scholarly journals Combination of Minimum-Maximum (m-m) Attribute and Zero-INTENS-Difference (z-i-d) Attribute for Estimating Seismically Thin-Bed Thickness

2011 ◽  
Vol 43 (2) ◽  
pp. 79-100
Author(s):  
Eko Widi Purnomo ◽  
Zuhar Zahir Tuan Harith
Keyword(s):  
Bed Thickness

Application of microgravimetric survey in Samawa salt deposit, Iraq

Geophysics ◽  
1989 ◽  
Vol 54 (4) ◽  
pp. 440-444 ◽  
Author(s):  
F. R. Al‐Rawi ◽  
A. S. Al‐Badri ◽  
J. S. Rezkalla
Keyword(s):  
Field Measurements ◽  
Control Points ◽  
Salt Deposit ◽  
General Shape ◽  
Maximum Thickness ◽  
Bed Thickness

The applicability of microgravimetric surveys for determining the thickness and shape of a salt deposit has been explored by carrying out field measurements. The survey includes five profiles crossing a Samawa salt deposit that attains a maximum thickness of about 8.5 m. The results indicate that the method can be applied successfully if a few boreholes are available as control points to define the local regional field. A simple sheet formula with a fixed density value was used in determining the bed thickness and the general shape of the deposit. The thicknesses calculated in this way agree well with the available borehole information.

High-resolution stratigraphic characterization of natural fracture attributes in the Woodford Shale, Arbuckle Wilderness and US-77D Outcrops, Murray County, Oklahoma

2018 ◽  
Vol 6 (1) ◽  
pp. SC29-SC41 ◽  
Author(s):  
Sayantan Ghosh ◽  
John N. Hooker ◽  
Caleb P. Bontempi ◽  
Roger M. Slatt
Keyword(s):  
Natural Fracture ◽  
Fracture Aperture ◽  
Aperture Size ◽  
Fracture Density ◽  
Area Formula ◽  
Woodford Shale ◽  
Fracture Spacing ◽  
Spacing Ratio ◽  
Fracture Intensity ◽  
Bed Thickness

Natural fracture aperture-size, spacing, and stratigraphic variation in fracture density are factors determining the fluid-flow capacity of low-permeability formations. In this study, several facies were identified in a Woodford Shale complete section. The section was divided into four broad stratigraphic zones based on interbedding of similar facies. Average thicknesses and percentages of brittle and ductile beds in each stratigraphic foot were recorded. Also, five fracture sets were identified. These sets were split into two groups based on their trace exposures. Fracture linear intensity (number of fractures normalized to the scanline length [[Formula: see text]]) values were quantified for brittle and ductile beds. Individual fracture intensity-bed thickness linear equations were derived. These equations, along with the average bed thickness and percentage of brittle and ductile lithologies in each stratigraphic foot, were used to construct a fracture areal density (number of fracture traces normalized to the trace exposure area [[Formula: see text]]) profile. Finally, the fracture opening-displacement size variations, clustering tendencies, and fracture saturation were quantified. Fracture intensity-bed thickness equations predict approximately 1.5–3 times more fractures in the brittle beds compared with ductile beds at any given bed thickness. Parts of zone 2 and almost entire zone 3, located in the upper and middle Woodford, respectively, have high fracture densities and are situated within relatively organic-rich (high-GR) intervals. These intervals may be suitable horizontal well landing targets. All observed fracture cement exhibit a lack of crack-seal texture. Characteristic aperture-size distributions exist, with most apertures in the 0.05–1 mm (0.00016–0.0032 ft) range. In the chert beds, fracture cement is primarily bitumen or silica or both. Fractures in dolomite beds primarily have calcite cement. The average fracture spacing indices (i.e., bed thickness-fracture spacing ratio) in brittle and ductile beds were determined to be 2 and 1.2, respectively. Uniform fracture spacing was observed along all scanlines in the studied beds.

GRAVITY ANOMALIES OF TWO‐DIMENSIONAL FAULTS

Geophysics ◽  
1966 ◽  
Vol 31 (2) ◽  
pp. 372-397 ◽  
Author(s):  
L. P. Geldart ◽  
Denis E. Gill ◽  
Bijon Sharma
Keyword(s):  
Fault Plane ◽  
Marked Effect ◽  
Gravity Anomalies ◽  
Two Dimensional ◽  
Gravity Effect ◽  
Fault Density ◽  
Wide Range ◽  
Bed Thickness ◽  
Two Sides ◽  
Simplified Formula

A simplified formula is given for the gravity effect of a horizontal semi‐infinite block truncated by a dipping plane. This formula is used to obtain curves illustrating the gravity anomalies for blocks having different thicknesses and depths truncated by planes dipping at various angles. By combining two blocks, results are obtained for faulted horizontal beds for a wide range of bed thicknesses and depths, fault displacements and dips. These should be useful as guides in interpreting fault anomalies, and in planning gravity programs intended to map faults. The most striking feature of the curves is the marked effect of the dip of the fault plane on the curves for faulted beds. The asymmetry of the fault curves is related mainly to the dip and can be used to determine dips between 30 and 90 degrees. If the dip of the fault, density contrast, and bed thickness are known, the depths to the bed on the two sides of the fault are given by the sizes and positions of the gravity maximum and minimum.

How Computational Grid Refinement in Three Dimensions Affects CFD-DEM Results for Psuedo-2D Fluidized Gas-Solid Beds

2017 ◽  
Author(s):  
Annette Volk ◽  
Urmila Ghia
Keyword(s):  
Three Dimensional ◽  
Computational Grid ◽  
Three Dimensions ◽  
Computational Grids ◽  
Grid Refinement ◽  
2D Simulation ◽  
Computational Fluid Dynamics Cfd ◽  
Bed Thickness ◽  
Simulation Results ◽  
Accuracy Of Results

Computational Fluid Dynamics (CFD)-Discrete Element Method (DEM) simulations are designed to model a pseudo-two-dimensional fluidized bed. Bed behavior and accuracy of results are shown to change as the simulations are conducted on increasingly refined computational grids. Trends of the results with grid refinement are reported for both three-dimensional, uniform refinement, and for grid refinement in only the direction of bed thickness. Pseudo-2D simulation results are examined against previously published experimental data to assess relative accuracy compared to fully 3D simulation results. Two drag laws are employed in the simulations, resulting in different trends of results with computational grid refinement. From these results, we present suggestions for accurate model design.

scholarly journals Design of a new hybrid artificial neural network method based on decision trees for calculating the Froude number in rigid rectangular channels

2016 ◽  
Vol 64 (3) ◽  
pp. 252-260 ◽  
Author(s):  
Isa Ebtehaj ◽  
Hossein Bonakdari ◽  
Amir Hossein Zaji ◽  
Charles Hin Joo Bong ◽  
Aminuddin Ab Ghani
Keyword(s):  
Decision Trees ◽  
Incipient Motion ◽  
Rigid Boundary ◽  
Sediment Bed ◽  
Economical Design ◽  
Rectangular Channels ◽  
Wide Range ◽  
Practical Engineering ◽  
Artificial Neural Network Method ◽  
Bed Thickness

Abstract A vital topic regarding the optimum and economical design of rigid boundary open channels such as sewers and drainage systems is determining the movement of sediment particles. In this study, the incipient motion of sediment is estimated using three datasets from literature, including a wide range of hydraulic parameters. Because existing equations do not consider the effect of sediment bed thickness on incipient motion estimation, this parameter is applied in this study along with the multilayer perceptron (MLP), a hybrid method based on decision trees (DT) (MLP-DT), to estimate incipient motion. According to a comparison with the observed experimental outcome, the proposed method performs well (MARE = 0.048, RMSE = 0.134, SI = 0.06, BIAS = -0.036). The performance of MLP and MLP-DT is compared with that of existing regression-based equations, and significantly higher performance over existing models is observed. Finally, an explicit expression for practical engineering is also provided.

Sign in / Sign up

Export Citation Format

Share Document