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

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