TRANS II
Advanced Well Testing
Software
R
eservoir Description Services has created features in
TRANS II to make the job of
designing and analyzing pressure
transient tests easier.
Features such as a free format
data import tool, interactive
estimates of reservoir parameters,
deliverability
analysis
and
gradient survey graphing are
included in TRANS II.
Data Import and Graphing
Up to ten data sets with an
unlimited number of points can
be simultaneously graphed and
analyzed.
“Smart” graphics
speed the process for large data
sets.
Analysis plots from multiple
gauge sets, and analysis periods
(build-ups, drawdowns) can be
graphed on the same plot.
After the data has been entered
the transient periods are defined
graphically and the rate history
can be modified via a spreadsheet
interface. Rate history can be
entered in real date and time.
Overview




Analysis
TRANS II will analyze drawdown, build-up period, for gas,
oil or water. The user can either
enter PVT data or use the PVT
calculation engine within the
program. Gas is analyzed using
pressure or pseudo pressure.
The analysis is easily performed
with the help of the log-log
diagnostic plot. It is used to
determine initial estimates of well
and reservoir parameters from
each of the flow regimes.
Specialized plots, such as the
Superposition and Cartesian plots
are then used to check results.
A multi-rate model can be
generated and graphed with the
measured data to confirm the
analysis. Once the model has
been generated it can be
presented on all of the analysis
plots. Such as the log-log, semilog and Cartesian plots.
that give the representative
pressure response.
A Pressure History Simulation of
the entire test period can also be
generated to help validate the
results.
Test Design
A “wizard” is available to
generate the theoretical pressure
response for test design. This tool
is very useful for job planning.
Convert Surface Pressure to
Bottomhole
Surface pressure can be converted
to bottomhole pressure using
Cullender and Smith. The user
can import and convert an entire
ASCII file, or convert data
entered directly into the program.
Reporting and Graphics
Graphics, in Windows Metafile,
and data are exchanged with
other programs via the clipboard.
Reports are generated with user
customizable EXCEL templates.
A non-linear regression routine is
available to quickly find the
combination of model parameters
Data Input, Validation, PVT,
Analysis - The Power of the Diagnostic Plot
Modeling
Features - Lite and Power Tool Versions
Reservoir Description Services (281) 531-5850, (281) 531-6076 FAX

Data Input and Validation
D
ata input and manipulation are the key to efficiently analyzing test data and TRANS II lets the user enter
Pressure-Temperature-Rate data in several ways.
One method uses the data import option to read in Multi-column ASCII files. With this option the user can
define and label each data column and actually preview a listing of the data before it is retrieved. The preview
option eliminates the
frustration of having to
get out of your well
Preview Your Data
testing program to
File Before Importing
determine which data
it Into TRANS II.
columns are pressure
TRANS II
and time.
Data can also be
manually entered or
retrieved from file
within TRANS II via an
internal
spreadsheet.
The spreadsheet alone
is a valuable tool
because the user can
view and edit more than
1 million lines of data;
spreadsheets only allow
up to 65,000 lines of
data.
Determines File
Size and The
Number Of Lines
Before Importing
Data
TRANS II Lets
You Identify Each
Column, Data
Type, And Then
Label the Data
with Your
Identifier
TRANS II’s internal
spreadsheet lets the Importing Pressure / Temperature Data into TRANS II Using the File Import
user filter, function, and Feature
delete data and the
spreadsheet is a springboard to copy data between other Windows tm programs through the clipboard. The
spreadsheet is also a great way to print selected portions of data or full, formatted, data reports.
Data Validation
The hardest part of preparing data for analysis is the process of validating the data. The validation process entails
picking the start of transient periods, defining the rate history so it corresponds with the pressure data, and
making sure the gauge data is correct. TRANS II makes the validation process easy by letting you plot multiple
data streams (gauges, rate, spinner, etc.) on the same graph. This is handy when you want to compare gauge
pressures, temperatures or rate data. You can also graphically pick the start of transient periods, which makes
building the rate history file much easier.
Reservoir Description Services (281) 531-5850, (281) 531-6076 FAX

Data Input and Validation
Easily mark the start and end of
transient periods. Find Closest
point, and exact screen location
TRANS II lets you mark and plot
flowing and static gradients.
Select the section of the data
you want to analyze (i.e. a
build-up).
Enter a unique
label to identify
the period (i.e.
Start build-up
#2).
Display rate and
pressure data to
validate your input.
The Mark Transient Screen in TRANS II - Transient Periods are Easily Defined

The Mark Transient screen (above) makes transient period
identification easy. The start of the transient period is
determined by finding the closest data point, the exact screen
location of the mouse cursor, or by entering time and
pressure manually.

The real time reference feature in TRANS II means you can
use real times and dates for the rate history instead of having
to figure out the equivalent gauge time. There is even a popup calendar to transfer dates to the rate history table (right).

TRANS II also lets the user mark and graph gradient plots.
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
Data Input and Validation
Fluid Properties
TRANS II has a powerful PVT calculation program that
makes PVT calculations fast and easy. A variety of PVT
correlations are available to estimate the fluid properties
for oil, gas, water, and rock compressibility. You can
either use the estimated values, or enter your own
properties. Psuedo pressure is calculated for gas and the
user can view the Pseudo pressure table.
An Advanced PVT calculation feature lets the user
calculate a list of PVT properties, or a graph of the PVT
properties, over a range of pressures and temperatures.
Another aspect of the Advanced PVT lets the user
calculate fluid properties at each pressure or temperature
point during the test. Sometimes this gives some insight
into how fluid properties change during drawdown or
injection periods.
Converting Surface Pressure to
Bottomhole Pressure
In this day and age of cost cutting and tight budgets The PVT Screen in TRANS II
engineers don’t always have the opportunity to run
bottomhole pressure gauges. Surface pressure can accurately reflect bottomhole pressure in most “dry” gas wells
and the analysis of the converted surface pressure can provide a good indication of permeability, skin and
reservoir properties.
TRANS II will convert multiple data points from file and then save the data for
analysis. TRANS II will also merge the rate history with the pressure data so friction
is accounted for during flow periods.

The analysis of daily flowing pressure and rate can define
transmissibility, skin, and drainage area. This is an alternative to ”decline
curve analysis” and has the benefit of giving a diagnostic plot to help
distinguish between transient and pseudo-steady state flow.

Surface pressure build-up tests are much easier to run and less risky than
bottomhole shut-ins.

TRANS II also converts surface shut-in’s to bottomhole and will display
the corresponding pressure, Z, and P/Z values for material balance
calculations.
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4
 The
Power of the Diagnostic Plot
The diagnostic plot is a single
Another
example
of
a
graph that can be used to
characteristic shape on the
analytically define nearly all the
derivative plot is the radial flow
well
and
reservoir
regime. Since the derivative is
characteristics that are of
a constant value in this flow
interest to the engineer.
regime a horizontal line appears
Permeability, Skin, Lambda,
on the screen and the calculated
Omega,
Partial
Penetration, Distance to
Boundaries,
and
“the diagnostic plot provides one stop
Boundary Types can all
shopping for the analysis of well test data”
be estimated from the
diagnostic plot.
TRANS II lets users pick
lines
and
calculate
parameters on the traditional
“specialized” plots, but the
diagnostic plot provides one
stop shopping for the analysis
of the well test data.
The philosophy TRANS II
employs in the analysis of well
test data is to let the user
identify well and reservoir
parameters that correspond
to a particular flow regime
from the log-log plot.
For instance, a unit slope
is indicative of wellbore
storage during the Early
Time flow regime. After
choosing the Early Time
flow regime option a unit
slope appears and as the
user moves the mouse the
wellbore
storage
coefficient is automatically
displayed. A click of the
mouse on top of the
wellbore storage data
transfers the wellbore
storage coefficient to be
used later in the modeling
process.
permeability is displayed as the
user moves the cursor.
Once permeability has been
defined a host of other
analytical
estimates
are
available; skin, distance to
boundaries, omega and lambda
for a two porosity system,
fracture half-length for a
hydraulically fractured system,
10
10
10
10
10
10
etc.
Flow regime markers are also
passed to the appropriate
specialized plots, such as the
superposition or Horner plot,
based on the Analytical
Estimate.
The purpose of the
analytical estimates in
TRANS II is to speed the
modeling process. You
don’t have to move the
data around on an
arbitrary family of type
curves and then iterate to fine
tune the match. This method
greatly reduces the amount of
time required to find a unique
match, and also gives the user a
better feel for how changes in
the various parameters affect
the analysis.
4
Unit slope(s)
indicates wellbore
storage
coefficient(s)
3
The increase in the
derivative marks the
distance to a no flow
boundary.
2
Horizontal Line Estimates
Permeability and Skin
1
“trough” relates to omega and
lambda.
0
-1
10
-3
10
-2
10
-1
10
0
10
1
10
2
10
3
10
4
Some examples of flow regime identification and parameter estimation in TRANS II
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5
 Analytical Models
It wasn’t long ago that the “type-curve” was
considered state of the art for modeling well test
data. Its use really started the process of what is
now
considered
modeling,
or
pressure
history
simulation.
Modeling
has
evolved from overlaying a graph of the
data on a printed
drawdown
typecurve
to
the
technique used in
TRANS II where the
exact solution is
generated using the
test’s rate history.
The log-log plot is
still a good place to
start the modeling
process because of
the character of the
various flow regimes
when plotted on loglog coordinates but
shouldn’t end there.
The data and model
should be graphically Multiple analysis plots displayed on the screen.
compared using a
variety of time functions. For instance, the
Cartesian plot can highlight differences between
Models in TRANS II
Homogeneous and Two-Porosity Solutions for the Well and
the model and the measured data that might not be
for Single Well Interference Test Interpretation.
apparent on a log-log plot.
Inner Boundary Conditions
A statistical comparison between the model and the
 Skin and Constant Wellbore Storage
data can be made to check the quality of the match.
 Skin and Changing Wellbore Storage
An optional regression module takes the matching
 Finite/Infinite Conductivity Hydraulic Fracture with
process even further by systematically adjusting
constant or changing storage
well and reservoir parameters until the best
statistical model fit is obtained.
TRANS II currently gives the user access to the
model types listed in the box on the right and will
also apply the multi-rate solution to any drawdown
type curve imported by the user.
Outer Boundary Conditions
 Closed Circle; Constant Pressure & No Flow
 Fault Models (Single, 90 Degree, Parallel)
 Closed Rectangle (homogeneous model)
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Features in TRANS II
Data Handling Features

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
Import multiple gauges or data streams. Each stream can have as many points as memory will allow.
A pre-filter reduces data during import
Preview data before importing.

Graphically shift data on the screen to line up gauge times or plot data using real time so a time shift
isn’t required.
Export “filtered” data to ASCII file.

Function data. Also subtract, multiply, divide, add gauge streams.

Enter rate history using real time and date.

Graphically or manually define start of transient periods.
Gradient Plotting

Static and flowing gradient identification and plotting.

TVD and MD are interactively calculated using deviation survey.
PVT Calculation

Calculate, list, and graph oil, gas and water PVT properties.

Determine percentage of volumetric flow from each fluid phase.

Use gas composition, or specific gravity and impurities in the calculation of gas properties.
Transient Analysis

Unique log-log diagnostic analysis and flow regime identification.


Specialized plots and analysis:
-- Semi-log (superposition, Horner MDH, and Dake analysis). Cartesian (early and late time)
Additional Specialized plots:
-- Linear Flow (early and late time), Bi-linear Flow , Spherical Flow
Analyze oil, water, gas (pressure method)

Gas pseudo-pressure method. Gas Pseudo pressure plots also display real pressure.

Generate multi-rate model solution on any plot.

Generate Pressure History Simulation of Entire Test Period

Single well interference analysis.

Non-linear Regression.

Test Design Module. Generate simulated pressure response.

Reporting and Graphics

Paste graphs into other Windows programs as metafiles

Print graphics and data reports from TRANS III

Send graphs and data to EXCEL report template.

Define line types, colors, fill areas, symbol types and size for each data set.
Convert Surface to Bottomhole Pressure

Convert any number of data points from surface pressure to bottomhole pressure using Cullender
and Smith.
Inflow Performance Tool

Calculate flow potential
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