohe depression. In this study, through core observation and thin section identification, various types of deformation structures are identified in the core samples which are collected from the upper Es4 in the Leijia region, western sag of Liaohe depression, such as liquefied dikes, liquefied breccia, convoluted laminae, annular bedding, synsedimentary faults, vein structures, etc. Based on the characteristics of core structure, single well profile and continuous well profile, combined with the regional background, this study clarifies that the deformation structure of soft sediments in the study area is mainly caused by seismic action. It is found that the permeability and porosity of deformation layers in the study area are higher than those of the undeformation layers, which proves that the deformation structure of soft sediments has a good effect on improving the physical properties of reservoirs.

软沉积物变形结构一直是研究热点，对于分析盆地构造、沉积演化背景以及储层物性具有重要意义。前期研究表明，辽河坳陷西部发育大量软沉积物变形构造。本研究通过岩心观察和薄片鉴定，识别出辽河坳陷西部凹陷雷家地区沙四上段岩心样品中存在液化岩脉、液化角砾岩、曲折岩等多种变形构造。纹层、环状层理、同沉积断层、脉状构造等。根据岩心构造、单井剖面和连续井剖面特征，结合区域背景，研究明确研究区软沉积物的变形结构主要是由地震作用引起的。研究发现，研究区变形层的渗透率和孔隙度均高于未变形层，证明软沉积物的变形结构对改善储层物性具有良好的作用。