Method of estimating the permeability of a fracture network from a connectivity analysis

A method for optimizing development of a reservoir including a fracture network, wherein the reservoir is discretized into a set of grid cells and a geometrical description of the fracture network of each cell, comprising:

• determining, within each cell, a connectivity degree of fractures of the fracture network by calculating a connectivity index depending at least on a number of intersections between fractures by use of the geometrical description;
• estimating permeability of cells of the fracture network with the connectivity index above a threshold;
• assigning a fixed permeability value within other cells with the connectivity index below the threshold to limit a number of permeability estimations;
• selecting with a computer a production scenario for optimizing development of the reservoir by using a flow simulator implemented as software in a computer to simulate fluid flows in the reservoir as a function of the permeability of the fracture network;
• and
• optimizing development of the reservoir by implementing in the reservoir the selected production scenario;
• and wherein
• the permeability of the fracture network is estimated by using for each cell a method of estimation of the permeability of the fracture network as a function of value of the connectivity index and the method of estimation is selected by defining first and second connectivity thresholds corresponding to two connectivity index values defining three connectivity index intervals, and a different method is selected for each of the intervals to optimize estimation of the permeability value in each cell.