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Non-intrusive wellhead surveillance to support brownfield production optimisation – recent case studies
Agenda
Introduction
Produce the Technical Limit
Typical Sonar Applications
Sonar Technology
Case Studies
Conclusion
Introduction
Production optimisation of mature fields plays a significant role in todays market
conditions where cost is at the top of the priority list and operators need to find
suitable technologies to support daily operations while keeping costs down without
jeopardizing or shutting down production.
Low oil price brings Optimization into sharp relief
RE
SE
RV
OIR
MA
NA
GE
ME
NT
DA
TA
Wel
ls &
Pip
elin
e D
ata
Pla
nt
Cap
acit
y &
Ch
oke
Mo
del
Dat
a
Pla
nt
Cap
acit
y
Map
pin
g
Pre
ssu
re
Map
pin
g
MANPOWER - RESOURCES
PTL, Cross
Discipline
Facilitation Team
EGIS
Asset, Cross Discipline Team
OPTIMISATION TOOLS
Reservoir Simulators
IAM Toolkit
Process
Simulators
PTL REVIEW
WORKSHOP
System
Bottlenecks
Identified
Opportunities
Identified
Prioritisation of
Opportunities
PTL
Opportunities
are Developed
further,
Resourced,
Costed and
Logged.
Activities
Implemented
Production Gains
Tracked
Produce the Technical Limit
• Wellhead Production Surveillance
• ESP Optimisation
• Gas lift Optimisation
• Pressure Support (water Injection)
• Post and pre intervention
Typical SONAR Applications
SonarTest™
Temporary
SonarMonitor™
Permanent
• Augment well testing regime
• New meter verification during start up
• Legacy metering verification
• Legacy metering replacement
©Copyright Expro 2015
SONAR Technology
ATEX/IECEX Zone 1,
2” to 32”,
Liquid Flow Velocity Range
(application dependant) =
0.5 to 50 m/s (1.5 to 150 f/s)
Gas Flow Velocity Range (application
dependant) =
0.5 to 50 m/s (1.5 to 150 f/s)
Well-suited for dry and wet gas
surveillance in heavy schedule piping.
ATEX Zone 2,
2” to 30”,
Liquid Flow Velocity Range (application
dependant) =
1 to 10 m/s (3 to 30 f/s)
Gas Flow Velocity Range (application
dependant) =
6 to 50 m/s (20 to 150 f/s)
Well-suited for high flow rates, large
diameter pipes and high liquid loadings.
ActiveSONARTM
Meter PassiveSONARTM
Meter
SONAR Technology Specifications
Case Studies
Centrica SNS: Mature Dry Gas (SPE171712)
Marathon NS : Liquid Loading Prone Gas (SPE166652-MS)
Algeria: Mature Oil Field
• Centrica operates South And North
Morecambe Gas Fields
• Production commenced in 1985
• S. Morecambe – 34 active wells, N.
Morecambe – 10 active wells
• Produced via volumetric depletion
• Wells gathered to drilling platforms –
Normally Unmanned Installations
Slide 12
SPE171712 • Application of Sonar Flow Measurement For Field Wide Surveillance Of A Mature Gas Field • Ahmed Hussein
Centrica Case Study: Mature Dry Gas (SPE171712)
• Venturi meters originally installed for both fields (1985 and 1994 respectively)
• Meters sized for peak production, outside measurement range as field
production declined.
• Production separators installed and subsequently removed.
• Rough well allocation performed by analyzing P & T trends.
• Different technologies evaluated before Sonar technology selected
after an initial trial campaign.
Slide 13
Well Allocation and Metering Background
Charlie Facility , Gross 14 MMscf/day,
• 5 wells
• Individual wells ~ 3 MMscf/day
• SONAR Meter diagnostics gave
overwhelming evidence that only 1 out of 5
wells were flowing,
• Flowing well was > 14 MMscf/day
• Production from only 1 well
• Customer made decision to shut in
facility, one well at a time
• Well #4 shut in last, confirmed all
production came from single well
• Wireline intervention downhole camera
highlighted Halite
• Well work program –fresh water Halite
wash and N2 Coil Tubing Lift
• Additional 4 wells were taken back onto
production,
• Overall Field production up.
Initial Meter Validation
• 44 Sonar meters permanently installed
across 6 platforms
• Meters directly clamped onto pipe, no flow
interference or pressure loss
• Short rig-up time
• Significantly lower production losses as
compared to individual well testing using
test separators.
• Availability of real time flow information for
each well.
Slide 15
SONAR Well Surveillance
Slide 16
0
1
2
3
4
5
6
7
Ap
r-1
2
Ma
y-1
2
Jun
-12
Jul-
12
Au
g-1
2
Sep
-12
Oct
-12
No
v-1
2
De
c-1
2
Jan
-13
Feb
-13
Ma
r-1
3
Ap
r-1
3
Ma
y-1
3
Jun
-13
Jul-
13
Au
g-1
3
Sep
-13
Oct
-13
No
v-1
3
De
c-1
3
Jan
-14
Feb
-14
Ma
r-1
4
Ap
r-1
4
Ma
y-1
4
Jun
-14
SO
NA
R Q
ga
s (M
msc
fd)
Well Alpha1 - Alpha Platform
46.3
24.2
6.2
47.2
54.2
0
10
20
30
40
50
60
70
SON
AR
Qga
s (M
Msc
fd)
Alpha Beta Charlie Delta Gamma
All Platforms (S. Morecambe) - 08 June 2014
1.9 1.90.2
6.1
0.7
10.2
0.6
25.1
7.5
0
5
10
15
20
25
30
SON
AR
Qga
s (M
Msc
fd)
X1 X2 X3 X4 X5 X6 X7 X8 X9
Gamma Platform - 08 June 2014
SONAR Real Time Data
• Following the start up of a new, high pressure field, wells on DPPA
platform dropped off in performance.
• Sonar meters used to establish worst affected wells and analyze
response to cycling procedures.
• Determination of the optimum shut in period is a trail and error
exercise until a suitable ratio is established
Slide 17
Well Production Optimization – Well Cycling
• Cycling program was then extended to other wells in the fields
• Wells responding to a cycling routine were subjected to batch foam treatment to
help unload larger amounts of liquid
• Selected wells from the batch program put forward as candidates for permanent
foam injection.
• Sonar test data used to diagnose unstable wells (due to liquid loading and/or other
issues)
• After Sonar data evaluation, PLT (Production Logging Test) runs are scheduled
for wells displaying unstable behavior due to liquid loading
Slide 18
Well Production Optimization – Well Cycling
90
86
75
6762
40
57
50
35
15 Test/ LP Sep
30
37
Se
pa
rato
r P
ressu
re (
Ba
rs)
Gas recycling
to maximise
condensate
recovery Gas Exporting
Blow-down
stage
Reducing
Separator
Pressure
with
Production Decline.
28 HP Sep
Marathon
• East Brae mature Gas Condensate Field
• Field in Production blow down
• Water Influx from active reservoir
• Mixture of core and lazy wells
• Well allocation using individual well
testing
Marathon Case Study: Liquid Loading Prone Gas (SPE166652-MS)
$
Production
Wells Injection
Wells
Power,
Fluid, Gas
Cap Rock Gas
Oil
Water
RESERVOIR
Facilities
A complete systems
approach
Water
Case Study: Liquid Loading Prone Gas (SPE166652-MS)
• Flow assurance
• Shell deliquifaction modelling tool
• Marathon Oil’s gas modelling
• Vertical lift performance
• In-flow performance
• Critical rate at HP & LP
Separator Pressures
• Production constraints
• Process modelling
Actions
• Convert test separator to LP
Production
• Maximise production at or below
critical gas rate
• Intensive well manipulation with
focused surveillance
• Pro longed Sonar well tests
• Temperature monitoring
• Production logging
interventions
Data Comparison
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
Jun-10 Oct-10 Feb-11 Jun-11 Oct-11 Feb-12 Jun-12 Oct-12
Qg
as (
MM
scfd
)
A3 Sonar Test Data
A3 Separator Test Data
19.1
8.4
12.8
18.6
27.9
18.3
7.5
11.4
17.9
25.3
0.0
5.0
10.0
15.0
20.0
25.0
30.0
A01 A02 A04 A05 A06
Qg
as (
MM
scfd
)
Wells
Test Separator Rates Sonar test rates
• Bi-monthly Surveillance clamp-on well
testing
• Clamp-on hardware is permanently
mounted to wellhead piping for
consistency of measurement and well
site efficiency
• Comparison of data from the test
separator gas meter and the sonar
meters was carried out.
• The percentage difference in
measured Qgas (volumetric gas flow
rate at standard conditions) varies
between 0% and 10%.
• Work with regulatory authorities to
have SONAR Meter accepted as
alternative to conventional Test
Separator based well tests
well A3 over a period of 2 years.
East Brae.
©Copyright Expro 2013 - STM00003 Rev 01
28.0
28.2
28.4
28.6
28.8
29.0
29.2
29.4
29.6
29.8
30.0
0.0
5.0
10.0
15.0
20.0
25.0
Pro
ce
ss
Pre
ss
. (b
arg
)
Qg
as
(M
Ms
cfd
)
Time
Qgas @ Std Conditions Process Pressure
0
5
10
15
20
25
30
35
40
.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
Pro
cess P
ress.
(barg
)
Qg
as (
MM
scfd
)
Time
Qgas @ Std Condiitions Process Pressure
Well closed in to change
compressors
HP
separator
HP
separator
LP
separator
• Use SONAR Meters to test core wells
when Test Separator is not available.
• Use of SONAR Meters to investigate
individual well performance in LP
Separator
• Identify performance based criteria for
well swinging operations
• 12 wells on 4hr swing cycle
• LP separator can accommodate
Maximum 3-5 wells
• Lazy wells on Huff and Puff
• Achieve 90% utilization of LP Separator
for well unloading,
Huff & Puff plus HP to LP Swing
Arrest Field Decline.
Ga
s P
rod
uct
ion
Decline pre testseparator crossover
Decline post test separator crossover
Arrested Decline
Algeria Water / Gas injection Case Study
Hassi Messaoud Mature Oil field 1956.
Super Giant reservoir with total proven
reserves of 6.4+ billion barrels of oil.
• Large scale water and gas injection
network
• Need for understanding and optimising
injection of increased importance in
current environment
• Identifying and trouble shooting gaps in
existing data
• Gas lift Optimisation
• Reservoir Pressure Support
• Gas Injection rates
• Water injection rates
• Multirate tests
Gas Lift Measurement -Algeria
• ActiveSONAR used to measure gas lift rates during production testing
• Expro provides personnel and equipment data analysis and reporting
• One test per day
• Measure lift gas flow rate at wellheads and manifolds
• Enhance the value of the ongoing production testing TMU package offering
Gas Lift Optimisation -Algeria
3565
2369
1777
3821
3088
2350 3.11 3.34 3.41
0.00
1.00
2.00
3.00
4.00
5.00
6.00
0
500
1000
1500
2000
2500
3000
3500
4000
4500
14/03/2015 15/03/2015 16/03/2015
SONAR Gas Injection (Sm3/h)
Produced Qgas Av (Sm3/h)
Produced Qoil Av (Sm3/h)
GAS Lift optimization
• Hydrocarbon lifting optimisation is enabled by simultaneous measurement of lift gas and production rates.
• Couple Sonar with PassiveSONAR for production measurement
• Single phase injection and gas lift is on
going
• SONAR now being deployed to monitor
production separator outlets to identify and
monitor cycling behaviours
• Next step is audits in the Production Plant
where client is experiencing instabilities
and uncertainties in the volumetric
behaviour
• Client solution Multiple SONAR Packages
run simultaneously
• measure the production rates from
the wells, manifolds, separators and
export lines
Algeria Production Plant
Sonar Surveillance aids production Optimisation
Sonar Surveillance has had major impact in aiding production allocation from
individual wells while minimizing separator well testing frequency and associated
production loses
Sonar Surveillance, in conjunction with other methods such as temperature
monitoring and PLTs, has helped to understand individual well performance and
analyze the impact of liquid loading
Sonar Surveillance have enabled the production engineering team to identify
underperforming wells and implement short-term de-liquification strategies such
as well cycling
Sonar Surveillance is able to evaluate the effectiveness of interventions and select
suitable candidates for further intervention work, helping to prolong the field life of
the mature asset
Once adopted the scope of work and value information invariably increases
Slide 29
Conclusions
The use of non conventional technologies such SONAR allows for;
Continuous Well and Reservoir Monitoring without process interruptions
Understanding individual well behavior
Real Time Data Collection
Optimize and evaluate well intervention activities
Access to Remote locations
Minimize HSE risks
Increase frequency of testing
Cost reduction
More Quality Data = Better field management = Increased Production
Conclusions
Questions
Any Questions?