Modified Hyperbolic Decline
Spreadsheet
29 rows x 5 columns
| A | B | C | D | E | |
|---|---|---|---|---|---|
| 1 | Modified Hyperbolic Decline Forecast | ||||
| 2 | Inputs | ||||
| 3 | Initial Rate (qi) | 30000 | bbl/month | ||
| 4 | Initial Decline (Di) | 0.08 | 1/month | ||
| 5 | Terminal Decline (Dlim) | 0.005 | 1/month (6%/year) | ||
| 6 | b-exponent | 0.8 | - | ||
| 7 | Economic Limit | 300 | bbl/month | ||
| 8 | Comparison: Modified Hyp vs Pure Arps | ||||
| 9 | t (months) | ModHyp Rate (bbl/month) | Arps Rate (bbl/month) | ModHyp Np (Mstb) | Arps Np (Mstb) |
| 10 | 6 | 19984.86146 | 19984.86146 | 146.3094833 | 146.3094833 |
| 11 | 12 | 14715.27657 | 14715.27657 | 248.9619394 | 248.9619394 |
| 12 | 24 | 9374.210322 | 9374.210322 | 389.187664 | 389.187664 |
| 13 | 36 | 6734.745774 | 6734.745774 | 484.2749978 | 484.2749978 |
| 14 | 60 | 4178.924767 | 4178.924767 | 610.8752579 | 610.8752579 |
| 15 | 120 | 2013.592562 | 2013.592562 | 782.6260353 | 782.6260353 |
| 16 | 180 | 1273.84282 | 1273.84282 | 878.2179931 | 878.2179931 |
| 17 | 240 | 911.5001492 | 911.7843435 | 942.6999702 | 942.7005087 |
| 18 | 360 | 500.2418882 | 563.5768892 | 1024.951622 | 1028.225724 |
| 19 | EUR Comparison | ||||
| 20 | Model | EUR (Mstb) | Notes | ||
| 21 | Modified Hyperbolic | 1065 | Bounded by terminal decline | ||
| 22 | Pure Arps (b=0.8) | 1128.549055 | May overestimate | ||
| 23 | EUR Difference | 63.54905521 | Mstb | ||
| 24 | Terminal Decline Sensitivity | ||||
| 25 | Dlim (1/month) | EUR (Mstb) | % of Pure Arps | ||
| 26 | 0.002 | 1128.549055 | 100 | ||
| 27 | 0.005 | 1065 | 94.36895942 | ||
| 28 | 0.008 | 993.9880122 | 88.07663323 | ||
| 29 | 0.01 | 953.0946637 | 84.45310014 |
Description
Modified Hyperbolic decline model that transitions from hyperbolic to exponential decline at a specified terminal decline rate. This addresses the unrealistic EUR predictions from pure hyperbolic decline with high b-factors.
Model Behavior:
- Early time: Hyperbolic decline (faster decline)
- Late time: Exponential decline (terminal Dlim)
- Prevents infinite EUR from b > 0
Units: rates are bbl/month against a time column in months, so the Np and EUR columns are true volumes (shown as Mstb). The decline functions are unit-agnostic — rate and time must share the same time base.
How to use this blueprint
- In Excel, go to the Petroleum Office ribbon tab and click Blueprint Manager
- Search for Modified Hyperbolic Decline
- Click on the blueprint to preview
- Click Insert to place it into your worksheet. Modify the input values to match your data.