Clay Mineral Preferred Orientation - How to Predict It and What It Might Control

2014 ◽  
Author(s):  
R.J. Day-Stirrat
Keyword(s):  
Clay Mineral ◽  
Preferred Orientation

The Alteration Characteristics of the Lower Oxford Clay

Clay Minerals ◽  
1973 ◽  
Vol 10 (2) ◽  
pp. 113-126 ◽  
Author(s):  
J. O. Jackson
Keyword(s):  
Clay Mineral ◽  
Laboratory Tests ◽  
Prolonged Exposure ◽  
Geotechnical Properties ◽  
Preferred Orientation ◽  
Mineral Component ◽  
Short Term ◽  
Clay Shales ◽  
Hard Samples

AbstractAlternating 'hard' and 'soft' bands at close intervals are exhibited by the slope faces of brick-pits in the Lower Oxford Clay which have been subjected to prolonged exposure. This phenomenon was investigated to evaluate the geotechnical properties which were significant in its development. The results of laboratory tests indicate that the alteration or short-term weathering characteristics of clay-shales may be influenced by the higher degree of preferred orientation of the clay-mineral component, in inducing a stronger inter-particle bond in 'hard' samples which inhibits weathering.

scholarly journals Computation of effective elastic properties of clay from X-ray texture goniometry data

Geophysics ◽  
2018 ◽  
Vol 83 (5) ◽  
pp. MR245-MR261 ◽  
Author(s):  
Laurent Louis ◽  
Ruarri Day-Stirrat ◽  
Ronny Hofmann ◽  
Nishank Saxena ◽  
Anja M. Schleicher
Keyword(s):  
Clay Mineral ◽  
Elastic Anisotropy ◽  
Clay Fraction ◽  
Preferred Orientation ◽  
Rock Properties ◽  
Data Set ◽  
Orientation Data ◽  
Large Variability ◽  
Shear Moduli ◽  
X Ray

We have developed a new method for estimating the contribution of a pure clay fraction (i.e., devoid of organic matter) to the total effective rock stiffness. The method is based on published clay mineral stiffness data and on an original preferred clay mineral orientation data set obtained by X-ray texture goniometry on 56 samples of Kimmeridgian and Devonian age from two North American shale plays. We find that (1) large variability in preferred orientation of clay results in moderate variability in effective clay elastic anisotropy and (2) the effect of variations in the preferred orientation on effective rock properties is small compared with the effects of variations in clay abundance. As a result, a single clay elastic tensor is computed to be used in effective medium models. In addition, to account for various degrees of hydration, water is incorporated into the dry clay tensor through inclusion models. In situations in which isotropic approximations are necessary, we also provide apparent bulk and shear moduli for a hydrated clay fraction as a function of porosity and propagation angle.

The Microstructure of Shock-Synthesized Diamond

1967 ◽  
Vol 25 ◽  
pp. 324-325
Author(s):  
Lucien F. Trueb
Keyword(s):  
Single Crystals ◽  
Preferred Orientation ◽  
High Magnification ◽  
Texture Pattern ◽  
Shock Process ◽  
New Type ◽  
Diffraction Diagram

A new type of synthetic industrial diamond formed by an explosive shock process has been recently developed by the Du Pont Company. This material consists of a mixture of two basically different forms, as shown in Figure 1: relatively flat and compact aggregates of acicular crystallites, and single crystals in the form of irregular polyhedra with straight edges.Figure 2 is a high magnification micrograph typical for the fibrous aggregates; it shows that they are composed of bundles of crystallites 0.05-0.3 μ long and 0.02 μ. wide. The selected area diffraction diagram (insert in Figure 2) consists of a weak polycrystalline ring pattern and a strong texture pattern with arc reflections. The latter results from crystals having preferred orientation, which shows that in a given particle most fibrils have a similar orientation.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Existence of Cubic ZrO2 at 300°C on Bulk Zirconium

1969 ◽  
Vol 27 ◽  
pp. 166-167
Author(s):  
R.A. Ploc
Keyword(s):  
Metal Oxide ◽  
Metal Substrate ◽  
Preferred Orientation ◽  
Monoclinic Zirconia ◽  
Epitaxial Relationship

The manner in which ZrO2 forms on zirconium at 300°C in air has been discussed in the first reference. In short, monoclinic zirconia nucleates and grows with a preferred orientation relative to the metal substrate. The mode of growth is not well understood since an epitaxial relationship which gives minimum misfit between the zirconium ions in the metal/oxide combination is not realized. The reason may be associated with a thin cubic or tetragonal layer of ZrO2 between the inner oxygen saturated metal and the outer monoclinic zirconia.

Preferred orientation of rolling-induced ε martensite in an Fe-Mn-Si alloy

2003 ◽  
Vol 112 ◽  
pp. 365-368 ◽  
Author(s):  
K. K. Jee ◽  
W. Y. Jang ◽  
Y. H. Chung
Keyword(s):  
Preferred Orientation ◽  
Ε Martensite

Depositional Environment Drive as Overpressure Generation: Study Case in “Gap” Field, North West Java Basin

2020 ◽  
Author(s):  
A., C. Prasetyo
Keyword(s):  
Clay Mineral ◽  
Depositional Environment ◽  
Mineral Content ◽  
Hydrocarbon Generation ◽  
Well Test ◽  
Burial History ◽  
The South ◽  
North West ◽  
The North ◽  
Geological Processes

Overpressure existence represents a geological hazard; therefore, an accurate pore pressure prediction is critical for well planning and drilling procedures, etc. Overpressure is a geological phenomenon usually generated by two mechanisms, loading (disequilibrium compaction) and unloading mechanisms (diagenesis and hydrocarbon generation) and they are all geological processes. This research was conducted based on analytical and descriptive methods integrated with well data including wireline log, laboratory test and well test data. This research was conducted based on quantitative estimate of pore pressures using the Eaton Method. The stages are determining shale intervals with GR logs, calculating vertical stress/overburden stress values, determining normal compaction trends, making cross plots of sonic logs against density logs, calculating geothermal gradients, analyzing hydrocarbon maturity, and calculating sedimentation rates with burial history. The research conducted an analysis method on the distribution of clay mineral composition to determine depositional environment and its relationship to overpressure. The wells include GAP-01, GAP-02, GAP-03, and GAP-04 which has an overpressure zone range at depth 8501-10988 ft. The pressure value within the 4 wells has a range between 4358-7451 Psi. Overpressure mechanism in the GAP field is caused by non-loading mechanism (clay mineral diagenesis and hydrocarbon maturation). Overpressure distribution is controlled by its stratigraphy. Therefore, it is possible overpressure is spread quite broadly, especially in the low morphology of the “GAP” Field. This relates to the delta depositional environment with thick shale. Based on clay minerals distribution, the northern part (GAP 02 & 03) has more clay mineral content compared to the south and this can be interpreted increasingly towards sea (low energy regime) and facies turned into pro-delta. Overpressure might be found shallower in the north than the south due to higher clay mineral content present to the north.

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