Tigress Petrophysics allows petrophysicists to characterise
reservoirs by analysing log and core data. The module provides a
comprehensive set of applications for log and core data
manipulation and correction, parameter calculation and log analysis
for both open- and cased-hole logs. Both input and output data can
then be zonally averaged for use in mapping. An automatic audit
trail records all processes, so that analyses can be easily rerun
using the latest input data or parameters.
On this page you can find summaries and features for:
Trace edit
Summary
Log and core trace manipulation by equation and graphical
editing methods.
Features
Trace types may be raw, depth-matched, corrected, interpreted or
previously edited.
Editing methods
Automatic editing methods include:
- smoothing, de-spiking and median functions
- infilling of gaps
- normalisation
- conversion of discrete core data to core traces.
Manual editing methods include:
- graphical and keyboard point and section editing
- horizontal shifting.
Equation editing methods include:
- standard, for example: f(x) = a*x + b
- user-defined.
Equations can be stored in the Tigress Project Data Store (PDS) for subsequent re-use.
Other features
Other features include:
- simple combining and complex merging of log runs
- multi-well processing of any number of wells using equations
applied to the displayed well
- creates new versions of traces with an edited status flag thus
preserving the original input traces.
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Log depth matching
Summary
Depth matching of log traces or complete runs.
Features
Features include:
- depth matching by block shifting of sections or tie-pointing of
individual trace peaks/troughs
- block and tie-point methods can be applied manually or
graphically
- depth shifting can be performed on each trace in a log, or a
common shift applied to all traces
- creates new versions of traces with a depth matched status flag
thus preserving the original raw inputs.
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Corrections
Summary
Correction of log traces for borehole and environmental
effects.
Features
Features include:
- Correction charts for Schlumberger, Western Atlas, Gearhart and
BPB logs.
- User-defined correction programs can be written in C, Fortran
or the Tigress programming language.
- Logging and mud details are automatically read from the log
header.
- Utilises caliper or bit-size data for borehole
corrections.
- Accepts a combination of induction log, laterolog, and
micro-resistivity log traces for environmental correction.
- Gaps in Rt and Rxo can be filled by merging with resistivity
traces, by logic or by interpolation .
- User-defined trace/chart combinations can be selected for
environmental corrections.
- Error listing facility to identify why gaps have been produced
and traces not corrected.
- Multi-well processing of any number of wells.
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Formation test analysis
Summary
Multi-well interpretation of RFT data to determine fluid contact
type, depth and pressure.
Features
Features include:
- displays up to 100 RFT runs simultaneously, coded by well, by
zone or by pressure type
- displays pressure/time data for individual RFT
measurements
- simple graphical clustering/selection of points for regression
to generate fluid gradients
- regression methods include X on Y, Y on X, RMA, forced and
user-defined
- gradients and contact type, depth and pressure are saved for
use in Tigress Geology and Simulation
- complete user control over plot layout, annotation, symbols,
colours, scales, grids and hardcopy.
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Well view
Summary
Entry of a well's historical construction and production history
events.
Features
Features include:
- ASCII file and spreadsheet entry of all events.
- Historical construction events are graphically illustrated as a
wellbore schematic diagram.
- Schematic can be displayed for any period in the well's
history.
- Display of well zonation to ensure correct
completion.
There are 21 construction events including:
- drilling
- casing
- cement
- perforation
- packers
- liners
- tubing
- pumps.
There are five geology and production events:
- production data
- flowmeter
- static tests
- logging
- coring.
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Crossplot
Summary
Display and crossplot analysis of multi-well data, geophysics
horizons and mapping surfaces for reservoir characterisation.
Features
Data types for display include:
- log and interpreted traces
- conventional and special core data
- zone parameters
- time/depth data
- structure and attribute maps and horizons.
Data on display can be filtered by well, zone, cluster, cut-off,
z-plot band prior to analysis, and there are hot links to Well
correlation and zonation, Log plot, other Crossplots and Cluster analysis for sample highlighting.
Industry standard pre-defined crossplots (and associated
regression techniques) include:
- Density/Neutron/Sonic
- D/N/S/Qv./FRF/K v. porosity
- Hingle/Pickett
- M/N
- Pef and NGT
- Leverett J/RI/height/depth v. Sw
- Porosity/Rt v. Sigma
- Grain density/porosity v. K
Other features
Other features include:
- User-defined crossplots can be generated using any input data
types.
- Zonal parameters are generated from standard analyses and
cut-offs defined in pre-defined plots.
- Normal regression methods include X on Y, Y on X, RMA, forced
and user-defined.
- Chart overlays for density/neutron/sonic crossplots, M-N plots
and NGS plots.
- Complete user control over plot layout, annotation, symbols,
colours, scales, grids and hardcopy.
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Histogram
Summary
Display and histogram analysis of multi-well trace and core
data.
Features
Features include:
- data display by well and/or by zone
- overlay of different data or similar data from different
wells/zones
- full statistical summary including mean, mode, median,
averages
- determination of GR min and max for clay volume
interpretation
- determination of matrix density for porosity
interpretation
- complete user control over plot layout, annotation, symbols,
colours, scales, grids and hardcopy.
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Parameter
table
Summary
Spreadsheet display, manipulation and export of input and output
zonal parameters.
Features
Features include:
- displays input zonal parameters required for log and core
interpretation and output parameters generated from averaging and
thickness calculations
- pre-defined parameter table views (crossplot, output, open-hole
and so on) and user-defined table views
- parameter population using default values for quick look
interpretation
- automatic copying of parameters between wells and zones
- table editor functions for copying and pasting parameter
values
- fast re-read of parameters when updated in another
application
- output file formats include ASCII, spreadsheet and Irap with
full control over the file format.
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Petrophysics interpretation
Summary
Determination of lithology volume, porosity and saturation from
log, core and zonal data using standard and user-defined
equations.
Features
Input data includes pre-corrected and corrected open hole logs,
cased hole logs, core data and zonal parameters generated in the
Crossplot and Histogram applications.
You can generate and display the porosity and saturation of:
- sand
- lime
- dolomite
- clay
- shale
- silt
- calcite
- coal
- salt
- anhydrite.
Other features include:
- Interpreted trace value can be user-defined where mineral flags
are set.
- Identifies bad hole using rugosity and caliper cut-offs
resulting in automatic use of DT method.
- Application of hydrocarbon corrections on porosity using a
selected saturation method.
- Comprehensive set of pre-defined industry standard equations:
- Clay volume:
- single trace (for example GR, SP)
- crossplot
- shaley sand
- NGT and ratio
- minimum
- no correction
- Porosity
- single trace
- crossplot
- secondary
- shaley sand
- core
- Saturation
- Archie
- Indonesia
- Simandoux + Modified
- Laminated Clay
- Waxman-Smits
- Dual water
- EPT
- Composite and user-defined methods per zone.
- Sensitivity analysis per zone or for all zones for up to 10
variations with graphical and numerical comparison.
- User-definable programs written in C, Fortran or the Tigress
programming language.
- Error checking facility to identify problems with applied
methods.
- Multi-well processing of any number of wells using methods
applied to the displayed well.
- Interpretation process is automatically written to the
Audit trail.
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Cluster analysis
Summary
Automatic statistical log facies analysis based upon a
clustering algorithm.
Features
Features include:
- Generates a hierarchical cluster succession based upon
similarities in selected log response.
- Analysis is initially performed on key well intervals and
additional wells/intervals are then aggregated using the statistics
derived from the key wells.
- Number of facies is determined by graphical selection of
dendrogram cuts.
- Hot links to Well correlation and zonation and Crossplot for data loading and to highlight and
review clusters and aggregation
- Generates cluster traces, reservoir flags, synthetic average
property traces and facies zonation for input into 3D reservoir
modelling.
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Zonal averaging
Summary
Calculation of zonal averages and net sand/pay from log,
interpreted trace and core data.
Features
Features include:
- Averaging of log, interpreted trace and conventional core data,
based upon cut-offs defined graphically or manually.
- Definition of new averaged parameters .
- Cut-offs can also be defined in the Crossplot and Parameter table applications.
- Calculates arithmetic, geometric and harmonic averages over net
sand, net pay and user-defined areas.
- Any other trace or core data can be used as discriminator for
net sand/pay identification and data averaging.
- Option to exclude thin layers of pay or sand from the averaging
process.
- Multi-well processing of any number of wells.
- Averaging process is automatically written to the Audit trail.
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Log plot
Summary
Generation of single well plot of raw and interpreted data for
visualisation and hardcopy.
Features
Features include two types of automatic plot generation:
- Quick look standard plots (API format) of density/neutron log,
induction log and laterolog log data
- Results plot of fluid saturation, lithology, matrix density and
net sand/pay.
Other features include:
- Comprehensive composite plot for flexible user-defined plotting
of all raw and interpreted trace data as well as RFT, dipmeter,
zones, core (raw and depth matched) and wellbore schematic.
- All plot types share an extensive range of display features
include trace shading and shading by value, depth markers, cut-off
markers.
- Composite plot has complete user control over plot layout, line
styles and colours, scales, grids, annotation and
hardcopy.
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Audit trail
Summary
Keeps an historical record of all editing and interpretation
methods that have been performed during the course of the
study.
Features
Features include:
- All data manipulation and interpretation applications write to
the Audit trail.
- Records show user, date, time and details of change.
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Tigress Facies Workflow
Tigress Facies Workflow is additional functionality in the
standard Tigress Geology and Petrophysics applications that
allows the display and interpretation of facies traces. These
square traces can be displayed, edited and interpreted to calculate
facies distribution.
Well correlation and zonation
Features include:
- display of facies traces
- conversion of zonations into traces
- all standard shading and scaling options available.
Trace edit
Features include:
- editing of facies traces
- combining of facies groups to a smaller number of sets
- inputting of individual descriptions for each facies.
Zonal averaging
Features include:
- calculation of facies distribution percentage for each
zone
- summary output of percentages and dominant facies per zone
- results saved to the database and stored in the Parameter
table.
Parameter table
Features include:
- facies percentage distribution for each zone stored in the PDS
database
- indication of dominant facies for each zone.
Log plot
Features include:
- display facies traces
- facies summary and description in the plot header.
Log load
Features include resampling of log data to one of three
options:
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