N-SOLATE™ Thermally Insulating Packer Fluids

“For External Distribution, © 2007 Halliburton. All Rights Reserved.”

N-SOLATE™

Thermally Insulating Packer Fluid Systems

Jay TurnerBaroid

•

Uncontrolled heat loss from production tubing presents a host of challenges for deepwater, heavy oil and geothermal well designs

•

Drilling Engineers and Operators–

Prevention of annular pressure build up

•

Completion and Reservoir Engineers–

Reduced well productivity –

Deposition of paraffin and asphaltenes –

Formation of gas hydrates

IntroductionWhy Insolated Packer Fluids?


Minimal HeatIs Transferred

Heat is lost toouter annuli

Production tubingis thermally isolated

Non

-insu

late

dPa

cker

Flu

idInsulatedPacker Fluid

Hig

h Te

mpe

ratu

re P

rodu

ced

Flui

ds

Heat Loss from Production Tubing


•

Multiple methods have been applied:

–

Vacuum insulated tubing (VIT)–

Non-aqueous insulating packer fluids–

Aqueous insulating packer fluids

•

Numerous disadvantages:–

VIT: cost, “hot spots”, strength, running–

IPFs: density, thermal stability, environmental, etc.

•

Aqueous IPFs

offer an attractive alternative

IntroductionPast Methods of Controlling Heat Loss from Tubing


•

Less costly than VIT and some non-aqueous fluids

•

Easily placed in annuli versus running VIT

•

Potentially more reliable than VIT

•

Can be formulated solids-free versus non-aqueous fluids

•

Can be more environmentally friendly than non-aqueous fluids

IntroductionAdvantages of Aqueous IPFs


•

Engineering a fluid with low inherent thermal conductance

•

Developing a viscosifier package with adequate thermal stability

over time

•

Breaking the industry paradigm concerning other options

IntroductionChallenges with Aqueous IPFs


DevelopmentalObjectives


To minimize the transfer of heat, we need to combat both modes•

Low inherent conductivity (use low k liquids)•

Gel the fluid to help prevent convective currents

heat source heat source

Modes of Heat TransferConductive Convective

With bothmodes intact,heat transfers

quickly throughliquids


Thermal Limitations of Aqueous IPFs

Operator testing of IPFs

available in 2006 demonstrated that none were thermally stable at 275ºF for over 28 days.

All test samples lost most or all of their gel performance, thus much of their insulating value.

Why did this happen?


Increasing Temperature

200 oF 250 oF 375 oF

Traditional Polymers

Synthetics and

Biopolymers

Synthetics and

Biopolymers

X-link

Synthetics

X-link

Synthetics

X-link gels

Inorganics

Eliminating Convection


SystemPerformance


N-SOLATE™ Systems

N-SOLATE™ 275:

• Densities from 8.5 to 14.2 lb/gal

• Thermally stable to 275°

F

• Thermally activated

N-SOLATE™ 400:

• Densities from 8.5 to ~15.0 lb/gal


F

• Thermally activated

N-SOLATE™ 600:

• Densities from 8.5 to 10.5 lb/bbl


F

• Not thermally activated


N-SOLATE™ System Performance

•

Thermal activation of N-SOLATETM 400 and N-SOLATETM 275 systems

•

Gel strengths inhibit convective currents

•

Gel strength and set time are each adjustable to optimumize

properties

Thermal Setting of IPF One

0

500

1000

1500

2000

2500

3000

0 5000 10000 15000 20000 25000Time (s)

Visc

osity

(cP) IPF One

Fluid 1Fluid 2

Thermal Setting of IPF Two

0

500

1000

1500

2000

2500

3000

0 50000 100000 150000 200000 250000 300000Time (s)

Visc

osity

(cP)

IPF Two

280°F

190°F

N-SOLATETM

400 System

N-SOLATETM

275 System

N-SOLATE 400

Biopolymers

N-SOLATE 275


Viscosity vs Temp (pre set)

0

500

1000

1500

2000

2500

20 70 120 170 220

Temperature (F)

Vis

cosi

ty (c

P)

N-SOLATE 275N-SOLATE 400N-SOLATE 600

Readings were recorded at 6 rpm (10 s-1)

275 and 400 systems are initially thin

600 system is easily pumpable

All systems enhibit

a thixotropic

rheology

All systems are tunable



- Application of “nano”-technology

- Extreme thermal stability

- Thixotropic fluid behavior

- 8.5 to 10.5 lb/gal tested

- Geothermal well completions

- Steam injection processes

N-SOLATE-600

10

100

1000

10000

0 5000 10000 15000 20000 25000 30000 35000 40000 45000

Time (s)

Visc

osity

(cP)

N-Solate-600

60 rpm (102 s-1)

3 rpm (5.0 s-1)

38343 rpm

40376 rpm

8884100 rpm

102109200 rpm

126125300 rpm

161160600 rpm

150 oF150 oFFann®

35 Viscometer,

10.59.5Density, lb/gal

0.1770.166Thermal conductivity, BTU/(hftoF)

600600N-SOLATE Fluid

100 °F 200 °F 300 °F 400 °F 500 °F 600 °F

N-SOLATE™ 600 System



Day 1 Day 14 Day 28

N-SOLATETM 275 system at 300°F

-

Note complete gelation of system-

Viscosity/insulating properties increase with temperature/time



N-SOLATETM Fluid 400 400 400 275

Thermal Conductivity, BTU/(hr ft °F) 0.158 0.171 0.177 0.164

Density, lb/gal 8.5 10.5 12.3 11.3

Oil and Grease*, mg/L < 0.8 < 0.8 < 0.8 < 0.8

GoM LC50**, ppm 143800 475000 265800 105000*EPA method 1664 (n-Hexane extractable, Gravimetric) was used in verifying the oil and grease content

**96 h LC50 bioassay testing for mysid

shrimp

N-SOLATETM System Toxicity and Oil/grease Testing

N-SOLATETM

System Compatibility• IPF compatibility was tested against predetermined contaminants:

-Glycols, methanol, crude oil, control line fluids, etc.

• Brine compatibility was tested as well: -

CaBr2, NaBr, NaCl, Formates, etc


RemovalStrategies


N-SOLATE™ Removal Strategies

•

System should be removable from the wellbore during interventions, etc.

•

Fluids registering on-scale at 300 rpm on the Fann 35 viscometer are readily pumpable

(300 dial reading at 300 rpm ≈

3000 cP)

•

N-SOLATE™

275 and 400 systems are thin when placed and then will thermally activate to minimize convective currents

•

N-SOLATE™

600 is placed “thick”

but is highly shear-thinning


N-SOLATE™ Removal Strategies

Viscosity vs Temp (post set)

0

2000

4000

6000

8000

10000

0 50 100 150 200 250

Temperature (F)

Vis

cosi

ty (c

P)

N-SOLATE 275

N-SOLATE 400

N-SOLATE 600

Readings were recorded at 6 rpm (10 s-1)

Tunable gelation

Adequate viscosity to minimize convection

Pumpable from the wellbore

≈

600 psi lift pressure


AttainDetailsProperty

YUnique base fluidEssentially non-corrosive

YUtilization of breaker or dilutionCan be removed from annulus

YEasily obtainable Commercially available additives

Y< 20°F at ambient < 38°F at 10,000 psi

Low TCT

Y8500 psi at 40 °FHydrate inhibitive

YBrines, glycols, control line fluids, pH, etc.Contaminant compatibility

YPump viscosity, gel strength, gel set timeTunable rheology

Y8.5 ~ 15.0 lb/gal or 1.02 ~ 1.80 SGDensity range

Y0.177 – 0.123 BTU/hft°FThermal conductivities (k)

Y90 – 600 °F or 32 – 315 °CThermal stability

YPasses oil and grease; GOM toxicityEnvironmentally friendly

Summary of Experiments


QUESTIONS?

N-SOLATE™ Thermally Insulating Packer Fluids

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