Simulation of shale gas transport and production with complex fractures using embedded discrete fracture model

Abstract

The goal of this study is to develop a new model to simulate gas and water transport in shale nanopores and complex fractures. A new gas diffusivity equation was first derived to consider multiple important physical mechanisms such as gas desorption, gas slippage and diffusion, and non-Darcy flow. For complex fractures, a state-of-the-art embedded discrete fracture model (EDFM) was implemented. Numerical model is verified against a commercial reservoir simulator for shale gas simulation with multiple planar fractures. After that, a series of simulation studies was performed to investigate the impacts of complex gas transport mechanisms and various fracture geometries on well performance. The critical parameters controlling well performance are identified. The simulation results reveal that modeling of gas production from complex fractures as well as modeling important gas transport mechanisms in shale gas reservoirs is extremely significant.Similarly, the other existing apparent permeability models considering complex nanopore phenomena such as surface

Assessment of extended Derjaguin–Landau–Verwey–Overbeek‐based water film on multiphase transport behavior in shale microfractures

“…Understanding the multiphase transport process in microfractures or microchannels is crucial to predict production performance in shale gas reservoirs [1][2][3] as well as control fluid transport in microfluidic devices. 4,5 Gas shale is a complex sedimentary system that is considered to exhibit different storage space types 6,7 and complex fluid transport properties.…”

Investigation of the Effect of Natural Fractures on Multiple Shale-Gas Well Performance Using Non-Intrusive EDFM Technology

“…Based on the history matching results with an actual shale-gas well, Yu et al [12] compared the long-term well productivity between simple and complex fracture geometries and found that complex fracture networks can produce 36.4% more gas recovery after 30 years than the simple fractures. Yu et al [13] built a synthetic single shale-gas well model including 11 planar hydraulic fractures and 200 natural fractures. The authors found that the well performance of 200 two-set natural fractures is much better than that of 200 one-set natural fractures due to the formation of a much more complex connected fracture network.…”

An Integrally Embedded Discrete Fracture Model with a Semi-Analytic Transmissibility Calculation Method

“…This concept was implemented by Li and Lee [29] to vertical fracture cases and implemented by Moinfar [26] to non-vertical fracture cases, in which the fractures have arbitrary dip and strike angles. Xu [30] and Yu [31] implemented EDFM to some more complex fracture-networks, such as nonplanar shape and variable aperture. Li [32] combined EDFM with DPDK for reservoirs with different scale fractures.…”