3D fracture modeling in Parsi oil field using artificial intelligence tools

Naturally fractured reservoirs are generally complex and highly heterogeneous. There are usually scarce data sources in these reservoirs that may be found over a wide range of scales. Therefore, fracture characterization is a complicated task and an integrated method is required to effectively overcome this multi-scaled problem and to combine data obtained from as many tools as possible. One sophisticated tool for this purpose is artificial intelligence. Recently, Fuzzy Logic and Neural Network have been used to obtain a 2D fracture intensity map in Hassi Messaoud field. m of this paper is to show the applicability of Artificial Neural Network and Fuzzy Logic in characterizing Parsi naturally fractured reservoir. First, using Fuzzy Inference System (FIS), Fracture Index (Fracture Intensity Index or FI) is calculated along the wellbore. For decreasing the uncertainty, using FIS, static and dynamic data (log, well test and core data) are coupled which results in a more reliable Fracture Index. Moreover, use of log data in FIS makes it possible to calculate the fractured index in those blocks where wells are perforated. Hence, a 3D characterization becomes possible. for calculating the spatial distribution of the Fracture Index, two types of Neural Networks, Multi-Layer Perceptron (MLP) and Radial Basis Function (RBF), are used. The inputs of these networks are some geological and geomechanical drivers (e.g. shale volume, porosity, permeability, bed thickness, proximity to faults, slopes and curvatures of the structure), and the output is the Fracture Index. Because of the overfitting problem in MLP network, fuzzy ranking method is used for selecting only parts of the mentioned drivers as inputs of MLP network, and also a partially connected MLP network are used. RBF network produces more reasonable Fracture Index. a 3D fracture intensity map in Parsi oil field is developed. According to this map, the high production rate of some wells can be explained in this field. Also, this 3D fracture intensity map can reduce the uncertainty in reservoir simulation. Therefore, a better field development scenario can be designed. sults are promising and can be easily extended in other naturally fractured reservoir.