Publicações

/Tag: Publicações

Uma implementação do método da refletividade para modelagem eficiente de dados sísmicos marítimos e de OBC

Uma implementação do método da refletividade para modelagem eficiente de dados sísmicos marítimos e de OBC Revista: Revista Brasileira de Geofísica, 2009, 27, 323-332. Abstract: In this paper, a special implementation of the reflectivity method is proposed to simulate marine seismic acquisitions. The method was designed for efficient calculation of pressure field, in the case of source and receptors (hydrophones) located in the water column and the vertical or horizontal displacement (or velocity) in the case of simulation of multicomponent OBC (Ocean Bottom Cable) or OBS (Ocean Bottom Sensor) acquisition. One of the main advantages of the method is [...]

Uma implementação do método da refletividade para modelagem eficiente de dados sísmicos marítimos e de OBC2018-12-26T14:06:12-02:00

L1 norm inversion method for deconvolution in attenuating media

L1 norm inversion method for deconvolution in attenuating media Revista: Geophysical Prospecting, 2013, 61, 771–777Abstract: In order to perform a good pulse compression, the conventional spike deconvolution method requires that the wavelet is stationary. However, this requirement is never reached since the seismic wave always suffers high-frequency attenuation and dispersion as it propagates in real materials. Due to this issue, the data need to pass through some kind of inverse-Q filter. Most methods attempt to correct the attenuation effect by applying greater gains for high-frequency components of the signal. The problem with this procedure is that it generally boosts high-frequency noise. In [...]

L1 norm inversion method for deconvolution in attenuating media2018-12-20T20:41:56-02:00

The value of information from time-lapse seismic data

The value of information from time-lapse seismic data Revista: The Leading Edge, 2011, 30. 572-576. The method presented here is an objective way to determine the value of information, as it establishes a relationship between the value of perfect information and the technical evaluation score. This makes it possible to compare the value of competing projects evaluated by different analysts. Additionally, the value of information of a 4D seismic survey can be calculated by its agreement with different management strategies. We tested three possible selections: optimistic, realistic, and conservative evaluations of VOI. In all cases where 4D seismic [...]

The value of information from time-lapse seismic data2018-12-26T14:45:24-02:00

Time–frequency spectral signature of Pelotas Basin deep water gas hydrates system

Time–frequency spectral signature of Pelotas Basin deep water gas hydrates system Revista: Marine Geophysical Researches, 2010, 31, 89-97 Abstract: Pelotas Basin has the largest gas hydrate occurrence of the Brazilian coast. The reserves are estimated in 780 trillion cubic feet, covering an area of 45,000 km2. In this work we apply spectral decomposition technique in order to better understand a gas hydrate deep water system, performing a continuous time–frequency analysis of seismic trace, where frequency spectrum is the output for each time sample of the seismic trace. This allows a continuous analysis on the effects of the geologic structures [...]

Time–frequency spectral signature of Pelotas Basin deep water gas hydrates system2018-12-26T14:38:52-02:00

An Automatic Porosity and Saturation Evaluation Based on the Inversion of Multiple Well Logs

An Automatic Porosity and Saturation Evaluation Based on the Inversion of Multiple Well Logs Revista: spwla.org We propose an automated method for inference of porosity and saturation, which can be used for quickly assessing reservoir rock quality and fluid volumes. The method is based on the inversion of multiple well logs using the Bayesian Theory. The well logs consist of neutron porosity, density, sonic (P-wave and S-wave velocities) and resistivity, which are related to porosity and saturation through the appropriate rock physics models. Following the Bayesian Theory, the formal solution of the inverse problem is a posterior distribution, [...]

An Automatic Porosity and Saturation Evaluation Based on the Inversion of Multiple Well Logs2018-12-21T23:16:08-02:00