PET305 Oil Production
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Transcript of PET305 Oil Production
PET305
Petroleum Production Engineering
Lay-out of Production System
PET305 Production
• What is the role of production engineers ?
3
Roles of Production Engineering
Petroleum production engineers to monitor production operations.
They design equipment and processes to achieve the maximum
profitable recovery of oil and gas.
They develop and use various enhanced recovery methods.
These include injecting water, chemicals, gases, or steam into an oil
reservoir to force out more of the oil, or fracturing to connect a
larger area of a reservoir to a single well.
Production engineers focus on production challenges, identifying,
testing, and implementing methods for improving oil and gas
production.
They might focus on economics, helping a team determine the
optimum number of wells appropriate for a given operation.
Perforations
Packer Casing
Casing head
Tubing head
Casing valve
Master valve
Tee
Pressure gauge Wing valve
Choke
Components of a Typical Producing
Well
To production equipment
Tubing
Main parts
of
Wellhead
assembly
Wing valve
Choke assembly
Dual master valves
Casing head
Braden head
Casing strings Tubing
Tubing hanger
Tubing head
Master valve
Wellhead components
Stops fluid flow,
shutting in well
Casing valve
Wing valve
Controls
production
line
To production equipment
Pressure gauges
Choke
Wellhead components
Tee
To production equipment
Production
• Flowing Wells – Pwf > oil column Pressure
• Production Tubing
• The Well Head • Casing Heads, Tubing Head, Christmas Tree
• List of Factors Affecting Production
• Skin & Productivity Index • Wellbore Damage; +Ve Skin factor
• Acidizing : negative Skin factor
9
Production
• Production Tubing
– Steel Pipe run with
Production Packer
• The Well Head – Casing Heads, of different
diameters (20”,13 3/8th”,7”)
– Tubing Head,
– Christmas Tree
– Production choke
valve
10
Wing valve
Choke assembly
Dual master valves
Casing head
Braden head
Casing strings Tubing
Tubing hanger
Tubing head
11
Cross-section for typical producing well
Production considerations • Initial Production
– Perforation
– TCP (tubing / casing pressure)
– Wireline Perforation
– Down Hole Pressure & Flow
12
Production
• Factors Affecting Production
– Reservoir Fluid Properties
– Porosity & Permeability
– Rock/Fluid Properties (Sw. Pc; wettability … etc)
– Production Design Criteria
– Production History
13
Production
Factors Affecting Production cntd,
• Skin
– Wellbore Damage – Positive
– Acidizing –Negative
– Productivity Index (PI) , STB/Day/PSI
14
Production
Acidizing –
Negative S
15
16
17
Formation damage
Skin & (Darcy’s Equation)
S. Steady state radial flow
Artificial Lift
• Non- Flowing Wells
– Pwf < Hydrocarbon Column Pressure
• Artificial Lift Systems
– Beam Pumping
– Gas Lift
– Submersible Pumps
19
Walking Beam Rod Pumping Unit
20
Artificial Lift
• Gas Lift
– Gas Lift Assembly
– Annular – Tubing Pressure
Differential
– Create “Artificial Flowing Well”
– Injection Gas Recirculate
– 6 STB/Day – 80,000 STB/day
21
22
Gas Lift
Artificial Lift
• Submersible Pumps
– Attached to Tubing
– Electric/Hydraulic
– Continuous/Intermittent
– Frequent Maintenance Issues
23
Electric Submersible Pump
24
ESP, electric
submersible pump,
consists of downhole
equipment,
Pump
Intake
Motor
Cable
Equalizer
…plus
...
Electric Submersible Pump
25
Electric Submersible Pump
26
…some of the most important
pieces of the system are above
ground: HVAC
supply
VSD/Control
panel
Junction
box Wellhead
Transformer
440-660v 440-660v
1000-
5000v
1000-
5000v
PET305 Production- outflow Pressure losses
PET305 Production system
Well
Reservoir
Surface
equipment
Inflow & outflow
Production Pressure losses – outflow
Example on pressure heads
A well with total depth of 10,000 ft. and 4600 psi
reservoir pressure (initial) Well Gas cut flowing oil= 5 lb/gal
Calculate; pressure gradient for gas cut oil
the DP (pressure Drop)
In outflow oil well: What are the other Pressure Drop
(back Pressure ); List them
Production Pressure losses –
outflow Now, What can be done to improve the out flow rate?
Friction pressure drop in production tubing
Chock pressure losses
Production Pressure losses –
outflow Now, What can be done to improve the out flow rate?
• Gradient of the fluid: Gas LIFT
•Flowing friction pressure drop: Larger tubing or lower
friction pressure
•Choke: why is a choke needed? Is it needed here? Test it!
Production Pressure losses –
outflow Potential energy pressure drop
For example
If oil density is 53 lb/ft3. for a well of 1000 ft vertical depth then
DP = 0.433 x (53/62.4) x 1000 = 367.7 psi
Production – pressure losses Pressure friction losses –
outflow
Production – pressure losses Pressure friction losses –
outflow
Then it has been modified by Chen in 1979 to
Production Pressure friction losses –
outflow
Production Pressure losses –
outflow For laminar flow
Production Pressure losses – friction in tubing –
outflow
NRe = 2100 the begin of transition flow
Production Pressure losses – friction in tubing –
outflow
Water density = 65.5 lb/ft3
Tubing diameter = 2 7/8 inches
f = 0.0063
Production Pressure losses – friction in tubing –
outflow
f = 0.0063
u in ft/s
D in ft
Density lb/ft3
L in ft
Surface Production
Facilities
Separators
41
Separation &
Treatment
Prod.
from
Wells
Gas
Oil
Water
Contaminants
Production Process
Schematic
Foam
emulsion
salt content
scale
corrosion
paraffin – wax
sand content
liquid carry over
Factors for design
Drop size
Retention time
Re-entrainment
Separation - sizing
The separator types
Vertical
Horizontal
Spherical
Two-phase separator
Three phase separator
Horizontal three phase separator
Other designs for Three phase separator
Two phase vertical separator
Double-drum separator for gas condensate
production