One of the main challenges in development of the fractured reservoirs is the identification of "sweet spots" which are the most intensely fractured areas of a field, maintaining a long term production with minimized risks in drilling. This paper presents a multi-disciplinary approach including G&G (geology & geophysics), petrophysics and reservoir engineering perspective to overcome this difficulty in a particular oil reservoir by defining the fracture systems that mainly contributes to the hydrocarbon storage capacity and flow dynamics.
Şambayat Field is one of the most important naturally fractured carbonate reservoirs located in the Southeast Turkey. Reservoir zones in the field include a number of reverse, synthetic and antithetic faults and related fracture sets which are hydraulically in contact with each other. In this context, characterizing the fracture network becomes the most critical issue in the analysis of production and the development strategy of the field.
For this purpose; besides the conventional open-hole log analyses, image log interpretations have also been performed in order to evaluate the properties of the fractures. To honor these interpretations; dynamic (drill stem test & production) and static (outcrop & core) data have been evaluated together. Distributions of the petrophysical properties and the fractures have been done by using stochastic methods in full-field scale. At the end of the modeling study, a dual porosity geological model has been generated by using the Discrete Fracture Network (DFN) approach with respect to the estimated fracture characteristics.
As the result of the previous characterization study, new well locations and their optimized orientations had been determined and the results coincided with the expected types of fractures estimated in the DFN model. After updating the model with the new well data and the enhanced functionalities in the modeling software, additional well locations have been proposed which will play a role in one step further of the study; simulation.
This study has contributed to our knowledge about the characteristics of a naturally fractured carbonate reservoir which is similar to the ones explored in Southeast Turkey and to some extend in Middle East. It should also be noted that, our approach in this particular study is a newly developing technique and could be used for the promising "previously overlooked" unconventional reservoirs.