• Permeability is a key parameter that affects fluids flow in reservoir and its accurate determination is a significant task. (civilejournal.org)
  • For these reasons applying well logging data in order to obtaining petrophysical properties of oil reservoir such as permeability and porosity is common. (civilejournal.org)
  • Neural network prediction of porosity and permeability of heterogeneous gas sand reservoirs using NMR and conventional logs. (civilejournal.org)
  • An intelligence approach for porosity and permeability prediction of oil reservoirs using seismic data. (civilejournal.org)
  • Hybrid computational intelligence models for porosity and permeability prediction of petroleum reservoirs. (civilejournal.org)
  • Permeability, porosity and sedimentary facies are the main factors of reservoir characteristics. (ac.ir)
  • The prior model represents one's prior knowledge of the prior mean and uncertainties of the reservoir parameters (such as permeability, porosity, distance to the fault, etc. (itu.edu.tr)
  • Hydrocarbon production from tight oil and/or shale plays requires drilling horizontal wells with very long laterals and hydraulic fracturing operations to stimulate the reservoirs which have generally very low porosity and permeability. (und.edu)
  • Electrofacies classification is essential to improve permeability-porosity relationships in non-cored intervals. (onepetro.org)
  • The FZI attains reservoir quality evaluation through hydraulic flow unit and kozeny-carman equation, which correlates between permeability, porosity, pore throat, pore geometry and tortuosity factor. (onepetro.org)
  • Finally, electrofacies identification through the FZI technique has similar ranges of FZI values with specific porosity and permeability values. (onepetro.org)
  • As the invasion fluid front gets deeper into the reservoir, the neutron and density porosity measurements approach the true porosity. (wikipedia.org)
  • The estimation of the shale volume in the zone of interest can be performed in the available wells using the normalized version of the Gamma-Ray log ( GRn ), and using both neutron and density porosity logs. (seg.org)
  • However, in the case of a reservoir where there is gas instead of water or oil in the pore space, the two porosity logs separate, to form what is referred to as gas crossover. (wikipedia.org)
  • In this research, the support vector machine (SVM) method has been used as the main method for regression and estimation of the reservoir porosity in one of the hydrocarbon reservoirs. (ac.ir)
  • The best way to get accurate values of physical properties of reservoir is to measure them directly in the laboratory. (ac.ir)
  • Shear wave velocity associated with compressional wave velocity can provide accurate results for geophysical study of a reservoir. (ijgeophysics.ir)
  • Reservoir characterization based on observed static data normally poses a linear estimation problem, whereas reservoir characterization based on observed dynamic data poses a nonlinear estimation problem. (itu.edu.tr)
  • As the observed (static and/or dynamic) data alone are usually not sufficient to determine a well-defined reservoir model, it is always useful to incorporate a prior model for the parameters to be estimated from observed data by linear or nonlinear estimation methods. (itu.edu.tr)
  • The k-mean clustering analysis was the most accurate method where each predicted electrofacies reflects the same vertical distribution of the lithofacies in the reservoir. (onepetro.org)
  • As a result of viewing the entire domain at once, our model is able to perform accurate prediction on domains exhibiting a large degree of heterogeneity. (springer.com)
  • The accurate prediction of the transaction volume of the core accounting system is of great significance to the stable operation of commercial banks. (hindawi.com)
  • Therefore, the research on the accurate prediction of system transaction volume is of great significance in reducing the redundancy of commercial bank systems [ 3 ]. (hindawi.com)
  • By properly combining the two erroneous answers from density and neutron logging, it is possible to arrive at a more accurate porosity than would be possible by interpreting each of the measurements separately. (wikipedia.org)
  • A popular method of obtaining a formation porosity estimate is based on the simultaneous use of neutron and density logs. (wikipedia.org)
  • Under these conditions, the true formation porosity lies between the measured neutron and density values. (wikipedia.org)
  • Under these conditions, a lower number of electrons is equivalent to a lower formation density, or a higher formation porosity. (wikipedia.org)
  • The increase in the amount of water in the near formation, i.e., the increase in the number of electrons, is interpreted by the density tool algorithm as a higher density which translates into a lower porosity estimate. (wikipedia.org)
  • A main complication in deriving an accurate porosity in the presence of shallow invasion comes from the fact that the neutron and density logging devices typically have different DOIs. (wikipedia.org)
  • It is well known that the 50% DOI of the thermal neutron porosity tool is 6 to 12 inches (15 to 30 centimetres) depending upon the porosity and gas saturation of the formation and the 50% DOI of the density tool is about 2 to 3 inches (5 to 8 centimetres). (wikipedia.org)
  • Support vector density estimation. (civilejournal.org)
  • All regression models presented coefficients of determination 'R 2 ' greater than 50%, where f M , f H,90 and W were best estimated by density apparent, E M and f H,0 were better estimated considering apparent density and porosity. (scielo.org)
  • BACKGROUND: Assessment of cortical bone porosity and geometry by imaging in vivo can provide useful information about bone quality that is independent of bone mineral density (BMD). (galileo-training.com)
  • Natural sediment flocs are fragile and highly heterogeneous aggregates of biogenic and minerogenic material typically with high porosity and low density. (cumbria.ac.uk)
  • Mathematical models that predict the behaviour of flocs rely on the accurate assessments of the size, shape, density, porosity and fractal dimension of flocs. (cumbria.ac.uk)
  • From left to right, total GR, the corrected GR for uranium and its normalized readings (thick black curve), neutron porosity and density, density porosity and the comparison between the estimated shale volumes (Vsh Grn , Vsh NPHI , Vsh PHI ). (seg.org)
  • Since the high-density porosity reading in the shales is due primarily to organic matter rather than porosity, values of shale volume in these two members are considered underestimated. (seg.org)
  • Another method for estimating the shale volume uses both the density and neutron porosity logs. (seg.org)
  • Where, Vsh PHI = Vshale from porosity logs, NPHI = neutron log reading in zone of interest, PHID = density log porosity reading in zone of interest, NPHIsh = Neutron log reading in 100% shale, PHIDsh = apparent density porosity in shale. (seg.org)
  • measure four masses at four static pressures to deduce the open porosity and the mass density of a porous material using the perfect gas law. (matelys.com)
  • Under normal logging conditions, the porosity estimates obtained from these tools agree, when plotted on an appropriate lithology and fluid scale. (wikipedia.org)
  • Do the LMR estimates from my 3D properly estimate porosity, lithology, or frac-ability? (csegrecorder.com)
  • The velocity ratio (Vp/Vs) usually depends on porosity, degree of consolidation, pore geometry and other factors. (ijgeophysics.ir)
  • The results confirm that the appropriate modelling of the fracture geometry plays a critical role in the estimation of the incremental oil recovery. (nature.com)
  • Automated, calibration-free quantification of cortical bone porosity and geometry in postmenopausal osteoporosis from ultrashort echo time MRI and deep learning. (galileo-training.com)
  • Semi-analytical models that rely on averaged structural properties (i.e., porosity and tortuosity) have been proposed, but these features only partly summarize the domain, resulting in limited applicability. (springer.com)
  • This method allows the simultaneous estimation of the high frequency limit of the dynamic tortuosity . (matelys.com)
  • While the surface tortuosity has no physical meaning, it can be noticed that this method could provide the opportunity to measure the surface porosity of a material designed with a skin effect without separating the skin from the core. (matelys.com)
  • Porosity and water saturations are the most important petrophysical parameters of hydrocarbon reservoirs that accurate assessment of them in hydrocarbon reservoirs is an effective tool, important and efficient for industry experts, in the context of a comprehensive study of reservoirs and production and management process of reservoir. (scirp.org)
  • The process of estimating the true porosity in the gas region relies on the appropriate use of the two porosity logs. (wikipedia.org)
  • The rate at which the two porosity logs approach the true porosity depends upon their radial sensitivities and their respective depths of investigations (DOI). (wikipedia.org)
  • In this paper, clustering analysis and flow zone indicator were adopted for the electrofacies characterization on a dataset obtained from incorporate of conventional core analysis and CPI logs (Effective Porosity, Water saturation and Shale volume) of three wells in the upper shale member/Zubair formation in Luhais oil field southern Iraq. (onepetro.org)
  • In this study, using data from five wells of Mansuri oil field, and using the sequential simulation Gaussian method and using Petrel software, the trend of Porosity and water saturation changes in the mentioned field for four zones was simulated. (scirp.org)
  • Also the average maps for each zone have been created that results of the simulation parameters in this map showed that highest average porosity is 0.1401 and 0.2756 at least saturation of water is related to zone 1. (scirp.org)
  • Given the neutron porosity log and the densities of clay (2.68 g/cc) and shale (2.35 g/cc), the volume fraction of shale ( Vsh NPHI ) can be calculated via determination of the clay-bound water by setting values representative of clean sand and pure shale that correspond to the maximum and minimum value of the neutron porosity log, respectively. (seg.org)
  • A model that could give fast and accurate approximations of a given petrophysical property is of great interest. (springer.com)
  • Pulsed thermography is advantageous because it is a non-contacting, nondestructive and fast photothermal testing method that allows the estimation of material parameters. (uni-linz.ac.at)
  • Estimation of all 6 parameters of Johnson-Champoux-Allard-Lafarge model for acoustical porous materials from impedance tube measurements , J. Acoust. (matelys.com)
  • Log interpreters often find it difficult to accurately estimate the true formation porosity from these two curves. (wikipedia.org)
  • Consequently, when a gas-filled formation is logged, which has a lower number of hydrogen atoms than a water-filled formation of the same porosity, the porosity estimate will be lower than the true porosity. (wikipedia.org)
  • Therefore, logging a gas-filled formation, results in a porosity estimate that is higher than the true porosity. (wikipedia.org)
  • Currently, no standard method exists to estimate the open porosity (abusevely shorten to porosity) $\phi$ for acoustical materials. (matelys.com)
  • Schemes of the 3 steps to estimate the porosity from Archimedes' principle using water as the saturating fluid. (matelys.com)
  • have developed a method to estimate the surface porosity of a material sample from the measurement, at ultrasound frequencies, of the reflection coefficients for two oblique incidences. (matelys.com)
  • Salissou Y., Panneton R., Pressure/mass method to measure open porosity of porous solids , J. Appl. (matelys.com)
  • Y. Agari and T. Uno, "Estimation on thermal conductivities of filled polymers," J. Appl. (scirp.org)
  • The categorical scores and transition analysis ages were subjected to multinomial logistic regression and decision tree analysis to derive accurate age interval estimates. (elsevierpure.com)
  • During the calibration process, water-filled formations are used to develop porosity algorithms, and under these conditions, a lower number of hydrogen atoms is equivalent to a lower porosity. (wikipedia.org)
  • Gas porosity is the fraction of a rock or sediment filled with a gas. (wikipedia.org)
  • Our study has significant implications for estimations of sediment flux at local to global scales within in aquatic environments. (cumbria.ac.uk)
  • So far, many approaches including linear / nonlinear regressions have been developed to predict porosity. (ac.ir)
  • Furthermore, the linear or nonlinear estimation problems can be classified as the underdetermined and overdetermined problems. (itu.edu.tr)
  • The geophysical methods, both airborne and land-based, are invaluable toosl when pinpointing the secondary porosity and drilling locations. (gtk.fi)
  • The geophysical methods gives 2D data in most cases, which can be interpreted in pseudo-3D or 2,5D to give an relatively accurate information in the resolution of the study of the areas where the hydraulic properties of the bedrock are such, that they can affect the environment or mine water management. (gtk.fi)
  • This model-based approach for porosity estimation delivers more accurate results for transmission and reflection configuration measurements compared to thermographic state-of-the-artmethods. (uni-linz.ac.at)
  • The results are validated by X-ray computed tomography reference measurements on a wide range of different porous carbon fiber reinforced plastic specimens with different number of plies and varying porosity contents. (uni-linz.ac.at)
  • This may be due to their low soil porosity, which results in more soil water drainage, as opposed to the case that winter crop roots help maintain SM. (ametsoc.org)
  • This quantity can be obtained via direct flow simulation, which provides the most accurate results, but is very computationally expensive. (springer.com)
  • The larger the samples the more accurate will be the results. (matelys.com)
  • With one click, you can include the results of a porosity analysis to simulate stress concentrations around defects. (volumegraphics.com)
  • Calculates stress concentration around microdefects by including the results of a porosity analysis run using any algorithm in VGSTUDIO MAX with one click. (volumegraphics.com)
  • The minerals' volume fractions from core XRD data and elemental capture spectroscopy (ECS) log data were used for estimation of rock stiffness and velocities. (und.edu)
  • Printed bone scaffolds with complex structures produced using additive manufacturing technology can mimic the mechanical properties of natural human bone, providing lightweight structures with modifiable porosity levels. (mdpi.com)
  • The primary effective porosity of such bedrock is low and the water flow is channeled in secondary structures such as joints, fissures and fractures which have higher hydraulic conductivity than in unfractured bedrock. (gtk.fi)
  • Like in hydraulic properties the scale of the secondary porosity structures vary from single fractures to fracture zones and major fault systems. (gtk.fi)
  • Geologists can predict subsurface geologic properties such as mineral concentrations and porosity. (arcgis.com)
  • The signal-to-noise ratio for the measurement of the dynamic bulk modulus is the main source of uncertainties when using these estimations given that one asymptote is visible in the frequency range of the measurement. (matelys.com)
  • K. Misra, A. K Shrotriya, R. Singh and D. R. Chaudhary, "Porosity correction for thermal conduction in real two-phase systems," J. Phys. (scirp.org)
  • V.V. Calmidi and R. L Mahajan, "The effective thermal conductivity of high porosity fibrous metal foam," ASME J. Heat Transfer, 121, 1999, 466-471. (scirp.org)
  • W. Pabst and E. Gregorova, "A new percolation-threshold relation for the porosity dependence of thermal conductivity," Ceramics International, 32, 2006, 89-91. (scirp.org)
  • Porosity is an unavoidable defect in carbon fiber reinforced polymers and has noticeable effects on mechanical properties since gas filled voids weaken the epoxy matrix. (uni-linz.ac.at)
  • Least Squares Estimation- Large-Sample Properties Ping Yu School of Economics and Finance The University of Hong Kong Ping Yu (HKU) Large-Sample 1 / 63. (everyconcertever.com)
  • Overall, it was observed that, the UB and LB shales, due to the presence of clay minerals, show lower properties than the MB and composed mainly of microfracture porosity. (und.edu)
  • abstract = "The os pubis is one of the most widely used areas of the skeleton for age estimation. (elsevierpure.com)
  • Champoux Y., Stinson M. R., Daigle G. A., Air-based system for the measurement of porosity , J. Acoust. (matelys.com)
  • Stretching the elevation values in this way allows accurate estimation of the semivariogram, and it allows the search neighborhood to find appropriate neighbors and assign correct weights. (arcgis.com)
  • One challenge of the estimation of the recovery is to properly model complex hydraulic fracture geometries which are often assumed to be planar due to the limitation of local grid refinement approach. (nature.com)
  • Collectively, their use allowed for accurate curve fitting to the lab data, by changing the pore's aspect ratios. (und.edu)
  • The vertebrae display clear sex discrepancy and have proven accurate in conventional morphometric sex estimation. (galileo-training.com)
  • Deep learning in sex estimation from a peripheral quantitative computed tomography scan of the fourth lumbar vertebra-a proof-of-concept study. (galileo-training.com)
  • In this work, a comparative study of statistical and machine learning methods used for MMP estimation is carried out. (deepai.org)
  • When studying the transport of water and potentially harmful substances or e.g. mine water management in hard rock bedrock the three dimensional locations of secondary porosity is the key to succesful study. (gtk.fi)
  • When the invasion front is greater than 12 inches (30 cm), both tools see only water-filled formations and the two porosity estimates agree and read true porosity. (wikipedia.org)
  • Accurate quality monitoring represents a challenging task, due to the different nature of the pollutants that can contaminate water, often in low concentrations. (springer.com)
  • In addition, although microdialysis is traditionally defined as a diffusion-limited process, it is shown in this work that under combinations of high perfused solution flow rate in the probe, high membrane porosity, and large membrane pore diameter, the influence of convective flux on the recovery of microdialysis sampling would be significant. (usm.my)
  • After the validation of the method for heterogeneous materials, effective medium theories can be used for quantitative porosity estimation from the estimated diffusion time. (uni-linz.ac.at)
  • Validation of the flow chart on a sample of 47 individuals provided by the Montana State Crime Lab yielded 94% accuracy overall, indicating that the method has the potential to deliver precise and accurate age estimates of individuals prior to the onset of advanced degenerative changes. (elsevierpure.com)
  • The main objective of this research work is to develop finite element mathematical models that could provide accurate simulations of concentration and fluid flow profiles for microdialysis. (usm.my)
  • However, the MARS model was marginally more accurate than the GEP and GMDH models. (researchgate.net)
  • It is a positive number that is multiplied to the Elevation field value prior to subsetting and model estimation. (arcgis.com)
  • Porosity indicates the ability of a rock to store fluids. (ac.ir)
  • Barton, 2007) can be applied in the estimation of rock quality when using 3-component equipment. (gtk.fi)
  • By measuring the pressure increase it's possible to determine the open porosity of the material. (matelys.com)
  • Knowing the volume of gas required to saturate the porous material we deduce its open porosity. (matelys.com)
  • Uses the sub-voxel accurate, local adaptive surface determination in VGSTUDIO MAX. (volumegraphics.com)
  • Despite its importance, accurate estimation of large-scale SM remains a challenge. (ametsoc.org)
  • Remote state estimation of large-scale distributed dynamic processes pla. (deepai.org)
  • Although there are already several mathematical modelling works on microdialysis, those works would focus only on providing accurate estimations of the recovery, while other features such as fluid flows are neglected. (usm.my)
  • If no elevation inflation factor is provided, a value will be estimated at run time using maximum likelihood estimation, and the value will be printed as a geoprocessing message. (arcgis.com)