Analysis on Acoustic Impedance Models in Namorado Oilfield, Campos Basin, Brazil

2017 ◽  
Author(s):  
Mario Martins Ramos ◽  
Rodrigo Bijani
Keyword(s):  
Acoustic Impedance ◽  
Campos Basin ◽  
Impedance Models

scholarly journals Seismically detected porous Zechstein carbonates in Southern Jutland, Denmark

1995 ◽  
Vol 42 ◽  
pp. 34-46
Author(s):  
Kim Gunn Maver
Keyword(s):  
Seismic Data ◽  
Acoustic Impedance ◽  
Seismic Reflection ◽  
Synthetic Seismograms ◽  
Lateral Distribution ◽  
Seismic Modelling ◽  
Seismic Sections ◽  
Well Data ◽  
Impedance Models

Zechstein carbonates in Southern Jutland, Denmark, have been explored by 10 wells since 1952, and a total of more than 2000 km of 2D seismic data has been acquired by various contractors. Seismic modelling, based on all the well data, is used as an aid to predict the lateral distribution of porous Zechstein carbonate intervals from the seismic data. ID seismic modelling is used to define the maximum number of intervals detected by the seismic sections at well locations. The ID seismic modelling results are also used to derive 2D acoustic impedance models and corresponding synthetic seismograms. The seismic modelling results illustrate a number of diagnostic reflection patterns associated with the porous carbonate intervals. The predicted distribution of porous carbonate intervals is, however, found to be uncertain, as thickness and porosity variations of each interval cannot be distinguished. Furthermore, thin porous carbonate intervals are not detected by the seismic sections, and the seismic reflection patterns indicating the presence of porous carbonate intervals can be associated with other lithologies. Porous Ca-la, Ca-lb, Ca-2 and Ca-3 carbonate intervals are found to be detected by the seismic sections only in the Zechstein platform area, and only the porous Ca-2 carbonate interval can be mapped

High-resolution acoustic impedance inversion to characterize turbidites at Marlim Field, Campos Basin, Brazil

2014 ◽  
Vol 2 (3) ◽  
pp. T143-T153 ◽  
Author(s):  
Tatiane M. Nascimento ◽  
Paulo T. L. Menezes ◽  
Igor L. Braga
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
Acoustic Impedance ◽  
Structural Information ◽  
Low Frequency ◽  
Seismic Inversion ◽  
Background Model ◽  
Rock Properties ◽  
High Porosity ◽  
Campos Basin

Seismic inversion is routinely used to determine rock properties, such as acoustic impedance and porosity, from seismic data. Nonuniqueness of the solutions is a major issue. A good strategy to reduce this inherent ambiguity of the inversion procedure is to introduce stratigraphic and structural information a priori to better construct the low-frequency background model. This is particularly relevant when studying heterogeneous deepwater turbidite reservoirs that form prolific, but complex, hydrocarbon plays in the Brazilian offshore basins. We evaluated a high-resolution inversion workflow applied to 3D seismic data at Marlim Field, Campos Basin, to recover acoustic impedance and porosity of the turbidites reservoirs. The Marlim sandstones consist of an Oligocene/Miocene deepwater turbidite system forming a series of amalgamated bodies. The main advantage of our workflow is to incorporate the interpreter’s knowledge about the local stratigraphy to construct an enhanced background model, and then extract a higher resolution image from the seismic data. High-porosity zones were associated to the reservoirs facies; meanwhile, the nonreservoir facies were identified as low-porosity zones.

scholarly journals Absorbing interfaces in structural-acoustic coupled problems

2008 ◽  
pp. 677-688
Author(s):  
Walid Larbi ◽  
Jean-François Deü ◽  
Roger Ohayon
Keyword(s):  
Finite Element ◽  
Porous Medium ◽  
Acoustic Impedance ◽  
Finite Element Formulation ◽  
Biot Theory ◽  
Element Formulation ◽  
Coupled Problems ◽  
Impedance Parameters ◽  
Finite Element Formulations ◽  
Impedance Models

This work concerns finite element formulations of structural-acoustic interior problems with dissipative interfaces. The main purpose is to establish the link between wall acoustic impedance models and poroelastic appraoches based on the Biot theory. The proposed method consists in determining the acoustic impedance parameters starting from intrinsic characteristics of the porous medium. This impedance is then introduced into the vibroacoustic finite element formulation to take into account the dissipative aspect of the fluid-structure interface.

Geostatistical seismic inversion for frontier exploration

2017 ◽  
Vol 5 (4) ◽  
pp. T477-T485 ◽  
Author(s):  
Ângela Pereira ◽  
Rúben Nunes ◽  
Leonardo Azevedo ◽  
Luís Guerreiro ◽  
Amílcar Soares
Keyword(s):  
Acoustic Impedance ◽  
Seismic Reflection ◽  
Seismic Inversion ◽  
Well Log ◽  
Data Set ◽  
Seismic Reflection Data ◽  
Log Data ◽  
The Real ◽  
Reflection Data ◽  
Impedance Models

Numerical 3D high-resolution models of subsurface petroelastic properties are key tools for exploration and production stages. Stochastic seismic inversion techniques are often used to infer the spatial distribution of the properties of interest by integrating simultaneously seismic reflection and well-log data also allowing accessing the spatial uncertainty of the retrieved models. In frontier exploration areas, the available data set is often composed exclusively of seismic reflection data due to the lack of drilled wells and are therefore of high uncertainty. In these cases, subsurface models are usually retrieved by deterministic seismic inversion methodologies based exclusively on the existing seismic reflection data and an a priori elastic model. The resulting models are smooth representations of the real complex geology and do not allow assessing the uncertainty. To overcome these limitations, we have developed a geostatistical framework that allows inverting seismic reflection data without the need of experimental data (i.e., well-log data) within the inversion area. This iterative geostatistical seismic inversion methodology simultaneously integrates the available seismic reflection data and information from geologic analogs (nearby wells and/or analog fields) allowing retrieving acoustic impedance models. The model parameter space is perturbed by a stochastic sequential simulation methodology that handles the nonstationary probability distribution function. Convergence from iteration to iteration is ensured by a genetic algorithm driven by the trace-by-trace mismatch between real and synthetic seismic reflection data. The method was successfully applied to a frontier basin offshore southwest Europe, where no well has been drilled yet. Geologic information about the expected impedance distribution was retrieved from nearby wells and integrated within the inversion procedure. The resulting acoustic impedance models are geologically consistent with the available information and data, and the match between the inverted and the real seismic data ranges from 85% to 90% in some regions.

Appraisal of the Bicudo Field with Seismic‐Derived Acoustic Impedance Data, Campos Basin, Brazil

1982 ◽  
Author(s):  
Sérgio Possato ◽  
Kaoru Tsubone ◽  
André L. Romanelli ◽  
José Tassini
Keyword(s):  
Acoustic Impedance ◽  
Impedance Data ◽  
Campos Basin

Uncertainties in low-frequency acoustic impedance models

2007 ◽  
Vol 26 (1) ◽  
pp. 74-87 ◽  
Author(s):  
Brian Cerney ◽  
David C. Bartel
Keyword(s):  
Acoustic Impedance ◽  
Low Frequency ◽  
Impedance Models

Acoustic-Reflex Dynamics for Pulsed Signals

1978 ◽  
Vol 21 (2) ◽  
pp. 295-308
Author(s):  
Terry L. Wiley ◽  
Raymond S. Karlovich
Keyword(s):  
Duty Cycle ◽  
Acoustic Impedance ◽  
Normal Hearing ◽  
Broadband Noise ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Acoustic Reflex ◽  
Stapedius Muscle ◽  
Duty Cycles

Contralateral acoustic-reflex measurements were taken for 10 normal-hearing subjects using a pulsed broadband noise as the reflex-activating signal. Acoustic impedance was measured at selected times during the on (response maximum) and off (response minimum) portions of the pulsed activator over a 2-min interval as a function of activator period and duty cycle. Major findings were that response maxima increased as a function of time for longer duty cycles and that response minima increased as a function of time for all duty cycles. It is hypothesized that these findings are attributable to the recovery characteristics of the stapedius muscle. An explanation of portions of the results from previous temporary threshold shift experiments on the basis of acoustic-reflex dynamics is proposed.

Broadband time-domain impedance models

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 1449-1454
Author(s):  
K.-Y. Fung ◽  
Hongbin Ju
Keyword(s):  
Time Domain ◽  
Impedance Models
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