T The research area are located on the field ”NAP”, which is administratively inTuban Block, East Java Province. In this research was conducted a several analysisbased on log data that validated with core data. The analysis are lithofacies analysis,sequence stratigraphy analysis, depositional environment analysis, petrophysicsanalysis, and rock typing interpretation which are located at carbonate rocks zoneof Tuban Formation from well NG-1, NG-2, NG-3, NG-4 and NG-5. Based on thelithofacies data from the core of well NG-1 there are two depositional environmentin the “N” layer of field “NAP” that is fore reef and inter reef. Based on thecalculation of the petrophysics parameters and the R35 (Windland Method) unit,there are three rock types in “NAP” field that is macroport, mesoport, and microportrock types. The macroport rock type is the dominant rock type of “N” layer. Thearea of which has the greatest potential of a reservoir is located in well NG-4 withan average value of porosity of 0.179 and an average value of permeability of 85md. The development wells that are based on the values of both porosity andpermeability are advised on the southwest and middle area of “NAP” field.