塔里木盆地塔中南坡地区奥陶系优质海相碳酸盐岩储层测井评价

Logging evaluation of high quality Ordovician marine carbonate reservoir on the south slope of Central Uplift Belt,Tarim Basin

通过"三孔隙度"测井系列交会识别岩性的方法,可以较易区分研究区奥陶系灰岩、中砂岩、灰质白云岩等典型岩性。根据常规测井方法与成像测井的处理成果,并结合岩芯观察和显微镜下观测结果,认为塔中南坡碳酸盐岩主要发育三类储层,即裂缝型储层、孔洞型储层以及裂缝—孔洞型储层;针对不同类型储层的特点,总结了各种类型储层在常规测井上的响应特征,并对塔中南坡奥陶系碳酸盐岩储层进行评价,研究区以Ⅲ类储层(裂缝型储层或孔洞型储层)最多,Ⅱ类储层(裂缝—孔洞型储层)次之,Ⅰ类储层(洞穴型储层)未见典型发育段。这些认识对寻找塔中南坡优质碳酸盐岩储层具有指导意义。

The lithological characteristics of Ordovician strata in the study area can be distinguished by crossplot of porosity logging series.Based on the data and results of conventional logging,FMI logging,core and microscope,the authors found three kinds of reservoirs on the south slope of Central Uplift Belt： fractured reservoir,vugular reservoir and fractured-vugular reservoir,which present different response characteristics.Ordovician carbonate reservoirs on the south slope of Central Uplift Belt in Tarim Basin can be classified into three types： type Ⅲ,consisting of fractured reservoir and vugular reservoir,is most developed in the study area,type Ⅱ,i.e.,fracturedvugular reservoir,takes the second place,type Ⅰ,i.e.,cave reservoir,is not typically developed.The authors＇ understanding is helpful to finding high quality Ordovician carbonate reservoir on the south slope of Central Uplift Belt,Tarim Basin.