An Overview of the Porosity Classification in Carbonate Reservoirs and Their Challenges: An Example of Macro-Microporosity Classification from Offshore Miocene Carbonate in Central Luconia, Malaysia
Biological and chemical activities in carbonates are responsible for the complexity of the pore system. Primary porosity is generally of natural origin while secondary porosity is subject to chemical reactivity through diagenetic processes. To understand the integrated part of hydrocarbon exploration, it is necessary to understand the carbonate pore system. However, the current porosity classification scheme is limited to adequately predict the petrophysical properties of different reservoirs having various origins and depositional environments. Rock classification provides a descriptive method for explaining the lithofacies but makes no significant contribution to the application of porosity and permeability (poro-perm) correlation. The Central Luconia carbonate system (Malaysia) represents a good example of pore complexity (in terms of nature and origin) mainly related to diagenetic processes which have altered the original reservoir. For quantitative analysis, 32 high-resolution images of each thin section were taken using transmitted light microscopy. The quantification of grains, matrix, cement, and macroporosity (pore types) was achieved using a petrographic analysis of thin sections and FESEM images. The point counting technique was used to estimate the amount of macroporosity from thin section, which was then subtracted from the total porosity to derive the microporosity. The quantitative observation of thin sections revealed that the mouldic porosity (macroporosity) is the dominant porosity type present, whereas the microporosity seems to correspond to a sum of 40 to 50% of the total porosity. It has been proven that these Miocene carbonates contain a significant amount of microporosity, which significantly complicates the estimation and production of hydrocarbons. Neglecting its impact can increase uncertainty about estimating hydrocarbon reserves. Due to the diversity of geological parameters, the application of existing porosity classifications does not allow a better understanding of the poro-perm relationship. However, the classification can be improved by including the pore types and pore structures where they can be divided into macro- and microporosity. Such studies of microporosity identification/classification represent now a major concern in limestone reservoirs around the world.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.2702789Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF
 R. Sharma and M. Prasad, "Characterization of heterogeneities in Carbonates," in SEG Technical Program Expanded Abstracts 2009: Society of Exploration Geophysicists, 2009, pp. 2149-2154.
 G. Baechle, M. Knackstedt, M. Madadi, C. Arns, and G. Eberli, "Carbonate Petrophysical Parameters Derived from 3D Images (Best of AAPG)," in 71st EAGE Conference and Exhibition incorporating SPE EUROPEC 2009, 2009.
 H. T. Janjuhah, A. Alansari, and J. A. G. Vintaned, "Quantification of microporosity and its effect on permeability and acoustic velocity in Miocene carbonates, Central Luconia, offshore Sarawak, Malaysia," Journal of Petroleum Science and Engineering, vol. 175, pp. 108-119, 2019.
 J. Garnham and K. Hatfield, "The Application Of Image Analysis To Improve Permeability Prediction," Petrophysics, vol. 42, no. 05, 2001.
 M. Epting, "Sedimentology of Miocene carbonate buildups, central Luconia, offshore Sarawak," 1980.
 K. Leong, The petroleum geology and resources of Malaysia. Malaysian National Petroleum Corporation, 2000.
 H. T. Janjuhah, A. Alansari, and P. R. Santha, "Interrelationship Between Facies Association, Diagenetic Alteration and Reservoir Properties Evolution in the Middle Miocene Carbonate Build Up, Central Luconia, Offshore Sarawak, Malaysia," Arabian Journal for Science and Engineering, vol. 44, no. 1, pp. 341-356, 2019.
 H. T. Janjuhah, J. A. Gamez Vintaned, A. M. A. Salim, I. Faye, M. M. Shah, and D. P. Ghosh, "Microfacies and depositional environments of miocene isolated carbonate platforms from Central Luconia, Offshore Sarawak, Malaysia," Acta Geologica Sinica‐English Edition, vol. 91, no. 5, pp. 1778-1796, 2017.
 N. Wardlaw, "Pore geometry of carbonate rocks as revealed by pore casts and capillary pressure," Aapg Bulletin, vol. 60, no. 2, pp. 245-257, 1976.
 P. W. Choquette and L. C. Pray, "Geologic nomenclature and classification of porosity in sedimentary carbonates," AAPG bulletin, vol. 54, no. 2, pp. 207-250, 1970.
 C. H. Moore, Carbonate diagenesis and porosity. Elsevier, 1989.
 R. G. Maliva, "Carbonate facies models and diagenesis," in Aquifer Characterization Techniques: Springer, 2016, pp. 91-110.
 G. T. Baechle, A. Colpaert, G. P. Eberli, and R. J. Weger, "Effects of microporosity on sonic velocity in carbonate rocks," The Leading Edge, vol. 27, no. 8, pp. 1012-1018, 2008.
 F. S. Anselmetti and G. P. Eberli, "Controls on sonic velocity in carbonates," in Experimental Techniques in Mineral and Rock Physics: Springer, 1993, pp. 287-323.
 L. A. Melim, F. S. Anselmetti, and G. P. Eberli, "The importance of pore type on permeability of Neogene carbonates, Great Bahama Bank," 2001.
 F. S. Anselmetti and G. P. Eberli, "The velocity-deviation log: a tool to predict pore type and permeability trends in carbonate drill holes from sonic and porosity or density logs," AAPG bulletin, vol. 83, no. 3, pp. 450-466, 1999.
 R. J. Weger, G. P. Eberli, G. T. Baechle, J. L. Massaferro, and Y.-F. Sun, "Quantification of pore structure and its effect on sonic velocity and permeability in carbonates," AAPG bulletin, vol. 93, no. 10, pp. 1297-1317, 2009.
 M. Kumar and D.-h. Han, "Pore shape effect on elastic properties of carbonate rocks," in 2005 SEG Annual Meeting, 2005: Society of Exploration Geophysicists.
 P. J. Fitch, M. A. Lovell, S. J. Davies, T. Pritchard, and P. K. Harvey, "An integrated and quantitative approach to petrophysical heterogeneity," Marine and Petroleum Geology, vol. 63, pp. 82-96, 2015.
 F. J. Lucia, "Rock-fabric/petrophysical classification of carbonate pore space for reservoir characterization," American Association of Petroleum Geologists, vol. 79, no. 9, pp. 1275-1300, 1995.
 F. S. Anselmetti and G. P. Eberli, "Sonic velocity in carbonate—a product of original composition and postdepositional porosity evolution: Ann," AAPG-SEPMEMD-DPA-CSPG Conv. Abstracts1992.
 E. D. Pittman, "Relationship of porosity and permeability to various parameters derived from mercury injection-capillary pressure curves for sandstone (1)," AAPG bulletin, vol. 76, no. 2, pp. 191-198, 1992.
 D. L. Cantrell and R. M. Hagerty, "Microporosity in Arab formation carbonates, Saudi Arabia," GeoArabia, vol. 4, no. 2, pp. 129-154, 1999.
 A. Lønøy, "Making sense of carbonate pore systems," AAPG bulletin, vol. 90, no. 9, pp. 1381-1405, 2006.
 F. Lucia and R. Loucks, "Microporosity in carbonate mud: Early development and petrophysics," Gulf Coast Association of Geological Socities, vol. 2, 2013.
 T. Jobe and J. Sarg, "Microporosity characterization of mud-rich carbonate rocks," in Pore Scale Phenomena: Frontiers in Energy and Environment: World Scientific, 2015, pp. 67-89.
 G. E. Archie, "Classification of carbonate reservoir rocks and petrophysical considerations," Aapg Bulletin, vol. 36, no. 2, pp. 278-298, 1952.
 M. E. Tucker and V. P. Wright, Carbonate sedimentology. John Wiley & Sons, 2009.
 J. C. Wilson and E. F. McBride, "Compaction and porosity evolution of Pliocene sandstones, Ventura Basin, California," AAPG Bulletin, vol. 72, no. 6, pp. 664-681, 1988.
 M. E. Wilson, "Global and regional influences on equatorial shallow-marine carbonates during the Cenozoic," Palaeogeography, Palaeoclimatology, Palaeoecology, vol. 265, no. 3, pp. 262-274, 2008.
 F. Lucia, "Petrophysical parameters estimated from visual descriptions of carbonate rocks: a field classification of carbonate pore space," Journal of Petroleum Technology, vol. 35, no. 03, pp. 629-637, 1983.
 R. J. Dunham, "Classification of carbonate rocks according to depositional textures," American Association of Petroleum Geologists, pp. 108–121, 1962.
 F. J. Lucia, "Rock-fabric/petrophysical classification of carbonate pore space for reservoir characterization," AAPG bulletin, vol. 79, no. 9, pp. 1275-1300, 1995.
 H. T. Janjuhah, A. Alansari, D. P. Ghosh, and Y. Bashir, "New approach towards the classification of microporosity in Miocene carbonate rocks, Central Luconia, offshore Sarawak, Malaysia," Journal of Natural Gas Geoscience, 2018.
 H. T. Janjuhah, A. Alansari, and P. R. Santha, "Interrelationship Between Facies Association, Diagenetic Alteration and Reservoir Properties Evolution in the Middle Miocene Carbonate Build Up, Central Luconia, Offshore Sarawak, Malaysia," Arabian Journal for Science and Engineering, pp. 1-16, 2018.
 H. T. Janjuhah et al., "Development of carbonate buildups and reservoir architecture of Miocene carbonate platforms, Central Luconia, offshore Sarawak, Malaysia," in SPE/IATMI Asia Pacific Oil & Gas Conference and Exhibition, 2017: Society of Petroleum Engineers.
 H. T. Janjuhah, A. M. A. Salim, and D. P. Ghosh, "Sedimentology and reservoir geometry of the Miocene carbonate deposits in central Luconia, offshore, Sarawak, Malaysia," J Appl Sci, vol. 17, no. 4, pp. 153-170, 2017.
 H. T. Janjuhah, A. M. A. Salim, A. Alansari, and D. P. Ghosh, "Presence of microporosity in Miocene carbonate platform, Central Luconia, offshore Sarawak, Malaysia," Arabian Journal of Geosciences, vol. 11, no. 9, p. 204, 2018.
 E. A. Clerke et al., "Application of Thomeer Hyperbolas to decode the pore systems, facies and reservoir properties of the Upper Jurassic Arab D Limestone, Ghawar field, Saudi Arabia: A “Rosetta Stone” approach," GeoArabia, vol. 13, no. 4, pp. 113-160, 2008.
 S. O. Moshier, "Development of microporosity in a micritic limestone reservoir, Lower Cretaceous, Middle East," Sedimentary Geology, vol. 63, no. 3-4, pp. 217-240, 1989.
 C. Domingo, J. García-Carmona, E. Loste, A. Fanovich, J. Fraile, and J. Gómez-Morales, "Control of calcium carbonate morphology by precipitation in compressed and supercritical carbon dioxide media," Journal of Crystal Growth, vol. 271, no. 1-2, pp. 268-273, 2004.
 L. Lambert, C. Durlet, J.-P. Loreau, and G. Marnier, "Burial dissolution of micrite in Middle East carbonate reservoirs (Jurassic–Cretaceous): keys for recognition and timing," Marine and Petroleum Geology, vol. 23, no. 1, pp. 79-92, 2006.
 M. D. de Periere et al., "Morphometry of micrite particles in Cretaceous microporous limestones of the Middle East: influence on reservoir properties," Marine and Petroleum Geology, vol. 28, no. 9, pp. 1727-1750, 2011.
 M. H. Rahman, B. J. Pierson, W. Yusoff, and W. Ismail, "Classification of microporosity in carbonates: examples from Miocene carbonate reservoirs of central Luconia, offshore Sarawak, Malaysia," in International petroleum technology conference, 2011: International Petroleum Technology Conference.