Resources
Resources in PetroVR
Resources in PetroVR are used for modeling any kind of asset which is not otherwise represented: manpower, ships and barges, cranes and other equipment, mud additives etc. are best represented as resources when it becomes necessary to keep track of their usage, costs and consumption.
It is important to note that resource utilization and consumption does not impact the scheduled activities in the project lifecycle. The system assumes that an unlimited quantity of resources of each kind exist and that they are permanently available, so that lack of resource to complete jobs is not an issue and cannot act as a constraint.
Resources are associated to jobs with a definable duration (see Scheduling Pane): it is assumed that resource usage is part of a process and extends for as long as the job lasts. Therefore, resource tracking is only available for the following job kinds: Compression Installation, Facility Expansion, Facility Maintenance, Geological and Geophysical Studies, Infrastructure, Other Spending, Well Decline Manipulation, Pipeline Laying, Facility Construction and Well Production Rerouting. For drilling and completion jobs, this option is not in the jobs themselves (which are actually macro-jobs) but in the Well Drilling Info Tab and the Well Completion Info Tab of each well.
It is also possible to define resource usage associated to the lifecycle of a well or a facility. For this, a special Operational Resource Requirements pane is available in the Maintenance Program Tab of each production and injection well, and in the Facility Node of each facility. Also, since Infrastructure jobs can be used to model facilities or other installations that have an operational lifecycle, operational resource requirements can be defined for them as well.
Resources are classified in two kinds: durable and consumable. Durable (or "hard") resources are those which yield services or utility over time rather than being completely used up when used once: from the point of view of the application, this means that the total amount of resources will be in use at the same time for as long as the job lasts. They are characterized by acquisition, dismissal and reallocation costs (computed as CapEx), and operational costs entered as a rate of usage over time and calculated on the actual duration of the job to which they are associated.
Consumable (or "soft", or "non-durable") resources, on the other hand, are those that are used up when used once: in the application this is reflected in their being used progressively as the job proceeds, so that the total amount is distributed over its duration. Examples of durable resources are cranes and equipment, people, ships, storage capacity; typical consumable resources are drilling additives, man-hours, fuel, power, raw materials etc. They are characterized by a price per unit, and the cost incurred (OpEx) is calculated based on the consumption rate entered in the job specification.
Durable resources are optionally defined by a number of reallocations, i.e. the maximum number of times it can be reused. The completion of a job always consumes one of the available allocations; when the number of allocations is over, the resource is dismissed. Therefore, every time an activity requires a durable type resource, it first checks whether there is stock available, that is, if there are resource units already acquired for another activity and not being used at the moment. If the available resources are not enough, it simply purchases/hires as many units as necessary.
Each resource is characterized separately in the Resources Catalog, with the following attributes: Type (durable or consumable), Unit type, Unit and optionally a Description. All resources have also definable costs; durable resources have an optional Reallocation Limit. Required resources for specific jobs are defined in the job's Resource Requirements Pane.
Resource usage after simulating the model can be viewed in the Results Window under Deterministic Results, and exported to Excel Reports. Durable resource usage will include Daily Utilization and Max Daily Utilization for each job separately as well as for the whole project. Consumable resource usage will include Daily Consumption, Max Daily Consumption and Total Consumption for each job and for the whole project. OpEx and CapEx breakdown for each resource is also provided.
Non-operational periods are taken into account as regards resource usage only for facilities, not for wells. This means that non-operational wells will keep on reporting operational costs and usage, whereas for facilities a special policy is used depending on resource type:
- - Facility durable resources report usage but not OpEx during non-operational periods. It is thus assumed that durable resource stand-by costs during these periods is zero.
- - Facility consumable resources stop reporting consumption and OpEx during non-operational periods, imitating the behavior of facility OpEx. Consumable resources are assumed to be released by the facility and assigned again after the period ends.
Note also that the allocation of costs associated to resource usage to different Cost Categories depends on the object that is using those resources (a well, a facility or a job); there is not a unique and direct relationship between a given resource and one category. Since a durable resource can be reallocated to different tasks, its cost may fall into different categories depending on the different objects to which it is associated. The Reallocation Cost related to a reused resource is not assigned to any category, and is only reported under the its own heading.