One of the most important problems facing reservoir management and additional development in depleted fields is the estimation of the Productivity Index for non-flowing wells.

Belayim Marine field is the first offshore field discovered in Egypt in 1961.Kareem-Rudeis Formation has been producing since Feb.1962 and represents about 65﹪ of Belayim Marine production with cumulative oil production reached to about 1439 MMSTB and the current oil production rate is 16,000 STB/D. By using the available old relationship derived from core data - assume water wet reservoir - it was observed that the calculated productivity index values deviate from actual values calculated using different methods (down hole sensors, well test, prosper software).

To combat the deviation of the productivity index, it was decided to cut a core and use more down hole sensors to monitor the actual productivity index, from core data it was observed that the reservoir is oil wet. Using new core data, a relation between Ko@swi and Φ was derived.

This relation showed excellent results compared with available sensors data, well test data, and prosper software.

The derived new relation will help in production optimization and knowledge of damaged wells and consequently maximize the oil reserve.

This paper highlights the work done by Petrobel to create a good relation between porosity and effective permeability, which should be representative of reservoir properties and the importance of considering the wettability to derive such relation.


Estimation of permeability is of pivotal importance for the description of different physical processes, such as hydrocarbon recovery. Mainly due to the intricate geometry of the connected pore space and to the complexity of porous media, it has been very difficult to formulate satisfactory theoretical models for permeability. Permeability of porous media is usually expressed as function of some physical properties of the interconnected pore system such as porosity and tortuosity. Although it is natural to assume that permeability values depend on porosity, it is not simple to determine which is the appropriate relationship. In order to expect how much a new well can produce, and knowledge of damaged wells, it is very important to create a good relation between porosity and permeability, which should be representative of reservoir properties in order to improve the production and maximize the oil reserve.

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