Determining the orientation of marine CSEM receivers using orthogonal Procrustes rotation analysis

Geophysics ◽  
2010 ◽  
Vol 75 (3) ◽  
pp. F63-F70 ◽  
Author(s):  
Kerry Key ◽  
Andrew Lockwood
Keyword(s):  
Field Vector ◽  
Northwest Coast ◽  
Gas Field ◽  
Procrustes Rotation ◽  
Data Application ◽  
Orientation Method ◽  
Marine Csem ◽  
2D Data ◽  
Independent Parameters ◽  
Good Agreement

Electromagnetic receivers deployed to the seafloor for CSEM surveys can have unknown orientations because of the unavailability of compass and tilt recordings. In such situations, only the orientation-independent parameters derived from the measured CSEM field vector can be interpreted, and this may result in less structural resolution than possible when the sensor orientations are known. An orthogonal Procrustes rotation analysis (OPRA) technique can be used to estimate the full 3D receiver orientation for inline and off-line CSEM receivers. The generality of this method allows it to be easily embedded into nonlinear CSEM inversion routines so that they iteratively search for both the receiver orientation and a seafloor electrical-conductivity model compatible with the data. Synthetic tests using the OPRA method jointly with a 1D inversion demonstrate that it can recover the rotation and tilt angles to about one degree accuracy for 1D data and to within a few degrees for 2D data. Application of this method to real survey data shows good agreement with a previous orientation method that is suitable only for determining the horizontal rotation of inline receivers. CSEM data collected over the Pluto gas field offshore the northwest coast of Australia were used to demonstrate how the OPRA method can be used to orient CSEM receivers prior to inversion of only the inline electric- and crossline magnetic-field components.

scholarly journals Mobility of an axisymmetric particle near an elastic interface

2016 ◽  
Vol 811 ◽  
pp. 210-233 ◽  
Author(s):  
Abdallah Daddi-Moussa-Ider ◽  
Maciej Lisicki ◽  
Stephan Gekle
Keyword(s):  
Detailed Comparison ◽  
Boundary Integral ◽  
Particle Orientation ◽  
Spheroidal Particle ◽  
Analytical Approximations ◽  
Elastic Interface ◽  
General Relations ◽  
Independent Parameters ◽  
Membrane Particle ◽  
Good Agreement

Using a fully analytical theory, we compute the leading-order corrections to the translational, rotational and translation–rotation coupling mobilities of an arbitrary axisymmetric particle immersed in a Newtonian fluid moving near an elastic cell membrane that exhibits resistance towards stretching and bending. The frequency-dependent mobility corrections are expressed as general relations involving separately the particle’s shape-dependent bulk mobility and the shape-independent parameters such as the membrane–particle distance, the particle orientation and the characteristic frequencies associated with shearing and bending of the membrane. This makes the equations applicable to an arbitrary-shaped axisymmetric particle provided that its bulk mobilities are known, either analytically or numerically. For a spheroidal particle, these general relations reduce to simple expressions in terms of the particle’s eccentricity. We find that the corrections to the translation–rotation coupling mobility are primarily determined by bending, whereas shearing manifests itself in a more pronounced way in the rotational mobility. We demonstrate the validity of the analytical approximations by a detailed comparison with boundary integral simulations of a truly extended spheroidal particle. They are found to be in a good agreement over the whole range of applied frequencies.

Exploring multiple 3D inversion scenarios for enhanced interpretation of marine CSEM data: an iterative migration analysis of the Shtokman gas field

First Break ◽  
2010 ◽  
Vol 28 (3) ◽  
Author(s):  
M.S. Zhdanov ◽  
E.P. Velikhov ◽  
M. Čuma ◽  
G. Wilson ◽  
N. Black ◽  
...  
Keyword(s):  
3D Inversion ◽  
Gas Field ◽  
Marine Csem ◽  
Migration Analysis

Marine CSEM of the Scarborough gas field, Part 1: Experimental design and data uncertainty

Geophysics ◽  
2012 ◽  
Vol 77 (4) ◽  
pp. E281-E299 ◽  
Author(s):  
David Myer ◽  
Steven Constable ◽  
Kerry Key ◽  
Michael E. Glinsky ◽  
Guimin Liu
Keyword(s):  
Perturbation Analysis ◽  
Data Uncertainty ◽  
Quality Data ◽  
High Quality ◽  
Gas Field ◽  
Data Set ◽  
Resistive Layer ◽  
Mapping Tool ◽  
Marine Csem ◽  
Processing Techniques

We describe the planning, processing, and uncertainty analysis for a marine CSEM survey of the Scarborough gas field off the northwest coast of Australia, consisting of 20 transmitter tow lines and 144 deployments positioned along a dense 2D profile and a complex 3D grid. The purpose of this survey was to collect a high-quality data set over a known hydrocarbon prospect and use it to further the development of CSEM as a hydrocarbon mapping tool. Recent improvements in navigation and processing techniques yielded high-quality frequency domain data. Data pseudosections exhibit a significant anomaly that is laterally confined within the known reservoir location. Perturbation analysis of the uncertainties in the transmitter parameters yielded predicted uncertainties in amplitude and phase of just a few percent at close ranges. These uncertainties may, however, be underestimated. We introduce a method for more accurately deriving uncertainties using a line of receivers towed twice in opposite directions. Comparing the residuals for each line yields a Gaussian distribution directly related to the aggregate uncertainty of the transmitter parameters. Constraints on systematic error in the transmitter antenna dip and inline range can be calculated by perturbation analysis. Uncertainties are not equal in amplitude and phase, suggesting that inversion of these data would be better suited in these components rather than in real and imaginary components. One-dimensional inversion showed that the reservoir and a confounding resistive layer above it cannot be separately resolved even when the roughness constraint is modified to allow for jumps in resistivity and prejudices are provided, indicating that this level of detail is beyond the single-site CSEM data. Further, when range-dependent error bars are used, the resolution decreases at a shallower depth than when a fixed-error level is used.

scholarly journals Reconstructing Orbits of Galaxies in Extreme Regions (ROGER) II: reliability of projected phase-space in our understanding of galaxy populations

2021 ◽  
Author(s):  
Valeria Coenda ◽  
Martín de los Rios ◽  
Hernán Muriel ◽  
Sofía A Cora ◽  
Héctor J Martínez ◽  
...  
Keyword(s):  
Phase Space ◽  
Galaxy Formation ◽  
Formation Rate ◽  
Stellar Mass ◽  
Cluster Galaxies ◽  
The Galaxy ◽  
Galaxy Populations ◽  
Galaxy Population ◽  
2D Data ◽  
Good Agreement

Abstract We connect galaxy properties with their orbital classification by analysing a sample of galaxies with stellar mass M⋆ ≥ 108.5h−1M⊙ residing in and around massive and isolated galaxy clusters with mass M200 > 1015h−1M⊙ at redshift z = 0. The galaxy population is generated by applying the semi-analytic model of galaxy formation sag on the cosmological simulation MultiDark Planck 2. We classify galaxies considering their real orbits (3D) and their projected phase-space position using the roger  code (2D). We define five categories: cluster galaxies, galaxies that have recently fallen into a cluster, backsplash galaxies, infalling galaxies, and interloper galaxies. For each class, we analyse the 0.1(g − r) colour, the specific star formation rate (sSFR), and the stellar age, as a function of the stellar mass. For the 3D classes, we find that cluster galaxies have the lowest sSFR, and are the reddest and the oldest, as expected from environmental effects. Backsplash galaxies have properties intermediate between the cluster and recent infaller galaxies. For each 2D class, we find an important contamination by other classes. We find it necessary to separate the galaxy populations in red and blue to perform a more realistic analysis of the 2D data. For the red population, the 2D results are in good agreement with the 3D predictions. Nevertheless, when the blue population is considered, the 2D analysis only provides reliable results for recent infallers, infalling galaxies and interloper galaxies.

Reconciling Time-lapse Seismic Data and Production Data: Application to a Gas Field

1999 ◽  
Author(s):  
Xuri Huang ◽  
Robert Will ◽  
Mashiur Khan ◽  
Larry Stanley
Keyword(s):  
Seismic Data ◽  
Time Lapse ◽  
Production Data ◽  
Gas Field ◽  
Data Application

scholarly journals Extremal bounds on earthquake movement from geodetic data: Application to the Landers earthquake

1994 ◽  
Vol 84 (3) ◽  
pp. 660-667 ◽  
Author(s):  
Hadley O. Johnson ◽  
Duncan Carr Agnew ◽  
Ken Hudnut
Keyword(s):  
Geodetic Data ◽  
Fault Geometry ◽  
Surface Rupture ◽  
Field Mapping ◽  
Landers Earthquake ◽  
Level Of Confidence ◽  
Data Application ◽  
The Moment ◽  
1992 Landers Earthquake ◽  
Good Agreement

Abstract We present a technique to place quantifiable bounds on the moment of an earthquake from geodetic data, assuming known fault geometry. Application of this technique to the 1992 Landers earthquake shows that the moment must have been between 0.84 and 1.15 × 1020 Nm with 90% confidence (M 7.25 to 7.34). We also find that to satisfy the data to this same level of confidence, the slip on the fault must have exceeded 7 m in at least one location, in good agreement with field mapping of the surface rupture.

scholarly journals Bayesian inversion of marine CSEM data from the Scarborough gas field using a transdimensional 2-D parametrization

2014 ◽  
Vol 199 (3) ◽  
pp. 1847-1860 ◽  
Author(s):  
Anandaroop Ray ◽  
Kerry Key ◽  
Thomas Bodin ◽  
David Myer ◽  
Steven Constable
Keyword(s):  
Bayesian Inversion ◽  
Gas Field ◽  
Marine Csem

Marine CSEM of the Scarborough Gas Field

2010 ◽  
Author(s):  
David Myer ◽  
Steven Constable ◽  
Kerry Key
Keyword(s):  
Gas Field ◽  
Marine Csem
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