scholarly journals Using BIB-SEM Imaging for Permeability Prediction in Heterogeneous Shales

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
C. J. A. Sinn ◽  
J. Klaver ◽  
R. Fink ◽  
M. Jiang ◽  
J. Schmatz ◽  
...  

Organic-rich shale samples from a lacustrine sedimentary sequence of the Newark Basin (New Jersey, USA) are investigated by combining Broad Ion Beam polishing with Scanning Electron Microscopy (BIB-SEM). We model permeability from this 2D data and compare our results with measured petrophysical properties. Three samples with total organic carbon (TOC) contents ranging from 0.7% to 2.9% and permeabilities ranging from 4 to 160 nD are selected. Pore space is imaged at high resolution (at 20,000x magnification) and segmented from representative BIB-SEM maps. Modeled permeabilities, derived using the capillary tube model (CTM) on segmented pores, range from 2.3 nD to 310 nD and are relatively close to measured intrinsic permeabilities. SEM-visible porosities range from 0.1% to 1.8% increasing with TOC, in agreement with our measurements. The CTM predicts permeability correctly within one order of magnitude. The results of this work demonstrate the potential of 2D BIB-SEM for calculating transport properties of heterogeneous shales.

2015 ◽  
Vol 23 (02) ◽  
pp. 1550011 ◽  
Author(s):  
R. O. Nunes ◽  
R. N. Faria ◽  
N. Bouzidi ◽  
L. Machado ◽  
R. N. N. Koury

This paper presents a mathematical model for a capillary tube using CO 2 as fluid in steady flow transcritical cycle. The capillary tube is divided into N volumes controls and the model is based on applying the equations of conservation of energy, mass and momentum in the fluid in each of these volumes controls. The model calculates the mass flow of the CO 2 in the capillary tube as a function of CO 2 pressures at the inlet and outlet of the capillary and the temperature of CO 2 at the input of this device. The capillary tube is considered to be adiabatic, and the limit of operation due to blocked flow condition is also considered in the model. The validation of the model was performed with experimental data and the results showed that the model is capable of predicting the mass flow in the capillary tube with errors less than 10%. The model was also used to determine the minimum diameter of the capillary tube for various conditions of CO 2 transcritical cycle.


2019 ◽  
Vol 58 (45) ◽  
pp. 20806-20814 ◽  
Author(s):  
Ying Li ◽  
Haitao Li ◽  
Shengnan Chen ◽  
Qirui Ma ◽  
Chang Liu

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Fuyong Wang ◽  
Peiqing Lian ◽  
Liang Jiao ◽  
Zhichao Liu ◽  
Jiuyu Zhao ◽  
...  

This paper investigated fractal characteristics of microscale and nanoscale pore structures in carbonates using High-Pressure Mercury Intrusion (HPMI). Firstly, four different fractal models, i.e., 2D capillary tube model, 3D capillary tube model, geometry model, and thermodynamic model, were used to calculate fractal dimensions of carbonate core samples from HPMI curves. Afterwards, the relationships between the calculated fractal dimensions and carbonate petrophysical properties were analysed. Finally, fractal permeability model was used to predict carbonate permeability and then compared with Winland permeability model. The research results demonstrate that the calculated fractal dimensions strongly depend on the fractal models used. Compared with the other three fractal models, 3D capillary tube model can effectively reflect the fractal characteristics of carbonate microscale and nanoscale pores. Fractal dimensions of microscale pores positively correlate with fractal dimensions of the entire carbonate pores, yet negatively correlate with fractal dimensions of nanoscale pores. Although nanoscale pores widely develop in carbonates, microscale pores have greater impact on the fractal characteristics of the entire pores. Fractal permeability model is applicable in predicting carbonate permeability, and compared with the Winland permeability model, its calculation errors are acceptable.


2007 ◽  
Vol 44 (12) ◽  
pp. 1446-1461 ◽  
Author(s):  
Greg Siemens ◽  
James A. Blatz ◽  
Douglas Ruth

Swelling mechanisms occurring on the pore scale or at the molecular level of high plasticity, unsaturated soils often control macroscopic behaviour. In this paper, a new capillary tube model is proposed. The model is used to represent laboratory-scale infiltration tests on a bentonite-rich soil. The goal is to develop a greater understanding of bulk behaviour by closely examining microscopic behaviour. A decrease in hydraulic conductivity with increasing water content has been observed in laboratory studies on flow through shrink–swell materials. The proposed mechanism causing a decrease in conductivity is a change in pore-size distribution. The unique feature of the new capillary-tube model is that, as water flows down the tube, the tube’s cross-sectional area contracts to restrict flow, thus representing the change in pore-size distribution observed in the physical tests. Flow data from the capillary tube are used to model the laboratory results, and new insight is gained into bulk flow behaviour. Finally, a comparison with a three-dimensional network model for bentonite-coated sand mixtures is presented.


Soil Research ◽  
1976 ◽  
Vol 14 (2) ◽  
pp. 121 ◽  
Author(s):  
P Basak ◽  
MR Madhav

Kozeny's equation based on a capillary tube model with constant viscosity does not give satisfactory results for fine-grained soils. When surface forces dominate over gravity forces, the pore water behaves abnormally and the physical properties of this pore water are found to be quite different from free water. Flow through saturated fine-grained soils is known to be affected by the properties and thickness of loosely and strongly bound water, whose viscosity is observed to be higher because of the modified water structure induced by clay-water interaction. An analytical solution based on a capillary tube model taking into account the changed viscosity of bound water and variation of viscosity within the bound water in relation to its thickness is attempted. The derived equation appears to be general in nature and is applicable for both surface active and inactive soils. It is shown that Kozeny's equation turns out to be the particular case of the derived equation when the thickness of the bound water is zero or when the variation of viscosity is not taken into account.


Author(s):  
Gunnar Zimmermann ◽  
Richard Chapman

Abstract Dual beam FIBSEM systems invite the use of innovative techniques to localize IC fails both electrically and physically. For electrical localization, we present a quick and reliable in-situ FIBSEM technique to deposit probe pads with very low parasitic leakage (Ipara < 4E-11A at 3V). The probe pads were Pt, deposited with ion beam assistance, on top of highly insulating SiOx, deposited with electron beam assistance. The buried plate (n-Band), p-well, wordline and bitline of a failing and a good 0.2 μm technology DRAM single cell were contacted. Both cells shared the same wordline for direct comparison of cell characteristics. Through this technique we electrically isolated the fail to a single cell by detecting leakage between the polysilicon wordline gate and the cell diffusion. For physical localization, we present a completely in-situ FIBSEM technique that combines ion milling, XeF2 staining and SEM imaging. With this technique, the electrically isolated fail was found to be a hole in the gate oxide at the bad cell.


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