低渗透储层裂缝表征——以车镇凹陷东南部为例

摘要

Low-permeability reservoirs usually presents low porosity and permeability.The development level of natural fracture systems can greatly improve the reservoir properties.As the main storage sites of oil and gas,it affects the oil and gas content of low permeability reservoir.We studied the fracture,attitude,length,fracture aperture,density and so on for low permeability reservoir fracture system.For the Chezhen Say of the low permeability reservoir's fracture system,its fracture types are mainly tensile cracks and shear crack,with high angle diagonal cracks account for large proportion,and fracture extension length 5-10 cm.Fracture density limestone is the largest,following with sandstone,and mudstone is the minimal.The effective crack opening of core are relatively small.The greater crack width is,the crack filling degree would be higher.%低渗透储层以低孔、低渗为主要物性特征.裂缝系统的发育极大改善了渗透系统,作为油气主要富集、储存的场所,最终影响低渗透储层的油气含量.对低渗透储层裂缝系统从裂缝的性质、产状、长度、开度、密度等方面进行研究,对车镇凹陷东南部的低渗透储层裂缝系统进行分析得出,裂缝类型主要为张性裂缝和剪性裂缝,高角度斜交裂缝居多,裂缝延伸长度在5～10cm,裂缝密度灰岩最大,砂岩次之,泥岩最小.岩心的有效裂缝开度相对较小,裂缝宽度越大,裂缝充填程度越高.