Petrophysical properties of greensand as predicted from NMR measurements

Hossain, Zakir; Grattoni, Carlos A.; Solymar, Mikael; Fabricius, Ida Lykke

doi:10.1144/1354-079309-038

Cited by 49 publications

(20 citation statements)

References 19 publications

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“…The krypton BET specific surfaces were used to approximate the NMR surface relaxivity ρ 2 according to equation , using the Halbach measurements [ Hossain et al ., ; Vincent et al ., ]:

\frac{true}{1} ≅ ρ_{2} * \frac{true}{S_{T}}

…”

Section: Methodsmentioning

confidence: 99%

Multiscale approach to (micro)porosity quantification in continental spring carbonate facies: Case study from the Cakmak quarry (Denizli, Turkey)

Boever

Foubert

Oligschlaeger

et al. 2016

Geochem Geophys Geosyst

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Carbonate spring deposits gained renewed interest as potential contributors to subsurface reservoirs and as continental archives of environmental changes. In contrast to their fabrics, petrophysical characteristics -and especially the importance of microporosity (< 1mm) -are less understood. This study presents the combination of advanced petrophysical and imaging techniques to investigate the pore network characteristics of three, common and widespread spring carbonate facies, as exposed in the Pleistocene Cakmak quarry (Denizli, Turkey): the extended Pond, the dipping crystalline Proximal Slope Facies and the draping Apron and Channel Facies deposits formed by encrustation of biological substrate. Integrating mercury injection capillary pressure, bulk and diffusion Nuclear Magnetic Resonance (NMR), NMR profiling and Brunauer-Emmett-Teller (BET) measurements with microscopy and micro-computer tomography (m-CT), shows that NMR T 2 distributions systematically display a single group of micro-sized pore bodies, making up between 6 and 33% of the pore space (average NMR T 2 cut-off value: 62 ms). Micropore bodies are systematically located within cloudy crystal cores of granular and dendritic crystal textures in all facies. The investigated properties therefore do not reveal differences in micropore size or shape with respect to more or less biology-associated facies. The pore network of the travertine facies is distinctive in terms of (i) the percentage of microporosity, (ii) the connectivity of micropores with meso-to macropores, and (ii) the degree of heterogeneity at micro-and macroscale. Results show that an approach involving different NMR experiments provided the most complete view on the 3-D pore network especially when microporosity and connectivity are of interest.

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“…The krypton BET specific surfaces were used to approximate the NMR surface relaxivity ρ 2 according to equation , using the Halbach measurements [ Hossain et al ., ; Vincent et al ., ]:

\frac{true}{1} ≅ ρ_{2} * \frac{true}{S_{T}}

…”

Section: Methodsmentioning

confidence: 99%

Multiscale approach to (micro)porosity quantification in continental spring carbonate facies: Case study from the Cakmak quarry (Denizli, Turkey)

Boever

Foubert

Oligschlaeger

et al. 2016

Geochem Geophys Geosyst

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“…Unlike the conventional rocks displaying consistent results in porosity and PSD among different fluid-penetration measurements [42], shales, however, tend to reveal significant discrepancies. For example, MICP porosity in Barnett shales exhibit~25-50% lower when compared to helium porosity values [43].…”

Section: Introductionmentioning

confidence: 80%

Comparative Porosity and Pore Structure Assessment in Shales: Measurement Techniques, Influencing Factors and Implications for Reservoir Characterization

Yuan

Rezaee

2019

Energies

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Porosity and pore size distribution (PSD) are essential petrophysical parameters controlling permeability and storage capacity in shale gas reservoirs. Various techniques to assess pore structure have been introduced; nevertheless, discrepancies and inconsistencies exist between each of them. This study compares the porosity and PSD in two different shale formations, i.e., the clay-rich Permian Carynginia Formation in the Perth Basin, Western Australia, and the clay-poor Monterey Formation in San Joaquin Basin, USA. Porosity and PSD have been interpreted based on nuclear magnetic resonance (NMR), low-pressure N2 gas adsorption (LP-N2-GA), mercury intrusion capillary pressure (MICP) and helium expansion porosimetry. The results highlight NMR with the advantage of detecting the full-scaled size of pores that are not accessible by MICP, and the ineffective/closed pores occupied by clay bound water (CBW) that are not approachable by other penetration techniques (e.g., helium expansion, low-pressure gas adsorption and MICP). The NMR porosity is largely discrepant with the helium porosity and the MICP porosity in clay-rich Carynginia shales, but a high consistency is displayed in clay-poor Monterey shales, implying the impact of clay contents on the distinction of shale pore structure interpretations between different measurements. Further, the CBW, which is calculated by subtracting the measured effective porosity from total porosity, presents a good linear correlation with the clay content (R2 = 0.76), implying that our correlated equation is adaptable to estimate the CBW in shale formations with the dominant clay type of illite.

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“…Paramagnetic ions increase the rate of relaxation of the hydrogen proton, consequently reducing T 2 values (Dodge et al 1995). Additionally, chlorite, muscovite and biotite have large surface area and elevated magnetic susceptibilities, leading to large magnetic field gradients and low T 2 values (Morriss et al 1997;Hossain et al 2011). Archimedes porosity (Table 1) increases moving from the white-channel (9.7-11.3%) to the sheet-like sandstone (15.9-17.6%) up to the red-channel sandstone (19.1-22.9%).…”

Section: Results: Petrophysical Analysismentioning

confidence: 99%

“…Differential pressures used for permeability tests ranged from 0.1 up to 30 kPa. NMR tests provided both total porosity and T 2 (transverse relaxation time) distribution (Hossain et al 2011;Megawati et al 2012). NMR measurements were made using a Resonance Instruments MARAN 2 spectrometer at ambient pressure and 34°C at a proton resonance frequency of 2.2 MHz.…”

Section: Methodsmentioning

confidence: 99%

Characterization of a fluvial aquifer at a range of depths and scales: the Triassic St Bees Sandstone Formation, Cumbria, UK

2017

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Fluvial sedimentary successions represent porous media that host groundwater and geothermal resources. Additionally, they overlie crystalline rocks hosting nuclear waste repositories in rift settings. The permeability characteristics of an arenaceous fluvial succession, the Triassic St Bees Sandstone Formation in England (UK), are described, from core-plug to well-test scale up to~1 km depth. Within such lithified successions, dissolution associated with the circulation of meteoric water results in increased permeability (K~10 −1 -10 0 m/day) to depths of at least 150 m below ground level (BGL) in aquifer systems that are subject to rapid groundwater circulation. Thus, contaminant transport is likely to occur at relatively high rates. In a deeper investigation (> 150 m depth), where the aquifer has not been subjected to rapid groundwater circulation, well-test-scale hydraulic conductivity is lower, decreasing from K~10 −2 m/day at 150-400 m BGL to 10 −3 m/day down-dip at~1 km BGL, where the pore fluid is hypersaline. Here, pore-scale permeability becomes progressively dominant with increasing lithostatic load. Notably, this work investigates a sandstone aquifer of fluvial origin at investigation depths consistent with highly enthalpy geothermal reservoirs (~0.7-1.1 km). At such depths, intergranular flow dominates in unfaulted areas with only minor contribution by bedding plane fractures. However, extensional faults represent preferential flow pathways, due to presence of high connective open fractures. Therefore, such faults may (1) drive nuclear waste contaminants towards the highly permeable shallow (< 150 m BGL) zone of the aquifer, and (2) influence fluid recovery in geothermal fields.

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Petrophysical properties of greensand as predicted from NMR measurements

Cited by 49 publications

References 19 publications

Multiscale approach to (micro)porosity quantification in continental spring carbonate facies: Case study from the Cakmak quarry (Denizli, Turkey)

Multiscale approach to (micro)porosity quantification in continental spring carbonate facies: Case study from the Cakmak quarry (Denizli, Turkey)

Comparative Porosity and Pore Structure Assessment in Shales: Measurement Techniques, Influencing Factors and Implications for Reservoir Characterization

Characterization of a fluvial aquifer at a range of depths and scales: the Triassic St Bees Sandstone Formation, Cumbria, UK

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