One of the major advantages of Future over our old Excel based approach to forecasting is that makes life easier when calculating the MPP (Maximum Production Potential). For this we copy the monthly forecast, open all wells that could be made available and change the uptime to 100% before re-running the forecast. Simple. We run this forecast on a monthly basis and again on a 7-day basis, so that we get the MPP for the next nine weeks.

This month, when I ran the MPP forecasts, I spent some time comparing the monthly and weekly MPPs. Something that was immediately apparent is the MPP for the first month (22, 895stb/d) was exactly the same as the MPP forecast for the first week. Can you tell me:

1. Is the rate quoted in the forecast an average over the time period, or is it the rate at the start of that particular timestep?

2. If it is the latter of the two options above, should it not be the former?

3. A colleague believes that in previous versions all rates were an average over the time period. Is he mistaken or has this changed for the latest version of the software?


In answer to your questions -

1) At each calculation step, FUTURE calculates the well potentials at the start of the calculation step. It assumes that the well potentials (and the resultant constrained rates per operating day) remain the same over the whole duration of the calculation step - i.e. the second of your two options.

2) This method was chosen because it is simple - using average well potentials would be reasonably complicated if there were significant facility constraints. If the resultant inaccuracy is too much, this can be corrected by using multiple calculation steps per reporting step ( set in Main Menu > File > Edit Settings for Current Model). The report step gives the average of the calculation step rates.

3) There have not been any changes in the last five years in this matter. Your colleague may be thinking about how FUTURE reports rates for Spectres. For these, FUTURE takes the cumulatives as the base and calculates the average rates that honour the cumulative vs date relationship (so the rate is the average over the time period, not the instantaneous rate that might be reported by WOPR in Eclipse, for example.