The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019)最新文献

Comparison of RTM results of Time-lapse imaging in Foam-assisted EOR 泡沫辅助提高采收率时移成像RTM结果比较

The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019) Pub Date : 2019-05-26 DOI: 10.3997/2352-8265.20140241

R. Tamura, H. Mikada, J. Takekawa

{"title":"Comparison of RTM results of Time-lapse imaging in Foam-assisted EOR","authors":"R. Tamura, H. Mikada, J. Takekawa","doi":"10.3997/2352-8265.20140241","DOIUrl":"https://doi.org/10.3997/2352-8265.20140241","url":null,"abstract":"Due to the oil demand staying high in the world, the technology of enhanced oil recovery (EOR) plays an important role to optimize the oil production from the existing reservoirs. Among the EOR methods, foam-assisted EOR, i.e., one of the chemical methods, has drawn attention for its enhancement in the sweep efficiency and in the incremental oil recovery. Although the mechanisms of the foam-assisted EOR have been revealed both in microscopic and macroscopic ways, methods for monitoring the movement or the alteration of pore fluids in the reservoir have not been fully established yet. Since the behavior of seismic waves reflects the change in the pore fluids where seismic wave propagates, we hypothesized that seismic methods could capture the movement of pore fluids in the reservoir. For testing this hypothesis, we conducted numerical experiments on the time-lapse monitoring of a reservoir before and after the application of foam-assisted EOR using reverse time migration (RTM) in our previous study. Our numerical results indicated that we could detect the advancement of injected fluids by RTM and showed the effectiveness of seismic exploration methods. However, in our previous study, we only utilized the vertical component of recorded data for RTM imaging and the effect of the recorded component (vertical and horizontal) on the imaging has not been fully investigated. Therefore, in this study, we conduct numerical experiments to confirm how the difference in the component of recorded data used in RTM procedure affects the resultant subsurface image. From obtained results, it is indicated that the integration of analyses of RTM results obtained from two components would help the interpretation of the results.","PeriodicalId":394545,"journal":{"name":"The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128716951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The relation between permeability and grain size distribution 渗透率与粒度分布的关系

The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019) Pub Date : 2019-05-26 DOI: 10.3997/2352-8265.20140242

R. Masumura, H. Mikada, J. Takekawa

{"title":"The relation between permeability and grain size distribution","authors":"R. Masumura, H. Mikada, J. Takekawa","doi":"10.3997/2352-8265.20140242","DOIUrl":"https://doi.org/10.3997/2352-8265.20140242","url":null,"abstract":"Interstitial fluid flow in reservoir rocks for oil, gas, and unconventional resources has a great influence to the production efficiency. In the present study, we simulate fluid flow in reservoir rocks and analyze the relationship between the permeability and the grain size distribution. We used a smoothed particle hydrodynamics (SPH) method, which is one of the particles methods, to simulate fluid flow in reservoir rocks. It is known that the grain size distribution of reservoir rocks obeys the Weibull distribution in many cases. The probability density function of the Weibull distribution is determined by the shape parameter and the mean value. We modeled plural three-dimensional digital specimens of poroelastic medium composed of matrix and pore space. The grain size distribution of the specimens has the Weibull distribution with different shape parameters. We estimated the permeability of each digital specimen using fluid flow simulations. The numerical results showed that the permeability of reservoir rocks is affected by the shape parameter and the mean value, i.e., two major parameter of the Weibull distribution. From this result, it is suggested that the permeability of reservoir rocks can be estimated from the shape parameter and the mean grain diameter of the grain size distribution, and the accuracy of the simulation of flow in reservoir rocks could be enhanced in the future.","PeriodicalId":394545,"journal":{"name":"The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127534344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Estimating the earthquake source mechanism using full waveform inversion 用全波形反演估计震源机制

The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019) Pub Date : 2019-05-26 DOI: 10.3997/2352-8265.20140243

Ik-Hee Jang

{"title":"Estimating the earthquake source mechanism using full waveform inversion","authors":"Ik-Hee Jang","doi":"10.3997/2352-8265.20140243","DOIUrl":"https://doi.org/10.3997/2352-8265.20140243","url":null,"abstract":"The system of earthquake and tsunami early warning system has been realized in some countries to step forward towards a practical use for disaster mitigation purposes. The success of early warning of geohazards depends on the accuracy and the promptness of information issued to the public at the occurrence of such geohazards. Earthquake source mechanism is one of the most indispensable data to be informed of as precisely as possible for disaster mitigation. The centroid-moment tensor (CMT) solution, that represents the stress tensor centered at the hypocenter at the occurrence moment, could be provided as an instantly available data for the focal mechanism of an earthquake, for example. It is, however, necessary to consider the location of a fault plane and the time sequence of fault propagation on the plane, which could not be directly estimated from the CMT solution because of the necessity of aftershock observation to identify the fault shapes and locations. We, therefore, try to deploy an approach using full waveform inversion scheme (FWI) to specify the shapes and locations of the fault system immediately without the aftershock observation that would cost several hours after the earthquake. As a first step in this study, we investigate the applicability of FWI evaluating three fault parameters (strike, dip, and rake) assuming a known source time function for a fault composed of a single segment. We conducted some numerical experiments in order to evaluate the effect of each parameter to the L2-norm error function which is often used in FWI. Our numerical results indicate that fault parameters can be estimated by FWI with sufficient accuracy.","PeriodicalId":394545,"journal":{"name":"The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115905285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Theoretical analysis of electromagnetic property estimation in the subsurface using dielectric relaxation in electromagnetic waves reflection 利用电磁波反射介质弛豫估计地下电磁特性的理论分析

The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019) Pub Date : 2019-05-26 DOI: 10.3997/2352-8265.20140240

K. Kimura, H. Mikada, J. Takekawa

引用次数: 0

Numerical description of flow channel in pipe conduits considering solid-fluid phase shift with Lattice Boltzmann Method 考虑固-液相移的管道流道的点阵玻尔兹曼方法数值描述

The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019) Pub Date : 2019-05-26 DOI: 10.3997/2352-8265.20140237

M. Iwata, H. Mikada, J. Takekawa

{"title":"Numerical description of flow channel in pipe conduits considering solid-fluid phase shift with Lattice Boltzmann Method","authors":"M. Iwata, H. Mikada, J. Takekawa","doi":"10.3997/2352-8265.20140237","DOIUrl":"https://doi.org/10.3997/2352-8265.20140237","url":null,"abstract":"For the optimization of power generation through the stable operation of geothermal power plant, it is significant to secure the flow channel in pipe conduits. The major barriers to this process include the scale formation and the pipe corrosion or erosion which would break down the pipe lines. Although it has been confirmed that both phenomena develop locally due to hydrodynamic effects, various simulations or experiments have not been conducted based on hydrodynamics and no unified method considering the influence of fluid flow has been established at present. In this research, we applied a prediction formula of silica deposition rate computed by particle analyses on an nm-µm scale and an empirical formula obtained from corrosion experiment taking shear stress into account to the lattice Boltzmann method. We described complicated shape of piping wall with gradual shift between solid and fluid cells using the proposed scheme. Our results are consistent with actual data and effectiveness and versatility of the lattice Boltzmann method are suggested.","PeriodicalId":394545,"journal":{"name":"The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019)","volume":"44 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120858230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

A fundamental study of proppant behavior in hydraulic fractures using particle based numerical simulations 基于颗粒的数值模拟对水力裂缝中支撑剂行为的基础研究

The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019) Pub Date : 2019-05-26 DOI: 10.3997/2352-8265.20140244

J. Takekawa, H. Mikada

{"title":"A fundamental study of proppant behavior in hydraulic fractures using particle based numerical simulations","authors":"J. Takekawa, H. Mikada","doi":"10.3997/2352-8265.20140244","DOIUrl":"https://doi.org/10.3997/2352-8265.20140244","url":null,"abstract":"Hydraulic fracturing technique has been widely used in the development of unconventional oil reservoirs or of enhanced geothermal systems. To prevent the induced fractures from closing, supporting materials (proppants) are pumped into the induced hydraulic fractures. The ultimate goal of hydraulic fracturing is to keep high conductive flow paths from the surrounding formation to the wellbore. In the past decade, some new techniques have been proposed to improve the fracture conductivity (e.g. surface modification agent). Among these techniques, making open channels throughout the induced fracture is one of the most effective options due to its drastic enhancement of conductivity, thereby production. In this technique, fluid with and without proppant is alternately pumped into the well. This treatment creates discontinuous proppant pillars in a hydraulic fracture, and then, the fracture conductivity could be improved significantly. However, proppant slurry behavior inside the fracture still remains poorly understood. In the present study, we applied a smoothed particle hydrodynamics (SPH) method to the fluid-solid interaction analysis in order to investigate proppant behavior inside the fracture. Our final goal is to establish analysis method for slurry behavior in hydraulic fractures. As a preliminary step toward the final goal, we simulate the Couette flow between coaxial cylinders to investigate the accuracy of the coupled simulation with the SPH method. We evaluate the L2-norm error as a function of the number of particles along the diameter of the inner cylinder. As a result, about 15 and 20 particles are required to achieve less than 15 % and 10 % error, respectively. Based on this result, at least 20 particles along the diameter of proppant grains should be used. In the future study, many effects (viscosity of fluid, grain shape, fracture roughness) on the efficiency of creating open channels will be investigated by using the proposed method.","PeriodicalId":394545,"journal":{"name":"The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125072177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fundamental study on hydraulic fracturing simulation with DEM under high pressure and high temperature condition 高压高温条件下基于DEM的水力压裂模拟基础研究

The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019) Pub Date : 2019-05-26 DOI: 10.3997/2352-8265.20140238

H. Ohtani, H. Mikada, J. Takekawa

{"title":"Fundamental study on hydraulic fracturing simulation with DEM under high pressure and high temperature condition","authors":"H. Ohtani, H. Mikada, J. Takekawa","doi":"10.3997/2352-8265.20140238","DOIUrl":"https://doi.org/10.3997/2352-8265.20140238","url":null,"abstract":"One of the most attractive topics in geothermal development is the realization of enhanced geothermal systems in ductile zones. Thermal energy extraction from hot dry rock may require hydraulic fracturing through rocks in ductile zones, where rocks are supposed to deform in a ductile way due to the high pressure and high temperature (HPHT) conditions. One of the key factors in its realization is, therefore, to understand mechanical behavior of ductile rocks and hydraulically created fractures under the HPHT conditions, which have not been well investigated in the past. Numerical simulations are widely accepted as the effective approach to understand the mechanism of hydraulic fracturing. Numerical studies taking cooling effects from injected fluid on hydraulic fracturing into consideration have been conducted. Though distinct element methods (DEM) are frequently used to understand brittle failure or ductile deformation mechanism of rock, hydraulic fracturing simulations including both ductile behaviors and cooling effects due to injected fluid in the HPHT environment has not been fully investigated yet. Since the mechanical response to the fluid injection shows drastic changes at the brittle-ductile transitional condition, incorporation of the transitional behavior of granite into DEM is an essential step. In this study, we demonstrated hydraulic fracturing simulations with degradation approaches for the bond properties in DEM, i.e. degradation model and bi-linear approximation model, to replicate semi-brittle or ductile behavior at the HPHT condition. The numerical simulation results showed that results from bi-linear approximation model, which is suitable for replicating ductile behavior of granite, were consistent with laboratory experiment results under the HPHT condition. We can observe the cooling of rock mass due to injected fluid, while a considerable interaction between solid and fluid cannot be observed due to the shortness of injection time.","PeriodicalId":394545,"journal":{"name":"The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125371667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluation of anisotropic parameters using virtual cross-dipole data with full waveform approach 利用全波形方法的虚拟交叉偶极子数据评价各向异性参数

The 23rd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2019) Pub Date : 2019-03-14 DOI: 10.3997/2352-8265.20140239

Yusuke Watanabe, H. Mikada, Junichi Takakawa

引用次数: 0