Seismic characterization of geothermal sedimentary reservoirs: A field example from the Copenhagen area, Denmark

We have seismically characterized a Triassic-Jurassic deep geothermal sandstone reservoir north of Copenhagen, onshore Denmark. A suite of regional geophysical measurements, including prestack seismic data and well logs, was integrated with geologic information to obtain facies and reservoir property predictions in a Bayesian framework. The applied workflow combined a facies-dependent calibrated rock-physics model with a simultaneous amplitude-variation-with-offset seismic inversion. The results suggest that certain sandstone distributions are potential aquifers within the target interval, which appear reasonable based on the geologic properties. However, prediction accuracy suffers from a restricted data foundation and should, therefore, only be considered as an indicator of potential aquifers. Despite these issues, the results demonstrate new possibilities for future seismic reservoir characterization and rock-physics modeling for exploration purposes, derisking, and the exploitation of geothermal energy as a green and sustainable energy resource.

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Rock-physics diagnostics of an offshore gas field

Geophysics ◽

10.1190/geo2016-0390.1 ◽

2017 ◽

Vol 82 (4) ◽

pp. MR121-MR132 ◽

Cited By ~ 5

Author(s):

Uri Wollner ◽

Yunfei Yang ◽

Jack P. Dvorkin

Keyword(s):

Rock Physics ◽

Rock Properties ◽

Gas Field ◽

Amplitude Variation With Offset ◽

Rock Physics Modeling ◽

Physics Modeling ◽

Using Data ◽

Physics Model ◽

Well Data ◽

Rock Physics Model

Seismic reflections depend on the contrasts of the elastic properties of the subsurface and their 3D geometry. As a result, interpreting seismic data for petrophysical rock properties requires a theoretical rock-physics model that links the seismic response to a rock’s velocity and density. Such a model is based on controlled experiments in which the petrophysical and elastic rock properties are measured on the same samples, such as in the wellbore. Using data from three wells drilled through a clastic offshore gas reservoir, we establish a theoretical rock-physics model that quantitatively explains these data. The modeling is based on the assumption that only three minerals are present: quartz, clay, and feldspar. To have a single rock-physics transform to quantify the well data in the entire intervals under examination in all three wells, we introduced field-specific elastic moduli for the clay. We then used the model to correct the measured shear-wave velocity because it appeared to be unreasonably low. The resulting model-derived Poisson’s ratio is much smaller than the measured ratio, especially in the reservoir. The associated synthetic amplitude variation with offset response appears to be consistent with the recorded seismic angle stacks. We have shown how rock-physics modeling not only helps us to correct the well data, but also allows us to go beyond the settings represented in the wells and quantify the seismic signatures of rock properties and conditions varying in a wider range using forward seismic modeling.

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Integrated Well Data And 3D Seismic Inversion Study For Reservoir Delineation And Description

Bulletin of the Geological Society of Malaysia ◽

10.7186/bgsm70202016 ◽

2020 ◽

Vol 70 (1) ◽

pp. 209-220

Author(s):

Qazi Sohail Imran ◽

◽

Numair Ahmad Siddiqui ◽

Abdul Halim Abdul Latif ◽

Yasir Bashir ◽

...

Keyword(s):

Reservoir Characterization ◽

Rock Physics ◽

Seismic Inversion ◽

Depositional Environments ◽

Well Log ◽

Reservoir Properties ◽

Rock Physics Modeling ◽

Physics Modeling ◽

And Performance ◽

Well Log Analysis

Offshore petroleum systems are often very complex and subtle because of a variety of depositional environments. Characterizing a reservoir based on conventional seismic and well-log stratigraphic analysis in intricate settings often leads to uncertainties. Drilling risks, as well as associated subsurface uncertainties can be minimized by accurate reservoir delineation. Moreover, a forecast can also be made about production and performance of a reservoir. This study is aimed to design a workflow in reservoir characterization by integrating seismic inversion, petrophysics and rock physics tools. Firstly, to define litho facies, rock physics modeling was carried out through well log analysis separately for each facies. Next, the available subsurface information is incorporated in a Bayesian engine which outputs several simulations of elastic reservoir properties, as well as their probabilities that were used for post-inversion analysis. Vast areal coverage of seismic and sparse vertical well log data was integrated by geostatistical inversion to produce acoustic impedance realizations of high-resolution. Porosity models were built later using the 3D impedance model. Lastly, reservoir bodies were identified and cross plot analysis discriminated the lithology and fluid within the bodies successfully.

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Rock Physics Modeling Assisted Reservoir Properties Prediction: Case Study in Malay Basin

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i3.32.18385 ◽

2018 ◽

Vol 7 (3.32) ◽

pp. 24 ◽

Cited By ~ 2

Author(s):

Amir Abbas Babasafari ◽

Deva Ghosh ◽

Ahmed M. A. Salim ◽

S Y. Moussavi Alashloo

Keyword(s):

Oil And Gas ◽

Rock Physics ◽

Shear Velocity ◽

Reservoir Modeling ◽

Reservoir Properties ◽

Rock Physics Modeling ◽

Physics Modeling ◽

Well Log Analysis ◽

Physics Model ◽

Rock Physics Model

Shear velocity log is not measured at all wells in oil and gas fields, thus rock physics modeling plays an important role to predict this type of log. Therefore, seismic pre stack inversion is performed and elastic properties are estimated more accurately. Subsequently, a robust Petro-Elastic relationship arising from rock physics model leads to far more precise prediction of petrophysical properties. The more accurate rock physics modeling results in less uncertainty of reservoir modeling. Therefore, a valid rock physics model is intended to be built. For a better understanding of reservoir properties prediction, first of all rock physics modeling for each identified litho-facies classes should be performed separately through well log analysis.

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Improved Reservoir Characterization Integrating Seismic Inversion, Rock Physics Model, and Petroelastic Log Facies Classification: A Real Case Application

10.2118/134919-ms ◽

2010 ◽

Cited By ~ 2

Author(s):

Fabio Roncarolo ◽

Dario Grana

Keyword(s):

Reservoir Characterization ◽

Rock Physics ◽

Seismic Inversion ◽

Real Case ◽

Facies Classification ◽

Case Application ◽

Physics Model ◽

Rock Physics Model

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Integration of Rock Physics Model in Reservoir Characterization - a Case Study from Malay Basin Malaysia

10.2523/iptc-18049-ms ◽

2014 ◽

Author(s):

Ravi Kant Pathak ◽

Zulfiqar Ali ◽

Rizal Bakar

Keyword(s):

Reservoir Characterization ◽

Rock Physics ◽

Physics Model ◽

Rock Physics Model

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Integrated VTI model building with seismic data, geologic information, and rock-physics modeling — Part 1: Theory and synthetic test

Geophysics ◽

10.1190/geo2015-0592.1 ◽

2016 ◽

Vol 81 (5) ◽

pp. C177-C191 ◽

Cited By ~ 11

Author(s):

Yunyue Li ◽

Biondo Biondi ◽

Robert Clapp ◽

Dave Nichols

Keyword(s):

Seismic Data ◽

Seismic Anisotropy ◽

Model Building ◽

Rock Physics ◽

Seismic Inversion ◽

Additional Information ◽

Synthetic Test ◽

Rock Physics Modeling ◽

Physics Modeling ◽

Geologic Information

Seismic anisotropy plays an important role in structural imaging and lithologic interpretation. However, anisotropic model building is a challenging underdetermined inverse problem. It is well-understood that single component pressure wave seismic data recorded on the upper surface are insufficient to resolve a unique solution for velocity and anisotropy parameters. To overcome the limitations of seismic data, we have developed an integrated model building scheme based on Bayesian inference to consider seismic data, geologic information, and rock-physics knowledge simultaneously. We have performed the prestack seismic inversion using wave-equation migration velocity analysis (WEMVA) for vertical transverse isotropic (VTI) models. This image-space method enabled automatic geologic interpretation. We have integrated the geologic information as spatial model correlations, applied on each parameter individually. We integrate the rock-physics information as lithologic model correlations, bringing additional information, so that the parameters weakly constrained by seismic are updated as well as the strongly constrained parameters. The constraints provided by the additional information help the inversion converge faster, mitigate the ambiguities among the parameters, and yield VTI models that were consistent with the underlying geologic and lithologic assumptions. We have developed the theoretical framework for the proposed integrated WEMVA for VTI models and determined the added information contained in the regularization terms, especially the rock-physics constraints.

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