Thermomagnetic Analyses of the Permeability-Controlling Minerals in Red and White Sandstones in Deep Tight Gas Reservoirs: Implications for Downhole Measurements
- Arfan Ali (Heriot-Watt University) | David K. Potter (University of Alberta)
- Document ID
- Society of Petroleum Engineers
- SPE Reservoir Evaluation & Engineering
- Publication Date
- October 2011
- Document Type
- Journal Paper
- 557 - 565
- 2011. Society of Petroleum Engineers
- 5.9.2 Geothermal Resources, 5.8.7 Carbonate Reservoir, 1.6.9 Coring, Fishing
- Permeability, non-destructive core analysis, Thermomagnetic analysis of rocks, Rapid, Downhole magnetic susceptibility measurements, Magnetic hysteresis
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- 476 since 2007
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Our recent work on deep tight gas reservoirs containing red and white sandstones (Potter et al. 2009) has suggested that the presence of small amounts of hematite in reservoir samples can have a dramatic effect on permeability. Such conclusions were made using laboratory-based low- and high-field magnetic-susceptibility measurements on reservoir-rock samples and by comparing these measurements with the permeability data. These rapid, nondestructive magnetic measurements have been applied previously in clastic reservoir samples (Potter 2007; Ivakhnenko 2006; Ivakhnenko and Potter 2008; Potter and Ivakhnenko 2008) and carbonate reservoir samples (Al-Ghamdi 2006; Potter et al. in press). However, such laboratory-based analyses are not representative of the downhole in-situ conditions, especially in deep gas reservoirs where the temperature can reach quite high values. Typical tight-gas-reservoir depths can reach approximately 4000 m (Abu-Shanab et al. 2005) and 6000 m (Tang et al. 2008), and the equivalent temperatures would measure 131 and 192°C, respectively, if one assumes the normal geothermal gradient (Mayer-Gurr 1976).
This paper investigates the in-situ magnetic properties of deep tight gas reservoir samples (containing permeability-controlling reservoir minerals hematite and illite) by means of laboratory experiments to model downhole temperature conditions. We perform magnetic hysteresis measurements at various temperatures in order to identify and quantify mineralogy and model changes in the magnetic behavior of these minerals at in-situ downhole conditions. From these measurements, we are able to show whether the mineralogy or domain state of the permeability-controlling minerals is likely to change with temperature in deep gas reservoirs. These changes can potentially have a major effect on permeability.
We also demonstrate that there are strong correlations between core-permeability and magnetic-susceptibility data in these tight-gas-reservoir samples. The permeability is low in red sections of the core wherever there is hematite.
|File Size||502 KB||Number of Pages||9|
Abu-Shanab, M.M., Hamada, G.M., Oraby, M.El. and Abdel Wally,A.A. 2005. Improved Porosity Estimation in Tight Gas Reservoirs from NMR andDensity Logs. Emirates Journal for Engineering and Research 10 (2): 9-13.
Al-Ghamdi, T. M., 2006. Carbonate Characterisation UsingMagnetic Measurements. MSc Individual Project thesis, Institute ofPetroleum Engineering, Heriot-Watt University, Edinburgh, UK.
Ivakhnenko, O.P. 2006. Magnetic Analysis of Petroleum Reservoir Fluids,Matrix Mineral Assemblages and Fluid-Rock Interactions. PhD thesis,Institute of Petroleum Engineering, Heriot-Watt University, Edinburgh, UK.
Ivakhnenko, O.P. and Potter, D.K. 2004. Magnetic Susceptibility of PetroleumReservoir Fluids. Physics and Chemistry of the Earth 29:899-907.
Ivakhnenko, O.P. and Potter, D.K. 2008. The Use of Magnetic Hysteresis andRemanence Measurements for Rapidly and Non-Destructively CharacterizingReservoir Rocks and Fluids: Petrophysics 49 (1): 47-56.
Kapicka, A., Hoffmann, V., and Petrovský, E. 2003. PressureInstability of Magnetic Susceptibility of Pyrrhotite Bearing Rocks from the KTBBorehole. Stud. Geophys. Geod. 47 (2): 381-391. http://dx.doi.org/10.1023/a:1023731910247.
LaTorraca, G.A., Bergman, D.J., and Dunn, K.J. 1995. MagneticSusceptibility Contrast Effects on NMR T2 Logging. Paper 1995-JJpresented at the SPWLA 36th Annual Logging Symposium, Paris, 26-29 June.
Liu, J., Zhu, R., Roberts, A.P., Li, S., and Chang, J.-H. 2004.High-Resolution Analysis of Early Diagenetic Effects on Magnetic Minerals inPost-Middle-Holocene Continental Shelf Sediments from the Korea Strait. J.Geophys. Res. 109 (B3): B03103. http://dx.doi.org/10.1029/2003jb002813.
Mayer-Gurr, A. 1976. Petroleum Engineering, Vol. 3. Geology ofPetroleum Series, Pitman Publishing.
Potter, D.K. 2007. Magnetic Susceptibility as a Rapid, Non-DestructiveTechnique for Improved Petrophysical Parameter Prediction. Petrophysics48 (3): 191-201.
Potter, D.K. and Ivakhnenko, O.P. 2008. Clay Typing--SensitiveQuantification and Anisotropy in Synthetic and Natural Reservoir Samples UsingLow- and High-Field Magnetic Susceptibility for Improved PetrophysicalAppraisals. Petrophysics 49 (1): 57-66.
Potter, D.K., Al-Ghamdi, T.M., and Ivakhnenko, O.P. In press.Sensitive Carbonate Reservoir Rock Characterization from Magnetic HysteresisCurves and Correlation with Petrophysical Properties. Petrophysics (inpress; submitted February 2011).
Potter, D.K., Ali, A., and Ivakhnenko, O.P. 2009. Quantifying the RelativeRoles of Illite and Hematite on Permeability in Red and White Sandstones UsingLow and High Field Magnetic Susceptibility. Paper SCA 2009-11 presented at the23rd International Symposium of the Society of Core Analysts, Noordwijkaan Zee, The Netherlands, 27-30 September.
Potter, D.K., Corbett, P.W.M., Barclay, S.A., and Haszeldine, R.S.2004. Quantification of Illite Content in Sedimentary Rocks Using MagneticSusceptibility--A Rapid Complement or Alternative to X-Ray Diffraction. J.Sediment. Res. 74 (5): 730-735. http://dx.doi.org/10.1306/021304740730.
Tang, J., Zhang, S., and Xiang-Yang, L. 2008. PP and PS SeismicResponse from Fractured Tight Gas Reservoirs: A Case Study. J. Geophys.Eng. 5 (1): 92. http://dx.doi.org/10.1088/1742-2132/5/1/010.