Numerical simulation of hydraulic fracturing and associated microseismicity using finite- discrete element method. Abstract. Hydraulic fracturing (HF) technique has been extensively used for the exploitation of unconventional oil and gas reservoirs. HF enhances the connectivity of less permeable oil and gas- bearing rock formations by fluid injection, which creates an interconnected fracture network and increases the hydrocarbon production. Meanwhile, microseismic (MS) monitoring is one of the most effective approaches to evaluate such stimulation process. In this paper, the combined finite- discrete element method (FDEM) is adopted to numerically simulate HF and associated MS. Several post- processing tools, including frequency- magnitude distribution (b- value), fractal dimension (D- value), and seismic events clustering, are utilized to interpret numerical results. A non- parametric clustering algorithm designed specifically for FDEM is used to reduce the mesh dependency and extract more realistic seismic information. Simulation results indicated that at the local scale, the HF process tends to propagate following the rock mass discontinuities; while at the reservoir scale, it tends to develop in the direction parallel to the maximum in- situ stress. Keywords. Hydraulic fracturing (HF); Numerical simulation; Microseismic (MS); Finite- discrete element method (FDEM); Clustering; Kernel density estimation (KDE)1. Introduction. The hydraulic fracturing (HF) technique, as a reservoir stimulation tool, has been used for more than six decades, and an extensive literature has been developed on the mechanics behind the HF progress (e. Evaluation Of Mineral Reserves A Simulation Approach Pdf995Evaluation Of Mineral Reserves A Simulation Approach Pdf CreatorHubbert and Willis, 1. However, it is the increasing demand of hydrocarbons and the exploration of unconventional reservoirs during the last two decades that spurred researchers to further develop HF techniques and to deeper investigate the stimulation processes. In an HF operation, a pressurized fluid is injected through a borehole and into the target formation to overcome the overburden stress and to initiate and extend fractures into the reservoir (Jasinski et al., 1. The fracturing fluid usually carries proppants, such as sand, glass beads, etc., which keep the fractured formation from closing under the in situ stress once the injection pressure is turned off. This increases the permeability of the formation, resulting in the economical production of hydrocarbons from unconventional reservoirs. At the same time, HF operations raise environmental and safety concerns. The MonteCarlo simulation applied to. Evaluation of Mineral Reserves: A Simulation. Evaluation Of Mineral Reserves A Simulation Approach.pdf Get Evaluation Of Mineral Reserves A Simulation Approach.PDF Now Evaluation Of Mineral Reserves A Simulation. EVALUATION OF MINERAL RESERVES: A SIMULATION APPROACH Andre G. Journel and Phaedon Kyriakidis. Title: Evaluation Of Mineral Reserves A Simulation Approach Author: Nicole Fassbinder Subject: evaluation of mineral reserves a simulation approach. Evaluation Of Mineral Reserves: A Simulation Approach (Applied. Simulation Approach (Applied Geostatistics Series) PDF,ePub, doc, txt, DjVu formats. Numerical simulation of hydraulic fracturing and. A new geomechanical modeling approach for simulating hydraulic fracturing and. The fluid injection could pollute groundwater (Osborn et al., 2. HF process may activate natural faults, resulting in earthquake hazards (Healy et al., 1. Therefore, it is necessary that HF operations be carefully planned and monitored. Monitoring of fracturing processes is the key to understand, control, and optimize HF treatments. Many tools have been developed to study fracture geometry, proppant placement, and induced fracture conductivity (Barree et al., 2. The technique of monitoring the small- scale seismic activity induced by HF, commonly known as microseismic (MS) monitoring, is one of the very few tools that can be used to monitor the stimulation process at the reservoir scale. Examining MS activities can help track stimulation processes and reveal details of the natural discrete fracture network (DFN) (Rutledge and Phillips, 2. Moreover, the study of HF- induced seismic activities can benefit from the studies concerning natural earthquakes and numerical simulations. During the HF activity, the fracture propagation direction is controlled by the in situ maximum principal stress and the local rock fabric features (Gale et al., 2. However, conventional analysis tools typically assume that rock mass is homogeneous, isotropic and linear elastic, and consider the HF to be a bi- planar, tensile crack propagation process (Adachi et. To capture the physics of discontinuous, heterogeneous and anisotropic reservoirs, techniques based on the discrete element method (DEM) are well- suited because they inherently incorporate fabric features, such as faults and joints (e. Al- Busaidi et al., 2. In this paper, a two- dimensional (2. D) FDEM code developed based on Munjiza et. Also, dedicated post- processing tools are developed to analyze and interpret the simulation results. Principles of FDEMFDEM, pioneered by Munjiza et al. It inherits the advantages of FEM in describing elastic deformations, and the capabilities of DEM in capturing interactions and fracturing processes of solids (Munjiza, 2. The progressive failure of rock material can be simulated in FDEM by explicitly modeling crack initiation and propagation, employing the principles of non- linear elastic fracture mechanics (Barenblatt, 1. Barenblatt, 1. 96. Lisjak et. Basics of FDEM and fundamental governing equations can be found in Munjiza et. In this section, only the FDEM approach to simulate HF is discussed. An FDEM simulation uses a triangular FEM mesh to construct a model, and then the model is discretized by introducing four- node elements between each contacting triangular element pair (Mahabadi et al., 2. The four- node elements will be referred to as cohesive crack elements in the following. Upon application of forces, the cohesive crack elements can deform elastically and break when the slip or opening distance is significantly large.
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