Well Details Tab

The Well Details tab comprises two main areas.

The Well Completion details pane allows to define the main variables of wells. They are:

Well Reserves: The well's technical reserves. The well will keep operating for as long as these reserves last, unless it is abandoned or reaches its economic limit. Depending on the performance type defined for the well, Well Reserves may be either an input or calculated by the system; see Well Performance Tab. It may also be disabled if the Override... option is checked (see below).
Initial Rate: Initial main fluid (oil or gas) production rate. It may also be disabled if the Override... option is checked (see below).
Economic Limit: Production rate below which a well ceases to be profitable and therefore PetroVR is instructed to abandon it.
Well OpEx: Periodical operating expense for producers and injectors (notice that total OpEx = Well OpEx + OpEx of required Resources + Maintenance Costs for Well interventions).
Abandonment Cost: OpEx incurred when the well is abandoned, for whatever reason (see Abandonment job).

The Well OpEx variable will assume the cost category selected in the Well Drilling Info Tab if drilling and completion have not been separated, and the one defined in the Well Completion Info Tab if they have been separated. See Cost Categories.

A well can only be drilled provided the reservoir available reserves are greater than the Well Reserves. During the simulation, when a well starts being drilled (or begins to be completed in the case of recompletions), its Well Reserves are 'booked'. This means that they will be substracted from the Remaining Reserves when calculating whether a new well can be drilled based on the existing reserves - it is assumed that they 'belong' to this well even if they have not been developed yet. If the well is Abandonment before it depletes its reserves or the Well Reserves are modified (e.g. by a Well Decline Manipulation job), the 'booked' reserves are re-calculated.

Save well for production: Exploration well Oil appraisal well Gas appraisal well Choose this option to turn an exploration or an appraisal well into a producer. When activated, all inputs normally only available for producers will appear (note that the well will keep its name and distinctive icon).

Separate drilling from completion: Oil production well Gas production well Choose this option to distinguish between the drilling of the wellbore and the performing of the primary completion at this well. This allows to allocate different rigs and to define different times and costs for either job. If enabled, a Well Completion Info Tab will appear.

Well behaves as an isolated reservoir: Oil production well Gas production well Enable this option to define performances for fluid components independent from those defined at the reservoir level. When activated, a new Fluids tab appears identical to the reservoir Fluids Tab where the fluid composition and performances override the reservoir level definition. The components defined in this tab are initially copied from those of the reservoir at the moment of enabling the option.

Override reservoir Well Rate Table settings: (Only if a Well Rate Table is activated in the reservoir Well Communication Tab.) Check this option to let PetroVR calculate Well Reserves and Initial Rate based on a Well Rate Table.

Different Levels of Separation between Drilling and Completion

Drilling and completion of a well are two different activities which from the point of view of economic evaluation are often regarded as one: every production or injection well drilled has its completion, and usually it is not necessary to take into account further recompletions.

There are, however, many reasons why you might want to model drilling and completion separately: using different rigs for each, distinguishing costs, referring more than one completion to a single wellbore, or scheduling each activity according to its own set of conditions. To do this, PetroVR offers the possibility to distinguish them either at the well level with the Well Completion Info tab, or at the job level with the Well Completion job.

These features, though related to each other, are actually serving two different purposes: separating the activities at the well level means the possibility to define different rigs, costs and times for each one, whereas separating them at the job level focuses on the circumstances in which each activity will be performed, since it allows you to define a different condition for each. This provides the following combinations:

One info tab, one job: This is the simplest approach, to be used when there is no reason to regard drilling and completion as separate activities for the economic evaluation of the project. To choose this combination, leave the Separate drilling... option unchecked, use a single Well Drilling job, and check the Complete wells... option in the job specification area.
One info tab, two jobs: This combination does not define different details (time, cost, rig) for drilling and completion; all details entered in the Well Drilling Info Tab are considered to apply to the drilling, while the completion is regarded as having cost and time zero (i.e., they are not relevant). Use it when you want to have separate conditions for each activity; leave the Separate drilling... option unchecked, and use a Well Drilling and a Well Completion job.
Two info tabs, one job: Use this combination when completion details (rig, cost and time) are relevant, but you do not wish to define separate conditions for each activity: the completion will be queued in the schedule to start as soon as the drilling is done and there is a rig unit available. Check the Separate drilling... option and enter completion details in the Well Completion Info Tab; use a single Well Drilling job, checking the Complete wells... option in the job specification area.
Two info tabs, two jobs: This is the extreme approach as regards detail: use it when you not only wish to define different rigs, costs and times for each activity, but also want to schedule them separately. Check the Separate drilling... option in the Well Completion Info Tab, and use both a Well Drilling and a Well Completion job, leaving the Complete wells... option unchecked.

These combinations work separately for each well, making it possible to use different strategies in the same project.

The rest of the tab contains optional information that helps identify the well:

Well ID: Use this field to enter an ID for the well, which will be included in Excel Reports. This is a unique alphanumerical identifier that can be used as an alternative name in contexts other than PetroVR. Only well prototypes have ID's.
Wellhead Location: (all well kinds) X, Y and Z coordinates of the wellhead on the map. X and Y coordinates will be used for display in the Map Tab, and to calculate Fixed Cost and Drilling Time when a Departure Curve is defined for the well.
Completion Location: X, Y and Z coordinates of the completion on the map.
Feet per map unit: See Preferences Tab. Add: Define a new completion to the well in addition to the primary completion. When a secondary completion is added, a Recompletion Policy must be selected from the list that now appears:

Don't use any policy: Choosing this option implies that completions at this wellbore are independent from each other: completion jobs do not affect in any way other completions already existing in the same wellbore. Jobs for all additional completions must be created manually in the Schedule.
When installation of a new completion starts, force abandonment of the previous completion: You must manually define a separate job for the new completion; once it is finished, the previous completion will be automatically abandoned.
When the previous completion is abandoned, automatically perform the next completion in the list: Let the system automatically schedule the next completion in the list when the previous one has produced all its reserves.

: Move the selected completion up and down in the list.
Go to completion: Go to the Well Details tab of the selected completion.

PetroVR will not force you to follow the order specified in this list to drill and complete wells. Provided the wellbore is drilled, you can perform secondary completions even if the primary one has not been performed yet.

When using the third recompletion option, Well Drilling and Well Completion jobs are not necessary for performing secondary completions defined in this tab - they will be executed automatically. You can include them in jobs anyway, and the completion dates established in these jobs may overrule the list order if they occur before the current completion is abandoned.

If well reserves are calculated (i.e., "Enable Well Spacing" and the "Compute well reserves from well spacing and reservoir area" are options are enabled in the reservoir Details Tab (Reservoir)) it is assumed that the recompletions will drain the same area as the original well.

When an injection well is recompleted as a producer and the Abandon when last row is reached option is not checked in the Well Performance Tab, the injector must be abandoned manually (by means of an Abandonment job) for the recompletion to be performed.