Natural Fracture Occurrence Model Based on FMI Imaging Logging.

Abstract

Natural fractures are crucial for connecting with reservoir matrix pores and influencing the fluid velocity in the matrix during unconventional oil and gas development. The development of natural fractures has significant impact on the effectiveness of extraction and even the final recovery factor. The development stage of natural fractures in reservoirs is characterized by fracture density and fracture occurrence, which are the key characteristics. The probabilistic models of fracture occurrence and density that are now available, however, still have several drawbacks. Therefore, a fracture occurrence model that may reflect both inclination and dip angles is proposed in a three-dimensional scenario in this study based on formation micro-imager imaging logging and the elliptic Fisher model. The findings demonstrate the accuracy and clarity of the proposed 3D fracture occurrence model in reflecting the fracture density and occurrence, as well as the superiority of data simulation. The algorithm described in this study is shown to be very close to the real distribution law. The results enable visualization of the fracture density and occurrence, which is crucial for directing engineering practice and assessing the sensitivity of directional data in other domains.