[PDF] Thermal Modeling Of Fractured Reservoir Wellbore Coupled System For Fracture Diagnosis And Geothermal Applications eBook

Author : He Sun (Ph. D.)
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Page : 0 pages
File Size : 27,39 MB
Release : 2022
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Distributed temperature sensing (DTS) is an enabling technology for fracture diagnosis and multiphase flow measurement in unconventional areas. Fracture characterization and flow profiling are crucial to evaluate the performance of hydraulic fractures. Enhanced Geothermal Systems (EGS) have gained great attention since they promise to deliver geographically disperse, carbon-free energy with minimal environmental impact. The objective of our DTS data analysis workflow is to provide a high-resolution quantitative diagnosis of hydraulic and natural fractures, which will benefit the fracturing operation design and decision-making process in the unconventional reservoir. Natural fracture networks have a major impact on EGS heat extraction. The objective of our model is to evaluate the impact of natural fracture networks on EGS producing temperature profiles. In this work, we developed a comprehensive numerical forward model for DTS data analysis and EGS economic evaluation. Our model includes reservoir and wellbore models. Also, the flow and thermal models are fully coupled. A thermal embedded discrete fracture model (Thermal EDFM) is developed to handle the thermal modeling of complex fracture networks. Subsequently, we implemented an ensemble smoother with multiple data assimilation (ESMDA) as the inverse model to match DTS data and characterize fractures. The DTS analysis with our model provides a high-resolution solution since the fracture diagnosis and flow profiling are performed for each fracture. The hydraulic and natural fracture properties and geometry such as fracture half-length, height, and fracture conductivity are evaluated. Our EGS model provides a comprehensive economic evaluation since we consider the flow and temperature behavior in each fracture without any upscaling. Although numerous simulators are developed for DTS data analysis and EGS economic evaluation, relatively few existing models can handle the full-physics such as complex fracture geometry and multiphase flow. Our models are more rigorous than the prior models to simulate and match the field DTS and EGS data

Author : Mohammadreza Safariforoshani
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Page : pages
File Size : 22,45 MB
Release : 2013
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The thesis considers three-dimensional analyses of fractures and wellbores in low-permeability petroleum/geothermal reservoirs, with a special emphasis on the role of coupled thermo-hydro-mechanical processes. Thermoporoelastic displacement discontinuity and stress discontinuity methods are elaborated for infinite media. Furthermore, injection/production-induced mass and heat transport inside fractures are studied by coupling the displacement discontinuity method with the finite element method. The resulting method is then used to simulate problems of interest in wellbores and fractures for related to drilling and stimulation. In the examination of fracture deformation, the nonlinear behavior of discontinuities and the change in status from joint (hydraulically open, mechanically closed) to hydraulic fracture (hydraulically open, mechanically open) are taken into account. Examples are presented to highlight the versatility of the method and the role of thermal and hydraulic effects, three-dimensionality, hydraulic/natural fracture deformation, and induced micro earthquakes. Specifically, injection/extraction operations in enhanced geothermal reservoirs and hydraulic/thermal stimulation of fractured reservoirs are studied and analyzed with reference to induced seismicity. In addition, the fictitious stress method is used to study three-dimensional wellbore stresses in the presence of a weakness plane. It is shown that the coupling of hydro-thermo-mechanical processes plays a very important role in low-permeability reservoirs and should be considered when predicting the behavior of fractures and wellbores. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151272

Author :
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Page : 13 pages
File Size : 45,56 MB
Release : 2011
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The primary objective of our current research is to develop a computational test bed for evaluating borehole techniques to enhance fluid flow and heat transfer in enhanced geothermal systems (EGS). Simulating processes resulting in hydraulic fracturing and/or the remobilization of existing fractures, especially the interaction between propagating fractures and existing fractures, represents a critical goal of our project. To this end, we are continuing to develop a hydraulic fracturing simulation capability within the Livermore Distinct Element Code (LDEC), a combined FEM/DEM analysis code with explicit solid-fluid mechanics coupling. LDEC simulations start from an initial fracture distribution which can be stochastically generated or upscaled from the statistics of an actual fracture distribution. During the hydraulic stimulation process, LDEC tracks the propagation of fractures and other modifications to the fracture system. The output is transferred to the Non-isothermal Unsaturated Flow and Transport (NUFT) code to capture heat transfer and flow at the reservoir scale. This approach is intended to offer flexibility in the types of analyses we can perform, including evaluating the effects of different system heterogeneities on the heat extraction rate as well as seismicity associated with geothermal operations. This paper details the basic methodology of our approach. Two numerical examples showing the capability and effectiveness of our simulator are also presented.

Author : Zhihong Zhao
Publisher : Springer Nature
Page : 267 pages
File Size : 32,67 MB
Release : 2023-11-12
Category : Science
ISBN : 9819962102

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This book presents the coupled Thermo-Hydro-Mechanical-Chemical (THMC) processes in fractured rocks at varying scales from single fractures to fracture networks. It also discussed the implication and potential application of the advanced understanding of coupled THMC processes in fractured rocks for geotechnical and geo-energy engineering.

Author : Shuang Zheng
Publisher :
Page : 928 pages
File Size : 12,36 MB
Release : 2021
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Numerical modeling plays a key role in assessing, developing, and managing energy resources (such as oil, gas and heat) from subsurface formations. Fluids are injected into wellbores during hydraulic fracturing, water flooding, parent well pre-loading, and improved oil recovery. Oil, gas and water are produced back to the surface during flowback, primary/secondary/tertiary production, and geothermal operations. Results from modeling these subsurface energy resources assist engineers and geologists in the decision-making process. Geomechanics, fluid/solid flow, and heat transport are coupled in the reservoir, fracture, and wellbore domains. The purpose of this dissertation is to develop integrated hydraulic fracturing and reservoir simulator that can accurately model multi-component, multi-phase fluid flow, geomechanics, fracture propagation and thermal processes in the reservoir, fracture and wellbore domains. In this dissertation, fully coupled reservoir, fracture, and wellbore domains are modeled. Geomechanics, fluid flow, and heat transport are modeled in an integrated manner in each domain and between each domain. Thermo-poro-elasticity, fracture opening/closing, and fracture propagation are modeled based on the stresses and strains computed in the domain. Four flow types including single-phase flow, multi-phase black-oil flow, multi-phase compositional flow, and water-steam two-phase flow are developed for different applications. Temperature and enthalpy formulations are developed to model the energy balance within the fully coupled system. A novel proppant transport model formulation which couples fracture opening/closing has also been developed. The governing equations are discretized in space using the finite volume/area methods. Multiple fully implicit Newton solvers have been developed to solve different sets of nonlinear systems of equations. A fully distributed memory parallelization workflow is constructed. The simulator is also coupled with simpler (analytical and DDM) fracturing models to achieve shorter run times. The modeling capability of the simulator has been demonstrated in the dissertation through many example applications. Typical applications of the simulator include multi-stage, multi-cluster, hydraulic fracture propagation, proppant settling and fracture closure analysis, mini-frac analysis, parent-child well interference, fracture monitoring, reservoir cooling and induced fracture propagation from water injectors, production analysis, gas huff-n-puff injection, improved oil recovery, geothermal reservoir production, and enhanced geothermal system analysis. These applications demonstrate the wide variety of problems that our simulator can be used to model

Author : Zihao Zhao
Publisher :
Page : 0 pages
File Size : 50,80 MB
Release : 2021
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The advancement of hydraulic fracturing techniques has boosted the economic development of the unconventional reservoir. The created complex fracture networks provide a high-conductivity flow channel for the production and increase the ultimate recovery. However, they also posed great challenges to efficiently model the flow inside. The newly developed Embedded Discrete Fracture Model (EDFM) enables efficient fracture modeling without sacrificing accuracy. It has been widely applied in many challenging research topics associated with complex fracture networks including Enhanced Geothermal System, gas huff-n-puff, well interference analysis, and automatic history matching. But the mechanism of EDFM makes it hard to incorporate a discrete wellbore module into the commercialized simulator, which limits its application in some topics that require detailed wellbore modeling. The objective of this study is to establish a new workflow that can integrate EDFM with a fully-coupled wellbore-reservoir model to simulate the flow behavior. The idea is to generate the pseudo parameters for the simulator input to force the simulator to get the correct wellbore perforation and trajectory information with EDFM. The developed wellbore EDFM module is integrated with thermal EDFM to simulate the temperature distribution in the wellbore and reservoir with complex fracture networks, which is applied as the forward model for fracture diagnosis through Disributed Temperature Sensing (DTS). A field case is conducted, which verifies the potential application of our workflow in fracture diagnosis. By matching the temperature distribution along the wellbore, we can estimate the fracture geometry and properties, which provide valuable information for future operation optimization. Subsequently, we applied our wellbore EDFM module to simulate the well interference through fracture hits. It verifies the great capacity of our wellbore EDFM module to handle complex flow regimes inside the wellbore even when counter flow exists. It is also the first time for the simulator to handle the wellbore flow at closed wells. Our newly developed wellbore EDFM should have great potential in other research topics in the future

Author : Hans-Joachim Kümpel
Publisher : Springer Science & Business Media
Page : 364 pages
File Size : 16,86 MB
Release : 2003-03-21
Category : Nature
ISBN : 9783764302535

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The supply and protection of groundwater, the production of hydrocarbon reservoirs, land subsidence in coastal areas, exploitation of geothermal energy, the long-term disposal of critical wastes ... What do these issues have in common besides their high socio-economic impact? They are all closely related to fluid flow in porous and/or fractured rock. As the conditions of fluid flow in many cases depend on the mechanical behavior of rocks, coupling between the liquid phase and the rock matrix can generally not be neglected. For the past five years or so, studies of rock physics and rock mechanics linked to coupling phenomena have received increased attention. In recognition of this, a Euroconference on thermo-hydro-mechanical coupling in fractured rock was held at Bad Honnef, Germany, in November 2000. Most of the twenty papers collected in this volume were presented at this meeting. The contributions lead to deeper insight in processes where such coupling is relevant.

Author : Kan Wu
Publisher : Elsevier
Page : 296 pages
File Size : 15,21 MB
Release : 2024-06-28
Category : Technology & Engineering
ISBN : 0323953611

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Fiber optic-based measurements are innovative tools for the oil and gas industry to utilize in monitoring wells in a variety of applications including geothermal activity. Monitoring unconventional reservoirs is still challenging due to complex subsurface conditions and current research focuses on qualitative interpretation of field data. Hydraulic Fracture Geometry Characterization from Fiber Optic-Based Strain Measurements delivers a critical reference for reservoir and completion engineers to better quantify the propagation process and evolution of fracture geometry with a forward model and novel inversion model. The reference reviews different fiber optic-based temperature, acoustic, and strain measurements for monitoring fracture behaviors and includes advantages and limitations of each measurement, giving engineers a better understanding of measurements applied in all types of subsurface formations. Stress/strain rate responses on rock deformation are given a holistic approach, including guidelines and an automatic algorithm for identification of fracture hits. Last, a novel inversion model is introduced to show how fracture geometry can be used for optimization on well placement decisions. Supported by case studies, Hydraulic Fracture Geometry Characterization from Fiber Optic-Based Strain Measurements gives today’s engineers better understanding of all complex subsurface measurements through fiber optic technology. Examine the basics of distributed fiber optic strain measurements Conduct a detailed analysis of strain responses observed in both horizontal and vertical monitoring wells Present a systematic approach for interpreting strain data measured in the field Highlight the significant insights and values that can be derived from the field measured strain dataset Support monitoring and modeling for subsurface energy extraction and safe storage

Author : Don Bruce Fox
Publisher :
Page : 324 pages
File Size : 50,95 MB
Release : 2016
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Enhanced/Engineered Geothermal Systems (EGS) have the potential to provide a significant amount of base load electricity and heat and to displace fossil fuel consumption globally. To determine the potential for the expansion of direct use geothermal energy, a detailed analysis of U.S. energy consumption was performed to estimate the amount of primary energy consumed as a function of its utilization temperature from 0 to 260? C. The analysis revealed that about 34 EJ annually, more than 30% of the U.S. annual energy demand is used for direct thermal use applications in the temperature range of 0 to 260? C. Both analytical and numerical models of discretely fractured reservoirs were developed to probe the thermal hydraulic behavior of model EGS reservoirs and quantify factors controlling performance. An analytical model for discrete, fixed aperture, rectangular fractures with specified uniform flow was used to illustrate the renew ability of EGS reservoirs with a ratio of production to renewal times of about 0.2 to 0.33. Fracture structure and connectivity were also shown to affect reservoir performance in modeling studies. In general, fracture connectivity is more important than aperture variations within the fractures. Flow channeling in fractures with spatially varying aperture fields were simulated using a developed numerical model. An ensemble of fracture realizations were used to illustrate how the magnitude of aperture variations lead to flow structures that often inhibit rather than enhance subsurface heat exchange. Finally, both conservative and reactive tracers were used to determine the spatially varying thermal field during heat extraction in a discrete fracture with variable aperture. Reduced order modeling of the fracture was used to create a tractable framework for inferring reservoir structure. Tracers revealed the capability to predict a reservoir's production temperature versus time, with reactive tracers providing better results. However, difficulties in accurately predicting the aperture field led to a non-unique outcome where more than one reservoir realization matched both the tracer curve and production temperature.

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Page : pages
File Size : 38,46 MB
Release : 2011
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The connectivity and accessible surface area of flowing fractures, whether natural or man-made, is possibly the single most important factor, after temperature, which determines the feasibility of an Enhanced Geothermal System (EGS). Rock deformation and in-situ stress changes induced by injected fluids can lead to shear failure on preexisting fractures which can generate microseismic events, and also enhance the permeability and accessible surface area of the geothermal formation. Hence, the ability to accurately model the coupled thermal-hydrologic-mechanical (THM) processes in fractured geological formations is critical in effective EGS reservoir development and management strategies. The locations of the microseismic events can serve as indicators of the zones of enhanced permeability, thus providing vital information for verification of the coupled THM models. We will describe a general purpose computational code, FEHM, developed for this purpose, that models coupled THM processes during multiphase fluid flow and transport in fractured porous media. The code incorporates several models of fracture aperture and stress behavior combined with permeability relationships. We provide field scale examples of applications to geothermal systems to demonstrate the utility of the method.