Application of a smart mesh generation technique in gas condensate reservoirs: Auto-tune PVT package for property estimation

Accurate knowledge of static and dynamic characteristics of the reservoir plays a key role in precise evaluation of the field performance. Pressure and temperature variations of the reservoir as well as precipitation of complex components like asphaltene during reservoir production change its characteristics including fluid flow and reservoir permeability. This effect is more significant in gas condensate fractured reservoirs; therefore, application of a dynamic mesh for accurate simulation of the reservoir is inevitable. In this paper, a novel technique has been proposed for generating a dynamic mesh in which static and dynamic parameters of a gas condensate fractured reservoir are combined with the capability of updating. Static parameters including permeability distribution and the location of active wells were combined with fluid patterns in the reservoir. This approach led to generating an element size map, and subsequently was applied for unstructured mesh generation. Afterward, this technique was applied in a multi-phase flow compositional simulator. Moreover, an auto-tune PVT package was developed for properties estimation. The priority of this package was freely choosing the number of regression parameters for properties estimation. To evaluate the performance of the developed model, the results for this model were compared with those obtained by uniform grid model. A grouping technique was also developed in the compositional simulator, to optimize the computation algorithm in terms of the CPU time. It was found that the proposed method provides more accurate results for the recovery of gas reservoir compared with the uniform grid model. Moreover, it is faster and computationally less expensive than the fine model. In addition, the proposed model would provide us with a new and different approach for studying the flow and rock physics and simulating fractured reservoirs, which could be an alternative to dual porosity-dual permeability methods.