东营凹陷下第三系深部碎屑岩储层次生孔隙垂向分布及成因分析  

DISTRIBUTION AND GENERATION OF DEEP RESERVOIR SECONDARY PORES,PALEOGENE,DONGYING SAG

作　　者：袁静[1] 王乾泽[2] 

机构地区：[1]石油大学(华东)石油资源科学系,山东东营257062 [2]胜利石油管理局孤东采油厂,山东东营257000

出　　处：《矿物岩石》2001年第1期43-47,共5页Mineralogy and Petrology

摘　　要：东营凹陷下第三系埋深大于 30 0 0 m的深部碎屑岩储层普遍发育 2～ 4个次生孔隙带 ,Φ=10 %～ 30 % ,K=0 .1× 10 - 3μm2～ 30× 10 - 3μm2 ,为中孔低渗低孔低渗油气储层。综合有机质热演化过程、成岩作用和构造断裂等分析 ,认为东营凹陷埋深大于 30 0 0m碎屑岩地层中 ,第一、二个次生孔隙带埋深在 30 0 0 m～ 390 0 m之间 ,其形成主要与有机质成熟过程释放有机酸对长石等颗粒的溶解有密切关系 ,在深大断裂附近储层同时受到大气淡水的影响 ,而深陷带包裹于暗色泥岩中的浊积砂岩的次生孔隙发育情况还与泥质岩异常压力带有关 ;第三个次生孔隙带埋深一般为 390 0 m～ 430 0 m,主要成因于粘土矿物转化造成的还原环境 ,同时受到硫酸盐热化学氧化还原反应的影响。这三个次生孔隙发育带对储集油气有效。第四个孔隙发育带埋深在 470 0 m以下 ,主要是构造成因的微裂缝 ,较难成为有效的油气储层。There are 2~4 zones of secondary pores in clastic rock of deep formation buried deep than 3 000 m in Dongying Sag with Φ \{max\}=10%~30%,K \{max\}=0.1×10\{-3\} μm2~30×10\{-3\} μm2.It is considered that changes of formation water chemistry caused by organic thermal evolution,clay minerals transformation and thermochemical sulfate reduction are the important factors influencing diagenesis and porosity evloution on the basis of synthetic analysis of organic thermal evloution,diagenesis and faulting of clastic rock in deep formation in the sag.The first and second zones of secondary pore of 3 000 m to 3 900 m in depth were controlled by organic acids dismissed during organ′s maturing ,fresh water permeating along the deep fault and abnormal pressure in argillite.At the depth ranging from 3 900 m to 4 300 m,the third zone of secondary pore was mainly related to clay minerals transformation and thermo-chemical sulfate reduction.These three secondary porosity zones are effective reservoir spaces.There were crevices in the forth zone of secondary pores which are unfavourable to the accumulation of oil.

关 键 词：东营凹陷 深部碎屑岩 次生孔隙 垂向分布 成因 储层 

分 类 号：P618.130.2[天文地球—矿床学] P588.212[天文地球—地质学]