The PIE user-manual is installed on your computer as a Windows Help-file. From the Windows task-bar, select the 'Start' button, then the 'Programs' menu, and then the 'PIE Well-Test' menu. This will show a big yellow question mark beside the "PIE Manual" option. Select this option to display a table of contents or a keyword 'Search' facility.
You can install the PIE well-test software from our web-site by clicking here.
A reference-time is requested when a table of data is to be displayed in a relative time format (e.g. in decimal hours, hours and minutes, or minutes). The reference-time defines where a time of zero is displayed in the time data. Manipulation of the reference-time allows the time data to be viewed and edited with respect to different points in the history of the well-test.
The reference-time is specified after selecting the time format to be used for editing. The reference-time is entered as a date/time value PLUS an optional time offset. The offset is a CONVENIENCE for specifying a date/time and has no effect on anything else. For example, entering a date/time of 80/12/11;04:00:00 together with an offset of 24 hours is the same as specifying a date/time of 80/12/12;04:00:00 with a zero offset.
The following example shows how the reference-time works. For this example, assume the test has the following rate-data from a production report:
| (hour) | Rates | ||
| 80/12/11;00:00:00 | 0.0 | 100 | |
| 80/12/26;00:00:00 | 360.0 | 0 | (SHUT-IN) |
| 80/12/30:00:00:00 | 456.0 | 0 |
Enter this information using the "Edit Rate-Data" option under the "EDIT" pull-down menu and select a 'decimal hours' time format. Enter the reference-time as 80/12/11;00:00:00. With this reference time, the decimal time values entered in the table are the same as those shown in the above production report. Select "OK" after the three rate values have been entered.
Continuing the example, the pressure data for the test reads as follows:
| (hours) | pressure (psi) | ||
| 0.0 | 2320 | ||
| 12 | 2310 | ||
| 80/12/26;00:00:00 | 24.0 | 2300 | (shut-in) |
| 26.0 | 2400 | ||
| 28.0 | 2500 | ||
| 36.0 | 2700 | ||
| 72.0 | 2800 | ||
| 120.0 | 2900 |
This data shows the gauge was run-in 24 hours prior to the shut-in. Select the option "Edit Test-Data" under the "EDIT" pull-down menu and select a 'decimal hours' time format. To enter the data from this report, set a reference-time of 80/12/26;00:00:00 and an offset of -24.0 hours. This will result in a display of the rate history with a value of 24.0 hours shown at the start of the shut-in. Enter the pressure data into PIE exactly as shown in the above table. Enter the command "OK" after entering the data.
You move data into PIE from another application (e.g. a spreadsheet) by using the standard "Copy and Paste" clipboard options that are available in all Windows programs. This process can be done on a column-by-column basis, or you can format the spreadsheet so the columns of data correspond to the table in PIE.
For example, lets say you have a spreadsheet with time (in hours) and pressure data. Here are the steps to move that data into PIE using the clipboard:
In the spreadsheet, highlight the column with the time data and select the "Copy" option under the "EDIT" pull-down menu in the spreadsheet program.
Start PIE and select the option "Edit Test-Data" under the "EDIT" pull-down menu. Select "hours" for the time-format and enter the date/time value that corresponds to a time value of zero (you can make up this reference time, but I recommend setting this value correctly; see the FAQ describing the reference-time).
In the PIE table, select the first field at the top of the time column. Then select the "Paste" option under the "EDIT" pull-down menu.
Switch back to the spread-sheet program, highlight the pressure data, and copy this data to the clipboard with the spreadsheet "Copy" option.
Switch back to PIE and use the scroll-bar to scroll the table back to the first line. Select the first field at the top of the pressure column. Then select the "Paste" option under the "EDIT" pull-down menu.
One of the big problems in well-testing is that there are no standards defining the file format for raw pressure data. To overcome this, PIE has a general purpose "ASCIIprep" module for preparing analysis data from ASCII text files. This module is controlled by the options under the "ASCIIprep" pull-down menu.
PIE will ALWAYS request a "Reference Time" when reading raw-data from a text file. This reference time specifies the date and time when the clocks were started for the gauge. I recommend you pay attention to setting the correct reference time whenever you read a text file. This will ensure the PIE-file correctly records when the test occurred and will greatly simplify the process of merging additional raw-data to an existing set of analysis-data.
Select the "Process ASCII-File" option from the "ASCIIprep" pull-down menu to display a plot of the rate and pressure verses data verses time. This data plot is the working display for all of the operations in processing an ASCII-file. The "ASCIIprep" options are in three main groups; the first is to read arbitrary gauge data from one or more ASCII-files, the second group is allows this raw data to be cleaned up, and the final group is used to select the analysis-data. The following describes the options within each of these groups:
Once the "Process ASCII-File" option is selected from the "ASCIIprep" pull-down menu, a plot of rate and pressure verses time is displayed. This data plot is the working display for all of the operations in processing an ASCII-file. If a new test is being prepared, then the "New PIE-file" option under the "FILE" pull-down menu should be used before the "ASCIIprep" pull-down menu. If an old test is being re-processed, then the PIE-file for that test should be opened with the "Open PIE-file" option under the "FILE" pull-down menu.
At this point, data can be read from an ASCII-file to create a new set of Gauge-Data, or a previously saved gauge can be re-loaded from the current PIE-file. Note that PIE can merge several ASCII-files into a single set of gauge-data; this is a very handy facility for gathering data from several service companies into a single data entity. The following "ASCIIprep" options are related to data loading operations:
Read File to Create New Gauge -
Select this option to read data from an ASCII-file to create a NEW set of Gauge-Data. This will result in the display of a menu to specify how to read data from a file.Load/Save/Delete Gauge -
Select the this option to reload a previously stored set of Gauge-Data, save the current Gauge to the current PIE-file, or delete a set of Gauge data. This option will display a table that shows all of the gauges stored in the current PIE-file and the current set of gauge-data.Add Delimited File to Gauge -
Sometimes data is supplied in a simple two-column format of time and data values with the columns separated by a standard delimiter (e.g. a tab character for a tab-delimited file). Use this option to read this type of simple file using a few quick steps.Add File to Gauge -
If the data for the test is split into several ASCII-files, this 'Merge' option can be used to add data to the current Gauge-Data. Remember that Gauge-Data represents ALL of the data for the test and not just the data from a single ASCII-file. Note that files MUST be read in a time-increasing order!Save Gauge to PIE-file -
Once a set of Gauge-Data is prepared, it can be saved to a PIE-file with this option. Once a gauge is saved, it can be re-loaded for further processing. It is recommended that the Gauge-Data is ALWAYS saved to a PIE-file because you will always find it handy to have around. This option also allows the gauge to be exported to a different PIE-file.
Once the Gauge-Data has been prepared, a set of options are available to prepare the test rate-history and select the Analysis-Data:
Add Flow-Periods to the Test -
This option will set-up the parameters for a "point and click" session to add flow-periods to the rate-history for the test. This option makes use of facilities in PIE to automatically locate a rate-change based on detecting discontinuities in the pressure data.Display Rate-Editing Functions -
This option will display a set of graphics functions that allow the rate-history to be manipulated by 'point and click' graphics operations. The time at which a flow-period starts can be adjusted, flow-periods can be merged together, etc.Delete Flow-Period(s) -
Use this option to get rid of one or more flow-periods in the rate-history.Select Pressure Data -
This option will set-up a "point-and-click" session to select pressure data for analysis from the Gauge-Data. There are several different selection algorithms to control the distribution of analysis pressure points within a flow-period. These can be used individually or in combination to obtain the desired Analysis-Data pressure points.Select Individual Points -
This option can be used to select individual pressure points to fill in gaps in the analysis-data.Delete Pressure Data -
This option is used to delete all or portions of the analysis-data that was selected by the preceding two options.
Consult chapter 4 of the user-manual (which is installed as a Windows HELP file) for an example of processing raw-data into a complete PIE-file ready for analysis. This example explores the various ways to handle raw data under different circumstances.
The best way is to use the "Plot/Edit Data" option under the "EDIT " pull-down menu to display a plot of the rate and pressure data, then use the "ADD-Q" graphics function to insert rates into the history.
After selecting the "ADD-Q" graphics function, click on the time where you want the new rate to START. The program will ask you for the value for the rate and allow you to adjust the exact time when the rate starts.
Also note the "EDIT-Q" function will allows you to alter the rate value for a particular flow-period.
If you want to duplicate an entire PIE-file while running the program, just use the "Save As..." option under the "FILE" menu and enter the name of the new PIE-file. If the current PIE-file contains plots and/or raw gauge-data, you will be given the option of including or discarding these items in the copy of the PIE-file.
If there is just a particular table of data you want to take from one PIE-file to another PIE-file, open the first PIE-file and display the table with the data you want to copy. Select the "Copy" option under the "EDIT" pull-down menu. Open the second PIE-file and display the same table, then select the "PASTE" option under the "EDIT" pull-down menu to place the copied data into the table.
If the table you are copying has a scroll-bar, then you will need to highlight the portion of the table you want to duplicate. This is done just like a spreadsheet program using "shift-click" or "click and drag" actions with the mouse, or the "shift-arrow" keys on the keyboard.
Graphics functions are the buttons displayed with an analysis plot. You use these functions to draw lines through the data, set parameters for a type-curve match, etc. etc. When you pick a graphics function, a hint telling you what to do will appear in the title-bar of the window that contains the buttons. Also (for Windows users) if you hold the mouse cursor over the button a long description of the function will appear ("tool-tips").
The graphics functions that are shown are tailored to what you are doing. For example, if you select a Horizontal-Well model for an analysis, only the functions that are appropriate for that model are displayed.
To find out what a particular graphics function does, select the "Explain How a Function Works..." option under the "HELP" pull-down men, and then pick the graphics function you want some information about.
The pull-down menus define the basic organisation of the analysis. The options under the pull-down menus allow you to choose the main areas for an analysis or start a new type of analysis. For example, you start a test design by selecting the "Test Design" option under the "MAIN" pull-down menu.
In general, you do an analysis by working from left to right with the pull-down menus. The "EDIT" pull-down menu is where you set-up the basis analysis data. The "ASCIIprep" menu is where you process raw ASCII text files into analysis data. The "MAIN" pull-down menu sets the main analysis type and overall settings for the analysis.
The "PLOTS" pull-down menu will display an analysis plot in a new window. You can open as many plots as you want. Opening the first analysis plot will tell the program that you have started an analysis.
The next pull-down menu contains the analysis options. The title for this pull-down menu depends on what type of analysis was selected from the "MAIN" pull-down menu (for a regular test, the pull-down menu has the name "ANALYSIS"). The options under this menu list the main options to carry out the analysis in the general order that they should be selected. However, you can select analysis options in any order you want; PIE imposes no restrictions on how you tackle a test interpretation.
The "GRAPHICS" pull-down menu contains all of the handy utility options used to manipulate graphics data on a plot. This menu also has the options to save and overlay (compare) analysis plots.
When you select a graphics function button, you can tell that it is 'active' because the button looks like it has been "pushed in". Also note that there is a "hint" displayed in the title bar of the window that holds the graphics function buttons. This hint will tell you what to do; like click on a data point, or pick two points to draw a line, etc.
OK, I admit that some functions are missing a "hint" prompt (I am working on this now...). In the mean-time, if you want to find out how a graphics function works, select the "Explain How a Function Works..." option under the "HELP" pull-down men, and then pick the graphics function you want some information about.
Most graphics functions will keep doing what they are supposed to do for each 'click' you make on the plot. To tell the program you are finished with a graphics function, hit the "Enter" key.
The "ESCAPE" key or the "Control-Break" key combination will cause PIE to stop what it is doing and wait for your next command. The program checks for these key strokes while it is doing a long calculation.
However, some type-curve models have quite a long calculation between the checks for an "ESCAPE" or "Control-Break" key. So don't expect an immediate response when you try to halt an operation; be patient and wait until the program gets around to checking for your request to stop.
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All of the really useful graphics utilities are grouped under the "GRAPHICS" pull-down menu. To hide the window that holds the buttons for the graphics functions, select the "Display Functions" option under this pull-down menu. Note that there is a check-mark beside this option on the pull-down menu when the graphics functions are visible.
All of the really useful graphics utilities are grouped under the "GRAPHICS" pull-down menu. To find the value of a particular spot on an analysis plot, select the "Report (x, y)" option under this pull-down menu. Each 'click' on the plot will display a label reporting the x-axis and y-axis value. If the plot uses a time-transform for the x-axis, the x-axis value reported is the real delta-time.
Another really useful function under the "GRAPHICS" pull-down menu is the "Report Date" function which will tell you what the date was at a particular point on the plot. Very handy for correlating events in the pressure data to well-site reports (as in "what on earth were they doing at that time?")
To leave the (x, y) label on the plot, just hit the "ENTER" key on the keyboard or select another graphics function. The label is removed from the plot if you hit the "Escape" key.
Labels are short bits of text to note various items on the plot. Labels are created by the options under the "GRAPHICS" pull-down menu or by PIE itself. If you want to get rid of these labels, select the "Delete Label(s)" option under the "GRAPHICS" pull-down menu and click on the label you want to remove. Keep clicking on labels to be removed, or hit the "ENTER" key to stop.
Pick the graphics function that set that line (e.g. the "STABIL" function sets the 'stabil' analysis line) and then pick a point outside the plot frame (the plot frame is the rectangle that defines the plot axis). To 'turn off' the graphics function, just hit the "Enter" key on the keyboard.
PIE is a program with a long history of running on many different operating systems. As such, there are a few legacy "features" that are kept for the old-timers who prefer commands instead of mouse clicks and buttons.
One of these legacy features is control of the display while entering data into a table. PIE contains a set of one-character commands that are similar to the UNIX "vi" editor (e.g. a "B" command character scrolls a table to the bottom). If the program sees one of these special characters in your input, it assumes you want to execute that command. These command characters are actually pretty useful; you can string together a fairly complex line of values and commands to do a bunch of changes in one go.
To bypass these command characters, place double quotes (") around the text that you want PIE to use.
I promise to yank these command characters in an update to the program so you won't have to worry about it.
This is one area of well-testing that is loaded with myths, opinions, and downright lies. There are innumerable "special" analysis methods that take a particular slant on this problem. While this provides endless opportunities for well-test specialists to discuss the merits of these special methods, this analysis proliferation is not very helpful for the engineer trying to get an answer.
PIE attempts to simplify the problem by dealing with closed reservoirs as simply another type-curve model to match to the measured data. When the program detects that you are using a closed reservoir model for the analysis, the results displayed after a type-curve simulation will include the average pressure for the cumulative production and the pore-volume of the specified reservoir geometry.
The average-pressure problem breaks down into three distinct cases:
It is important to note that when a test DOES NOT show closed reservoir effects, you MUST make an assumption about reservoir size in order to calculate the average reservoir pressure. This is true even for the specialised analysis methods. There is no escape from the fact that you cannot determine the reservoir size if a test does not show closed reservoir effects.
If you cannot make a reasonable assumption about the reservoir size and the test does not show closed reservoir effects, then you can carry out a "Minimum reservoir volume" calculation. This is simply the smallest reservoir size that DOES NOT affect the match of the measured data i.e. all the unknown reservoir boundaries are outside of the radius-of-investigation of the test. This calculation is particularly useful for exploration wells as it defines the minimum "proven reserves" for the test.
PIE does include an MBH analysis as an option under the "MAIN" pull-down menu. The methodology for this special analysis is described in the SPE Monograph "Pressure Build-up and Flow Tests in Wells" by Matthews and Russell.
When there is voidage replacement (i.e. water or gas injection) in a developed field, the drainage area around each well takes on a very peculiar geometry (see the chapter on determining average reservoir pressure in the SPE Monograph "Pressure Build-up and Flow Tests in Wells" by Matthews and Russell). What is important to note for this type of problem is that each production well has a connection to one or more of the injection wells. This connection creates one or more "constant pressure boundaries" in the drainage area for the well. For example, the drainage-area for each producer in a balanced 5-spot water-flood is a rectangle with half the pattern area and a constant-pressure boundary on all four sides.
For all practical purposes, the average pressure for a well with constant-pressure boundaries is the pressure AT the constant-pressure boundary. The pressure at the constant pressure boundary is exactly equal to the initial-pressure used for the type-curve simulation in PIE with a constant-pressure boundary model.
Therefore, when you analyse a test for a well in a field with voidage replacement, match the test data with a closed reservoir model with one or more constant pressure boundaries. The initial-pressure from this match will be the average reservoir pressure in the drainage area of the well.
OK, OK already. So you aren't keen on the idea of doing a real well-test analysis...
Once you prepare the analysis data using the "EDIT" pull-down menu, just select the "Horner Plot" option under the "PLOTS" pull-down menu. Then select the "Diagnostic" option under the "ANALYSIS" pull-down menu. Use the "AUTOSL" graphics-function to draw a least-squares straight-line through a range data to get the permeability, skin-factor, and extrapolated pressure.
If you are a really "advanced" user, select the "Derivative" option under the "PLOTS" pull-down menu. Select the "Diagnostic" option under the "ANALYSIS" pull-down menu and use the "STABIL" graphics function to pick a stabilisation, and the "UNITSL" function to pick a well-bore storage unit-slope.
If you want to put these plots into your "well-test" report, for each plot select the "Copy" option under the "EDIT" pull-down menu, and paste the plot into your favourite word-processor.
A type-curve in PIE is really a type-curve MODEL. The program uses a model to match the test data by doing a type-curve simulation i.e. we compute the pressures given a type-curve model and a set of model parameters. So a type-curve match in PIE involves using a MODEL to simulate a pressure response which is matched to the measured data.
PIE has an option for the more traditional draw-down type-curve match under the "MAIN" pull-down menu. This is where you can 'slide' the data over a set of type-curves. However, I strongly recommend avoiding this type of archaic analysis. You can do a much better job matching a type-curve model to the data with a simulation.
Once you have the analysis data set-up, select the "Derivative" option under the "PLOTS" pull-down menu. All of the options in the following steps are located under the "ANALYSIS" pull-down menu. Select the "Type-Curve Model" option and choose a representative model from the multitude of choices available in PIE. You can use the "Estimate Parameters" option to draw some lines on the plot to estimate model parameters, or you can jump to the "Set-up Simulation" option to prepare a type-curve simulation.
The model parameters are set with the "Model Parameters" option and the simulation is started by the "Do Simulation" option. The type-curve simulation will display a calculated curve for the model on the all of the open analysis plots. The parameters for the type-curve model can be adjusted for a better match, or you can use the "Optimise Fit" option to start a non-linear regression.
Note that you can change the model parameters by clicking on the value displayed on the analysis plot.
First, you need to select the horizontal-well model so PIE knows that this is the type of well you want to analyse. Select the "Derivative" option under the "PLOTS" menu if you haven't already done so. Then select the "Type-Curve Model" option under the "ANALYSIS" pull-down menu and choose the horizontal-well in a homogeneous reservoir with a radial geometry. Enter the length of the horizontal-well and the vertical location of the well-bore in the reservoir; note that these values are just initial defaults for the calculations.
The derivative response for a horizontal well consists of well-bore storage (WBS) effects (usually a 'hump' in the derivative), a vertical-radial flow (VRF) stabilisation, a linear-flow (LF) transition period, and a final pseudo-radial-flow (PSR) stabilisation.
If there is a section of data with a unit-slope, select the UNITSL graphics function and pick a point somewhere in this data. This defines the storage coefficient from the WBS effects.
The first stabilisation in the derivative after the WBS effects will be the VRF regime. Select the "HORSTB" graphics function and click on a point in this first stabilisation. This will set the perforation skin-factor and a permeability equal to the geometric average of the vertical and horizontal permeability's. (Note that the VRF regime and the HORSTB function is sufficient to get the perforation skin-factor. This is a handy way to get a quick measurement of the quality of a horizontal-well completion.)
If there is an final stabilisation, select the "STABIL" graphics function a pick a point in this data. This will set the horizontal permeability and allow the program to calculate the Kv/Kh permeability anisotropy ratio.
If there is a obvious (i.e. longer than 1/2 a log-cycle) upward trend in the derivative that is something like a 1/2 slope, select the "HALFSL" graphics function and pick a point in this data. This will estimate the effective producing length of the horizontal-well. This is a rough estimate, so you might want to skip this step if you have PLT information that defines the producing length of the well. If you don't like the results from this calculation, remove the "HALFSL" analysis line, hit the "Enter" key, click on the "Drain Length/2" value shown on the plot, and type in the desired horizontal-well half length.
The above steps are just an estimate of the various horizontal-well parameters. Select the "Set-up Simulation" option under the "ANALYSIS" pull-down menu to take these estimates and set-up the parameters for a type-curve simulation. Select the "Do Simulation" option under the "ANALYSIS" pull-down menu to generate the horizontal-well model pressure response for these parameters. Use the "Optimise Fit" option to do a non-linear regression of the model parameters to find the best fit.
Flow into a well with a complex well-bore geometry develops a complex pattern of streamlines into the perforations. The convergence or divergence of these streamlines near the well-bore will appear as a skin-factor relative to the long-term flow behaviour of the well. This is called the "Geometric Skin" because this skin effect is caused by the geometry of the flow streamlines into the well-bore.
In addition to this geometric skin-factor, there is the intrinsic damage physically on the perforated interval. This skin-factor is called the "perforation skin" for the obvious reason that this is the skin on the perforations of the well.
The total skin effect caused by BOTH the perforation-skin and the geometric skin is called the "Global Skin". The Global-Skin is NOT a simple addition of the perforation and geometric skin values; it depends on the geometry of the well and reservoir. The Global-Skin is the skin-factor to apply to a simple vertical-well in a homogeneous reservoir to obtain the same long-term radial-flow behaviour as the well with the complex geometry. For example, the long-term productivity for a horizontal well can be found by substituting the Global-Skin for the horizontal-well into the simple vertical-well productivity-index equation.
Once you have set-up the analysis data, display one or more analysis plots by selecting an option under the "PLOTS" pull-down menu. Under the "ANALYSIS" pull-down menu, select the desired type-curve with the "Type-Curve Model" option and then select the "Set-up Simulation" option.
Set the starting point for the automatic type-curve match by filling in all of the model parameters either by 'clicking' on the values shown on the plot, or by selecting the "Model Parameters" option under the ANALYSIS pull-down menu. Use the "Do Simulation" option to create the type-curve to check that the starting point is reasonable (note: chapter 9.8.1 in the PIE user-manual has a good description of what constitutes a good starting point; this is NOT necessarily a curve that is close to the measured data...).
Once the starting point is set, select the "Optimise Fit" option under the "ANALYSIS" pull-down menu. If you have pressure data in more than one flow-period, you have the option to regress on the last flow-period (the one that has the data for the analysis plots), or all of the flow-periods. The Optimiser plot is shown along with a set a graphics functions that control the automatic type-curve match. Note the hint that is given in the title-bar of the window that holds the graphics-function buttons. Select the "GO!" graphics-function to start the automatic type-curve fit and note the hint given in the title-bar.
If the pressure observation well (observer) is 'static' (i.e. shut-in) and there is only one other active well (a pulser), then you can do the analysis just like a regular well-test. Set-up the test data using the options under the EDIT pull-down menu with the pulser rate-history and the observer pressure-data. When you do the analysis, select a type-curve model with the 'interference-test' geometry by using the "Type-Curve Model" option under the ANALYSIS pull-down menu.
If the observer is NOT static or there is more than one pulser well, then you will need to use the "Multi-Well Simulation" option under the MAIN pull-down menu. This is a fairly complicated module and you should read chapter 13 in the PIE user-manual.
When you select a model with boundaries, the model parameters will include the distance from the well to the boundary AND a boundary "fog-factor". This fog-factor defines the type of boundary with a value of 1.0 representing a no-flow boundary, a value of -1.0 representing a constant-pressure boundary, and a value of 0.0 removing the boundary from the model.
Fractional values of the fog-factor represent a change in the reservoir transmissibility for a constant diffusivity.
Create a new PIE-file using the option under the FILE pull-down menu. Set-up the basic test constants using the options under the EDIT pull-down menu. Define the duration of the prediction by selecting the "Edit Test Data" option under the EDIT pull-down menu and entering two time values with a NULL (-9999.0) rate. Then select the "Production Prediction" option under the MAIN pull-down menu.
At this point, you need to set the type-curve model and the production constraints using the options under the PROD.PREDICTION pull-down menu. The constraints data define how the well will be produced i.e. on a fixed flowing pressure, a fixed rate, or limited to a maximum rate. Set the model parameters and then select the "Do Simulation" option to have PIE calculate the production rates for the well.
Note that there is a "Well Productivity Index" plot available under the PLOTS pull-down menu.
The "Production Prediction" option is part of the PIE Analytic Simulator. Chapter 13 in the PIE user-manual describes this option in more detail.
Under the "ANALYSIS" pull-down menu is the option "View/Load/Save Results". Selecting this option will display the PIE "Results Manager" which provides facilities to manipulate sets of analysis results in the current PIE-file and the set of results for the current analysis. To save the current results, just click on the field "Current Results in Memory", type in a descriptive comment, and then click on the "Select/Save" button. You will see the results appear in the table "Previously Saved Results".
Note that the Results Manager will automatically save results when you change the type-curve model or end the analysis. These automatically saved results are given a prefix of "AUTO-SAVE" in the descriptive comment.
When you have an analysis plot you particularly want to save, select the "Save Plot" option under the "GRAPHICS" pull-down menu. You can enter a descriptive comment to associate with this saved plot. The plot is saved in the current PIE-file.
To view a list of the saved plots in the current PIE-file, select the "List Saved Plots" option also under the "GRAPHICS" pull-down menu. Note that you can delete a saved plot from this listing.
I recommend saving plots frequently to simplify preparation of a report. You can access a "Plot Manager" from the "Reports" option under the "MAIN" pull-down menu. The Plot Manager allows you to re-display a saved plot and construct comparisons of different plots.
As you proceed through an analysis, you store a plot in the current PIE-file with the "Save Plot" option under the "GRAPHICS" pull-down menu. Several plots of the same type can be compared by using the "Overlay Plot" option also located under the "GRAPHICS" pull-down menu. You can overlay a plot of the same type from the current PIE-file or from a different PIE-file.
This facility is a very powerful analysis tool. Where possible, PIE constructs analysis plots using a 'normalised' axis so the same reservoir properties measured by two different tests will yield the same shape on the analysis plot. Comparison of the plots from different tests is a powerful diagnostic of whether or not the tests measured the same well and reservoir properties. This comparison can also identify which properties have changed in the time between the tests. The best plots for doing these comparisons are the derivative or superposition plot.
Under the GRAPHICS pull-down menu are two embellishment options; "Add Labels" and "Add Arrows". The "Add Labels" option allows you to enter a list of text labels to position on the plot. The "Add Arrows" option allows you to draw arrows to direct attention to a particular feature on the plot.
Alternatively, you can copy a plot to the clipboard by using the "Copy" option under the "EDIT" pull-down menu and then "Paste" the plot into a Windows presentation program (e.g. PowerPoint). PIE generates plots using the Windows Metafile format which all presentation programs can manipulate. For example, in PowerPoint you can convert a Windows Metafile into PowerPoint objects which can be individually edited or gathered into groups.
Use the "List (x, y) Data" option under the "GRAPHICS" pull-down menu. This function allows you to 'click' on any curve displayed on an analysis plot and list the data in a scrolling table. Columns in this table can be highlighted like a spreadsheet and copied to the system clipboard to be pasted into another application.
Where possible, the table displayed by the "List (x, y) Data" option converts the x-axis data into time values in decimal hours.
The data in a scrolling table can be highlighted by using standard window "shift" commands. To highlight a range of lines and columns in a table, click the mouse on the start of the range, then hold down the shift key while clicking the mouse on the end of the marked range. A range can be extended by repeating the "shift-click" operation with the mouse, or by holding down the shift key and using the arrow keys. A range can also be highlighted by holding down the left button on the mouse and dragging the mouse pointer over the desired range of the table. Moving the mouse pointer above or below the table will auto-scroll the table to extend the range during a "mouse drag" operation.
Once a portion of the table has been highlighted, use the "Copy" option under the "EDIT" pull-down menu to place the selected data on the system clipboard. You can then paste this data into another application.
Alternatively, you can save the entire table in a text file by selecting the "Print" option under the "FILE" pull-down menu. Check the "print to file" box in the "Printer" options and select the "OK" button. You can then select the text file to store the table.
This is a set of real data from a well in the swamps of Louisiana that is used as the default oil-well test in PIE. It was actually called "Great Horny Toad Gusher #1", but this caused some offense to people who didn't know that the swamps in that area have some large frogs called "Horny Toads". In deference to these sensitive souls, the well name was changed to "Jolly Big Frog".
A well-test looks at the pressure distribution in the reservoir caused by a change in production rate changes over time i.e. it is "Transient". This is the opposite of "steady-state" which corresponds to the long-term behaviour of an oil-well.
Why, myself of course...
Ooof. This is a bit too general a question to answer in a FAQ! I recommend reading the Monograph titled "Pressure Buildup and Flow Tests in Wells" by C.S. Matthews and D.G. Russell. This monograph can be obtained from the SPE.
The Dietz method to compute the average reservoir pressure is about as archaic a method as you can get. However, if you really insist on using this potentially erroneous calculation, here are the steps to carry out.
There is no particular advantage to this method. You can obtain much more information by matching the data using type-curve simulation with a closed reservoir model. PIE will compute the average pressure for you and you might even discover some interesting information about the size of the drainage area given enough data. The simulation approach requires some care in doing the analysis (setting the initial pressure, fixing boundary distances, etc.) but the result is a lot more meaningful.
For the diehard special-analysis people out there, use the "MBH analysis" option under the MAIN pull-down menu. The answers from an MBH analysis are exactly the same as a Dietz calculation.
A really easy question. Once you have PIE installed on a computer and you want to move the installation to another computer, just copy the PIE installation folder to the target system and run the SETPIE.EXE program located in the PIE folder. PIE does not depend on any operating system files and does not alter the system files in any way. So it does not really care about the computer it is running on.
How you move the PIE folder is a different question. The PIE.EXE file is pretty big, so you will have to use a file-compression program (WINZIP for example). Alternatively, you can usually hook a cable between two computers and "squirt" the files across.
"Pression Interpretation d'Essais des puits" which is extremely mangled French for "pressure analysis of well-tests". In French, the acronym is pronounced "Pee" (Anglo-Saxon's think this is hilarious) and in English it is pronounced "Pie" as in what you take a slice of to eat (like apple pie).