britannia’s low rate well strategy - alrdc egwdc... · © 2012 britannia operator limited...

© 2012 Britannia Operator Limited CONFIDENTIAL – This information is proprietary to BOL and is to be used, disclosed or reproduced only under

permission granted by BOL. All rights reserved.

Britannia’s Low Rate Well

Strategy

Eduard Nederlof Britannia Operator Limited 7th European Conference on Gas Well Deliquification, Groningen, September 26th 2012



2

Introduction

Low Rate Well Strategy

Challenges

Lessons Learned & Best Practices

Outline



3

One of the largest gas-condensate

fields developed on the UKCS

• IGIP 4 TCF

• At plateau contributed 10% of

total UK gas supply

Operated by Britannia Operator Ltd.

(BOL):

• 50% ConocoPhillips

• 50% Chevron

Britannia Field – Location Map

58.65% 32.38%

8.97%

Conoco

Phillips Chevron

BP Britannia



4

Britannia Field – Installations

Britannia

Steel Jacket Platform

43 wells

Subsea Centre at 15 km

9 subsea wells

Satellites

Callanish at 25 km

4 Oil wells

Brodgar at 41 km

2 Gas condensate wells



5

Fladen Ground

Spur

16/26 16/27a

15/30 15/29a

stratigraphic pinch-out

Gas-liquid-contact

Britannia Field

Witch Ground

Graben B01 B02

B03

B04

B05

B31

B12 B35

B10

B27

B14 B08

B29 B20 B11Z

B15

B33

B06

B21

B28

B17 B23Z B07

B19

B13Z B30

B26 B16

B34

B22 B09Z B25Z

B32 B24 16/26-23

16/26-26

16/26-5 16/26-9

16/27A

-6

16/26-24 16/26-16

B36

B38Z

B37 B18

B40

16/26-2

16/26-29

16/27B-4

Z

16/27A-

7

16/26-21Z

16/26-21 15/30-13

M06

M04

M08

M01

M03

M02

M09

M07

M05Z

M10

15/30-3

15/30-9

15/30-6

15/30-7

15/30-12

15/30-2

15/29A-5

15/29A-14 15/29A-7

15/29A-3

15/29A-8 15/29-2

15/29A-6 15/29A-11

15/29B-4Z

15/30-4

16/26-1

16/26-4 16/26-19

B41Z

B40Z

16/27a-3

B45

B44

Platform Area

Sub-sea Centre

Depth (x1000ft) -13 -12.5 -12 -11.5 -11

Britannia Field – Top Structure Map

0 2 4 km

Geology/Static Properties

Crest at 11,800 ft TVDSS

Average reservoir thickness 300 ft

Average porosity 15%

Average permeability 20 mD

Fluids/Reservoir Properties

Initial CGR 70-100 bbl/MMscf

Initial pressure 5,990 psia

Dew point 5,600 psia

Temperature 275 oF



6

Low Rate Well Strategy

Inflow Performance

• Re-Perforation

• Solvents

• Acidizing

• Hydraulic Fracturing

Vertical Lift Performance

Composite Performance

• Compression

• Wet Gas Metering

• Jet Pump Use

• Production Optimization

Applied / trialled / engineered / ready for application

Pending projects being analyzed / progressed

Being considered

• Cap Strings + Foam

• Isolation Plugs

• Velocity Strings

• Plunger Lift

Rejected



7

Inflow Performance

• Re-perforating wells (since 2007)

Vertical Lift Performance

• Batch foamer treatments (since 2008)

• Continuous foam injection (SPE 130672) (since 2009)

Composite performance

• Production Optimization - cycling wells (since 2007)

• Compressor Re-wheel (2009)

Opportunities Realized



8

Well Cycling & Batch Foamer Treatments

0

10

20

30

40

50

60

70

80

28-A

ug

-10

30-A

ug

-10

01-S

ep

-10

03-S

ep

-10

05-S

ep

-10

07-S

ep

-10

09-S

ep

-10

11-S

ep

-10

13-S

ep

-10

15-S

ep

-10

17-S

ep

-10

19-S

ep

-10

21-S

ep

-10

23-S

ep

-10

25-S

ep

-10

We

llh

ea

d P

res

su

re [

bar]

0

10

20

30

40

50

60

70

80

Flo

wli

ne

Te

mp

era

ture

[d

eg

C]

Liquid loading well -

frequent low pressure

routing necessary

(cycling)

Liquid loading well post-batch foamer treatment -

less frequent low pressure routing necessary



9

Capillary String Installation Options

Wellhead Modification

Option:

•Install tubing bonnet with

injection mandrel

•Lock out TRSV – primary

control line

•Run lower cap string

•Connect WISV to lower cap

string and set

•Run upper cap string and

sting into WISV

Primary control line obsolete

Secondary control line controls

WISV

Legend:

Tubing

Primary control line

Secondary control line

Capillary string

Safety Valve

Safety Valve Cut Option:

•Lock out TRSV

•Make cut in TRSV body

•Run lower cap string

•Connect WISV to lower cap

string and set – seals both

control lines separately

Primary control line to inject foam

Secondary control line to operate

WISV



Alternative to capillary string

Advantages

Lower Opex

Interventions/ logging possible

Batch foamer

Disadvantages

Reduced rate

More complex and challenging installation

10

Velocity String



11

Composite performance, medium term

• Facilities upgrade, lower topsides pressure to ~6-7 bar

Vertical Lift performance, long term

• Low rate wells workover development

(capillary / velocity strings)

Potential satellite tie-in

Future Opportunities



12

Production Prediction

Time

Ga

s R

ate

Low Rate Well Work Over Development

Long Term Compression

2010 New Wells

2011 Capillary Strings

Cycling

Base



13

1. Assessing effect of individual well solutions on

neighboring wells in a well connected field

2. Adapting and implementing “new technology”

3. Changing operating philosophy

4. Modeling liquid loading

Challenges



14

1. Consider technologies/strategies early in field life to

delay liquid loading problems

2. Develop and implement a range of remedial solutions to

address liquid loading

3. Well design to consider well interventions

4. Implement easy, low cost/high impact solutions

Lessons Learned & Best Practices



Britannia Operator Limited

– Peter Fowler, Richard Reverol, Bruce Bremner, Linda van der Bol

Conocophillips

BP

Chevron

15

Acknowledgements



QUESTIONS?

britannia’s low rate well strategy - alrdc egwdc... · © 2012 britannia operator limited...

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