Many oil and gas production come from naturally fractured reservoirs. The reservoir properties and production performance of this reservoir show a unique behavior, which are different from the homogeneous reservoir. Hence, evaluation and forecasting production of these reservoirs require special models and approaches.
This paper attempts to utilize production data inversion method to obtain parameters such as permeability, skin factor, initial fluid-in-place and production potential in a naturally fractured reservoir. The model can then be used to forecast production from this type of reservoir.
The method uses type curve approach that incorporate concepts of both transient and boundary dominated flow models. Application of this method to oil field data is presented as well as comparison with results obtained from other methods (such as well test analysis and volumetric calculation).
The results of this research provide engineers a tool to evaluate and monitor production/reservoir performance of naturally fractured reservoirs regularly by analyzing production data (which are always recorded) without additional testing.
Modeling of single phase flow in fractured reservoir involve the description of the shapes, orientation and sizes orf fractures network, and the mechanism for the transfer of fluid from the matrix to the fracture network. The process of transfer of fluid between matrix blocks and fissures (or fractures) is the points at which various model differ. Some investigators have considered a pseudosteady-state relation for the interporosity flow term. This approach was first suggested by Barenblatt et al1 and was taken up by Warren and Root2 in their pioneering study of the pressure response of naturally fractured reservoirs. Others3,4,5 considered the effect of transient interporosity flow. The transient model is physically much more appealing since it allows for all regimes of internal block flow, i.e. transient, late transient and pseudosteady-state. This was first proposed by Kazemi,3 where the matrix blocks were composed of slabs.