Seismic Predictions

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Seismic Predictions

Predicting rock properties from seismic data is one of the pillars of dGB. In fact, back in 1995 we started out as a QI (Quantitative Interpretation) specialist company. Our first software system GDI focuses on integrating geology, logs and seismic data and supports stochastic pseudo-well modeling and neural networks for non-linear analysis. GDI is still a work horse for our in-house service projects that cover the entire spectrum of QI work: seismic inversion, fluid-replacement, pre- and post-stack modeling, AVO analysis, 4D etc.

With the development of OpendTect and plugins, we have broadened our technology but our passion for QI remains. More and more work flows originating from GDI are now supported in a more user-friendly way in OpendTect. For example the Neural Networks plugin supports waveform segmentation (visualizing seismic patterns along horizons) as well as inversion along well tracks. In the long run we intend to migrate all GDI functionalities to OpendTect, which should thus become the ultimate QI workbench.

Publications...

OpendTect Plugins

SynthRock

Forward pseudo-well modeling and probabilistic inversion to achieve qualitative and quantitative seismic interpretation. It includes wedge models, stochastic models, pre- and post-stack synthetic seismograms and cross-matching (HitCube) inversion.

Sophisticated workflows in which model parameters are varied stochastically can be run to create a data base of pseudo-wells, representative of the expected geologic and seismic variations at target level. Such models are then used to predict rock properties with uncertainties from pre- and post-stack seismic volumes.

Neural Networks

All kind of rock properties can be predicted with the use of the neural networks plugin. It is possible to relate any well log to seismic data. Examples are porosity, Vshale, lithology, permeability.

HorizonCube

hc-faults

HorizonCube is a game-changing technology that impacts every level of seismic interpretation. A HorizonCube consists of a dense set of correlated 3D stratigraphic surfaces that are assigned a relative geological age. The technology was initially developed for sequence stratigraphic interpretation and as such was part of the SSIS plugin where it was called chronostratigraphy. Because the technology has a much wider application range the HorizonCube became a separate plugin in v.4.2. The HorizonCube can be utilized to build geo-models by interpolating well logs following the many horizons contained in the HorizonCube. Such geo-model can further be used to create low frequency models, necessary input for any model-based inversion.

Deterministic and Stochastic Inversion

Deterministic Inversion

Deterministic Inversion includes a 3D model builder for the construction of a priori impedance models using well log and seismic horizon data; a 2D error grid generation module to provide spatial inversion constraints and a model-based deterministic acoustic impedance inversion module.

Stochastic Inversion

Stochastic Inversion includes the MPSI UltraFast stochastic inversion module for the generation of multiple geostatistical realizations. This plugin allows the user to explore the impact of the geophysical uncertainties in the inversion process. Utilities for post-processing the multiple realizations are available to create expectation, standard deviation, and (joined) probability and trend volumes. This plugin requires a license for the deterministic inversion plugin to be in place.

Coloured Inversion

ARK CLS Seismic Coloured Inversion enables rapid band-limited acoustic impedance inversion of seismic data. A single convolution inversion operator is derived which optimally inverts the data. The spectrum of the inverted data honours the available well data spectra in a global sense. Generally, traditional inversion methods (e.g. sparse-spike) are time consuming, expensive, require specialists and are not performed routinely by the Interpretation Geophysicist, whereas SCI is rapid, easy to use, inexpensive, robust and does not require expert users. SCI and unconstrained sparse-spike appear to give broadly equivalent results.

CLAS Lite

clas screen

CLAS Lite is an open-hole log analysis plugin by Sitfal for geoscientists providing tools for different purposes:

Log viewing and editing.
Petrophysical analysis and computation of rock properties.
Geophysical velocity analysis and linking log properties to seismic data.

Well Modeling Products

Log-log predictions
Lithology clustering
Pattern analysis (Markov chain)
Sensitivity modeling
Stochastic pseudo-well modeling
AVO analysis, rock physics

Inversion Products

Seismic Spectral Blueing
Clustered/classified seismic
(Extended Elastic) Impedance inversion
HorizonCube-based geo-models
HorizonCube-based low frequency models
Rock properties prediction

Additional Services

Full 3D calibration to well data (amplitude and depth mapping)
4D time-lapse studies (monitoring of saturation changes)

dGB Earth Sciences

Nijverheidstraat 11-2 - 7511 JM Enschede - The Netherlands - Tel. +31 (0)53 431 51 55 - Fax. +31 (0)53 431 51 04

1 Sugar Creek Center Boulevard, Suite 935 - Sugar Land, TX, 77478 - USA - Tel. +1 281 240 3939 - Fax. +1 281 240 3944

310, Gateway Plaza, Hiranandani Gardens - Powai, Mumbai 400 076 - India - Tel. +91 22 25704984 - Fax +91 22 25704977