Abstract: Fractured reservoir is a main type of Ordovician limestone reservoir in Lunnan region of Tarim basin, northwestern China. The reservoir is characterized by low matrix porosity(about 1%),abundant fractures and some solution vugs. According to comprehensive analysis of electrolog(dual laterlog and microresistivity log),high resolution dipmeter tool(HDT), sonic log(sonic wavetrain anomalies),compensation density log and other well-logging data,combined with core analysis and formation testing data,we proposed an effecient method forevaluation of fractured limestone reservoir,i.e. a comprehensive fracture probability method,by which we study and evaluate the Ordovician reservoirs in this working region.According to detection of conductivity anomalies,formation microscanner,and borehole sonic televisionlog fracture orientation of Ordovician reservoir in the working region were detected and thedevelopment of fractures was studied with the use of con1prehensive fracture probabilitymethod and structural stress analysis. Petroleum exploration showed that the method proposed is efficient and results of reservoir evaluation are significant to oil exploration and development in the working region.

Key words: fracture, reservoir, well logging, evaluation, origin, study, Lunnan region, Ordovician

摘要： 裂缝型储层是塔里木盆地轮南地区奥陶系灰岩的主要储层类型。岩石基质孔隙度很低,约1.0%左右。储集空间以裂缝为主,其次为溶孔、溶洞。结合岩心、地层测试资料,应用电法测井、高分辨率地层倾角测井、声波全波测井、补偿密度测片等,提出了一种裂缝型灰岩储层的评价方法,即裂缝综合概率法。通过电导率异常检测、地层微电阻扫描和井下声波电视测井,对区内奥陶系的裂缝方向进行了检测;结合构造应力分析和裂缝综合概率法,对裂缝发育机体进行了研究。勘探实践证明,本文提出的裂缝综合概率法是有效的,裂缝发育规律及储层评价成果对该区石油勘探和开发具有指导意义。

关键词: 裂缝, 储层, 测井, 评价, 成因, 研究, 轮南地区, 奥陶纪