Pump battery
The sample case Pump-Battery.opi demonstrates how OLGA can be used to model a pump battery.
The system consists of a 2 km long well tubing followed by a 150 m long wellhead pipe. A pump battery is installed downstream of the well bottom hole in order to increase the production. The pump battery speed is controlled by the flow rate at the wellhead. A sketch of the model is shown below.
Operation scenario:
Due to the reservoir conditions, this well can only produce a flow of 6 kg/s. After the pump battery is installed near the well bottom hole, the production can be increased to 10 kg/s or higher.
Case comments
CaseDefinition
OPTIONS: The full heat transfer calculation option with heat transfer through the pipe walls is used. The
FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The ambient temperature is vertically interpolated from 80°C at the bottom of the borehole to 20°C at the wellhead. The heat transfer coefficient on outer walls is set to 500 W/m2K. The minimum heat transfer coefficient on inner walls is set to
10 W/m2K.
FLOWPATH — Boundary&InitialConditions — WELL: The reservoir pressure is 200 bara and reservoir temperature 80°C. Production and injection type is LINEAR. AINJ=APROD=0, BINJ=10-7 kg/s/Pa and BPROD=10-6 kg/s/Pa.
FLOWPATH — ProcessEquipment — PUMP: The pump battery is defined by following parameters:
MAXCAPACITY=0.06 m3/s; MINCAPACITY=0 m3/s; MAXPRESSURE=230 bara; MAXSPEED=8000 rpm;
MINSPEED=0 rpm.
FLOWPATH — Output — TRENDDATA: Pump variables are plotted.
FLOWPATH — Output —SERVERDATA: Server variables are available for plotting in interactive simulations.
NODE: The outlet pressure held constant at 60 bara and the temperature is 20°C.
Output
ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds.
OUTPUT: OLGA variables are printed to the output file every 10 hours.
TREND: Trend variables are plotted every second.
PROFILE: Profile variables are plotted every 30 minutes.
Centrifugal pump
Centrifugal pump
The sample case Pump-Centrifugal.opi demonstrates how OLGA can be used to model a centrifugal multiphase pump with recycle function and bypass lines.
The system consists of a 100 m long horizontal wellhead pipe followed by a 300 m long pipe containing a pump inlet valve, a centrifugal pump, a pump outlet valve, and a check valve at the outlet of that pipe.
Following this is a 100 m long pipe leading up to a 200 m tall riser to the topside. A bypass pipeline is connected to the pump pipeline. This line has a bypass valve on the inlet and a check valve on the outlet.
A sketch of the model is shown in the figure below.
Operation scenario:
In the first hour, the system's inlet pressure is 8 bar higher than its outlet pressure. The production is to go through the bypass line and the total flow rate is about 45 kg/s. In the second hour, the inlet pressure is reduced to be the same as the outlet pressure so that no production is expected without a pump. Then, the pump line is opened, the bypass line closed, and the centrifugal pump starts to increase the pump speed in order to yield the flow rate 50 kg/s.
Case comments
CaseDefinition
OPTIONS: The full heat transfer calculation option with heat transfer through the pipe walls is used. The steady state pre-processor is turned off.
FILES: The characteristic data of the pump is found in the file ol-pumpc-2.tab.
MANUALCONTROLLER: C-PUMP-C-BY: This controller is required by the Multiphase pump module.
However, the built-in bypass function of the Multiphase pump module is obsolete since any bypass line can be modeled using an additional flow-path. In this sample case, the bypass controller is a manual controller withSETPOINT=0, which means that the built-in bypass line is closed.
MANUALCONTROLLER: C-PUMPV-1: This controller is optional. The controller is used to control the built-in valve in the Centrifugal pump module to stop the flow if the pump is deeded, e.g., if the pump is shut down and no back flow is allowed. In this sample case, this controller is defined as TYPE=MANUAL and SETPOINT=1, which means that the valve is fully opened.
FlowComponent
FLOWPATH — Boundary&InitialConditions — INITIALCONDITIONS: Since the steady state pre-processor is not used, the initial conditions have to be given.
FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The ambient temperature is set to 15°C. The heat transfer coefficient on outer walls is set to 500 W/m2K. The minimum heat transfer coefficient on inner walls is set to 10 W/m2K.
FLOWPATH — ProcessEquipment — PUMP: The centrifugal pump is defined by following parameters:
DENSITYR=900 kg/m3; EFFIMECH=0.7; FLOWRATED=0.15 m3/s; HEADRATED=150 m;
SPEEDR=1500 rpm; MAXSPEED=8000 rpm; RECDIAMETER=0.1 m (diameter of the built-in recycle pipe); BYDIAMETER=0 (bypass diameter, zero means no bypass flow through the built-in bypass).
FLOWPATH — Piping: The pipeline consists of a 500 m long pipe horizontal pipe with a 0.2 m diameter which leads up to a 200 m tall riser. At topside a 100 m pipe leads to the outlet. The bypass line, constituted by six sections, is 300 m long and has the same diameter, 0.2 m, as the rest of the pipe.
FLOWPATH — Output — TRENDDATA: Pump variables are plotted.
FLOWPATH — Output —SERVERDATA: Server variables are available for plotting in interactive simulations.
NODE: Both the inlet and outlet nodes are pressure nodes. The inlet pressure is 47 bara over the first hour and is then reduced to 39 bara. The inlet temperature is held constant at 30°C. The outlet pressure is held constant at 39 bara and the temperature is 20°C. Two internal nodes are used to connect the bypass around the pump.
Output
ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds.
OUTPUT: OLGA variables are printed to the output file every 10 hours.
TREND: Trend variables are plotted every second.
PROFILE: Profile variables are plotted every 30 minutes.
Displacement pump
Displacement pump
The sample case Pump-Displacement.opi demonstrates how OLGA can be used to model a displacement multiphase pump with recycle function and bypass lines.
The system consists of a 100 m long horizontal wellhead pipe followed by a 300 m m long pipe containing a pump inlet valve, a displacement pump, a pump outlet valve, and a check valve at the outlet of that pipe.
Following this is a 100 m long pipe leading up to a 200 m tall riser to the topside. A bypass pipeline is connected to the pump pipeline. This line has a bypass valve on the inlet and a check valve on the outlet.
A sketch of the model is shown below.
Operation scenario:
In the first hour, the system's inlet pressure is 4 bar higher than its outlet pressure. The production is to go through the bypass line and the total flow rate is about 22.2 kg/s. In the second hour, the inlet pressure is reduced to be the same as the outlet pressure so that no production is expected without a pump. Then, the pump line is opened, the bypass line closed, and the displacement pump starts to increase the pump speed in order to yield the flow rate 30 kg/s.
Case comments
CaseDefinition
OPTIONS: The full heat transfer calculation option with heat transfer through the pipe walls is used. The steady state pre-processor is turned off.
FILES: The characteristic data of the pump is found in the file ol-pump1-2.tab.
Controller-models
PIDCONTROLLER: C-PUMP-D-SP: This controller is required by the Multiphase pump module. In this
can be modeled using an additional flow-path. In this sample case, the bypass controller is a manual controller with set-point 0, which means that the built-in bypass line is closed.
FlowComponent
FLOWPATH — Boundary&InitialConditions — INITIALCONDITIONS: Since the steady state pre-processor is not used, the initial conditions have to be given.
FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The ambient temperature is set to 15°C. The heat transfer coefficient on outer walls is set to 500 W/m2K. The minimum heat transfer coefficient on inner walls is set to 10 W/m2K.
FLOWPATH — ProcessEquipment — PUMP: The centrifugal pump is defined by following parameters:
SPECAPACITY=0.01 m3/R; PREFSPEED=3000 rpm; MAXSPEED=8000 rpm; RECDIAMETER=0.1 m (diameter of the built-in recycle pipe); BYDIAMETER=0 (bypass diameter, zero means no bypass flow through the built-in bypass).
FLOWPATH — Piping: The pipeline consists of a 500 m long pipe horizontal pipe with a 0.2 m diameter which leads up to a 200 m tall riser. At topside a 100 m pipe leads to the outlet. The bypass line, constituted by six sections, is 300 m long and has the same diameter, 0.2 m, as the rest of the pipe.
FLOWPATH — Output — TRENDDATA: Pump variables are plotted.
FLOWPATH — Output —SERVERDATA: Server variables are available for plotting in interactive simulations.
NODE: Both the inlet and outlet nodes are pressure nodes. The inlet pressure is 43 bara over the first hour and is then reduced to 39 bara. The inlet temperature is held constant at 30°C. The outlet pressure is held constant at 39 bara and the temperature is 20°C. Two internal nodes are used to connect the bypass around the pump.
Output
ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds.
OUTPUT: OLGA variables are printed to the output file every 10 hours.
TREND: Trend variables are plotted every second.
PROFILE: Profile variables are plotted every 30 minutes.
Simplified pump
Simplified pump
The sample case Pump-Simplified.opi demonstrates how to model a simplified pump in OLGA.
The system consists of a 500 m long horizontal pipe followed by a 250 m tall vertical riser, and a 100 m long horizontal topside pipe. The inlet pressure is only 5 bara and the outlet pressure is 50 bara. A pump is installed in order to deliver the water to a higher pressure tower. No speed controller is required for a simplified pump. A valve and check vale are placed at the topside pipe. A sketch of the model is shown below.
Case comments
CaseDefinition
OPTIONS: The full heat transfer calculation option with heat transfer through the pipe walls is used. The initial conditions are determined by the steady state pre-processor.
FlowComponent
FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The ambient temperature is 20°C.
The heat transfer coefficient on outer wall is set to 500 W/m2K. The minimum heat transfer coefficient on inner wall is set to 10 W/m2K.
FLOWPATH — Output —SERVERDATA: Server variables are available for plotting in interactive simulations.
NODE: Both the inlet and outlet nodes are pressure nodes. The inlet pressure is 5 bara and the outlet pressure is 50 bara. Both nodes have a temperature of 20°C.
Output
ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds.
OUTPUT: OLGA variables are printed to the output file every 10 hours.
TREND: Trend variables are plotted every second.
PROFILE: Profile variables are plotted every 30 minutes.