Sandstone compaction, grain packing and Critical State Theory

Pettersen, Øystein

doi:10.1144/1354-079305-677

Cited by 10 publications

(12 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the initial loading of sands, a rapid increase of packing density and soil strength is expected due to grain reorganization (Pettersen, 2007). As packing becomes tighter, further packing will be increasingly more difficult to achieve, each packing level is more stable than previous levels and deformation is permanent.…”

Section: B Rogiers Et Al: Testing Outcrop Hydrogeological Parametermentioning

confidence: 99%

The usefulness of outcrop-analogue air-permeameter measurements for analysing aquifer heterogeneity: testing outcrop hydrogeological parameters with independent borehole data

Rogiers

Beerten

Smeekens

et al. 2013

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. Outcropping sediments can be used as easily accessible analogues for studying subsurface sediments, especially to determine the small-scale spatial variability of hydrogeological parameters. The use of cost-effective in situ measurement techniques potentially makes the study of outcrop sediments even more attractive. We investigate to what degree air-permeameter measurements on outcrops of unconsolidated sediments can be a proxy for aquifer saturated hydraulic conductivity (K) heterogeneity. The Neogene aquifer in northern Belgium, known as a major groundwater resource, is used as the case study. K and grain-size data obtained from different outcropping sediments are compared with K and grain-size data from aquifer sediments obtained either via laboratory analyses on undisturbed borehole cores (K and grain size) or via large-scale pumping tests (K only). This comparison shows a pronounced and systematic difference between outcrop and aquifer sediments. Part of this difference is attributed to grain-size variations and earth surface processes specific to outcrop environments, including root growth, bioturbation, and weathering. Moreover, palaeoenvironmental conditions such as freezing-drying cycles and differential compaction histories will further alter the initial hydrogeological properties of the outcrop sediments. A linear correction is developed for rescaling the outcrop data to the subsurface data. The spatial structure pertaining to outcrops complements that obtained from the borehole cores in several cases. The higher spatial resolution of the outcrop measurements identifies small-scale spatial structures that remain undetected in the lower resolution borehole data. Insights in stratigraphic and K heterogeneity obtained from outcrop sediments improve developing conceptual models of groundwater flow and transport.

show abstract

Section: B Rogiers Et Al: Testing Outcrop Hydrogeological Parametermentioning

confidence: 99%

The usefulness of outcrop-analogue air-permeameter measurements for analysing aquifer heterogeneity: testing outcrop hydrogeological parameters with independent borehole data

Rogiers

Beerten

Smeekens

et al. 2013

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

“…Most laboratory mechanical compaction studies acquiring acoustic and petrophysical measurements reported in the literature employ normal loading stress paths, where the stress increment applied to the samples mimics normal progressive burial, for example in sands or sandstones (Yin 1992;Tao, King and Nabi-Bidhendi 1995;Dvorkin and Nur 1996;Chuhan et al 2003;Pettersen 2007;Mondol et al 2010;Fawad et al 2011;Grande, Mondol and Berre 2011;Bhuiyan, Holt and Stenebråten 2013), and in different clays, mudstones and shales (Jones and Wang 1981;Goulty 1998;Hornby 1998;Wang 2002a,b;Mondol et al 2007;Dewhurst et al 2011, Sarout et al 2014, 2017.…”

mentioning

confidence: 99%

Acoustic and petrophysical properties of mechanically compacted overconsolidated sands: part 1 – experimental results

Narongsirikul

Mondol

Jahren

2019

Geophysical Prospecting

View full text Add to dashboard Cite

This paper part one is set out to lay primary observations of experimental compaction measurements to form the basis for rock physics modelling in paper part two. P‐ and S‐wave velocities and corresponding petrophysical (porosity and density) properties of seven unconsolidated natural sands with different mineralogical compositions and textures are reported. The samples were compacted in a uniaxial strain configuration from 0.5 up to 30 MPa effective stresses. Each sand sample was subjected to three loading cycles to study the influence of stress reduction on acoustic velocities and rock physical properties with the key focus on simulating a complex burial history with periods of uplift. Results show significant differences in rock physical properties between normal compaction and overconsolidation (unloaded and reloaded). The differences observed for total porosity, density, and P‐ and S‐wave velocities are attributed to irrecoverable permanent deformation. Microtextural differences affect petrophysical, acoustic, elastic and mechanical properties, mostly during normal consolidation but are less significant during unloading and reloading. Different pre‐consolidation stress magnitudes, stress conditions (isotropic or uniaxial) and mineral compositions do not significantly affect the change in porosity and velocities during unloading as a similar steep velocity–porosity gradient is observed. The magnitude of change in the total porosity is low compared to the associated change in P‐ and S‐wave velocities during stress release. This can be explained by the different sensitivity of the porosity and acoustic properties (velocities) to the change in stress. Stress reduction during unloading yields maximum changes in the total porosity, P‐ and S‐wave velocities of 5%, 25%, and 50%, respectively. These proportions constitute the basis for the following empirical (approximation) correlations: Δϕ ∼ ±5 ΔVP and ΔVP ∼ ±2ΔVS. The patterns observed in the experiments are similar to well log data from the Barents Sea. Applications to rock physics modelling and reservoir monitoring are reported in a companion paper.

show abstract

Section: Introductionmentioning

confidence: 99%

“…The seismic and rock mechanical relations of normally compacted sediments have been investigated extensively through laboratory experiments on compacted sands studies (Yin 1992;Tao, King and Nabi-Bidhendi 1995;Dvorkin and Nur 1996;Chuhan et al 2003;Pettersen 2007;Mondol et al 2010;Fawad et al 2011;Bhuiyan et al 2013). Such experiments lead to a good collection of data that can be utilized for geomechanics and seismic integration for normal consolidation (NC) stress conditions.…”

Section: Introductionmentioning

confidence: 99%

Effects of stress reduction on geomechanical and acoustic relationship of overconsolidated sands

Narongsirikul

Mondol

Jahren

2019

Geophysical Prospecting

View full text Add to dashboard Cite

A B S T R A C TRelationship between different geomechanical and acoustic properties measured from seven laboratory-tested unconsolidated natural sands with different mineralogical compositions and textures were presented. The samples were compacted in the uniaxial strain configuration from 0.5 to 30 MPa effective stress. Each sand sample was subjected to three loading-unloading cycles to study the influence of stress reduction. Geomechanical, elastic and acoustic parameters are different between normal compaction and overconsolidation (unloaded and reloaded). Stress path (K 0 ) data differ between normal consolidated and overconsolidated sediments. The K 0 value of approximately 0.5 is founded for most of the normal consolidated sands, but varies during unloading depending on mineral compositions and textural differences. The K 0 and overconsolidation ratio relation can be further simplified and can be influenced by the material compositions. K 0 can be used to estimate horizontal stress for drilling applications. The relationship between acoustic velocity and geomechanical is also found to be different between loading and unloading conditions. The static moduli of the overconsolidated sands are much higher than normal consolidated sands as the deformation is small (small strain). The correlation between dynamic and static elastic moduli is stronger for an overconsolidation stage than for a normal consolidation stage. The results of this study can contribute to geomechanical and acoustic dataset which can be applied for many seismic-geomechanics applications in shallow sands where mechanical compaction is the dominant mechanism.

show abstract

Sandstone compaction, grain packing and Critical State Theory

Cited by 10 publications

References 18 publications

The usefulness of outcrop-analogue air-permeameter measurements for analysing aquifer heterogeneity: testing outcrop hydrogeological parameters with independent borehole data

The usefulness of outcrop-analogue air-permeameter measurements for analysing aquifer heterogeneity: testing outcrop hydrogeological parameters with independent borehole data

Acoustic and petrophysical properties of mechanically compacted overconsolidated sands: part 1 – experimental results

Effects of stress reduction on geomechanical and acoustic relationship of overconsolidated sands

Contact Info

Product

Resources

About