standardized mobile wellhead compressor for onshore gas ... · standardized mobile wellhead ......

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


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


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


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


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


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


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


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

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– 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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standardized mobile wellhead compressor for onshore gas ... · standardized mobile wellhead ......

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