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Gas Well Deliquification Workshop
Sheraton Hotel, Denver, Colorado
February 23 – 26, 2014
James Donald (presenter), Marco Marino, Kees
Veeken (Shell)
Standardized Mobile Wellhead Compressor for Onshore Gas Wells in The Netherlands
Outline
• Background of Nederlandse Aardolie Maatschappij BV (NAM),
Onshore gas, Netherlands
• The game of deliquification in NAM Onshore
• Portoflio review - defining a business case for Mobile Wellhead
Compression (MWHC)
• Deriving design parameters for a generic MWHC
• The next step – integration with gas lift
Feb. 23 - Feb 26 2014 2014 Gas Well Deliquification Workshop Denver, Colorado 2
NAM
3 November 2013
LAND ASSET
NAM is a joint venture,
shareholders Shell
(50%) and ExxonMobil
(50%).
~90 producing fields
~270 producing wells
via 26 treatment
facilities
The game of deliquification in NAM Onshore
Feb. 23 - Feb 26 2014 2014 Gas Well Deliquification Workshop Denver, Colorado 4
Reduce critical velocity (e.g. foam injection)
Deliquification & ‘depressurization’ techniques
5
Increase gas velocity (e.g. velocity string or gas lift)
Artificially lift water (e.g. downhole pump or
plunger)
Reduce tubing
pressure (e.g. third stage compressor)
Deliq operating envelope
6
0.0
5.0
10.0
15.0
20.0
25.0
30.0
0.0 100.0 200.0 300.0 400.0 500.0
Tub
ing
pre
ssu
re (b
ara)
Flow rate Q (km3/day)
MWHC PERFORMANCE CURVES
PQ curve Sept 2012 PQ curve Sept 2013 PQ curve Sept 2014 PQ curve Sept 2015 PQ curve Sept 2016 MWHC (discharge=12barg)
Typical min. suction pressure 2-stage
compressor (12bara)
Liquid loading line
Discharge 12bara
Additional
reserves
Operating area
foam injection
Operating line MWHC
(discharge 12bara)
Project objective “Maximize recovery of mature low-pressure fields by lowering the
THP preventing the well to liquid load and preventing back-out”
Build a comprehensive portfolio
I. Settle on universal design conditions
II. Recognize interaction with other (deliquification)
developments
STANDARDISE
I. Define ‘generic’ BfD
7
Joule-Thompson
valve
1-stage2-stage
LTS
Satellite #1
Satellite #2
Satellite #3
Treatment facility/ hub
CustomerGasunie Transport
Services
70-90bar
60-65bar
10-25bar 25-50bar
3-stage
Portoflio review
• Defining a business case for Mobile Wellhead
Compressrion (MWHC)
• Consider the lifecycle of deliq methods
Feb. 23 - Feb 26 2014 2014 Gas Well Deliquification Workshop Denver, Colorado 8
Discharge pressure – initial capacity compressor
9
89 single wells
MWHC
Depletion compression
Discharge pressure – initial capacity compressor
10
With manifold solutions
less compressors are
needed
28 possible
single wells + manifolds
54 possible
single wells
Choice of deliq methods
Feb. 23 - Feb 26 2014 2014 Gas Well Deliquification Workshop Denver, Colorado 11
Compression (CO) – in all cases, recovers the most significant volumes
Continuous Foam (CF) – complementary to compression (although not
technically desirable due to foaming)
Gas lift (GL) – complementary to compression
Ultim
ate
re
co
ve
ry
Deriving design parameters for a generic MWHC
• A generic design that meets 80-20 rule
Feb. 23 - Feb 26 2014 2014 Gas Well Deliquification Workshop Denver, Colorado 12
Fthp – minimum rate (@ Liquid loading)
13
West & North production systems
Tube ID ≈ 4 in Tube ID ≈ 3 in
Tube ID ≈ 6 in
Max discharge
pressure = 20
bara
Ftht – minimum rate (@ Liquid loading)
14
West & North production systems
Max inlet
temperature = 60
°C
Defining liquid capacity
Where to draw the line? What about possible formation
water breakthrough in the future? Feb. 23 - Feb 26 2014 2014 Gas Well Deliquification Workshop Denver, Colorado 15
LGR limit per possible MWHC candidates
16
Max rate = 420
kNm^3/d
Max LGR = max
liquid rate/rate
The comfort factor
Slug size
Feb. 23 - Feb 26 2014 2014 Gas Well Deliquification Workshop Denver, Colorado 17
Key parameters:
Tubing ID ^2
Difference in CITHP and FTHP
Designed for: 1 m3 produced within minutes.
Matches (limited) field data
Theoretical slug sizes
Summary design criteria
18
Criteria Abbreviation Value Unit Closed in tubing wellhead pressure CITHP ≤80 barg
Flowing tubing wellhead pressure FTHP ≤12 barg
Max. skid inlet temperature FTHT ≤60 °C
Max. skid outlet temperature ≤80 °C
Overall liquid rate 50 m3/d
Slug size (instantaneous; within 1 min.) S 1.0 m3
Number of slugs at start-up 1x
Carbondioxide content CO2 10 mol%
Hydrogensulfide content H2S 0.5 mbar
Sand (continuous production) ≤0.2 kg/mln.Nm3
Oil carry-over ≤5 ppm
Corrosion inhibitor content ≤1000 ppm
Concept table third stage compression
19
Centrifugal Reciprocating Rotary screw Gas Jack
Capacity
(mln.Nm3/d) >10 0,05-10 0.01-1.0 <0.01
Min. suction
pressure (bara) >10 3-4 1.1-5 1.1
Max. discharge
pressure (bara) 200 100-300 20-50 20
Compression ratio 1.2-1.5 per
impeller 2-4 per stage 2-10 2-20
Advantages
High capacity
Medium/high
efficiency
2-Stage machines
offer high efficiency
High discharge pres.
Low CAPEX (1-stage)
Sour gas solution
Wide operating range
High compression
ratio
Capable of handling
various gas
compositions
Low/medium CAPEX
and maintenance cost
Simple design
High
compression
ratio
Capable of
handling various
gas compositions
Low CAPEX
Disadvantages
High CAPEX
Narrow operating
range e.g.
flexibility
Specialized
maintenance &
control
High maintenance
cost e.g many moving
parts
Each unit is designed
for a specific gas
comp.
Vibrations
Low adiabatic
efficiency
Short life expectancy
Noise
Low capacity
Not following
Shell DEP/DEMs
Noise and
vibrations
EU regulations
Selected
MWHC Functional modules
20
1. Pre - treatment Optional:
Sand/Foam/Large slugs
2a.Slug handling &
3. Compression 4. Fluid mixing 2.Slug handling
& liquid separation
(small)
Mobile wellhead compressor
7. Air cooling
8. Power supply
6. Liquid pumping
5. Oil processing
SKIDDABLE
”PLUG AND PLAY”
Process flow scheme MWHC
SMSM(V-102)
Oil/gas separator
(V-103)
Oil-flooded rotary screw compressor
Oil cooler(E-102)
P-2
P-3
Industrial air coolers
Natural gas
Compressor oil
Water/natural gas condensate
Cooling fluid
Start-up heater
ROV-1
ROV-4
Gas inlet cooler(E-101)
M
6"
Slugcatcher (V-101)
PSV-101@25barg
DP
= 1
00
bar
g
8"
P-1
60
0kW
DP
= 2
5b
arg
PSV-102@25barg
PSV-103@25barg
MOBILE WELLHEAD COMPRESSIONOIL-FLOODED SCREW COMPRESSOR (HOWDEN 255-193)
PCV-102
PCV-103
PC
V-1
01
Salt filters
ROV-5
ROV-6
Electric motor
1. Slug separation
2. Cooling
3. Mist separation
4. Compression
5. Oil separation
IN
OUT
Design life MWHC skid = 25years
0
1
2
3
4
5
6
7
8
0 50,000 100,000 150,000 200,000 250,000 300,000 350,000 400,000 450,000 500,000
Suct
ion
pre
ssu
re (
bar
a)
Flow rate (Nm3/d)
Operating envelope MWHC
20%
40%
60%
80%
Compressor performance curves
22
B
A
Compressor load
C
D
Discharge = 12bara Discharge = 20bara
Discharge = 3bara
Next steps.....gas lift
Feb. 23 - Feb 26 2014 2014 Gas Well Deliquification Workshop Denver, Colorado 23
Well performance curves
with compression
and gas lift only gas lift
Gas lift with MWHC
Gas lift recovers
more than
continuous foam
Gas lift with
wellhead
compression
(2bara) recovers
30% more
Feb. 27 - Mar. 2, 2011 2014 Gas Well Deliquification Workshop Denver, Colorado 24
Ulti
mat
e re
cove
ry
Gas lift with MWHC
Feb. 23 - Feb 26 2014 2014 Gas Well Deliquification Workshop Denver, Colorado 25
With SPM
Retrofit
Straddle to
maintain well
barrier.
Completions:
>= 4 ½
<= 3 ½”
Workover is
cost prohibitive
recycle
Well operating envelope:
Corrosion – wet gas
Technical work to be done
Conclusions
Conclusions and Achievements:
Bottom-up approach proved to be successful. Analysis enabled by
simple screening tool to analyse many wells
Parameters for MWHC for Basis for Design delivered
Gas Lift and Continuous Foam not an alternative to MWHC
Gas Lift to be preferred to Continuous Foam with MWHC
Next steps:
Design specific solutions or alternative compressors for wells outside
of current MWHC operating envelope
Subsurface retro-fit solution to enable gas lift
26
Feb. 23 - 26, 2014 2014 Gas Well Deliquification Workshop
Denver, Colorado
27
Copyright
Rights to this presentation are owned by the company(ies) and/or author(s) listed on the title page. By submitting this presentation to the Gas Well Deliquification Workshop, they grant to the Workshop, the Artificial Lift Research and Development Council (ALRDC), and the Southwestern Petroleum Short Course (SWPSC), rights to:
– Display the presentation at the Workshop.
– Place it on the www.alrdc.com web site, with access to the site to be as directed by the Workshop Steering Committee.
– Place it on a CD for distribution and/or sale as directed by the Workshop Steering Committee.
Other use of this presentation is prohibited without the expressed written permission of the author(s). The owner company(ies) and/or author(s) may publish this material in other journals or magazines if they refer to the Gas Well Deliquification Workshop where it was first presented.
Feb. 23 - 26, 2014 2014 Gas Well Deliquification Workshop
Denver, Colorado
28
Disclaimer
The following disclaimer shall be included as the last page of a Technical Presentation or Continuing Education Course. A similar disclaimer is included on the front page of the Gas Well Deliquification Web Site.
The Artificial Lift Research and Development Council and its officers and trustees, and the Gas Well Deliquification Workshop Steering Committee members, and their supporting organizations and companies (here-in-after referred to as the Sponsoring Organizations), and the author(s) of this Technical Presentation or Continuing Education Training Course and their company(ies), provide this presentation and/or training material at the Gas Well Deliquification Workshop "as is" without any warranty of any kind, express or implied, as to the accuracy of the information or the products or services referred to by any presenter (in so far as such warranties may be excluded under any relevant law) and these members and their companies will not be liable for unlawful actions and any losses or damage that may result from use of any presentation as a consequence of any inaccuracies in, or any omission from, the information which therein may be contained.
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The Sponsoring Organizations cannot and do not warrant the accuracy of these documents beyond the source documents, although we do make every attempt to work from authoritative sources. The Sponsoring Organizations provide these presentations and/or training materials as a service. The Sponsoring Organizations make no representations or warranties, express or implied, with respect to the presentations and/or training materials, or any part thereof, including any warrantees of title, non-infringement of copyright or patent rights of others, merchantability, or fitness or suitability for any purpose.