DCQ Daily Contract Quantity
For many gas production contracts the operator is enter contract to sell its gas with set volumes over fixed periods. MBAL enables production forecasts to be run to see what level of gas production can be delivered from the reservoir at a sustained level - contract.
MBAL in this mode the program calculates the maximum daily gas contract quantity that the reservoir can deliver for every year of the prediction period. This can be useful when determining the "Daily Contract Quantity" - DCQ - quantities to be set in a gas contract.
The MBAL model can be run in forecast mode to calculate the maximum DCQ the reservoir can deliver for the forecast period, e.g. one year. This is an iterative calculation to determine the maximum DCQ that can sustained for the forecast period.
The program takes into account seasonal swing factor entered in the "DCQ Swing Factor", and a maximum swing factor in the "DCQ Schedule". The program also honours (if physically possible) the constraints entered in the "Production and Constraints". If Gas Well model and Well schedules are available, MBAL calculates the production manifold pressure (or compressor back pressure) required to achieve a DCQ for a yearly period.
DCQ Max
(For Reservoir Pressure and Production from manifold Pressure Schedule prediction type)
Defines the maximum gas DCQ. At each time step, MBAL will calculate the maximum gas constraint from the maximum DCQ and the swing factors. It will then raise the manifold pressure in order to satisfy the calculated maximum gas constraint. The program checks this constraint against the average rate.
DCQ Min
(For Reservoir Pressure and Production from manifold Pressure Schedule prediction type)
Defines the minimum gas DCQ. At each time step, MBAL will calculate the minimum gas constraint from the maximum DCQ and the swing factors. When one of these constraints is triggered, the program shuts down all the production wells (apart from the aquifer producers). This means it is effectively an abandonment constraint.
DCQ Max
(For DCQ from Manifold Pressure Schedule and Swing Factor prediction type)
Defines
Max. Swing Factor
Depending on the gas contract, the gas producer may be required to produce above the DCQ for a short period of time. The maximum swing factor can be used to ensure that the reservoir will be able to produce DCQ * MaxSwing at any time.
Use DCQ and Swing Factor
This option is only available for gas and condensate systems. The meaning is different depending on the prediction type.
