The productive carbonate sediments of the Lower Devonian and the Upper Silurian deposits of R. Trebs oil field are represented by porous fractured vuggy reservoir rock. According to core analysis and well logging data these sediments have similar reservoir properties such as porosity, permeability, residual water saturation and clay content. In the same time they are characterized by irregular performance parameters as in a whole on the area, as in individual wells. This work studies the application of additional criteria identified by well logging rock to classify reservoirs by their productivity.
Based on synthesis of special core studies results the authors investigated cavern porosity and fracturing of sediments and developed a conceptual model. According to research results productive deposits vary in number, distribution and size of caverns and fractures. Obtained results were considered together with logging data (petrophysical characteristics) and PLT data (working intervals). It is shown that void space is associated with secondary changes. It is justified that Lower Devonian and Upper Silurian deposits differ by number, distribution and size of caverns and fractures. Reservoirs were classified by production capacity and their characteristics. The authors proposed criteria to forecast highly productive layers using inflow intensity and data integration on open and secondary porosity, and relative clay content coefficients. Basic productive intervals are characterized by higher capacity properties of the matrix and secondary porosity in comparison with other reservoirs.
References
1. Shumatbaev K.D., Kuchurina O.E., Shishlova L.M., Integrated analysis of void space in carbonates by the example of R. Trebs oil field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2014, no. 6, pp. 91–93.
2. Shumatbaev K.D., Gaynullina E.K., Malysheva A.E. et al., Integrated approach to secondary porosity characterization for complex carbonate reservoirs of R.Trebs oil field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2015, no. 11, pp. 108–110.
3. Shumatbaev K.D., Gaynullina E.K., Malysheva A.E. et al., Petrophysical framework for interpretation of Lower Devonian and Upper Silurian heterogeneous carbonate reservoirs: a case study from R. Trebs oil field (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2015, no. 5, pp. 44–46.
4. Shumatbaev K., Privalova O., Gainullina E. et al., Dynamic attributes for characterization of complex oil reservoirs, A case study from R. Trebs oil field, SPE 180002-MS, 2016.
