Data Transformation and User Modes in Property Modelling

It provides more realistic reservoir simulation results in the dynamic modelling phase.

To remove trends and represent the data as a Gaussian distribution (Residual component).

To link the parameters being simulated or conditioned to other data, such as seismic data.

<p>To quantify the spatial continuity and variability of the data.</p> Signup and view all the answers

<p>The purpose of petrophysical modelling is to calculate volumetrics (porosity &amp; SW) and provide input for reservoir simulation (permeability).</p> Signup and view all the answers

<p>The facies model provides a geological representation of the reservoir and characterizes good/medium/poor reservoir. The petrophysical model adds detail to the facies model.</p> Signup and view all the answers

<p>Some of the distributions and transformations considered in petrophysical modelling include basic transformation, skewness transformation, geological trends, intrabody trends, 3D trends, and transformation sequence.</p> Signup and view all the answers

<p>There are 3 user modes: Basic mode, Intermediate mode, and Advanced mode.</p> Signup and view all the answers

<p>The purpose of a variogram in facies and petrophysical modelling is to determine the likely value of a particular property by indicating the degree of dissimilarity between points and the relationship between residual values at different separation distances.</p> Signup and view all the answers

<p>Declustering is used to account for the clustering of data and allows a weighting to be attached to each data point.</p> Signup and view all the answers

<p>The range in a variogram represents the correlation length, which is the distance at which the variance is equal to the sill.</p> Signup and view all the answers

<p>The 6 transformation categories are: Basic Transformations, Skewness Transformations, Compactional Depth Trend, Depositional Depth Trend, 1D Lateral Trend, and 2D Lateral Trend.</p> Signup and view all the answers

<p>The nugget value in a variogram represents the degree of dissimilarity at zero distance, which is typically due to microstructure or measurement error in sampling.</p> Signup and view all the answers

<p>An intrabody trend defines a change in petrophysical property within an individual facies body.</p> Signup and view all the answers

<p>The cloud transform is used to calculate the 2D probability density function for the 3D parameter and the well log parameter.</p> Signup and view all the answers

<p>The residual component represents what cannot be explained by geological features.</p> Signup and view all the answers

<p>The correlation factor indicates the strength of the relationship between two variables.</p> Signup and view all the answers

<p>Correlations are defined by the degree to which the value of one variable is related to another, with positive correlation indicating that the values tend to be small or high at the same time, and negative correlation indicating that the value of one variable tends to be small if that of the other variable is high.</p> Signup and view all the answers

<p>The main function of the Distributions tab is to transform the input data into a Gaussian or 'Normal' distribution, prior to simulation, then transform the Gaussian distribution back to the input data after simulation.</p> Signup and view all the answers

<p>Kriging is a mean value description algorithm that relies on a measure of spatial continuity encapsulated in a variogram. Mathematically, it is the expectation of the Gaussian Random Field.</p> Signup and view all the answers

<p>Prediction (or kriging) is a locally accurate and smooth mean value description, while Simulation aims at a more realistic global representation of geological heterogeneity and is stochastic (noisy) in nature.</p> Signup and view all the answers

<p>Pros: Zones can be grouped together when working with a multizone grid to allow data to cover more than one zone, DA from one zone can be used in another zone, analogue data can be set up in a DA object and used as input, variogram analysis can be performed in a DA object. Cons: If a DA object is used, the Distributions, Correlations &amp; Variograms can still be changed manually in their respective tabs, it takes slightly longer.</p> Signup and view all the answers