米脂气田上古生界盒8段储层特征及成岩作用评价  

Reservoir characteristics and diagenesis evaluation of 8th member of Shihezi Formation of upper Paleozoic in Mizhi Gasfield,Ordos Basin

作　　者：徐波[1] 韩宗元[2] 

机构地区：[1]西安石油大学石油工程学院,陕西西安710065 [2]胜利油田石油开发中心,山东东营257100

出　　处：《西安石油大学学报（自然科学版）》2011年第5期17-22,29,共7页Journal of Xi’an Shiyou University（Natural Science Edition）

基　　金："十一.五"国家科技支撑计划"延长特低/超低渗透油藏注水开发方式优化研究"(编号:2007BAB17B02)资助

摘　　要：为加强鄂尔多斯盆地米脂气田的天然气勘探,对研究区辅助产层上古生界盒8段砂岩储层进行了综合研究.储层属低孔低渗类型,以残余剩余粒间孔为主.储层主要岩石类型为岩屑砂岩,含量较高的岩屑为储层致密化提供了物质基础.早成岩阶段的机械压实作用使储层原始孔隙度急剧下降(孔隙度减少了75%),压实作用是导致储层致密化以及储层孔隙结构和孔隙连通性变差的主要原因;晚成岩阶段铁方解石、铁白云石的胶结作用、石英次生加大和自生黏土矿物形成不但加剧了储层原始孔隙度损失,更使各井渗透率大多降至0.5×10-3μm2以下;成岩晚期的溶蚀作用虽然较弱,但对储层物性有一定的改善作用,使孔隙度和渗透率均有所提高.辫状河水下分流河道微相控制着储层有效砂体的展布,寻找此类微相发育区是研究区天然气进一步勘探的重点.The comprehensive research on the sandstone reservoir of 8th member of Shihezi Formation is carried out for the exploration of natural gas in Mizhi Gas-field.It is shown that the reservoir is characterized by low porosity and low permeability,and its pores are mainly residual intergranular pores.The main rock type of the reservoir is lithic sandstone,the debris of high content provides the material basis for the densification of the gas reservoir.The compaction in early diagenesis stage makes the original porosity of the sediment decreased by 75%,and it is one of the main causes leading to the bad pore structure and pore connectivity of the reservoir.The cementation of ferrocalcite and ferrodolomite,the secondary enlargement of quartz and the formation of authigenic clay minerals not only reduce the original porosity but also make the permeability decreased to below 0.5×10-3 μm2 in the late diagenesis stage.The dissolution in late diagenesis stage improves the reservoir property in certain degree although it is weak.Braided distributary channel facies controls the distribution of the effective sandbodies of the reservoir,and its development zones are the key to the further gas exploration in the studied area.

关 键 词：米脂气田 盒8储层 储层特征 成岩作用 

分 类 号：TE121[石油与天然气工程—油气勘探]