scholarly journals Benchmark study using a multi-scale, multi-methodological approach for the petrophysical characterization of reservoir sandstones

2020 ◽  
Author(s):  
Peleg Haruzi ◽  
Regina Katsman ◽  
Matthias Halisch ◽  
Nicolas Waldmann ◽  
Baruch Spiro
Keyword(s):  
Methodological Approach ◽  
Middle Layer ◽  
Micro Ct ◽  
Pore Scale ◽  
Geological Interpretation ◽  
Quartz Arenite ◽  
Scale Modelling ◽  
Porosity And Permeability ◽  
Reservoir Sandstones

Abstract. This paper presents a detailed description and evaluation of a multi-methodological petrophysical approach for the comprehensive multiscale characterization of reservoir sandstones. The suggested methodology enables the identification of Darcy-scale permeability links to an extensive set of geometrical, textural and topological rock descriptors quantified at the pore scale. This approach is applied to the study of samples from three consecutive sandstone layers of Lower Cretaceous age in northern Israel. These layers differ in features observed at the outcrop, hand specimen, petrographic microscope and micro-CT scales. Specifically, laboratory porosity and permeability measurements of several centimetre-sized samples show low variability in the quartz arenite (top and bottom) layers but high variability in the quartz wacke (middle) layer. The magnitudes of this variability are also confirmed by representative volume sizes and by statistical anisotropy analyses conducted on micro-CT-imaged 3D pore geometries. Two scales of porosity variability are revealed by applying variogram analysis to the top layer: fluctuations at 150 μm are due to variability in the pore size, and those at 2 mm are due to the occurrence of high- and low-porosity bands occluded by iron oxide cementation. This millimetre-scale variability is found to control the laboratory-measured macroscopic rock permeability. Good agreement between the permeability upscaled from the pore-scale modelling and the estimates based on laboratory measurements is shown for the quartz arenite (top) layer. The proposed multi-methodological approach leads to an accurate petrophysical characterization of reservoir sandstones with broad ranges of textural, topological and mineralogical characteristics and is particularly applicable for describing anisotropy at various rock scales. The results of this study also contribute to the geological interpretation of the studied stratigraphic units.

scholarly journals Benchmark study using a multi-scale, multi-methodological approach for the petrophysical characterization of reservoir sandstones

Solid Earth ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 665-689
Author(s):  
Peleg Haruzi ◽  
Regina Katsman ◽  
Matthias Halisch ◽  
Nicolas Waldmann ◽  
Baruch Spiro
Keyword(s):  
Pore Size ◽  
Methodological Approach ◽  
Vertical Direction ◽  
Micro Ct ◽  
Pore Scale ◽  
Multi Scale ◽  
Depositional Processes ◽  
Quartz Arenite ◽  
Reservoir Sandstones

Abstract. This paper presents a detailed description and evaluation of a multi-methodological petrophysical approach for the comprehensive multi-scale characterization of reservoir sandstones. The suggested methodology enables the identification of links between Darcy-scale permeability and an extensive set of geometrical, textural and topological rock descriptors quantified at the pore scale. This approach is applied to the study of samples from three consecutive sandstone layers of Lower Cretaceous age in northern Israel. These layers differ in features observed at the outcrop, hand specimen, petrographic microscope and micro-CT scales. Specifically, laboratory porosity and permeability measurements of several centimetre-sized samples show low variability in the quartz arenite (top and bottom) layers but high variability in the quartz wacke (middle) layer. The magnitudes of this variability are also confirmed by representative volume sizes and by anisotropy evaluations conducted on micro-CT-imaged 3-D pore geometries. Two scales of directional porosity variability are revealed in quartz arenite sandstone of the top layer: the pore size scale of ∼0.1 mm in all directions and ∼3.5 mm scale related to the occurrence of high- and low-porosity horizontal bands occluded by Fe oxide cementation. This millimetre-scale variability controls the laboratory-measured macroscopic rock permeability. More heterogeneous pore structures were revealed in the quartz wacke sandstone of the intermediate layer, which shows high inverse correlation between porosity and clay matrix in the vertical direction attributed to depositional processes and comprises an internal spatial irregularity. Quartz arenite sandstone of the bottom layer is homogenous and isotropic in the investigated domain, revealing porosity variability at a ∼0.1 mm scale, which is associated with the average pore size. Good agreement between the permeability upscaled from the pore-scale modelling and the estimates based on laboratory measurements is shown for the quartz arenite layers. The proposed multi-methodological approach leads to an accurate petrophysical characterization of reservoir sandstones with broad ranges of textural, topological and mineralogical characteristics and is particularly applicable for describing anisotropy and heterogeneity of sandstones on various rock scales. The results of this study also contribute to the geological interpretation of the studied stratigraphic units.

Pore-scale characterization of tight sandstone in Yanchang Formation Ordos Basin China using micro-CT and SEM imaging from nm- to cm-scale

Fuel ◽  
2017 ◽  
Vol 209 ◽  
pp. 254-264 ◽  
Author(s):  
Xuefeng Liu ◽  
Jianfu Wang ◽  
Lin Ge ◽  
Falong Hu ◽  
Chaoliu Li ◽  
...  
Keyword(s):  
Ordos Basin ◽  
Micro Ct ◽  
Pore Scale ◽  
Tight Sandstone ◽  
Yanchang Formation ◽  
Sem Imaging ◽  
Scale Characterization

Pore-scale modelling of NMR relaxation for the characterization of wettability

2006 ◽  
Vol 52 (1-4) ◽  
pp. 172-186 ◽  
Author(s):  
S.H. Al-Mahrooqi ◽  
C.A. Grattoni ◽  
A.H. Muggeridge ◽  
R.W. Zimmerman ◽  
X.D. Jing
Keyword(s):  
Nmr Relaxation ◽  
Pore Scale ◽  
Scale Modelling

Microfluidics Underground: A Micro-Core Method for Pore Scale Analysis of Supercritical CO2 Reactive Transport in Saline Aquifers

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Phong Nguyen ◽  
Hossein Fadaei ◽  
David Sinton
Keyword(s):  
Carbon Sequestration ◽  
Chemical Analysis ◽  
Supercritical Co2 ◽  
Small Sample ◽  
Co2 Injection ◽  
Micro Ct ◽  
Pore Scale ◽  
Core Method ◽  
Porosity And Permeability ◽  
Supercritical Co2 Injection

Carbon sequestration in microporous geological formations is an emerging strategy for mitigating CO2 emissions from fossil fuel consumption. Injection of CO2 in carbonate reservoirs can change the porosity and permeability of the reservoir regions, along the CO2 plume migration path, due to CO2-brine-rock interactions. Carbon sequestration is effectively a microfluidic process over large scales, and can readily benefit from microfluidic tools and analysis methods. In this study, a micro-core method was developed to investigate the effect of CO2 saturated brine and supercritical CO2 injection, under reservoir temperature and pressure conditions of 8.4 MPa and 40 °C, on the microstructure of limestone core samples. Specifically, carbonate dissolution results in pore structure, porosity, and permeability changes. These changes were measured by X-ray microtomography (micro-CT), liquid permeability measurements, and chemical analysis. Chemical composition of the produced liquid analyzed by inductively coupled plasma-atomic emission spectrometer (ICP-AES) shows concentrations of magnesium and calcium in the produced liquid. Chemical analysis results are consistent with the micro-CT imaging and permeability measurements which all show high dissolution for CO2 saturated brine injection and very minor dissolution under supercritical CO2 injection. This work leverages established advantages of microfluidics in the new context of core-sample analysis, providing a simple core sealing method, small sample size, small volumes of injection fluids, fast characterization times, and pore scale resolution.

scholarly journals Petrographic and Petrophysical Characteristics of Lower Cretaceous Sandstones from northern Israel, determined by micro-CT imaging and analytical techniques

2019 ◽  
Author(s):  
Peleg Haruzi ◽  
Regina Katsman ◽  
Baruch Spiro ◽  
Matthias Halisch ◽  
Nicolas Waldmann
Keyword(s):  
Surface Area ◽  
Lower Cretaceous ◽  
Large Scale ◽  
Bottom Layer ◽  
Ct Imaging ◽  
Micro Ct ◽  
Pore Scale ◽  
Pore Throat ◽  
Quartz Arenite ◽  
Macro Scale

Abstract. In this study petrophysical characteristics of three consecutive sandstone layers of the Lower Cretaceous Hatira Formation from northern Israel were comprehensively investigated and analysed. The methods used were: experimental petrographic and petrophysical methods, 3D micro-CT imaging and pore-scale single-phase flow modelling, conducted in parallel. All three studied sandstone layers show features indicative of high textural and mineralogical maturity in agreement with those reported from the Kurnub Group in other localities in the Levant. The occurrence of cross-bedding in layers enriched in silt and clay, between the quartz arenite rich beds, may suggest a deposition in a fluvial environment. A higher degree of Fe-ox cementation was observed in the top layer contrasting with a low extent of Fe-ox cementation in the bottom layer. Both quartz-arenite layers are located above and below the intermediate 20 cm thick least permeable quartz wacke sandstone layer. The latter presumably prevented the supply of the iron-rich meteoric water to the bottom layer. Evaluated micro-scale geometrical rocks properties (pore size distribution, pore throat size, characteristic (pore-throat) length, pore throat length of maximal conductance, specific surface area, grain roughness) and macro-scale petrophysical properties (porosity and tortuosity) predetermined the permeability of the studied layers. Large-scale laboratory porosity and permeability measurements show low variability in the quartz arenite (top and bottom) layers, and high variability in the quartz wacke (intermediate) layer. These degrees of variability are confirmed also by anisotropy and homogeneity analyses conducted in the μCT-imaged geometry. Qualitative evaluation of anisotropy (based on statistical distribution of pore space) and connectivity (using Euler Characteristic) were correlated with mineralogy and grain surface characteristics, clay matrix and preferential location of cementation. Two scales of porosity variations were found with variogram analysis of the upper quartz arenite layer: fluctuations at 300 μm scale due to pores size variability, and at 2 mm scale due to the appearance of high and low porosity occlusion by ferruginous bands showing iron oxide cementation. We suggest that this cementation is a result of iron solutes transported by infiltrating water through preferential permeable paths in zones having large grains and pores. Fe-ox precipitated as a result of reaction with oxygen in a partly-saturating realm at the large surface area localities adjacent to the preferential conducting paths. The core part of the study is the investigation of macroscopic permeability, upscaled from pore-scale velocity field, simulated by free-flow in real μCT-scanned geometry on mm-scale sample. The results show an agreement with lab petrophysical estimates on cm-scale sample for the top and bottom layers. Estimated permeability anisotropy correlates with the presence of beddings with 2 mm scale variability in the top layer. The results show that this kind of anisotropy rather than a variability at the pore-scale controls the macroscopic rock permeability. Therefore, we suggest that in order to upscale reliably to the lab permeability, a sufficiently large modelling domain is required to capture the textural features that appear at a scale larger than the pore scale. We also discuss imaging and modelling practices able to preserve the characteristics of the pore network during the entire computational workflow procedure, applicable to studies in the fields of hydrology, petroleum geology, or sedimentary ore deposits.

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