Using 3D finite-difference modeling to design wide-azimuth surveys for improved subsalt imaging

Geophysics ◽  
2007 ◽  
Vol 72 (5) ◽  
pp. SM231-SM239 ◽  
Author(s):  
Carl J. Regone
Keyword(s):  
Image Quality ◽  
Finite Difference ◽  
Three Dimensional ◽  
Design Parameters ◽  
Ocean Bottom ◽  
Field Development ◽  
Wide Range ◽  
Dense Grid ◽  
Subsalt Imaging ◽  
Important Design

Three-dimensional finite-difference modeling studies conducted over subsalt structures in the deepwater Gulf of Mexico confirm the deficiencies of narrow-azimuth towed-streamer surveys and predict significant improvement in image quality with wide-azimuth methods. Finite-difference modeling has provided important design parameters for two separate approaches for wide-azimuth surveys: ocean-bottom receivers distributed in a sparse grid on the ocean floor coupled with a dense grid of source points on the surface, and a wide-azimuth towed-streamer method using multiple seismic vessels in a novel configuration. These two methods complement each other. Ocean-bottom receivers may be used effectively where field development has resulted in many obstacles that might interfere with towed-streamer methods, where the required size of the 3D survey is not too extensive, or where very long offsets are required for all azimuths. Towed-streamer methods are more efficient for large surveys, and key parameters in the wide-azimuth towed-streamer method can be varied to provide a wide range of cost versus data-quality options to make the method suitable for application in scenarios ranging from exploration to field development.

Acquire Ocean Bottom Seismic Data and Time-Lapse Geochemistry Data Simultaneously to Identify Compartmentalization and Map Hydrocarbon Movement

2021 ◽  
Author(s):  
Rick Schrynemeeckers
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
Time Lapse ◽  
Field Trials ◽  
Detection Methods ◽  
Ocean Bottom ◽  
Field Development ◽  
Dense Grid ◽  
Hydrocarbon Charge ◽  
Sweet Spots

Abstract Current offshore hydrocarbon detection methods employ vessels to collect cores along transects over structures defined by seismic imaging which are then analyzed by standard geochemical methods. Due to the cost of core collection, the sample density over these structures is often insufficient to map hydrocarbon accumulation boundaries. Traditional offshore geochemical methods cannot define reservoir sweet spots (i.e. areas of enhanced porosity, pressure, or net pay thickness) or measure light oil or gas condensate in the C7 – C15 carbon range. Thus, conventional geochemical methods are limited in their ability to help optimize offshore field development production. The capability to attach ultrasensitive geochemical modules to Ocean Bottom Seismic (OBS) nodes provides a new capability to the industry which allows these modules to be deployed in very dense grid patterns that provide extensive coverage both on structure and off structure. Thus, both high resolution seismic data and high-resolution hydrocarbon data can be captured simultaneously. Field trials were performed in offshore Ghana. The trial was not intended to duplicate normal field operations, but rather provide a pilot study to assess the viability of passive hydrocarbon modules to function properly in real world conditions in deep waters at elevated pressures. Water depth for the pilot survey ranged from 1500 – 1700 meters. Positive thermogenic signatures were detected in the Gabon samples. A baseline (i.e. non-thermogenic) signature was also detected. The results indicated the positive signatures were thermogenic and could easily be differentiated from baseline or non-thermogenic signatures. The ability to deploy geochemical modules with OBS nodes for reoccurring surveys in repetitive locations provides the ability to map the movement of hydrocarbons over time as well as discern depletion affects (i.e. time lapse geochemistry). The combined technologies will also be able to: Identify compartmentalization, maximize production and profitability by mapping reservoir sweet spots (i.e. areas of higher porosity, pressure, & hydrocarbon richness), rank prospects, reduce risk by identifying poor prospectivity areas, accurately map hydrocarbon charge in pre-salt sequences, augment seismic data in highly thrusted and faulted areas.

Computational Study of a Target Fluidic Flowmeter

2010 ◽  
Author(s):  
Andrzej F. Nowakowski ◽  
Franck C. G. A. Nicolleau ◽  
S. M. Muztaba Salim
Keyword(s):  
Reynolds Number ◽  
Computational Study ◽  
Numerical Technique ◽  
Three Dimensional ◽  
Boundary Layer Separation ◽  
Structure Design ◽  
Design Parameters ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Wide Range

The computational studies on the flow structure, design and performance of a target fluidic flowmeter have been carried out. The computational challenge was to find a universal approach to study a wide range of flow regimes. To this end the Detached Eddy Simulation (DES) approach for unsteady flows was applied. The numerical technique enabled to accurately reproduced three dimensional flow structures in a target fluidic flowmeter. The signal analysis of the obtained results was conducted for a range of Reynolds numbers from laminar case up to 4000. The results show that a number of factors such as meter geometry and aspect ratio can influence the performance of the flow meter significantly. A minimum Reynolds number constraint for the measurements to be accurate was evaluated for various design parameters. The significance of using knife edges which influence boundary layer separation was also established. The experimental data, which were obtained for a prototype of flowmeter setup were used to validate numerical tools in the important area of low Reynolds number flows.

Probabilistic Investigation of Foundation Design for Offshore Gravity Structures

1976 ◽  
Vol 16 (02) ◽  
pp. 97-109 ◽  
Author(s):  
L.M. Kraft ◽  
J.D. Murff
Keyword(s):  
Prestressed Concrete ◽  
Soil Property ◽  
Probabilistic Method ◽  
Design Parameters ◽  
Ocean Bottom ◽  
Foundation Design ◽  
Sea Bed ◽  
Uncertainty Analyses ◽  
General Configuration ◽  
Important Design

Abstract This paper lays the groundwork for establishing foundation safety criteria for offshore gravity structures. The concepts are explained in terms of first- and second-order uncertainty analyses. Various uncertainties associated with foundation analyses are identified and applications are illustrated with examples. Introduction Gravity structures play a prominent role today in North Sea oil development. These structures are not supported by piles, as are most ocean structures, but rather sit directly on the ocean bottom and depend on their foundation geometries and large weights m resist severe environmental loadings. A number of structural and foundation configurations have been proposed; however, attention is restricted here to a general configuration typical of the most prominent structures presently being constructed. prominent structures presently being constructed. An example of a gravity structure is illustrated in Fig. 1. The structure foundation consists of a large caisson placed directly on the unprepared sea-bed surface. The deck is supported by large columns extending from the caisson. Various combinations of steel and reinforced concrete have been proposed, but most structures are being constructed almost entirely of reinforced and prestressed concrete. prestressed concrete. One of the primary engineering concerns with these structures is foundation design. Because of the variability associated with the environmental forces, as well as the basic soil properties, this problem lends itself well to modem probabilistic problem lends itself well to modem probabilistic procedures. Such procedures provide a rational, procedures. Such procedures provide a rational, quantitative means for evaluating uncertainties affecting appropriate design, even though a degree of subjectivity will always remain in any such evaluation. The probabilistic method requires the engineer to formally and consistently recognize die variability of many of the important design parameters. The method gives management and parameters. The method gives management and others responsible for setting design criteria an opportunity to appraise cost/benefits of design levels required for given reliability levels. It also quantifies reliability to permit direct comparison with other options. This paper presents a method for analyzing the reliability of gravity-structure foundations in terms of simple loading and resistance models. The sources of variability in estimating resistance to loads are discussed, with particular emphasis on the nature of soil-property variability and uncertainty. These concepts are illustrated through an analysis of a typical gravity-structure foundation. SPEJ P. 97

Characterization of Tissue Scaffolds Fabricated by Rapid Prototyping Techniques Aided by Finite Element Analysis

2006 ◽  
Author(s):  
Andrew R. Thoreson ◽  
James J. Stone ◽  
Kurtis L. Langner ◽  
Jay Norton ◽  
Bor Z. Jang
Keyword(s):  
Finite Element ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Cartilage Regeneration ◽  
Element Model ◽  
Tissue Scaffolds ◽  
Design Parameters ◽  
Element Analysis ◽  
Apparent Modulus ◽  
Wide Range

Numerous techniques for fabricating tissue engineering scaffolds have been proposed by researchers covering many disciplines. While literature regarding properties and efficacy of scaffolds having a single set of design parameters is abundant, characterization studies of scaffold structures encompassing a wide range of design parameters are limited. A Precision Extrusion Deposition (PED) system was developed for fabricating poly-ε-caprolactone (PCL) tissue scaffolds having interconnected pores suitable for cartilage regeneration. Scaffold structures fabricated with three-dimensional printing methods are periodic and are readily modeled using Computer Aided Design (CAD) software. Design parameters of periodic scaffold architectures were identified and incorporated into CAD models with design parameters over the practical processing range represented. Solid models were imported into a finite element model simulating compression loading. Model deformation results were used to identify apparent modulus of elasticity of the structure. PCL scaffold specimens with design parameters within the modeled range were fabricated and subjected to compression testing to physically characterize scaffold modulus. Results of physical testing and finite element models were compared to determine effectiveness of the method.

scholarly journals Signals of electromagnetic tool with toroidal coils in highly deviated wells

2021 ◽  
Vol 2099 (1) ◽  
pp. 012059
Author(s):  
I Mikhaylov ◽  
I Surodina ◽  
V Glinskikh ◽  
M Nikitenko
Keyword(s):  
Numerical Analysis ◽  
Finite Difference ◽  
Three Dimensional ◽  
Simulation Algorithm ◽  
Wide Range ◽  
Electromagnetic Signals ◽  
Water Saturated ◽  
Oil Gas ◽  
Logging Tool ◽  
Deviated Wells

Abstract The research is aimed at expanding the applicability of the logging tool with toroidal coils from vertical to highly deviated wells. Its electromagnetic signals are computed with a three-dimensional finite-difference simulation algorithm on the computing resources of the Siberian Supercomputer Center of SB RAS, which is accompanied by a multi-aspect numerical analysis of the signals. We consider a wide range of geoelectric models with various resistivity contrasts: those of oil-, gas- and water-saturated reservoirs having a different number of horizontal boundaries and varying thicknesses, including the case of fine layering.

FE Simulation of the Effect of Tire Design Parameters on Lateral Forces and Moments

2004 ◽  
Vol 32 (3) ◽  
pp. 146-163 ◽  
Author(s):  
O. A. Olatunbosun ◽  
O. Bolarinwa
Keyword(s):  
Finite Element ◽  
Rapid Development ◽  
Three Dimensional ◽  
Design Parameters ◽  
Operational Conditions ◽  
Lateral Forces ◽  
Design Variables ◽  
Wide Range ◽  
Vibration Responses ◽  
Tire Models

Abstract Finite Element (FE) tire models are increasingly being used for tire design, vehicle design studies and dynamic investigations. Such tire models have the inherent advantage of being able to cover a wide range of tire design variables (such as detailed tire geometry and material composition), in addition to an extensive coverage of operational conditions (such as tire load, inflation pressure and driving speed). A variety of road input disturbances can also be considered. This paper presents a three-dimensional (3D) Finite Element tire model developed using ABAQUS, a commercial finite element code for use in the development of new tire designs and simulation of vehicle dynamics. Of particular interest are rolling tire output responses, such as lateral forces and self-aligning moment generated due to steering input during vehicle maneuvering and vibration responses to road disturbances. The model will also be applicable in investigating other tire design issues, such as the heat generated in the carcass of the rolling tire. This can present particular problems in heavily loaded tires, for example aircraft tires during take-off. This model should enable the rapid development of new tire designs to satisfy specific requirements.

The influence of confocal microscope design on imaging performance

1993 ◽  
Vol 51 ◽  
pp. 144-145
Author(s):  
C J R Sheppard
Keyword(s):  
Image Quality ◽  
Fluorescence Imaging ◽  
Confocal Microscope ◽  
Industrial Applications ◽  
Three Dimensions ◽  
Design Parameters ◽  
Weak Signals ◽  
Size And Shape ◽  
Imaging Performance ◽  
Fundamental Limitation

The confocal microscope is now widely used in both biomedical and industrial applications for imaging, in three dimensions, objects with appreciable depth. There are now a range of different microscopes on the market, which have adopted a variety of different designs. The aim of this paper is to explore the effects on imaging performance of design parameters including the method of scanning, the type of detector, and the size and shape of the confocal aperture.It is becoming apparent that there is no such thing as an ideal confocal microscope: all systems have limitations and the best compromise depends on what the microscope is used for and how it is used. The most important compromise at present is between image quality and speed of scanning, which is particularly apparent when imaging with very weak signals. If great speed is not of importance, then the fundamental limitation for fluorescence imaging is the detection of sufficient numbers of photons before the fluorochrome bleaches.

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