Abstract: The key parameter in evaluating fractured carbonate reservoirs is fracture porosity. However, the evaluation of such reservoirs with conventional logging data has for the most part been qualitative. On the basis of qualitative identification, the fracture porosity of the Changxing fractured carbonate reservoir in the T gas field was determined in the present work, by calibrating log curves with core data. Results indicate a higher loginterpretation precision although available log curves were much limited. Considering the situation in many of the old oil/gas fields where log data are extremely inadequate, it is believed that the proposed method is promising in application.

Key words: carbonate reservoir, fracture, qualitative identification, log interpretation, method, application