Properties Of Sedimentary Rocks Research Articles

Evaluation of drying shrinkage effects on the elastic properties of porous sandstones using a modified micromechanical model

SUMMARY The effects of pore fluids on the elastic properties of sedimentary rocks can be broadly categorized into two mechanisms: variations in pore compressibility due to the physical properties of the fluids and alterations in the stiffness of the rock frame resulting from rock–fluid interactions. Particularly, as rock–fluid interactions alter the stiffness of contacts between mineral grains, changes in the fluid properties around grain contacts can induce volumetric deformation of the rock as well as in variations of the associated elastic coefficients. Even though many previous studies have explored the influence of swelling of clay minerals, the relationships between changes in elastic moduli and deformation in rocks, which hardly contain swellable minerals, remain to date enigmatic. In this paper, to evaluate quantitatively these effects, drying rates, strains and ultrasonic velocities of small cylindrical Berea sandstone samples were measured as their water saturation was decreased by evaporative drying. The measurements clearly showed drying shrinkage and drastic increases in shear and compressional moduli for all the samples under an almost fully dried condition. Previous studies considered that the alteration in surface energy of grain minerals between wet and dry states affected the contact stiffness between them. Some of them used micromechanical model, uniting the Digby grain contact model with the effective medium theory, to interpret the changes in elastic moduli observed in the non-swellable sandstones during water adsorption on the grain surface. The conventional micromechanical model assumes that a mineral grain is a pure sphere and that the number of contacts between the grains is one. However, grains in a sedimentary rock are generally not purely spherical, and the contact surface is composed of several adhesive asperities. We therefore modified the conventional model by introducing the curvature radius and the number of asperities per contact surface. The modified model well reproduced the shear moduli under wet conditions using the strain and moduli measured under dry conditions. On the other hand, the predictions of the compressional moduli using the model were partially in agreement with the experimental results. Therefore, we attempted to qualitatively interpret the relationship by combining the model with the viscoelastic effect associated with wave-induced fluid flow. The deformation and changes in the elastic moduli of rocks resulting from multiple pore fluids within them can be better understood by the present combined model.

The effect of temperature on the mechanical and hydraulic properties of sedimentary rocks

The evaluation of the geomechanical and hydraulic properties of rocks under in situ conditions is essential for optimizing subsurface industrial operations. In this study, we investigate the impact of temperature on the hydraulic and mechanical properties of sandstone and carbonate rocks collected from southern Lebanon. The properties include the Unconfined Compressive Strength, Young's modulus, Poisson's ratio, compressional wave velocity, porosity, and permeability. Four distinct rock samples were examined: bioturbated limestone, bioturbated siliceous limestone, bioclastic intraclastic sandstone, and quartz arenite, which were analyzed through thin-sectioning and scanning electron microscopy. Mechanical properties were determined through uni-axial compression testing and ultrasonic measurements, while a gas permeameter and Helium porosimeter were employed for measuring permeability and porosity, respectively. In carbonate rocks, no significant changes in mechanical properties were observed with varying temperatures, whereas in sandstone samples, these properties decreased as temperature increased. The compressional wave velocity decreased for all rock types as temperature increased due to the formation of thermal cracks and the expansion of intra-granular pores. We note that the permeability initially decreased when temperature varied between 25°C and 85°C, which is attributed to the narrowing of pre-existing intergranular microcracks caused by thermal expansion of the porous solid matrix. However, permeability subsequently increased beyond 85°C as thermal cracks developed and created interconnected pathways. Porosity, however, increased continuously with temperature, influenced by both inter- and intra-granular pore space as well as the presence of cracks. The study suggests that with adequate implementations, rock properties can be improved for application in geothermal exploration and carbon storage.

Analysis of thermal properties of main sedimentary rocks in the Beijing area

The Beijing area is abundant in geothermal resources, yet there has been limited research on the thermal properties of rocks and their influencing factors. This paper focuses on the thermal properties of sedimentary rocks in the region, conducting experimental analysis to investigate these properties and their influencing factors. The experiment involved collecting primary sedimentary rock outcrop samples from around Beijing, testing the thermophysical parameters of 48 samples using a Hot Disk thermal constant analyzer. By combining this data with the standard stratum profile and historical information about Beijing, the thermal conductivity of the formation was calculated using the harmonic mean method, allowing for an analysis of the thermal properties of primary sedimentary rocks in the study area. The results indicate that overall distribution of thermal conductivity for sedimentary rocks in the Beijing area ranges from 1.48 to 6.55 W/(m·K), while thermal diffusivity ranges from 0.76 × 10−6 to 4.04 × 10−6 m2/s, and specific heat distribution ranges from 0.57 to 2.52MJ/(m3·K). Furthermore, according to harmonic mean calculations, it was found that Jixian formation exhibits the highest thermal conductivity value, whereas Triassic formation displays the lowest. This study on the thermal properties of sedimentary rocks provides valuable insights for the geothermal field research in the Beijing area.

Fracture of bio-cemented sands

Bio-chemical reactions enable the production of biomimetic materials such as sandstones. In the present study, microbiologically-induced calcium carbonate precipitation (MICP) is used to manufacture laboratory-scale specimens for fracture toughness measurement. The mode I and mixed-mode fracture toughnesses are measured as a function of cementation, and are correlated with strength, permeability and porosity. A micromechanical model is developed to predict the dependence of mode I fracture toughness upon the degree of cementation. In addition, the role of the crack tip T-stress in dictating kink angle and toughness is determined for mixed mode loading. At a sufficiently low degree of cementation, the zone of microcracking in the vicinity of the crack tip is sufficiently large for a crack tip K-field to cease to exist and for crack kinking theory to not apply. The interplay between cementation and fracture properties of sedimentary rocks is explained; this understanding underpins a wide range of rock fracture phenomena including hydraulic fracture.

Texture-Dependent Thermal Properties of Sandstone Rocks Examined by Scanning Electron Microscopy for Thermal Energy Storage Applications

Abstract Sedimentary rocks are widely used as geological reservoirs and as host rocks for geothermal energy systems. The thermal properties of sedimentary rocks, such as thermal conductivity, thermal diffusivity, and volumetric specific heat, play a critical role in their suitability for these applications. This study examined the thermal properties of 30 different sandstone rock samples using scanning electron microscopy (SEM) analysis. The SEM images of rock samples with different thermal properties were compared to analyze how textural properties influence thermal properties. Our results suggest that the thermal properties of sedimentary rocks are highly dependent on their texture. Specifically, we found that rocks with a higher degree of roughness, tend to exhibit lower thermal conductivity and thermal diffusivity. The presence of pores and cracks impacted the thermal properties of the sandstone rocks examined. The average surface roughness extracted from images showed a strong negative correlation with thermal conductivity and diffusivity (−0.59 and −0.6, respectively) obtained experimentally, while pore, cracks, and voids area have a less apparent negative correlation (−0.18 and −0.17) likely due to their complex effect on heat transfer. The size, shape, and distribution of voids affect heat transfer, with interconnected voids providing networks for heat flow, and smaller voids trapping heat more effectively. The texture of sedimentary rocks plays a critical role in determining their thermal properties. This knowledge can be used to optimize the understanding of the potential of sandstone reservoirs in applications, such as geothermal energy or thermal energy storage.

Influence of water content on the basic friction angle of porous limestones—experimental study using an automated tilting table

An accurate evaluation of the shear strength of discontinuities is frequently a key aspect for determining the safety of mining and civil engineering works and for solving instability issues at rock mass scale. This is usually done by using empirical shear strength criteria in which the basic friction angle (φb) is a relevant input parameter. Tilt testing is probably the most widespread method to obtain the φb due to its simplicity and low cost, but previous research has demonstrated that the results are strongly affected by several factors (e.g. surface finishing, cutting speed, specimen geometry, wear, time and rock type). In this connection, despite it is well known that water significantly reduces the mechanical properties of sedimentary rocks, very scarce research has focused on assessing the impact of the variations in water content on tilt test results. With the aim to fill this gap, saw-cut slabs of three limestone lithotypes were tilt tested in dry state, wet condition (fully water saturated, non-submerged samples) and under exposure to an environmental relative humidity (RH) of 90%. The results revealed that full water saturation caused moderate φb reductions in two lithotypes and a φb increase in one lithotype. This can be explained by their different microstructure and mineralogy, which makes that lubrication effect prevails over suction effect or vice versa. However, the exposure to a high RH environment did not cause significant φb variations. In addition, some important considerations related to tilt testing are provided and discussed, such as the intrinsic variability of the sliding angle (β) and the impact of multiple sliding on the same rock surfaces on β.

Deformation properties of sedimentary rocks in the process of underground coal gasification

Deformation properties of sedimentary rocks in the process of underground coal gasification

Sediment textural characteristics of the Ravenglass Estuary; Development of a method to predict palaeo sub-depositional environments from estuary core samples

Here we present a new way to automatically classify the exact sub-environment of deposition of sediment from estuarine sediment cores. It can be challenging to define the exact sub-environment of deposition in core as sediment of a given appearance, or facies, can be found in multiple settings. This issue is important given that petrophysical, geomechanical and reservoir quality properties of sedimentary rocks are typically strongly influenced by the specific sub-environment of deposition. Here, using a ten-fold classification of depositional sub-environments, we have determined the sub-environments of 482 sample sites from the Ravenglass Estuary, in NW England, UK. We then analysed the textural characteristics of each of these samples using laser particle size analysis. A novel automatic textural classification scheme was then developed using a combination of visual discrimination of gravel and vegetated surfaces, principal component analysis and a recursive partitioning routine (RPART) in Rstudio. The new automatic textural classification scheme can resolve eight of the ten sub-environments of deposition: gravel beds, salt-marsh, mud flat, mixed flat, sand flat, tidal inlet, combined south foreshore/ebb-tidal delta and combined tidal inlet/north foreshore. Our scheme cannot differentiate the spatially adjacent tidal inlet and north foreshore sediments as they are texturally identical. Similarly, the scheme cannot differentiate the spatially adjacent ebb-tidal delta and southern foreshore sediments as they also are texturally identical. We have applied our surface-calibrated method to a 3 m Holocene core drilled through fine-grained surface sand flats into interbedded fine- and coarse-grained sands in the Ravenglass Estuary and successfully defined palaeo sub-environments of deposition. Our automatic approach to the definition of palaeo-environment of deposition supersedes a simple lithofacies-based approach for the Ravenglass Holocene core, as we can define, cm-by-cm, how the exact estuarine sub-environments evolved over the last 10,000 years. This approach could also be applied to other modern estuaries and could be trialled for use with ancient and deeply buried sedimentary rocks deposited in equivalent marginal marine estuarine environment.

Biostratigraphic and petrological characteristics of Cretaceous\u2013Paleogene sediments in the eastern Cuu Long delta

The basic structure of reservoir models is strongly affected by the stratigraphic interpretation and the properties of reservoir rock. The estimation of the volume of hydrocarbon accumulation will depend on the accuracy of predicting and distributing reservoir quality. Biostratigraphic and sedimentary petrologic results provide geological information to clarify the stratigraphy and properties of sedimentary rocks on the eastern margin of the Cuu Long delta plain trough. On the basis of stratigraphic correlation of the wells and studying the structures of the area, the deposition, thickness of sediments and the ability to correlate with prospect rocks on the southeastern Vietnam continental shelf were determined. The results have identified the basement rock of wells TC-1 and TC-2, which are Cretaceous metasandstones and were deposited in freshwater fluvial environments with high-energy conditions. The upper Paleogene sediments were overlaid directly on the Cretaceous basement rock in the TC-2 well but were completely absent in the TC-1 well. The lithologic composition is mainly feldspathic litharenite sandstone, which is formed in freshwater fluvial and freshwater lacustrine environments. This study provides new data on stratigraphic column of the eastern Cuu Long delta plain. The data show that the age of the sedimentary basement rock is Cretaceous which has not been determined in previous studies. The findings of this study can help for better understanding of the geological development history and the completely stratigraphic column of the Cuu Long delta to correlate with objects that are hydrocarbon accumulation in Cuu Long sedimentary basin in order to improve efficiency in petroleum exploration activities.

Relationship between physical and mechanical properties of jointed rocks in Central Iran (Bafgh Block)

Central Iran is one of the active mining zones of Iran and has great mining potential. Large iron mines such as Choghart, Chadormalu, Sechahoon, Chahgaz, Lake Siah, Mishdavan, etc. are located in this zone. Other metals also exist in this zone Like lead and zinc in Koushk, Chahmir and Taj-Kooh mines. Also, non-metallic deposits such as Fahraj limestone mines and building stone mines such as Bishedar marble, Taft travertine, Shirkooh granite, etc. are being extracted in this zone. Considering mineral resources and current explorations, the mines continue to develop and one of the important topics in the exploration and exploitation phase is the study of geomechanical conditions in the zone under study. The relationship between the physical and mechanical properties of rocks makes it possible to predict the strength of intact rock which can be used in preliminary designing of the mine at less cost and less time and just with some simple tests on exploratory boreholes and surface samples. It can also be used in mines under extraction to gain more comprehensive knowledge of the mechanical properties of mine rocks. In this study, mechanical properties such as uniaxial compressive strength, point load, indirect tensile strength (Brazilian) as well as physical properties of rock such as density, porosity, compressive wave velocity (P-wave) and electrical resistivity were measured on selected samples taken from Choghart, Sechahoon, Lakeh Siah, Koushk, Bishehdar marble, Taft travertine, Ravar sandstone and the cores of 5 geotechnical boreholes from the Anomaly VI of Central Iran Iron Ore and 4 geotechnical boreholes of Chahgaz iron ore mine. The purpose of these measurements is investigating the relationship between mechanical and physical properties of the samples, especially electrical resistivity. In the first step, 300 surface and depth samples were collected from the mines mentioned above. After preparing the cores, effective porosity and density were recorded according to the standards (weighing the saturated and dry sample method). Also, the electrical resistivity was calculated by measuring the voltage and electrical current in the samples. The results demonstrated that there is a high correlation between P-wave velocity and electrical resistivity in all the samples. Furthermore, both parameters of P-wave velocity and electrical resistivity are dependent on porosity, and electrical resistivity like P-wave velocity, has a good relationship with mechanical properties of sedimentary rocks and volcano-sediments. Hence, the special electrical resistivity can be used as a non-destructive test to estimate the mechanical properties of rocks. Additionally, the presence of metal ores in the samples in low percentages does not cause errors in estimating physical and mechanical parameters as long as density is less than 2.8 gr/cm3. For samples with high metal content, induced polarization measurements can reduce uncertainty of the electrical resistivity.

Mineralosphere Microbiome Leading to Changed Geochemical Properties of Sedimentary Rocks from Aiqigou Mud Volcano, Northwest China.

The properties of rocks can be greatly affected by seepage hydrocarbons in petroleum-related mud volcanoes. Among them, the color of sedimentary rocks can reflect the changes of sedimentary environment and weathering history. However, little is known about the microbial communities and their biogeochemical significance in these environments. In this study, contrasting rock samples were collected from the Aiqigou mud volcano on the southern margin of the Junggar Basin in Northwest China as guided by rock colors indicative of redox conditions. The physicochemical properties and mineral composition are similar under the same redox conditions. For example, the content of chlorite, muscovite, quartz, and total carbon were higher, and the total iron was lower under reduced conditions compared with oxidized environments. High-throughput sequencing of 16S rRNA gene amplicons revealed that different functional microorganisms may exist under different redox conditions; microbes in oxidized conditions have higher diversity. Statistical analysis and incubation experiments indicated that the microbial community structure is closely related to the content of iron which may be an important factor for color stratification of continental sedimentary rocks in the Aiqigou mud volcano. The interactions between organics and iron-bearing minerals mediated by microorganisms have also been hypothesized.

Deformation characteristics of sedimentary rock due to continuous changes of moisture content in wetting process

In recent years, the number of cases where tunnels are constructed in sedimentary rock layers has increased. It is essential to investigate the deformation characteristics of sedimentary rocks for predicting tunnel deformation. The mechanical properties of sedimentary rocks are widely varied due to moisture content. The rocks are dried by tunnel excavation and wetted by groundwater gushing or backfilling. It is necessary to grasp the changes of deformation characteristics of sedimentary rocks due to moisture changes. In this study, soaking tests were conducted on Neogene period Japanese tuff sampled at Utsunomiya, Japan. In the test, the cylindrical tuff specimens are air dried by over 240 hours at first. Then the tuff specimens are taken in pure water with measuring deformations in detail. There are no effective stress increases by soaking and only uniform matric suction are acted on the specimen without any restraints. The results demonstrated that strain tensor was reached to stable state for 2 - 3 days, and the value of the normal strain perpendicular to the bedding plane is greater than the other normal components and shear strains are also observed in both cases. Although the orientation of the maximum principal strain is in the near of the bedding orientation at the initial dry state, the orientation are suddenly rotated to the normal orientation of the bedding plane. It means that the principal orientation of anisotropy are rotated due to continuous moisture changes.

Hydrologic and geomechanical characterization of deep sedimentary rocks and basement for safe carbon sequestration in the Cook Inlet Basin, Alaska

Understanding the hydrologic and geomechanical properties of sedimentary rocks and the underlying basement is important for the success of fluid extraction and injection operations, including carbon sequestration. This study analyzes the hydrologic and geomechanical properties of the reservoir (Hemlock Formation), overlying confining unit (Tyonek Formation), and underlying confining unit/basement (Talkeetna volcanics and Mesozoic igneous intrusive - diorite). This study shows the potential of fault slip due to carbon sequestration in the Cook Inlet basin of Alaska. We integrate core, well-log, and 3D seismic data to perform hydrologic and geomechanical analysis of the deep sedimentary formations, basement, and simulation of the fault slip potential (FSP). The FSP results show that faults have the potential to slip, depending on several factors, such as the local in-situ stress conditions, pore pressure, and CO2 injection rate. The azimuth of the maximum horizontal stress (σH) with respect to fault orientation is a critical factor for fault stability in the Cook Inlet basin.

Experimental Investigation into the Influences of Weathering on the Mechanical Properties of Sedimentary Rocks

The time-dependent behaviors of the sedimentary rocks which refer to the altering of the mechanical and deformable properties of rock elements in the long-term period are of increasing importance in the investigation of the failure mechanism of the rock strata in underground coal mines. In order to obtain the accurate and reliable mechanical parameters of the sedimentary rocks at different weathering grades, the extensive experimental programs including the Brazilian splitting test, uniaxial compression tests, and direct shear tests have been carried out on the specimens that exposed to the nature environments at different durations. The correlation between the weathering grades and mechanical parameters including uniaxial tensile strength, uniaxial compression strength, elastic modulus, Poisson’s ratio, cohesion, and friction coefficient was proposed. The obtained results suggested that uniaxial tensile strength, uniaxial compressive strength, elastic modulus, and cohesion dramatically decreased with increasing weathering time, characterized as the negative exponential relationship in general. The influences of various weathering grades on fracture behavior of the rock specimens were discussed. The cumulative damage of the rock by the weathering time decreased the friction coefficient of the specimens which led to the initiation and propagation of microcrack within the rock at lower stress conditions. The obtained results improved the understanding of the roles of weathering on the mechanical properties of sedimentary rocks, which is helpful in the design of the underground geotechnical structures.

Stress-orientation effects on the effective elastic anisotropy of complex fractured media using the lattice spring models coupled with discrete fracture networks model

Stresses oriented differently often cause azimuthal anisotropy in the effective elastic properties of sedimentary rocks. A quantitative analysis of stress-orientation effects is important to interpret the anisotropic characteristics of mechanical and sonic responses. Brazilian tests are conducted to numerically investigate the stress orientation dependence in complex fractured media. We have developed a consistent workflow of lattice spring models (LSMs) coupled with discrete fracture networks (DFNs). This LSM-DFN model could enable a highly accurate modeling by properly choosing reasonable meshing resolutions, damping values, and strain loading rates. Numerical experiments demonstrate that the angle between the preferred azimuth of cracks and the orientation of the loading stress significantly affect the equivalent elastic moduli. The stress-induced anisotropy of cracked media could be reflected by the tendency of stress-strain responses. LSM-DFN modeling of prestressed cracks has the potential for reconstructing realistic structural attributes and analyzing stress-orientation effects.

A cross-anisotropic elastoplastic model applied to sedimentary rocks

Strength and deformability properties of sedimentary rocks are difficult to characterize as these geomaterials show anisotropic mechanical behavior, which cannot be adequately evaluated by an isotropic constitutive model. This essay proposes a cross-anisotropic elastoplastic model to evaluate stress–strain relationships of sedimentary rocks. The approach couples the twelve-parameter Lade–Kim isotropic model with a non-uniform scaling of the stress tensor and includes two scaling parameters that link the orientation of the bedding planes with the loading direction. The anisotropic model parameters can be conveniently determined using Bayesian analysis. We illustrate our method using triaxial tests on a variety of confining stresses and bedding plane orientations for a travertine and a Tournemire shale. Our results demonstrate that the predicted maximum deviatoric stresses and the simulated stress–strain curves are shown to be in good agreement with the measured data.

Thermal Properties of Evaporitic Rocks and their Geothermal Effects on the Kuqa Foreland Basin, Northwest China

Many hydrocarbon reservoirs show a strong relationship with evaporitic rocks worldwide. Data regarding the thermal properties of evaporitic rocks are crucial for temperature prediction and basin modelling of salt-bearing sedimentary basins; however, their systematic measurement remains limited. This study reports a complete dataset of thermal properties of 20 evaporitic and clastic rocks from the Kuqa foreland basin, a typical Cenozoic salt-bearing basin with prolific hydrocarbon potential in northwest China. The results indicate that gypsum and rock salt have the lowest and highest thermal conductivity (1.57 ± 0.04 and 4.51 ± 0.73 W/m·K, respectively) and clastic rocks have an intermediate mean of 1.87–2.78 W/m·K. The average radiogenic heat production of evaporitic rocks is 0.10–0.14 μW/m3, remarkably lower than that of clastic rocks (1.33–1.38 μW/m3). Accordingly, thermal properties of the sedimentary rocks show a large variability in lithology. The mineral composition and porosity influence the thermal properties, and the geometric mixing model is confirmed to well predict the thermal properties of sedimentary rocks. Contrasts in the thermal properties between evaporites and other common sedimentary rocks could change the basin’s geothermal regime. This new dataset of thermal properties of evaporitic rocks provides parameters necessary in accurate basin modeling for salt-bearing basins.

Prediction of Mechanical Properties of Sedimentary Type Rocks Using Rotary Drilling Parameters

The estimation of strength properties of sedimentary rocks is most often needed during the preliminary phase of many rock engineering projects carrying out in sedimentary regions. The main drawback of determining the rock properties in a test center is the requirement of the number of superior quality rock core specimens. In this experimental investigation, the uniaxial compressive strength (UCS) and tensile strength of sedimentary rocks are estimating using well-identified drilling variables and acoustic parameters obtained during the rotary type rock drilling. The drilling variables such as thrust, torque, and vibration parameters are used to develop the mathematical models of strength properties of rock. A drill type dynamometer was used to measure the drilling variables, and the vibration parameter would measure using the NI-9234 data acquisition system. The prediction efficiency of the mathematical model is evaluating using performance indices. Results show that the used experimental method can estimate the considered responses (UCS and tensile strength) with the acceptable percentage errors of 10.52% and 11.27% respectively, and may be useful to measure the UCS and BTS of sedimentary rocks in a laboratory capacity without test core samples.

Influence of Humidity on the Energy of Specific Strain in the Process of Loading Sedimentary Rocks

Abstract This article presents the results of tests on the energy properties of sedimentary rocks in the Upper Silesian Coal Basin. The rocks were tested both in an air-dry state and in a water saturation state. Samples of sedimentary rocks were collected from boreholes drilled in the underground workings of coal mines located within the area of the city of Jastrzębie, in the areas of the Chwałowice Trough and Rybnik Trough (south-western part of the Upper Silesian Coal Basin) and in the Main Trough. Influence of saturation condition on the values of the tested energy parameters was observed. The values of elastic energy and dissipated energy obtained for the samples tested in water saturation were lower compared to the values obtained for samples tested in air-dry state. As observed, an increase in the values of the given types of specific energy corresponds to an increase in the uniaxial compression strength in air-dry state and in water saturation state. Results of the tests are original and they can be applied while analysing the possibility of the occurrence of some dynamic phenomena and hazards in mine workings in Carboniferous rock mass in the Upper Silesian Coal Basin, caused by mining operations.

A Darcy‐Brinkman‐Biot Approach to Modeling the Hydrology and Mechanics of Porous Media Containing Macropores and Deformable Microporous Regions

AbstractThe coupled hydrology and mechanics of soft porous materials (such as clays, hydrogels, membranes, and biofilms) is an important research area in several fields, including water and energy technologies as well as biomedical engineering. Well‐established models based on poromechanics theory exist for describing these coupled properties, but these models are not adapted to describe systems with more than one characteristic length scale, that is, systems that contain both macropores and micropores. In this paper, we expand upon the well‐known Darcy‐Brinkman formulation of fluid flow in two‐scale porous media to develop a “Darcy‐Brinkman‐Biot” formulation: a general coupled system of equations that approximates the Navier‐Stokes equations in fluid‐filled macropores and resembles the equations for poroelasticity in microporous regions. We parameterized and validated our model for systems that contain either plastic (swelling clay) or elastic microporous regions. In particular, we used our model to predict the permeability of an idealized siliciclastic sedimentary rock as a function of pore water salinity and clay content. Predicted permeability values are well described by a single parametric relation between permeability and clay volume fraction that agrees with existing experimental data sets. Our novel formulation captures the coupled hydro‐chemo‐mechanical properties of sedimentary rocks and other deformable porous media in a manner that can be readily implemented within the framework of Digital Rock Physics.