Handling well cost in fm_well_trajectory and 'fm_npv'

[slawekszklarz]

Currently, when optimizing well trajectories with NPV as objective funtion, the length-dependent well drilling cost is calculated by fm_well_trajectory forward job. The cost per km is provided in --config file:

wells:
  - name: WELLNAME                                       
    cost: COST_PER_KM                   

Then the calculated cost is inserted by fm_well_trajectory into the YAML input file --config to fm_npv replacing any values:

well_costs:
- currency: EUR
  value: COST
  well: WELLNAME

In addition fm_npv requires the standard transaction file --input (file passed between forward models, each adding information), i.e., JSON file with well names and dates at which to insert the drilling cost.

The issues with this approach are:

• YAML config file for the fm_npv cannot be linked (instead of copied) with install_data in Everest config anymore since forward jobs for different realizations would be editing the same file with possibly different cost.
• So far the standard was for forward model jobs to not edit users' YAML input files but only the transaction JSON file.
• It's not clear which costs are per length and which are total.
• There might be some cost in well_costs that will be unintentionally overwritten.
• It's more natural for fm_npv to be responsible for calculating any costs instead of fm_well_trajectory which is responsible for geometric design.

One of possible solutions would be to move the drilling cost calculation to fm_npv:

• fm_well_trajectory writes out well length for each well into the transaction JSON file. Field cost: COST_PER_KM is removed from the input.
• fm_npv calculates the cost, a new input defining cost per length is introduced in the --config file:

well_costs:
- currency: EUR
  #value: COST
  value_per_km: COST
  well: WELLNAME

If value_per_km and value is specified then an error should be thrown at pydantic level. New approach would be backward compatible for the fm_npv.