Geovariances: Where no one has gone before

Isatis contains a wide range of general tools for data management and variable computations as well as specific tools for mining and petroleum applications.

• General Tools
  
  

  

  Choice of the best declustering window

• A powerful scientific Calculator enables complex arithmetic operations on variables achieved through numerous elementary transformations (includes mathematical, Boolean and interval operators, mathematical, trigonometric, date and statistical functions).
• Specific functionalities enable alphanumerical encoding/decoding.
• Various selection utilities enable to build masks on samples based on numeric, alphanumeric or geographic criteria. These selections may be combined among themselves using logical operators.
• A specific selection tool is used for checking the presence of too nearby data points (duplicates) and for masking them if necessary to avoid any inversion problems.
• Declustering is accessible inside Isatis and is invaluable for clustered data sets in order to weight variables when studying their distribution.
• Various applications for data transformations are available: normation, truncation, raw to gaussian values, multi-linear regression, raw values to factors, raw to residual values.
• Copy or Migration of variables between two files (possibly of different types) is possible.
• Some procedures are designed for filtering or processing images through simple tool (smoothing of variables along lines or on grids using filters) or more sophisticated and powerful algorithms based on finite differences or morphological mathematics.
• Unfolding and Folding applications allow to flatten complex geological structures from several units at the same time and come back to the original stratigraphy system.
  
• Tools for Mining Geostatistics
  
  

  

  Grade Tonnage Curves

• Regularization of information along drillholes may be performed in order to get composites of the same size from an irregular line sampling (compositing).
• Many tools to compute specific variograms from standard variogram models are available: Variogram Regularization to get the variogram model on a given block suppor, Block Gaussian Variogram to prepare a variogram model for the Disjunctive Kriging.
• The accumulation of a grade variable along lines may be computed and attached to the line.
• A specific module computes the service variables (Probable Ore and Probable Metal) at data points, on a given support above a certain cutoff. These variables can be processed later on to estimate ore and quantity of metal above a cutoff grade (through a standard kriging procedure).
• The Grade-Tonnage curves application enables numerical and graphical interpretation of results obtained through standard Kriging, Disjunctive Kriging or Uniform Conditioning in terms of global tonnage.
• The Probability from Conditional Expectation functionality is designed to calculate the probability for a variable to be above a given cutoff at a given point.
  
• Tools for Petroleum Geostatistics
  
  

  

  Map of probability to be below spill point

• A Spill Point functionality enables to delineate potential reservoirs on simulation results. In Isatis, a reservoir is described as a dome filled with a valuable fluid with an extension limited either by a location where fluid has not been encountered (this is called a Water Point), or by the edge of the field.
• A specific Volumetrics application is dedicated to the quantification of uncertainties applied to simulation results obtained from any of the Conditional Simulation methods offered in ISATIS. Using the different possible combinations between the geometrical parameters (thickness, top and bottom elevations of horizons, oil/gas-water contact, etc.) and the petrophysical parameters (porosity, water saturation and net/gross ratio), the aim is to get probability and quantile maps as well as probability curves of the reservoir volume.
• A Time Sampling functionality, which is designed for people dealing with seismic datasets referenced in time rather than depth, allows to extract seismic attributes for a given horizon interpretation in time.