Review of Embedded Discrete Fracture Models: Concepts, Simulation and Pros & Cons

Abstract

The oil and gas industry faces significant challenges when simulating fractured reservoirs. With the rising cost of hydrocarbons, there is a growing interest in exploiting unconventional reservoirs using hydraulic fracturing technologies. However, unconventional reservoirs typically contain fractured systems at various scales, ranging from nano to kilometer, making it difficult to simulate and predict these reservoirs accurately. Therefore, a rapid and precise method is crucial for this purpose. This paper presents a comprehensive review of the Embedded Discrete Fracture Model (EDFM), a novel approach designed for this purpose. This work begins by reviewing and comparing common methods for simulating naturally and hydraulically fractured reservoirs with EDFM, considering each method's advantages and disadvantages. The concept and formulation of EDFM are then discussed, focusing on adding mass balance equations and making them compatible with reservoir simulators. Additionally, this paper considers the concept and application of non-neighboring connections, which are crucial in simulating fractured reservoirs using EDFM models. This work also highlights the importance of considering changes in the EDFM formulation and simulation when fractures are treated as dynamic systems; failure to do so can lead to significant errors that deviate from actual results. Finally, the disadvantages of EDFM and proposed solutions for enhancing this method are discussed.