Evaluation of Multistage Hydraulic Fracture Patterns in Naturally Fractured Tight Oil Formations Utilizing a Coupled Geomechanics-Fluid Flow Model - Case Study for an Eagle Ford Shale Well Pad

摘要

The traditional approaches used in evaluation of fracturing have been typically based on the flow simulation using models incorporating synthetic fracture network with a geometry pre-determined at fixed locations. Interactions between natural fractures and the approaching hydraulic fracture are impacted by stress state and formation geomechanical properties, stress shadow due to local in situ stress alteration, and fluid and proppant transport. The created combined natural fracture-hydraulic fracture network is very complex and will represent more realistically the production forecasting through reservoir simulation in shale reservoirs. In this research study, a new approach using the integrated 3D complex discrete fracture network (DFN) and hydraulic fracturing flow model has been applied as a case study to accurately evaluate hydraulic fracturing in naturally fractured shale reservoirs. Production forecast as a result of the fluid flow simulation has been handled utilizing unstructured grid blocks exclusively created for the specific 3D DFN. A case study elaborating these processes has been conducted based on the data from the Eagle Ford shale. The complex DFN model, the integrated DFN, fluid flow model, and the input dataset have been validated against microseismic fracture mapping and commingled production data obtained from a well pad located in the Eagle Ford oil window. The integrated model based on the fracturing model developed in this study can be used to evaluate the hydraulic fracturing patterns in various aspects.