| Creating a Fill Facility Task |  |
Creating a Fill Facility Task
Drilling to fill facilities is a scheduling function that allows you to automatically fill facilities based on the production encroaching on a facility limit (constraint). In order to create a Fill Facility task you must already have one or more Type Wells (Template Wells) defined and a facility with an active constraint which may either be entered in the Network tab or through a Facility Construction task in the Scheduler tab.
To add a fill facility task to your project, navigate to the Scheduler tab, and click "Fill Facility" task. The following screen will appear:
The following screen will appear:
Fill Facility Options
Start Trigger Function - This task becomes active when the expression evaluates to non-zero (can supplement the earliest start date and conditions or be used to exclude the task from a particular scenario altogether). *Note that the task will not start until the Earliest Start Date (see below) - even if this flag is true.
Calculation Order - See Calculation Order for Schedule Items for information on the calculation order for tasks.
Earliest Start Date: This is the earliest the task can start. Note that the task will not start (even if the start trigger is valid) until the Earliest Start Date.
Production Target Type - Production Potential looks at the unconstrained production of the well in the current month (the default) to see how many wells would be required. Actual Production looks at the capability of the well after all constraints in the network have been applied.
Months to look Forward - number of months to look forward to see the production potential (default is 0, i.e. current month). This feature can be quite useful if you have a rapidly changing production profile.
Minimum Production Trigger - WellSpring will trigger additional drilling when the production potential drops below this percentage of facility capacity. E.g. For a 105% value and 1,000 bbl/d capacity, drilling will start when the production potential falls below 1050 bbls/d.
Maximum Refill Production Target - Additional wells will be drilled to achieve this value of potential production for the current month. 100% would attempt to keep production at the constrained value, but due to finite drilling time will not succeed in doing so. More than 100% would over drill. A number over 100% would be useful where you had very steep declines such as with a shale gas well. E.g. if this is 110% for a 1,000 bbl/d constraint, WellSpring will attempt to achieve a production potential of 1100 bbl/day with additional drilling.
Fill Facilities Example
A drilling plan can be created anywhere upstream of a constrained facility. The idea is that wells will be drilled which add production to this network to enable it to produce at its capacity. The following is an example of a simple constrained network.
The network uses a Type well (See Using a Type Well) flowing into a Drilling plan, which flows into a compressor with a maximum throughput of 25mmcf/day. (See Constraints to specify the maximum rate for the compressor).
The "Fill Facilities" was specified at the constrained compressor. The plan specified 20 wells (using the type well shown) flowing into the drilling plan. When the project was calculated, it produced the following network:
The wells shown in red are "Auto added" assets generated by the Scheduler tab. You can delete these assets (they will be automatically deleted on re-calc) or by selecting "Asset - Clear Auto Added Assets".
If you right click on the Drilling Plan, you can see the production at this node (and subsequently flowing into the compressor).
The Scheduler Gantt chart output would look like the following:
Fill Facility Example 2
In this example a type well capable of 4.5 mmscf/day initial production with a steep decline is put in a drilling program which takes 30 days to drill/complete and tie-in the well. The gas plant has a maximum capacity (constraint) of 30 mmcf/d.
Type Well:
A Fill Facility task is created in scheduler:
The Facility is "Gas Plant" which has a constraint of 30 mmscf/d. We have specified a refill target of 110% due to the steep decline in the type well. This would translate to a target amount of 30*110%=33 mmscf/d.
In the well task for this fill facility, we have specified 50 locations to drill:
There is a single drilling step which takes 30 days to drill and complete. This step requires a drilling rig.
Results
From the Gantt chart we can see that the drilling program is flat out for 2011 and most of 2012 to try and fill the facility.
If we also look at the "ullage" graph on the graph tab, we can see the ramp-up of the production
Conditions
Refer to Scheduler Conditions for details on dependencies on other tasks for this task to begin.
See also