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Hydraulic Fracturing Engineering and Software Solution, for Your Most Challenging Reservoirs.

May, 1998 Update – Version 2.62/3.02 (Release 2)


  • Incorporated E-StimPlan calculations directly into WINDOWS 95/NT 32-bit version of StimPlan. Added extensive plotting capabilities to allow easy integrated access to these more rigorous calculations.
  • Fix bug associated entry of fluid rheology data at shear rate conditions OTHER than the old default value of 170 re-ciprocal seconds. NOTE that the bug was associated with how the fluid data was stored in the FRK & STP files. Thus, files created with past versions of StimPlan will still have the incorrect rheology data. Simply opening the old files with this updated version will NOT repair this problem for that file; the data must be re-input.
  • Fixed bug with Fluid Loss Input. If when inputting Multiple Layer Fluid Loss Data a “blank” line was left in the input dialog, this was carried over to the simulator as a “0” thickness fluid loss layer, and in some cases caused errors or bombs.
  • Fixed problems associated with FORTRAN compiler. We have discovered (and received from you) several cases where the optimizing feature of the newest Microsoft FORTRAN compiler was causing significant changes in the results! For this release, this problem has been “cured” by not using optimized code. This has an impact on solution speed, of course, but the speed reduction is only significant for E-StimPlan. Alternative compilers will now be in-vestigated, and another E-StimPlan version scheduled as soon as possible to correct this.

Analysis Module (Version 3.02 only)

  • Added an option to “Shift” the StimPlan stress layer input to match the closure pressure determined in the Analysis Module. When net pressure data is “Transferred” from Analysis to StimPlan, a prompt will open allowing the option to shift the input Stress Layering Data. Note that this will NOT alter the stress differences, etc. It simply “shifts” the entire stress profile and thus has little impact on the actual calculations (height growth, net pressure, etc.).
  • Fix minor bug in “Frac Job Test Type”. With previous version, the input actual data was changed to a schedule with “Constant PPG” steps, and the average PPG (and pump rate) between selected time points was automatically calculated. In the “Schedule Dialog”, however, this was sometimes marked as a “Fluid Volume Ramp” type schedule. Since the “ramps” went, for example, from 2.4 PPG to 2.4 PPG, this really had no effect on the calculations; however, the transferred pump schedule is now ALWAYS correctly marked as a “Constant PPG” type schedule.

July 29, 1998 Update – Version 2.62/3.02 (Release 2)


  • Fix bug involving automatic design feature of 3-D simulator. After iterating to a new design, the modified pump schedule was not correctly transferred into the input data. The output information (plots, reports, StimPlan.PRN) did reflect the results from the revised pump schedule, however, the actual input data which one would access from “Simulator Data”, “Proppant Schedule” was NOT being updated with the modified schedule. Since this resulted in the input data and the output results being uncoordinated, this was considered a major bug and this was the basis for this update.
  • Fix minor bug involving accessing the plot “Settings” for the Contour Plots following an E-StimPlan simulation.