Microstructures and physical properties in carbonate rocks: A comprehensive review (original) (raw)

Highlights

•
Rock physical properties are linked to many microstructural parameters.
•
Those parameters can interact at many different scales.
•
Early studies on those problems discussed the geological concepts of pore systems.
•
Recent work have shown that pore space must be defined using geometrical factors.
•
This concerns both elastic and transport properties in carbonate rocks.

Abstract

Carbonate rocks are well-known to be tremendously heterogeneous. They mainly consist of component particles (from biological and non-biological origin) embedded in a lime-mud matrix and/or in a cement (composed of even smaller particles). The size, shape, density and spatial arrangement of those particles, alongside with natural fractures and cracks (although those are certainly not exclusive to carbonate rocks), define a microstructural pattern that is known to have a great influence on rock physical properties.

Introduction

Further knowledge of rock physical and mechanical properties is necessary, and has been a long-time major focus of geophysics. The implications are wide, from fundamental science to applied geology, involving exploration and production of fossil energies, groundwater, geological storage of wastes, earthquakes prediction, and on larger scales the behavior of the Earth's lithosphere. The Earth's crust is a very complex geological domain, where the physical properties of rocks are very heterogeneous and sometimes anisotropic. Those heterogeneities are often a reflection of the complex association between microstructures, inherited from sediment deposition and diagenesis conditions, stress state, pressure and temperature conditions, or the nature of saturating fluids. This statement is even more obvious if we consider the carbonate rocks, which are inherently heterogeneous rocks. They mainly consist of component particles (from biological and non-biological origin) embedded in a lime-mud matrix and/or in a cement (composed of even smaller particles). Those elements generally undergo an intense diagenesis over time because of the very high chemical sensitivity of the carbonate mineral species (calcite, aragonite and dolomite). This usually results in a complex medium, with strong impacts on rock physical properties. The microstructures resulting from all these mechanisms often have a coupling effect within the rocks, and lead to modify both their solid framework and porous network irreversibly.

Thus, to understand carbonate rock systems at large scales (formation, reservoir …), geophysicists have to study them at the pore scale, hoping to resolve the so-called “upscalling” problem. With this in mind, unravelling and identifying the relations between physical properties and carbonate rock microstructures is paramount for a global comprehension of a carbonate rock system. This statement however, is far more easily said than done because of the wide heterogeneity of microstructures encountered in those media, and attempting to make sense of their physical properties can be a major challenge. Until today, and despite the many publications on this topic, only a few general compilations exist about all the factors that are known to control those physical parameters. This review attempts to fill this gap, by proposing a comprehensive review of this specialized literature, from the early and recent contributions in rock physics, with emphasis on the recent studies on carbonate rocks from the Paris basin, developed by the research group at the Geosciences and Environment laboratory at the University of Cergy-Pontoise. Effects related to temperature, stress, frequency and the nature of the saturating fluid will not be treated here, as they are more linked to the environmental conditions and measurement than to intrinsic rock properties.

Section snippets

Microstructures classifications and their limits

The solid structure (grains, matrix) is usually characterized using the Dunham carbonate rock classification (Dunham, 1962). It was originally developed for sedimentology studies of carbonate rock reservoirs, and its approach to define carbonate constituents is mostly descriptive. The reason for this terminology to be widely used in carbonate rock physics is because it gives a quick overview of some crucial parameters controlling the response of some physical properties: the nature of “grains”

Microstructures and elastic properties

The development of sequential stratigraphy and the revival for oil exploration in the 70's and 90's, made many geological investigations possible from drilling and geophysical measurements. Given the importance taken by the subsurface exploration and investigation, understanding the elastic properties of rocks is essential to the interpretation of seismic reflectors, logs, and velocity data measured in the laboratory. Seismic waves are, by nature, small mechanical perturbations of the medium.

Microstructures and transport properties

On larger scales, petroleum systems, hydrothermal, geothermal energy, mineral deposits and underground storage are all domains where transport properties play a decisive role. At the laboratory scale, the characterization of reservoir properties essentially relies on permeability and electrical conductivity measurements. The latter is also widely used as a logging tool. Those two physical parameters are representative of the porous network in terms of geometry, pore connectivity, and

Recent advances on micritic carbonate rocks

A lot of work on the physical properties in carbonate rocks has been carried out on coarse-grained, granular and macroporous specimens and few studies concern fine micritic carbonate series. It can be explained by the low fluid recovery rates in these reservoirs, although micritic limestones exhibit large variation of (1) sedimentary texture from mudstone to grainstone, (2) and facies composition. Those heterogeneities imply a peculiar elastic/acoustic signature and a complex distribution of

Conclusion

Rock physical properties such as porosity, permeability, seismic velocity, electrical conductivity, are linked through many parameters such as pore size and shape, grain contacts or cracks, pore network connectivity or mineralogy. Those parameters can interact at many scales, from the microscopic scale for micritic carbonate rocks, to the meter scale. Furthermore, feedback processes and coupled interactions make it difficult to attribute changes in physical properties to any one parameter. The

Acknowledgments

We are grateful to Lisa Casteleyn, Yasin Makhloufi and Pierre-Yves Collin for their collaboration in the project on the Oolithe Blanche formation, as well as Jérôme Fortin and Béatrice Yven; and Benjamin Brigaud, for his help in the project focused on Middle Jurassic Limestones from the Paris Basin. This work was supported by a research grant (Groupement National de Recherche FORmation géologiques PROfondes-Programme sur l’Aval du Cycle et l’Energie Nucléaire CNRS/PACEN) given to Philippe

References (58)

et al.

Acoustic properties of Neogene carbonates and siliciclastics from the subsurface of the Florida Keys: implications for seismic reflectivity

Mar. Geol.

(1997)

B. Brigaud et al.

Growth and demise of the Jurassic carbonate platform in the intracratonic Paris Basin (France) : interplay of climate change, eustasy and tectonics

Mar. Petrol. Geol.

(2014)

L. Casteleyn et al.

Interrelations of the petrophysical, sedimentological and microstructural properties of the Oolithe Blanche formation (bathonian, saline aquifer of the Paris basin)

Sediment. Geol.

(2010)

L. Casteleyn et al.

An integrated study of the petrophysical properties of carbonate rocks from the “Oolithe Blanche” formation in the Paris Basin

Tectonophysics

(2011)

M. Deville de Periere et al.

Morphometry of micrite particles in cretaceous microporous limestones of the Middle East : influence on reservoir properties

Mar. Petrol. Geol.

(2011)

J. Dvorkin et al.

Effective properties of cemented granular materials

Mech. Mater.

(1994)

O. Faÿ-Gomord et al.

New insight into the microtexture of chalks from NMR analysis

Mar. Petrol. Geol.

(2016)

L. Lambert et al.

Burial dissolution of micrite in Middle East carbonate reservoirs (Jurassic-Cretaceous) : keys for recognition and timing

Mar. Petrol. Geol.

(2006)

Y. Makhloufi et al.

Impact of sedimentology and diagenesis on the petrophysical properties of a tight oolitic carbonate reservoir. The case of the Oolithe Blanche Formation (Bathonian, Paris Basin, France)

Mar. Petrol. Geol.

(2013)

J.B. Regnet et al.

Influence of microporosity distribution on the mechanical behavior of oolithic carbonate rocks

Geomech. Energy Environ.

(2015)

B. Vincent et al.

NMR relaxation of neritic carbonates : an integrated petrophysical and petrographical approach

J. Appl. Geophys.

(2011)

K. Walton

The effective elastic moduli of a random packing of spheres

J. Mech. Phys. Solids

(1987)

G.E. Archie

The electrical resistivity log as an aid in determining some reservoir characteristics

Transact. AIME

(1942)

J.G. Berryman

Long‐wavelength propagation in composite elastic media II. Ellipsoidal inclusions

J. Acoust. Soc. Am.

(1980)

J.V.M. Borgomano et al.

Dispersion and attenuation measurements of the elastic moduli of a dual‐porosity limestone

J. Geophys. Res.: Solid Earth

(2017)

T. Bourbié et al.

Hydraulic and acoustic properties as a function of porosity in Fontainebleau sandstone

J. Geophys. Res.: Solid Earth

(1985)

B. Brigaud et al.

Acoustic properties of ancient shallow-marine carbonates : effects of depositional environments and diagenetic processes (middle jurassic, Paris basin, France)

J. Sediment. Res.

(2010)

E.,. Brosse et al.

Selection and characterization of geological sites able to host a pilot-scale CO2 storage in the Paris Basin (geocarbone-PICOREF)

Oil Gas Sci. Technol.

(2010)

P. Choquette et al.

Geologic nomenclature and classification of porosity in sedimentary carbonates

AAPG (Am. Assoc. Pet. Geol.) Bull.

(1970)

H. Darcy

Les fontaines publiques de la ville de Dijon : exposition et application des principes à suivre et des formules à employer dans les questions de distribution d’eau

(1856)

C. David

Geometry of flow paths for fluid transport in rocks

J. Geophys. Res.

(1993)

J. Delmas et al.

Petrophysical properties of the middle jurassic carbonates in the PICOREF sector (south champagne, Paris basin, France)

Oil Gas Sci. Technol. Revue de l’Institut Français du Pétrole

(2010)

P.J. Digby

The effective elastic moduli of porous granular rocks

J. Appl. Mech.

(1981)

R.J. Dunham

Classification of Carbonate Rocks According to Depositional Textures

(1962)

G. Eberli et al.

Factors controlling elastic properties in carbonate sediments and rocks

Lead. Edge

(2003)

A. El Husseiny et al.

Porosity-permeability relationship in dual-porosity carbonate analogs

Geophysics

(2016)

I.L. Fabricius et al.

How depositional texture and diagenesis control petrophysical and elastic properties of samples from five North Sea chalk fields

Petrol. Geosci.

(2007)

R.L. Folk

A review of grain-size parameters

Sedimentology

(1966)

J. Fortin et al.

Effects of pore collapse and grain crushing on ultrasonic velocities and Vp/Vs

J. Geophys. Res.: Solid Earth

(2007)

Cited by (0)

View full text