| In this paper,diagenesis and diagenetic minerals of Chang 7 tight sandstone oil reservoir in Heshui area of Ordos Basin are studied by using core observation,thin section examination,scanning election microscope data,cathode luminescence and physical property analysis.According to the types and intensity of diagenesis and the combination feature of diagenetic minerals,diagenetic facies in research area is qualitatively divided into four types,including instable components dissolution facies,clay minerals filling facies,carbonate cementation facies and tight compaction facies.Then based on the analysis of conventional logging curves,such as gamma log,density log,acoustic transit time log,compensated neutron log and resistivity log,which are sensitive to diagenetic facies,crossplots are made to further quantitatively classify the four diagenetic facies and establish logging cognition model of diagenetic facies.Take Cheng 96 well in Heshui area,for example,the quantitative recognition and classification of diagenetic facies coincide well with thin section of sampling point,formation testing and physical property analysis in single well on the longitude,which verifies the reliability of the model.Then combined with the result of logging interpretation and oil gas test,quantitative control of diagenetic facies on reservoir effectiveness is further illustrated.At last,diagenetic facies of each well in research area is continuous classified by logging,and longitudinal distributions of diagenetic facies is expounded.On that basis,lateral distributions of diagenetic facies are compared and plane figure is made.Thus,sweet spot is predicted by the distribution law of diagenetic facies vertically and horizontally.The study of quantitative logging characterization method of diagenetic facies can provide theoretical guidance and technical support for comprehensive assessment of tight sandstone oil and for prediction of favorable zones in oil-gas reservoir development. |
PDF Full Text Request