Presentation: 1.PIPESIM Basics: 1. PIPESIM File Naming and structure 2.Single Branch Model Basics (Iteration Options). 3.Building a Model. 4.Description of PIPESIM Model Components. 5.Single Branch Operations.
PIPESIM Single Branch Model:
PIPESIM Single Branch Model:
1. PI PIP PESIM Fi Fille nam amiing ng..
File naming
GUI input files xxx.bps PIPESIM input file (single branch)
xxx.bpn PIPESIM input file (network)
xxx.pgw input file
xxx.pvt
Fluid Property PIPESIM-GOAL input file
xxx.fpt
FPT input file
Output file
xxx.out
Output file
xxx.sum Summary file
xxx.plt
Job plot (1 data point for each case)
xxx.plc
Case plot (1 data point for each node)
2. PIPE PIPESI SIM M Sin Singl gle e Br Bran anch ch Mo Mod del Basics:
Iteration Options:
PIPESIM is a steady state multiphase flow simulator.
PIPESIM performs simultaneous pressure and temperature calculations. It has three fundamental iteration options (with inlet temperature always defined):
• Non-Iterative Pin and Qin known, calculate P out
• Iterate on Pressure Qin and Pout known, calculate P in
• Iterate on Flowrate Pin and Pout known, calculate Q in
Solution algorithm
Solution computed in flow direction
Each pipeline is divided into a number of segments determined automatically
Pressure and energy balances in each segment
Fluid physical properties are calculated at averaged conditions across each segment
Flow regime determined from gas and liquid superficial velocities
3. Building a Model:
Building a model
Define objects in the model, i.e. well completion, tubing, etc using the toolbox
Enter physical data, i.e. tubing ID, etc.
Enter fluid data: black oil/compositional
Set boundary conditions
Select an operation
Single branch toolbox VERTICAL COMPLETION
ANNOTATION
BOUNDARY NODE
REPORT TOOL
SEPARATOR COMPRESSOR
PUMP
HEATER/ COOLER
NODE POINTER
SOURCE
RISER
CONNECTOR
MULTIPHASE BOOSTER HORIZONTAL COMPLETION
KEYWORD INSERTER
NA POINT MULTIPLIER/ ADDER
EXPANDER
TUBING
INJECTED GAS CHOKE
FLOWLINE
4. Description of PIPESIM model components:
Well completion models
Well PI (Oil & Gas)
Vogel Equation (Oil)
Jones (Oil & Gas)
Fetkovich Equation (Oil)
Back Pressure Equation (Gas)
Pseudo Steady State (Oil & Gas)
Forcheimer’s Equation (Gas & Condensate)
Hydraulic Fracture (Oil & Gas)
Transient (Oil & Gas)
Inflow performance relationships
Oil Reservoirs:
Gas and Gas Condensate Reservoirs:
Well Productivity Index
Well Productivity Index
Vogel Equation
Back Pressure Equation
Fetkovich Equation
Jones Equation
Jones Equation
Pseudo-Steady-State Equation
Pseudo-Steady-State Equation
Hydraulic Fracture
Forcheimer
Transient
Hydraulic Fracture
Transient
Well productivity index (PI)
For Liquid
Q = PI x (P ws - P wf )
F o r g a s c o m p r es s i b l e r es e r v o i r s
Q = PI x (P ws2 - P wf 2 ) where,
P ws = static reservoir pressure P wf = flowing bottom-hole pressure Q = flowrate
Vogel’s equation
Empirical relationship for fluid below bubble point pressure: q/qmax = 1 - (1 - C)(Pwf /Pws) - C(Pwf /Pws)2 where,
C = PI Coefficient, normal value is 0.8 qmax = Absolute Open Hole Potential Pws = Static Reservoir Pressure Pwf = Bottom Hole Flowing Pressure
Fetkovich’s equation
Alternative to Vogel’s equation Empirical correlation q / qmax = [ 1 - ( P wf / P r )2 ] n
The lower the value of n, the greater the degree of turbulence
Jones equation
Gas and saturated oil reservoirs
Equations: Gas:
(P 2 )
Oil:
(P )
= AQ + BQ2
= AQ + BQ2
where A : Laminar flow coefficient (Darcy) B : Turbulent flow coefficient (Non Darcy)
Also known as “Forcheimer equation”
Back pressure equation
For gas wells Q = C (P ws2 - P wf 2 )n
Schellhardt & Rawlins empirical equation
Normally, 0.5 < n < 1.0
Pseudo - steady - state equation
Oil and gas reservoirs Darcy equation Parameters used in equation : Permeability Thickness Radius (reservoir external drainage) / Area / Shape Skin (dimensionless skin factor) Wellbore diameter Gas well: laminar and turbulent flow Oil well: laminar flow
Well completion options
ONLY valid when used with the pseudo-steady-state equation inflow performance model.
To calculate skin factor and turbulence coefficient (for gas wells).
Completion options:
None (i.e. no skin resistance to inflow)
Open Hole (well is not cemented or cased)
Perforated (McLeod model)
Gravel Packed (Jones model)
Horizontal completion models
Distributed PI (finite conductivity):
Distributive PI: PI p e r u n i t l e n g t h
Steady State PI (Joshi)
Pseudo Steady State PI (Babu & Odeh )
Single Point PI (infinite conductivity):
Steady State PI (Joshi)
Pseudo Steady State PI (Babu & Odeh)
Tubing data
Well Tubing Details
Depth (TVD / MD)
Detailed Profile Data
Tubing ID’s - can be changed at any point along the tubing
Artificial Lift: Gas Lift, ESP etc.
Tubing/annular/combined flow
Ambient temperature profile
Flowline details
Flowline geometry: Length, ID
Undulation profile
Simple or Complex Heat Transfer
Flowline, Tubing Heat transfer
Energy balance for each segment Heat enters
Two options:
with flowing fluid through pipe wall User specified overall U-value User supplied pipe coating information
Reference: A.C. Baker, M. Price. “modelling the Performance of High-Pressure HighTemperature Wells”, SPE 20903, (1990).
Heat transfer (cont.)
U-values - Overall heat transfer coefficient relative to the pipe outside diameter (OD)
Defaults
Insulated pipe 0.2
BTU/hr/ft 2/F
Coated
2.0
BTU/hr/ft 2/F
Bare (in Air)
20
BTU/hr/ft2/F
Bare (in Water)
200
BTU/hr/ft2/F
Heat transfer (cont.)
Overall heat transfer coefficient can be calculated from the user supplied data User can supply up to 4 coatings on the pipe w/
Thickness Thermal Conductivity
Also specify
Pipe thermal conductivity Burial depth Ground thermal conductivity Ambient air/water velocity
Equipment • Pump
Multiphase Booster
• Compressor
Generic Pump
• Flow Multiplier/Divider
Separator
• Flow Adder/Substractor
Expander
Heater Exchanger
• Injection Point
Generic Equipment (dP / dT)
• Choke
Multiphase
5. Single Branch Operations:
Single branch operations
System Analysis
Pressure/Temperature Profile
Flow Correlation Matching
Nodal Analysis
Optimum Horizontal Well Length
Reservoir Tables
Gas Lift Rate v Casing Head Pressure
Artificial Lift Performance
Flow correlation matching
To determine the most suitable flow correlation
Select the required flow correlations
Enter measured pressure and temperature survey data (FGS), through “MEASURED DATA”.
Enter known boundary conditions
Results show each correlation and the entered data
Pressure/temperature profile
Compute the pressure and temperature profile for a system and also vary some other parameters within system
Enter sensitivity variable
Enter boundary conditions
Resulting PSPLOT shows pressure or temperature against depth (well) or elevation (flowline).
Can plot measured data also.
System analysis
Set up multiple sensitivity operation.
Set up System Analysis Plot :
Specify calculated variable.
Select X axis variable.
Select any number of sensitivity variables (Z axis variables).
In addition, also specify sensitivity relation.
One variable
Several variables that change together
Several variables permuted against one another
Nodal analysis
Classical nodal analysis at any point (insert NA point in the model).
Break the system into two and compute the inflow and outflow around that point.
Resulting PSPLOT inflow/outflow curves.
shows
the
classical
Nodal analysis Inflow/outflow curves Pres ID = 3" e r u s s e r P
ID = 3 1/2" ID = 4" Reservoir Performance Flow Rate
Psep
e l o h m o e r t t u o s s B e g r P n i w o l F
Reservoir Performance Flow Rate
Reservoir tables
Produce a table of bottom-hole pressures that can be utilised by reservoir simulators. (VFP tables).
Interface to common reservoir simulators such as:
ECLIPSE
VIP
PORES
COMP4
MoRes
Artificial lift performance
Allows artificial lift performance curves (gas or ESP lift) to be generated and also varies some other parameters within system.
To produce input performance curves for GOAL.
Resulting plot is gas lift quantity (or ESP power) versus oil production rate.
Artificial lift systems
Gas lift
Two Model Options :
Fixed injection depth & rate.
Multiple injection points (Gas Lift Valves).
ESP (Electrical Submersible Pump)
Gas Lift Design • New mandrel spacing. • Design for existing mandrels (current spacing). Casing & tubing pressure sensitive valves (IPO / PPO valves). Valve spacing, test rack pressure calculations and valve sizing. Unloading gas and liquid rate calculations – sizing of unloading valves. Bracketing valve calculations. • Multiple static gradient options. • Database of valve parameters (editable).
Gas Lift Design
Additional Design Tools / Operations :
Deepest injection point calculation.
Bracketing range calculations.
Lift Gas Response Curves – how production rate and injection depth respond to various sensitivities. Analysis can be performed assuming “Optimum Depth of Injection” or “Injection at Specified Mandrel Depths only”.
Gas Lift Dagnostics
Simulate an existing well design (for current production & injection conditions).
Calculate valve status (open, closed, throttling).
Determine valve throughput (based on bellows load rate).
Troubleshoot existing gas lift installation for multiporting, shallow injection etc.).
Gas lift design : Pressure – Depth Plot.
Electrical submersible pump
Database with a list of ESP manufacturers and models (i.e. Reda, Centrilift etc) is made available.
Base data: casing diameter, minimum & maximum flowrates and base speed.
Design data: pump speed, number of stages, head factor.
ESP performance curve
ESP variable speed curves
ESP Design
Selects & Designs a pump to meet design conditions of production rate and production pressure.
Select appropriate pump for casing size and production rate.
Select required number of stages.
Identify requirements for separation.
Identify power requirements.
Analyse variable speed performance of the pump / well system. Simple motor and cable screening requirements.
6. Multiphase Flow Modelling in PIPESIM:
Pressure change calculation method
Determine the phase(s) present
Determine the inclination angle
Determine the flow pattern
Calculate the elevational, frictional and accelerational pressure losses or gains
Phases present
If the liquid volume fraction < 0.00001 then single phase gas exists
If the liquid volume fraction > 0.99 liquid exists
otherwise multiphase flow exists
then single phase
Single phase flow correlations
Available
Moody (default) AGA - Dry Gas Equation
Panhandle A
Panhandle B
Hazen-Williams
Weymouth
Inclination angle
If the inclination angle > 45° or < -45° then vertical flow patterns and pressure change correlations apply
otherwise horizontal flow patterns and pressure change correlations apply
