IHS PowerTools (US)

Yes. You are able to edit/add either Lease Header information or Lease History, which includes production data or test data. Point to a lease name in the Project Tree, right click, and select Edit. Edit the lease headers under the Lease tab and edit pressure tests and production history in the Pressure and Production tabs.

Yes. An interface utility is included on the PowerTools CD. This utility can create a DOS or Windows ARIES project from a PowerTools database, or a PowerTools project from a DOS or Windows ARIES database.

No. Only the curve handle positions are stored, but they are sufficient for PowerTools to redraw the forecasts. If you need the individual monthly values for the forecast, select the Lifetime Monthly Production Forecast Report.

Price changes can be defined either by Escalations or Schedules. Click on the Add to Settings Tree button and select Add Escalation or Add Schedule, or double-click on the name of an escalation or schedule to modify it. Escalations define the changes in time using segments (up to twenty segments). They are excellent for multiplying or incrementing a value each month. Schedules may be used to define inputs month-by-month from 1/1950 through 12/2149. Schedules are well adapted for historical reviews in which monthly input values are available. Once the escalation or schedule has been defined, it can be applied to a loaded lease by selecting the model name in the Economics tab, or it can be applied to a project-level case in the Settings tab. See the multimedia tutorials for instructions on creating escalations.

Select some leases in the Lease tree, then click the summation button and select Create Summary Lease. Provide a name for the new lease, and it will be added to the Lease tree. Load the new lease, and go to the R/T graph to perform decline analysis.

PowerTools estimates the pseudocritical temperature and pseudocritical pressure from gas gravity for both condensate fluids and miscellaneous reservoir gases. The calculated values for Tc and Pc are corrected for sour gas content with a Wichert-Aziz correction.

PowerTools records both the shut-in tubing pressure and bottom-hole pressure. PowerTools also determines whether the bottom-hole pressure was calculated or measured. If the bottom-hole pressure was measured, then the system uses the pressure as given. If the bottom-hole pressure was calculated, then PowerTools will recalculate the bottom-hole pressure based on input and default values. PowerTools uses an iterative procedure to calculate bottom-hole pressure based on the Cullender-Smith technique. This technique consists of iterations based on a calculation of the average Z-factor for the gas conditions, well depth and temperature.

The gas volume factor is calculated using the ideal gas law with a Z factor correction, using standard pressure and temperature as specified by the state, otherwise using a temperature of 60° F and pressure of 14.65 PSI.

PowerTools estimates the oil formation volume factor at the bubble point, above the bubble point, and below the bubble point. The oil formation factor is used to correct to surface barrels of oil from reservoir conditions in the volumetric calculations.

PowerTools calculates the real gas deviation, or Z factor (Z), for hydrocarbon gases. The technique used by this program was developed by Dranchuk, Purvis, and Robinson. The Benedict-Webb-Rubin equation of state is fit to the Z factor surface defined by the Standing-Katz Z factor correlation. The resulting nonlinear equation is then solved for Z as a function of reduced temperature and pressure using Newton-Raphson iteration. The Dranchuk, Purvis, and Robinson correlation has the lowest average error of the eight most commonly used methods for estimated Z factors.

Oil in place = (7758 * porosity * (1 - Water saturation) * acres * net pay) Oil volume factor Gas in place = (43.56 * porosity * (1 - Water saturation) * acres * net pay) Gas volume factor

If a lease has an Inactive status, forecasts are not drawn. You can use the Edit Lease Header Dialog to change the lease status to Active, to draw the forecasts. For Oil and Gas curves on Active leases, the forecast will not project into the future if the curve slope is positive. Only water curves are allowed to project with a positive slope (note: PowerTools “caps” monthly water production at 1,000,000,000 bbls, to prohibit unreasonable forecasts from water flood projects).

This is probably because the curve is too flat, and PowerTools constrains the curve to a valid hyperbolic solution. Toggle the curve to Exponential, give the curve some (negative) slope, and then toggle back to Hyperbolic. Or drag the right-most curve handle downward, and then drag the left-most curve handle upward, and the projection should become easier to edit.