Combined porosity, saturation and net‐to‐gross estimation from rock physics templates

Assuming that a turbidite reservoir can be approximated by a stack of thin shale-sand layers, we use standard amplitude variaiton with offset (AVO) attributes to estimate net-to-gross (N/G) and oil saturation. Necessary input is Gassmann rock-physics properties for sand and shale, as well as the fluid properties for hydrocarbons. Required seismic input is AVO intercept and gradient. The method is based upon thin-layer reflectivity modeling. It is shown that random variability in thickness and seismic properties of the thin sand and shale layers does not change significantly the AVO attributes at the top and base of the turbidite-reservoir sequence. The method is tested on seismic data from offshore Brazil. The results show reasonable agreement between estimated and observed N/G and oil saturation. The methodology can be developed further for estimating changes in pay thickness from time-lapse seismic data.

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Rock physics estimation of cement volume, sorting, and net-to-gross in North Sea sandstones

The Leading Edge ◽

10.1190/1.3064154 ◽

2009 ◽

Vol 28 (1) ◽

pp. 98-108 ◽

Cited By ~ 34

Author(s):

Per Avseth ◽

Arild Jørstad ◽

Aart-Jan van Wijngaarden ◽

Gary Mavko

Keyword(s):

North Sea ◽

Rock Physics ◽

Net To Gross

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Stochastic inversion of seismic PP and PS data for reservoir parameter estimation

Geophysics ◽

10.1190/geo2013-0456.1 ◽

2014 ◽

Vol 79 (6) ◽

pp. R233-R246 ◽

Cited By ~ 4

Author(s):

Jinsong Chen ◽

Michael E. Glinsky

Keyword(s):

Parameter Estimation ◽

Rock Physics ◽

Real Field ◽

Layer Model ◽

Converted Wave ◽

Amplitude Variation With Offset ◽

Net To Gross ◽

Versus Amplitude ◽

Physics Model ◽

Reservoir Parameter

We have investigated the value of isotropic seismic converted-wave (i.e., PS) data for reservoir parameter estimation using stochastic approaches based on a floating-grain rock-physics model. We first performed statistical analysis on a simple two-layer model built on actual borehole logs and compared the relative value of PS data versus amplitude-variation-with-offset (AVO) gradient data for estimating the floating-grain fraction. We found that PS data were significantly more informative than AVO gradient data in terms of likelihood functions, and the combination of PS and AVO gradient data together with PP data provided the maximal value for the reservoir parameter estimation. To evaluate the value of PS data under complex situations, we developed a hierarchical Bayesian model to combine seismic PP and PS data and their associated time registration. We extended a model-based Bayesian method developed previously for inverting seismic PP data only, by including PS responses and time registration as additional data and PS traveltime and reflectivity as additional variables. We applied the method to a synthetic six-layer model that closely mimics real field scenarios. We found that PS data provided more information than AVO gradient data for estimating the floating-grain fraction, porosity, net-to-gross, and layer thicknesses when their corresponding priors were weak.

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Integration of Rock Physics and Seismic Inversion for Net-To-Gross Estimation: Implication for Reservoir Modelling and Field Development in Offshore Niger Delta

10.2118/198765-ms ◽

2019 ◽

Author(s):

Obinna Chudi ◽

James Iwegbu ◽

Gerard Tetegan ◽

Obinna Ikwueze ◽

Oghogho Effiom ◽

...

Keyword(s):

Niger Delta ◽

Rock Physics ◽

Seismic Inversion ◽

Reservoir Modelling ◽

Field Development ◽

Net To Gross

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Deepwater reservoir heterogeneity delineation using rock physics and extended elastic impedance inversion: Nile Delta case study

Interpretation ◽

10.1190/int-2014-0056.1 ◽

2014 ◽

Vol 2 (4) ◽

pp. T205-T219 ◽

Cited By ~ 2

Author(s):

Ahmed Hafez ◽

Folkert Majoor ◽

John P. Castagna

Keyword(s):

Nile Delta ◽

Rock Physics ◽

Amplitude Variation ◽

Amplitude Variation With Offset ◽

Impedance Inversion ◽

Net To Gross ◽

Deepwater Channel ◽

Static Connectivity ◽

Elastic Impedance

Deepwater channel reservoirs in the Nile Delta are delineated using extended elastic impedance inversion (EEI). We used the following workflow: seismic spectral blueing, rock physics and amplitude variation with offset modeling, seismic EEI and interpretation of the inverted cubes in terms of geologic facies, net-to-gross ratio, and static connectivity among depositional geobodies. Three subenvironments within the targeted reservoir interval were recognized using a combination of shale volume and [Formula: see text]-inverted cubes. These were used to generate 3D geobodies and a net-pay thickness map that were used in turn to calculate reservoir volumetrics. The results from the workflow matched well logs and could thus be used to investigate the potential of nearby prospects that have the same geologic settings.

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Simplified Approach to Calculating Geometric Stiffness Properties of Tread Pattern Elements

Tire Science and Technology ◽

10.2346/1.2135265 ◽

2003 ◽

Vol 31 (3) ◽

pp. 132-158 ◽

Cited By ~ 6

Author(s):

R. E. Okonieski ◽

D. J. Moseley ◽

K. Y. Cai

Keyword(s):

Development Process ◽

Functional Design ◽

Simplified Approach ◽

Tire Industry ◽

Geometric Stiffness ◽

Stiffness Properties ◽

Engineering Parameters ◽

Net To Gross ◽

Significant Effort

Abstract The influence of tread designs on tire performance is well known. The tire industry spends significant effort in the development process to create and refine tread patterns. Creating an aesthetic yet functional design requires characterization of the tread design using many engineering parameters such as stiffness, moments of inertia, principal angles, etc. The tread element stiffness is of particular interest because of its use to objectively determine differences between tread patterns as the designer refines the design to provide optimum levels of performance. The tread designer monitors the change in stiffness as the design evolves. Changes to the geometry involve many attributes including the number of sipes, sipe depth, sipe location, block element edge taper, nonskid depth, area net-to-gross, and so forth. In this paper, two different formulations for calculating tread element or block stiffness are reviewed and are compared to finite element results in a few cases. A few simple examples are shown demonstrating the basic functionality that is possible with a numerical method.

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