1. Key: Initial (or only) ownership or a reversion from that original ownership based on a criteria
   
2. WI - Sum of modeled entity’s working interest in this well
   
3. NRI - Sum of modeled entity’s revenue interest including any overrides owned.  Add the RI and ORRI together for example.
4. Lease NRI - Used for economic cut-off. Calc’d by NRI/WI but may need to be manually adjusted.  LNRI should represent grossed-up WI minus total lease burdens for when OPERATOR would shut-in well due to economics.  If unknown and offset analogues are unavailable, 75% is used as a proxy
   
5. Reversions:
1. Reversion Type & Reversion Value - *Click the +Reversion button at the top to open up to 10 reversions*  Reversions are changes in well ownership based on triggers calculated either on Gross or Net current balances or other criteria
   
1. IRR (%) Internal Rate of Return hurdle above payout ($ invested in CAPEX minus $ in cash flow) at a given return
   
2. PO W/INV ($) Remaining payout plus any investments based on the CAPEX in the Investment Section.
   
3. PO ($) Remaining payout (investments not considered)
   
4. Undisc ROI (%) Undiscounted return on the investments as a multiple (1x is return on the original CAPEX, 2x+ are for statutory or contractual penalty for nonparticipation for example)
   
5. As Of (months) After As Of date
   
6. Date (date) Specified calendar date
   
7. WH Cum Oil (bbl) Gross wellhead oil prod from As Of date (Production or Forecast output)
   
8. WH Cum Gas (Mcf) Gross wellhead gas prod from As Of date (Production or Forecast output)
9. WH Cum BOE (bbl) Gross wellhead boe (at equivalency set for project) prod from As Of date (Production or Forecast output)
   
2. Reversion Tied to - For selections of: IRR, PO W/INV, PO and Undisc ROI it is necessary to pick the starting point used to start taking in to account (or whittling down) the cash flow using the below selections.  This is for instances of when you might not want have just a uniform date applied to everything but to allow modeling of pro-forma amounts like when you have a payout balance as of today rather than the original investment.  ie, you ask the operator or your accounting department for the current book value of a well.
   
1. Include NPI - should the NPI (if present) be considered in the calculation of the items above or not (yes/no).
3. Balance: Whatever criteria picked can be Gross (8/8ths) or Net (portion you own)
   
4. Rev Basis Net - The Rev Basis Net columns allow users to specify the Working Interest (WI) and Net Revenue Interest (NRI) used to calculate the reversion date for cash flow-based reversions. This provides an alternative to the standard Gross (100%) or Net (same interests as the cash flow calculation) reversion basis options. By entering values in the Oil NRI, Gas NRI, NGL NRI, and Drip Con NRI columns, users can tie a reversion trigger to a specific party's interest — for example, the interests of a working interest partner or third party — rather than to the well's gross production or the owner's own net revenue. 
6. Hidden unless populated or selected to display on "Optional Headers" at top-right ("Unless Populated" means, if a well has not phase ownership for NGL for instance, it will not be displayed unless selected to always display by checking the box.  If it does have a value on this model, it WILL show up however even if it is not explicitly selected to show up.  This is to avoid "hiding data" which might affect well economics.
   
1. NPI - % of net operating income (Rev–Exp–PTax) not included in the normal interests above. NPI entered below but selection here represents whether it is positive or negative.  Type:
   
1. Revenue (+) bonus - owns NPI paid them by another
   
2. Expense (-) burden - pay another’s ownership of NPI
   
2. Phase NRI - Phase Ownership only selected when different for modeled entity based on separate product –vs- the primary phase. All products assumed equals to the entered "master" NRI unless populated here (null means use primary).
   
1. Does NOT yet support Custom Streams (on phase ownership)
   
7. Columns (top-right) allow display/hiding any of the column headers including the Optional Headers.

Common Examples

Full Carry/Back-In After Payout

Fully Carry/Back-In at First Production

Convertible ORRI

In this situation the farmor retains a 4% ORRI during D&C, which will convert to 25% WI the moment the well pays out (which is interchangeable with first production trigger of WH Cum Oil/Gas > 0).

Promoted Deal - Disproportionate Cost Share Pre-Payout

The above is when non-op carries 20% of costs in exchange for a promoted 25% WI pre-payout, then reverts to a standard working interest. Operator holds 80% WI but only pays 75% of costs (promoted). The operator then drops to proportionate WI at payout.

Rev Basis Net Example - Third Party Interest Reversion

With Rev Basis Net set to 45% NRI — instead of measuring payout on a gross (100%) basis, the payout calculation is run using 45% NRI revenues and costs. This means rather than tracking payout at the full gross (100%) or the owner's own net (75% NRI) level, ComboCurve calculates cumulative revenues and costs using the specified 45% NRI. The reversion triggers when payout is reached under that 45% interest — meaning the well must generate enough cumulative net revenue, at a 45% NRI, to recover its costs before the ownership change takes effect.

This is useful when the reversion is contractually tied to a specific third party's interest — for example, a carried party who owns 45% NRI — and your reversion triggers when their share of the well reaches payout, not yours.

Referencing Headers for Ownership Values