Costs
Costs in PetroVR are classified in two great groups:
- OpEx (Operating Expense)
- CapEx (Capital Expense)
Both types are used to input information as well as to output results. When you input information in PetroVR Plan costs are ubiquitous: some model objects have both CapEx and OpEx (facilities, for example), some have only OpEx (e.g., rigs) and some have only CapEx (e.g., a Bonus Payments job). Jobs are key model objects from the point of view of expenditure: many jobs exist solely for the sake of modeling a cost under a given category. Job costs are described in detail in the Cost pane section.
Indirectly all jobs may have both CapEx and OpEx in their usage of Resources, which is itself characterized by capital expense (Acquisition Cost and Disposal Cost) and operating expense (Reallocation Cost and OpEx).
OpEx can appear broken down in two variables: Fixed OpEx, and Variable OpEx. Again, a typical example is the facility, whose operating costs can be defined by a fixed part (what the facility spends when on standby), and a part dependent on the amount of fluid processed.
Since CapEx refers to a fixed amount to be spent, it is usually expressed as Money, whereas OpEx is more commonly defined as Money per Time (see Units). However, this distinction is not always clear-cut, because in some cases the Time, since it is the money spent per day during the drilling process; nevertheless, it is included in the general well CapEx, since it is only a part of the whole well installation cost. On the other hand, well Intervention expenditure (see Maintenance Program tab) is always regarded as OpEx, since it is related to the well's operating phase; however, it may have a Fixed Cost expressed as Money.
OpEx and CapEx Composition per Type of Object
The following table illustrates the composition of the total CapEx and OpEx of wells, facilities and jobs:
| Object | Expenditure | Components |
|---|---|---|
| Well | CapEx | Drilling Fixed Costs + (drilling) Rig Cost Rate * Well Drilling Time + (Well Completion Info) Resources CapEx + Completion Fixed Cost + (completion) Rig Cost Rate * Well Completion Time + (Well Completion Info) Resources CapEx |
| OpEx | Well OpEx + (Well Drilling Info) Resources OpEx + (Well Completion Info) Resources OpEx + (Maintenance Program) Operational Reourses OpEx +Well Abandonment Cost | |
| Facility | CapEx | (Facility Construction Job) Fixed CapEx + (Facility Construction Job) Resources CapEx + Expansion CapEx + (Facility Expansion Job) Resources CapEx |
| OpEx | (Facility Construction Job) Fixed OpEx + (Facility Construction Job) Resources OpEx + Variable OpEx + Operational Resources OpEx + Expansion OpEx + (Facility Expansion Job) Resources OpEx | |
| Job | CapEx | Job CapEx + Resources CapEx |
| OpEx | Job OpEx + Resources OpEx |
Reallocation Cost of durable resources is not assigned to well, facility or job OpEx. Operational Resource CapEx is not included in Facility CapEx or in Infrastructure job CapEx. Rig Cost Rate, Drilling Fixed Cost and Completion Fixed formula in the table. Specific entries for oil/gas production and injection wells omit Abandonment costs as these are provided in a separate row.
CapEx Proration
CapEx associated to a job with a defined duration is prorated, i.e., it is distributed evenly throughout the time the job lasts. For jobs longer than the Period Type defined in the General tab, this implies that the cost will be allocated proportionally to each period:
The proration of CapEx costs can be modified by defining Activities: for example, if you wish, the whole CapEx of a job to be spend the first day, define a first activity with duration 1 day and allow the whole CapEx to it. If the duration of a job extends beyond the end of the simulation, or the job is aborted (i.e., a Facility Construction job whose facility is abandoned while being built), all costs after that point are disregarded.