Experimental apparatus and method to investigate permeability and porosity of shale matrix from Haenam Basin in Korea
- 309 Downloads
- 2 Citations
Abstract
This study presents a new apparatus, which can simultaneously measure petrophysical properties such as low-permeability and porosity in a shale gas reservoir. Using the apparatus, the experiments have been performed to measure the low-permeability and porosity of three shale core samples, which are from Haenam Basin in Korea. As for the experimental results, porosity ranges from 4.65 to 11.6 % and the permeability measured in forward and reverse direction is 1.27E−16 and 1.32E−16 m2 for HS-1, 1.65E−17 and 1.77E−17 m2 for HS-2, and 6.91E−18 and 7.90E−18 m2 for HS-3, respectively. As a validation of measurement, regression analysis was carried out using the dimensionless pseudo-pressure between the measured data and analytical solution. The results showed that correlation coefficient of dimensionless pseudo-pressure increased to 0.95 in upstream and downstream reservoirs. From the positive results, it is found that both are approximately equal in terms of permeability and porosity. To represent the effect of geological features inside core sample on permeability and porosity, X-ray scan of the shale core samples was taken by Microfocus X-ray CT. Clearly, the value of permeability is subject to geological features such as micro-crack. This means that the micro-crack acts as an important factor in terms of permeability variation by its direction and length in a shale gas reservoir.
Keywords
Shale gas Low-permeability Pulse decay process Microfocus CT X-rayList of symbols
- \(A\)
Cross-sectional area of cylindrical core, m2
- \(a\)
Volume ratio between upstream and pore
- \(b\)
Volume ratio between downstream and pore
- \(c_{\text{g}}\)
Gas compressibility, kPa−1
- \(c_{\text{pv}}\)
Gas isothermal compressibility of pore, kPa−1
- \(c_{\text{t}}\)
Total compressibility, kPa−1
- \(c_{\text{vd}}\)
Gas isothermal compressibility of downstream, kPa−1
- \(c_{\text{vu}}\)
Gas isothermal compressibility of upstream, kPa−1
- \(f_{0}\)
First factor of Eq. 2, fraction
- \(f_{1}\)
Gas compressibility correction factor, fraction
- \(k\)
Permeability, m2
- \(L\)
Length of cylindrical sample, m
- \(n\)
Number of moles
- \(P_{\text{D}}\)
Dimensionless pressure
- \(P_{\text{d}}\)
Pressure in downstream reservoir, kPa
- \(P_{\text{u}}\)
Pressure in upstream reservoir, kPa
- \(R\)
Universal gas constant, 8.3144 J K−1 mol−1
- \(T\)
Temperature, K
- \(s_{1}\)
Gradient of Eq. 2, constant
- \(t\)
Time, s
- \(V_{\text{d}}\)
Volume of downstream reservoir, m3
- \(V_{\text{u}}\)
Volume of upstream reservoir, m3
- \(x\)
Distance from downstream end of core, m
- \(Z\)
Gas compressibility factor
- \(\phi\)
Porosity, fraction
- \(\mu\)
Gas viscosity, Pa s
- \(\theta_{n}\)
The nth roots of transcendental equation, radians
- \(\xi\)
Dummy variable
- \(\varPsi\)
Pseudo-pressure, kPa s−1
Notes
Acknowledgments
This research was supported by the Energy Efficiency and Resources of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Trade, Industry and Energy (2011201030001B) and also supported by the Research Project (GP2015-034) of the Korea Institute of Geoscience and Mineral Resources (KIGAM) funded by the Ministry of Science, ICT and Future Planning of Korea.
References
- Brace WF, Walsh JB, Frangos WT (1968) Permeability of granite under high pressure. J Geophys Res 73:2225CrossRefGoogle Scholar
- Dicker AI, Smits RM (1988) A practical approach for determining permeability from laboratory pressure pulse decay measurement. In: The SPE International Meeting in Petroleum Engineering. Tianjin, China, 1–4 NovemberGoogle Scholar
- Haskett SE, Narahara GM, Holditch SA (1988) A method for simultaneous determination of permeability and porosity in low permeability cores. Soc Petrol Eng Form Eval 3:651–658Google Scholar
- Hsieh PA, Tracy JV, Neuzil CE, Bredehoeft JD, Silliman SE (1981) A transient laboratory method for determining the hydraulic properties of tight rocks: I. Theory. Int J Rock Mech Min Sci Geomech Abstr 18:245–252CrossRefGoogle Scholar
- Hwang KG (2001) Dinosaur and pterosaur tracks from the Late Cretaceous Uhangri Formation, Haenam, SW Korea. Dissertation, Chonbuk National UniersityGoogle Scholar
- Jones SC (1997) A technique for faster pulse-decay permeability measurement in tight rocks. Soc Petrol Eng Form Eval 12:19–25Google Scholar
- Josh M, Esteban L, Delle PC, Sarout J, Dewhurst DN, Clennell MB (2012) Laboratory characterization of shale properties. J Petrol Sci Eng 88–89:107–124CrossRefGoogle Scholar
- Kamath J, Boyer RE, Nakagawa FM (1992) Characterization of core-scale heterogeneities using laboratory pressure transients. Soc Petrol Eng Form Eval 7:304–310Google Scholar
- Yamada SE, Jones AH (1980) A review of a pulse technique for permeability measurement. J Soc Petrol Eng 20(5):357–358CrossRefGoogle Scholar