Petrophysical characteristics of shales from the Scotian shelf

Geophysics ◽  
1991 ◽  
Vol 56 (10) ◽  
pp. 1681-1689 ◽  
Author(s):  
T. J. Katsube ◽  
B. S. Mudford ◽  
M. E. Best
Keyword(s):  
Sedimentary Basin ◽  
Mercury Porosimetry ◽  
Flow Path ◽  
Basin Modeling ◽  
Formation Factor ◽  
Scotian Shelf ◽  
Stress Strain ◽  
Porosity Formation ◽  
Strain Measurements ◽  
Shale Permeability

Permeability, porosity, formation factor, mercury porosimetry, and stress‐strain measurements were made on 10 shale samples taken at depths between 4500 m and 5600 m in three wells on the Scotian shelf. The purpose was to obtain shale permeability values for quantitative sedimentary basin modeling and to investigate the reasons for the very low permeabilities, less than [Formula: see text] (10 nD), exhibited by many tight shales. Permeabilities of [Formula: see text] ([Formula: see text]) and porosities of 0.9–9.2 percent were measured. The results suggest that the extremely low permeabilities occur because the flow path consists of a network of very tortuous pores (true tortuosity = 3.3) with small diameters, of the order of 8–16 nm. Presence of calcite and dolomite apparently is associated with reduced porosity, possibly a result of blocking of the pores, while kaolinite shows the reverse trend.

scholarly journals Comparison of waveform-derived corneal stiffness and stress-strain extensometry-derived corneal stiffness using different cross-linking irradiances: an experimental study with air-puff applanation of ex vivo porcine eyes

2020 ◽  
Vol 258 (10) ◽  
pp. 2173-2184 ◽  
Author(s):  
Robert Herber ◽  
Mathew Francis ◽  
Eberhard Spoerl ◽  
Lutz E. Pillunat ◽  
Frederik Raiskup ◽  
...  
Keyword(s):  
Experimental Study ◽  
Ex Vivo ◽  
Cross Linking ◽  
Displacement Curve ◽  
Stress Strain ◽  
Strain Measurements ◽  
Deflection Amplitude ◽  
Force Displacement ◽  
Stiffening Effect ◽  
Porcine Eyes

Abstract Purpose To assess corneal stiffening of standard (S-CXL) and accelerated (A-CXL) cross-linking protocols by dynamic corneal response parameters and corneal bending stiffness (Kc[mean/linear]) derived from Corvis (CVS) Scheimpflug-based tonometry. These investigations were validated by corneal tensile stiffness (K[ts]), derived from stress-strain extensometry in ex vivo porcine eyes. Methods Seventy-two fresh-enucleated and de-epithelized porcine eyes were soaked in 0.1% riboflavin solution including 10% dextran for 10 min. The eyes were separated into four groups: controls (n = 18), S-CXL (intensity in mW/cm2*time in min; 3*30) (n = 18), A-CXL (9*10) (n = 18), and A-CXL (18*5) (n = 18), respectively. CXL was performed using CCL Vario. CVS measurements were performed on all eyes. Subsequently, corneal strips were extracted by a double-bladed scalpel and used for stress-strain measurements. K[ts] was calculated from a force-displacement curve. Mean corneal stiffness (Kc[mean]) and constant corneal stiffness (Kc[linear]) were calculated from raw CVS data. Results In CVS, biomechanical effects of cross-linking were shown to have a significantly decreased deflection amplitude as well as integrated radius, an increased IOP, and SP A1 (P < 0.05). Kc[mean]/Kc[linear] were significantly increased after CXL (P < 0.05). In the range from 2 to 6% strain, K[ts] was significantly higher in S-CXL (3*30) compared to A-CXL (9*10), A-CXL (18*5), and controls (P < 0.05). At 8% to 10% strain, all protocols induced a higher stiffness than controls (P < 0.05). Conclusion Several CVS parameters and Kc[mean] as well as Kc[linear] verify corneal stiffening effect after CXL on porcine eyes. S-CXL seems to have a higher tendency of stiffening than A-CXL protocols have, which was demonstrated by Scheimpflug-based tonometry and stress-strain extensometry.

Differential ultrasonic stress–strain measurements

1999 ◽  
Vol 106 (4) ◽  
pp. 2167-2167
Author(s):  
Sissay Hailu ◽  
Gary R. Halford ◽  
Dov Hazony ◽  
Gerhard Welsch
Keyword(s):  
Stress Strain ◽  
Strain Measurements

Historical-geological modeling of hydrocarbon generation in the Mesozoic–Cenozoic sedimentary basin of the Kara Sea (basin modeling)

2013 ◽  
Vol 54 (8) ◽  
pp. 917-957 ◽  
Author(s):  
A.E. Kontorovich ◽  
L.M. Burshtein ◽  
N.A. Malyshev ◽  
P.I. Safronov ◽  
S.A. Gus’kov ◽  
...  
Keyword(s):  
Sedimentary Basin ◽  
Kara Sea ◽  
Hydrocarbon Generation ◽  
Basin Modeling ◽  
Geological Modeling

scholarly journals Direct Stress-Strain Measurements from Bulged Membranes Using Topography Image Correlation

2014 ◽  
Vol 54 (5) ◽  
pp. 717-727 ◽  
Author(s):  
J. Neggers ◽  
J. P. M. Hoefnagels ◽  
F. Hild ◽  
S. Roux ◽  
M. G. D. Geers
Keyword(s):  
Image Correlation ◽  
Stress Strain ◽  
Strain Measurements

Tensile Stress—Strain Measurements for Characterization of Gum Elastomers and Filled Compounds

1990 ◽  
Vol 63 (4) ◽  
pp. 624-636 ◽  
Author(s):  
N. Nakajima ◽  
M. H. Chu ◽  
R. Babrowicz
Keyword(s):  
Shear Modulus ◽  
Tensile Stress ◽  
Shear Deformation ◽  
Tensile Modulus ◽  
Nonlinear Behavior ◽  
Material Behavior ◽  
Structural Constraints ◽  
Stress Strain ◽  
Strain Measurements ◽  
Diene Rubbers

Abstract For a gum elastomer in its amorphous, isotropic state, shear modulus and tensile modulus are related with a factor of three. This relation is maintained in the range of temperature and time scale defining the rubbery region of the material behavior. When a large deformation is imposed, for example, in tensile stress—strain measurements, the above relation may still be preserved, if the nonlinear behavior can be linearized. The strain—time correspondence principle is the linearization scheme of this work. When a gum elastomer contains various structural constraints, the factor three relation does not apply, even after the application of the above linearization scheme. Example of constraints are excessive amounts of long branches, gel, molecular associations, and reinforcing fillers. These constraints usually make the factor larger than three. This is because the constraints make the large, elongational deformation more difficult to achieve compared to shear deformation. An example of gum elastomer in this work is a polyethylacrylate containing a significant amount of gel. With this polymer, both the presence of gel and the molecular association act as the constraints. However, when 50 phr of carbon blacks are added, the fillers do not act as strong constraints as they do when they are in the diene rubbers. This is because the polyethylacrylate is known to have a weaker affinity to carbon black compared to the diene rubbers. Triblock copolymers, styrene—isoprene—styrene, were examined according to the above treatment; 25% polystyrene copolymer exhibited crosslink-like behavior by the polystyrene domains. However, 14% polystyrene copolymers acted as if they are no crosslinks. When these copolymers are diluted to 44% with an addition of 56% tackifier, the ratio of tensile to shear modulus became less than three. The styrene domains must have effective crosslinks at the small shear deformation, but at large tensile deformations such crosslinks must not be present.

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