Characterization and Modeling of Fractures in the Bereketli-Pirgui Carbonate Reservoir, The Right Bank of the Amu Darya

Abstract

This paper, based on an example from the Bereketli-Pirgui carbonate reservoir in the right bank of the Amu Darya, introduces a method for modeling the discrete fracture network (DFN) and fracture attributes with static and dynamic data. Firstly, the fracture sets, geometric attributes, and distribution of fractures are determined through a static fracture characterization (e.g., seismic-based fracture prediction, core and borehole image analysis). Then, a DFN model is built based on several geologic controls, including the structure setting, lithology, and thickness, and the hydraulic properties of fractures (aperture and conductivity) are corrected using the dynamic data (e.g., production, well test, and pressure data). Lastly, the equivalent fracture attributes model (e.g., fracture porosity and fracture permeability) is built based on the corrected DFN model. The result of the study suggests that: (1) the fracture network and the attributes model built based on geologic controls reflect the spatial distribution of fractures, and provide the attribute model for reservoir numerical simulation; and (2) the distribution of fractures in the Bereketli-Pirgui gas field controls the vertical and lateral reservoir connectivity, the difference in gas-water system, the single-well productivity, the water breakthrough time in gas well, and the DFN model has directive significance to designing the well location and optimizing the well completion method.