"Basic Surveillance" Spreadsheet is No Longer Supported

for Microsoft EXCEL® Version 2003 only

This spreadsheet does not work properly with current versions of EXCEL and is no longer supported by WTS

Please use the free "PIE Reader" application instead

If you still want the spreadsheet, please read the following and note the terms and conditions.

This spreadsheet can be used to carry out well-test analysis calculations that are typically used for basic well performance surveillance and eliminates the need for a specialised software package (e.g. PIE) for this type of work. The key features in the spreadsheet are:

  1. Use individual sheets for each set of shut-in data, with up to 32000 data points for each set of data and as many sheets as you want. A data "filter" is included to reduce the input pressure data to a manageable size.
  2. A pseudo-pressure calculation is included which uses a table of gas viscosity and Z-factor data that you supply. The pseudo-pressure is used to transform the shut-in pressure data so the correct analysis results are obtained.
  3. A Derivative plot for each shut-in is displayed along with a graphics control that is used to define a derivative stabilisation. This stabilisation is then used to estimate the reservoir permeability-thickness.
  4. A Superposition plot for each shut-in is displayed along with a graphics control that is used to define a straight-line through the the data. This line is used to estimate the extrapolated reservoir pressure (P*) and the skin-factor.
  5. Multiple sets of shut-in data can be compared on rate-normalised Derivative and Superposition plots (plot overlay). This comparison shows how well performance and reservoir pressure change over time.
  6. The "Time to pseudo-steady-state flow" (Tpss) is estimated from a simple radius-of-investigation calculation, and a value of Tpss can be entered to control the length of the rate-history used in the superposition calculations.

All of the calculations are visible and unprotected so you can also use this spreadsheet to learn how basic well-test analysis calculations are carried out. All of the basic algorithms needed to prepare a derivative plot are included as Visual Basic code in the spreadsheet. This includes a general superposition function, and a simple derivative calculation which includes smoothing. Everything in the spreadsheet is open for you to modify as desired.

If you are wondering why this is being made available free of charge, please read the discussion of what is meant by "Basic Surveillance".

If you want to use the "Basic Surveillance" spreadsheet, please read the following terms, then click on the "I Accept" button below to download a ZIP-file containing the spreadsheet.

Basic Surveillance Spreadsheet Terms and Conditions

IN THE FOLLOWING:

·      "YOU" REFERS TO , the end user of the Program as an individual or as a single entity

·      "SPREADSHEET" refers to the "BASIC SURVEILLANCE" spreadsheet made available to YOU as a binary download of a "Zip" file.

THIS SPREADSHEET IS PROVIDED “AS IS”, WITH NO WARRANTIES WHATSOEVER; THE AUTHOR DOES NOT, EITHER EXPRESSED, IMPLIED OR STATUTORY, MAKE ANY WARRANTIES, CLAIMS OR REPRESENTATIONS WITH RESPECT TO THIS SPREADSHEET, INCLUDING, WITHOUT LIMITATION, WARRANTIES OF QUALITY, PERFORMANCE, NON-INFRINGEMENT, MERCHANTABILITY, OR FITNESS FOR USE OR A PARTICULAR PURPOSE.

YOU MAY MODIFY THIS SPREADSHEET. YOU ACKNOWLEDGE AND AGREE THAT THE ENTIRE RISK ARISING OUT OF THE USE OR PERFORMANCE OF THIS SPREADSHEET AND YOUR MODIFICATIONS REMAINS WITH YOU, TO THE MAXIMUM EXTENT PERMITTED BY LAW.

THIS SPREADSHEET IS BEING PROVIDED TO YOU FREE OF CHARGE. ACCORDINGLY, YOU ACKNOWLEDGE AND AGREE THAT THE AUTHOR WILL HAVE NO LIABILITY IN CONNECTION WITH OR ARISING FROM YOUR USE OF THE SPREADSHEET.

IN NO EVENT SHALL THE AUTHOR BE LIABLE, WHETHER IN CONTRACT, WARRANTY, TORT (INCLUDING NEGLIGENCE), PRODUCT LIABILITY OR ANY OTHER FORM OF LIABILITY, FOR ANY INDIRECT, INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES (INCLUDING WITHOUT LIMITATION ANY LOSS OF DATA, INTERRUPTION, COMPUTER FAILURE OR PECUNIARY LOSS) ARISING OUT OF THE USE OR INABILITY TO USE THE SPREADSHEET, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

YOUR ONLY RIGHT OR REMEDY WITH RESPECT TO ANY PROBLEMS OR DISSATISFACTION WITH THE SPREADSHEET IS TO CEASE USE OF THE SPREADSHEET.

YOU EXPRESSLY ACKNOWLEDGE THAT YOU HAVE READ THE ABOVE AND UNDERSTAND THE RIGHTS, OBLIGATIONS, TERMS AND CONDITIONS SET FORTH HEREIN. BY CLICKING ON THE "I ACCEPT" BUTTON AND/OR USING THE SPREADSHEET, YOU EXPRESSLY CONSENT TO BE BOUND BY THESE TERMS AND CONDITIONS.

Back to the WTS Home Page

® EXCEL is a registered trademark of Microsoft Corporation.