塔河油田奥陶系碳酸盐岩储集层成像测井地质解释

Geological Interpretation of Ordovician Carbonate Reservoir in Tahe Oilfield:Application of Imaging Logging Technology

地层微电阻率扫描成像(FMI)测井图像直观可视、分辨率高、地质信息量大,描述含有复杂储集空间的非均质性地层时具有明显优势。以FMI测井图像为主,结合岩心、常规测井资料,对塔河油田8口探井奥陶系碳酸盐岩储集层的重点层段精细刻画,建立FMI测井地质解释模型,并推广到未取心井段,识别出奥陶系储集层岩性主要为砂屑灰岩、砂屑泥晶灰岩、泥晶灰岩和灰质白云岩;储集空间类型主要分为孔、洞和缝3类。利用FMI测井图像显示的电阻率差异、孔洞缝展布特征及岩性和构造标志可识别层序不整合面。通过单井相分析和连井剖面对比,认为构造运动、岩溶作用和海退暴露溶蚀作用导致的层序不整合面控制着储集空间的发育。

Formation micro-resistivity scanning imaging logging（FMI） can provide visualized and high-resolution images, which has obvi-ous advantages in describing heterogeneous strata containing complicated reservoir spaces. Combined with the core and conventional log-ging data, FMI images are used to detailedly describe the key intervals of the Ordovician carbonate reservoir in 8 prospecting wells of Taheoilfield, and a geological interpretation model is established for FMI logging. The model is used in the non-coring intervals and the litholo-gies of the Ordovician reservoir are identified, which is dominated by calcarenite, sand-clastic micrite, micrite and calcite dolomite; the res-ervoir spaces are composed by pores, caves and fractures. The sequence unconformity surfaces can be identified by using resistivity differ-ence, reservoir space distribution and lithological and structural markers displayed in FMI images. Based on the single-well facies analysisand well tie correlation, it is considered that the sequence unconformity surface resulted from tectonic movement, karstfication and regres-sive erosional dissolution controls the development of the reservoir spaces.