Publications

In a reservoir, vertical aligned fracture can enhance the horizontal permeability. Permeability is an important parameter because it can affect the preferential fluid flow. Therefore, the fracture porosity or secondary fracture becomes important in order to develop the efficiency of the reservoir. Based on the research before, P-Wave AVOA (amplitude variation with offset and azimuth) can be used to detect the fracture porosity. In this case we modified the method. The most important part of determination the fracture porosity is the factor properties of crack (D) and anisotropy gradient (Gan). The crack properties can be computed after fluid replacement modeling using Gassmann Equation to find P-wave velocity, S-wave velocity in both dry and wet condition. The anisotropy gradient has been found using anisotropy AVO modeling. The Thomsen parameters calculated using empirical relationship between clay volume and P-wave velocity. Then we applied the method in a carbonate layer. Zone interest appears in CDP 402 until 600 at about 1200 ft. The average value of fracture porosity is 1.202%. Then, we use neural network based on multi attribute data to ensure the result, several attribute that we used are attribute which based frequency and amplitude. The target log is fracture porosity log which computed using fracture porosity index. The result shows similar trend with the fracture porosity inversion from anisotropy AVO.