Tergovis II Efficiency Fluid

Gunnar Lende, Technology Manager, Cementing Scandinavia

Norway 2013 workshopPlug & Abandonment

Forum

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New settable spacer – Tergovis II Efficiency Fluid

1. Closing remarks 2012 – setting the scene2. Geopolymer confusion?3. Barrier material requirements4. Tergovis II Efficiency Fluid – complementary to cement

- Primary- Well plugging

5. Tergovis II Efficiency Fluid – barrier material?

Topics in this presentation

Portland cement is well known and proven as sealant barrier element!

• Shortcomings, but reliable, environmentally compliant and cost effective material

• For critical barriers - modify to mitigate shortcomings• Modified Portland cement is a highly competent

barrier material!

1. Place plug properly, make it stay there2. Reduce shrinkage, post set expansion

• Ensure external water source in one end of plug• Allow expansion time

3. Hydrocarbon response – self healing

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2012 message: a) accept, b) deal with, c) be OK

Pantheon Y 126

It is about recognizing what a material is suitable for

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Realistic expectations

≠

The best solution is often a hybrid

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Some times we have to compromise

Want NeedCompromise

Buy one!

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If you need a hybrid for your well

Portland Elastomers ++

Hybrid

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Six different definitions of the term geopolymer[Wikipedia]

For chemists'...It is known that alkali-activated aluminosilicates are able to produce alumino-silicate geopolymers. The hardening mechanism involves the chemical reaction of geopolymeric precursors, such as alumino-silicate oxides, with alkali polysilicates yielding polymeric Si–O–Al bonds.' For geopolymer chemists'...Geopolymers consist of a polymeric Si–O–Al framework, similar to zeolites. The main difference to zeolite is geopolymers areamorphous instead of crystalline. The microstructure of geopolymers on a nanometer scale observed by TEM comprises small aluminosilicate clusters with pores dispersed within a highly porous network. The clusters sizes are between 5 and 10 nanometers.' For geopolymer material chemists'...The reaction produces SiO4 and AlO4, tetrahedral frameworks linked by shared oxygens as poly(sialates) or poly(sialate–siloxo) or poly(sialate–disiloxo) depending on the SiO2/Al2O3 ratio in the system. The connection of the tetrahedral frameworks is occurred via long-range covalent bonds. Thus, geopolymer structure is perceived as dense amorphous phase consisting of semi-crystalline 3-D alumino-silicate microstructure.' For geopolymer ceramic chemists'...Although geopolymer is generally X-ray amorphous if cured at standard pressures and temperatures, it will convert into crystalline ceramic phases like leucite or pollucite upon heating.' For alkali-cement scientists'... Geopolymers are framework structures produced by condensation of tetrahedral aluminosilicate units, with alkali metal ions balancing the charge associated with tetrahedral Al. Conventionally, geopolymers are synthesized from a two-part mix, consisting of an alkaline solution (often soluble silicate) and solid aluminosilicate materials. Geopolymerization occurs at ambient or slightly elevated temperature, where the leaching of solid aluminosilicate raw materials in alkaline solutions leads to the transfer of leached species from the solid surfaces into a growing gel phase, followed by nucleation and condensation of the gelphase to form a solid binder.' For ceramic scientists'...Geopolymers are a class of totally inorganic, alumino-silicate based ceramics that are charge balanced by group I oxides. They are rigid gels, which are made under relatively ambient conditions of temperature and pressure into near-net dimension bodies, and which can subsequently be converted to crystalline or glass-ceramic materials.'

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Definitions of the term geopolymer[Wikipedia]

For everybody:

• Geopolymerization is the process of combining many small molecules known as oligomers into a covalently bonded network

• Geopolymerization forms aluminosilicate frameworks that are similar to those of rock-forming minerals

• From a terminological point of view, geopolymer cement is a binding system that hardens at room temperature, like regular Portland cement. If a geopolymer compound requires heat setting it may not be called geopolymer cement but rather geopolymer binder.

• Tergovis II EF is not a geopolymer cement

• Or is it?

• It may in fact not be a geopolymer

• But it looks like one..

• That is quite OK, as long as it works! Portland cement chemistry comparedto geopolymerization GP

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Barrier material requirements• D-010 R4 will be released any time now• Lack of industry agreed requirements, or requirements at all

So what do we use to qualify our materials? Who can say this is OK or not OK?

Permanent well barrier property requirements

Property UOM N‐D010‐R4 CoPNo BP GP 10‐60 Statoil Total EXM CT ShellUnconfined compressive strength psi ‐ ≥ 750 ≥ 200 ‐Tensile strength psi ‐ ≥ 100 ‐ ‐Permeability, water mD 0 ≤ 0,02 ≤ 0,1 ‐Hydration shrinkage % 0 ≤ 2,8 ‐ ‐Net end point volume change (change from fluid density) % ‐ ‐0,5 ‐ +1 ‐ ‐Silica flour concentration % BWOC 35 30 ‐ 40 35 35Pressure integrity test (final curing state) in cased hole environment, pressure media = fresh water psi/ft ‐ ≥ 200 ‐ ‐

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Improving zonal isolation on primary jobsTergovis II EF to reclaim spacer/cement interfaceIssue: Primary cementing implies large interfaces plus long spacer interval

Section slice

May not be possible to improve parameters or increase cement volumeThis is what you have

Interface

Pure spacer

Cement

Mud

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Improving zonal isolation on primary jobsTergovis II EF to reclaim spacer/cement interface

Issue: • Primary cementing implies large interfaces plus long spacer interval• Mud to spacer interface/transition is “lost” for zonal isolation• Spacer to cement interface/transition and spacer interval is lost,

but can be reclaimed with a settable spacer

Tergovis II EF can salvage zonal isolation interval otherwise lostTergovis II EF can prevent remedial work or lost sectionTergovis II EF can reduce risk when long setting time is neededReward is saved unproductive time

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Improving Perforate-Wash-Cement methodChallenge:• Method “forces” spacer into annulus with wash tool• Cement placement dependent on buoyancy driven displacement• plus optional post placement “stirring”• 100% cement placement cannot be guaranteed

Solution 1:• Different placement method• force cement into annulus• Risk vs reward considerations

Solution 2:• Spacer becomes a barrier• But still acts like a spacer• Tergovis II EF

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P&A methods – Perforate-Wash-Cement methodTailored AbandaCem & Tergovis Efficiency Fluid solutions

AbandaCem K:• Special expanding cement• Compatible with TergoVis EF spacer and wash fluid• Clay inhibitive (KCl to match Tergovis II EF)• Intended for use on P-W-C jobs

TergoVis II Efficiency Fluid K (spacer):• Clay inhibitive (KCl to match wash fluid)• New XXX based sealant (no cement, patented)• Works as spacer with the WBM used on P-W-C jobs• If left in well will develop strength and solidify with time• If mixed with cement will contribute to strength and isolation

These fluids are designed to be used together on any job where spacer can contaminate the cement or spacer pockets may be left in the well

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P&A methods – Hydrawash cementing solutions

Tailored AbandaCem & Tergovis II EF spacer solutions

0

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0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280

Pressure/Tem

perature [p

si/°C]

Flow

 Rate [m

l/min]

Time [hrs]

ExpandaCem plug integrity test ‐ water injection  & expansion Step 2 ‐Water injection test 144°C, ΔP = 1000 psi (1200 psi inlet 10 cm off bottom, 200 psi on top)

Flow Rate (Injection) Flow Rate (Receive) Delta P cement Temperature Oil Temperature

Stable flow at 0,01 ml/min ‐‐> permeability 

Flow out ≈  flow in ‐‐> end of expansive reaction

Portland cement shrinkage test AbandaCem integrity test

AbandaCem shrinkage test

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P&A methods – Hydrawash cementing solutions

Tailored AbandaCem & Tergovis II EF spacer solutions

Initiate cooling

End of cooling

Viscosity increase impacts flow 0,01 mD equivalent

Step up dP

Tergovis II EF shrinkage test

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P&A methods – Hydrawash cementing solutions

Tailored AbandaCem & Tergovis II EF spacer solutions

Rapid strength development at elevated temperature

Controlled with retarders

93°C

124°C

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P&A methods – Hydrawash cementing solutions

AbandaCem & Tergovis II EF mixture strength development

Maximum

Minimum

100/0

75/25

50/50

25/75

0/100

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Tergovis II EF as barrier material ?Tergovis II EF has properties needed for barrier material

• Non-reversible reaction• Stays fluid until activator is added• Controllable set time at high temperature• Low hydration shrinkage • Sufficient strength • Favorable mechanical properties • Acceptable permeability• Potential for expansion?

y = 2810,2x + 0,6445R² = 0,9951

y = ‐16178x + 0,5783R² = 0,9967

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1

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‐0,001 0,000 0,001 0,002 0,003 0,004 0,005

Stress [M

pa]

Strain[mm/mm]

Tergovis EF UNi‐axial Stress/Strain curveNO‐136143‐14 ‐ 14 days curing 10 C 3000psi 

Axial Strain Lateral Strain

Stress-strain curve

Tergovis II EF shrinkage test(no water access)

Permeability test

Can one log Tergovis II EF properly? • Acoustic impedance in the range 3,8 – 4,2 MRayl• Drilling fluid typically has AI of 2 – 2,5 MRayl• Relatively low strength• Low Young’s Modulus• Should be possible to recognize (as for low density cement slurries)

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Tergovis II EF logging?

© 2013 HALLIBURTON. ALL RIGHTS RESERVED.20

Several projects ongoing Patents pending Looking for partners and funding Looking for cases to work on

Summary & questions

Thomas Alva Edison:

I haven’t failed, I’ve found 10,000 ways that don’t work.”

1. Closing remarks 2012 – setting the scene2. Geopolymer confusion?3. Barrier material requirements4. Tergovis II Efficiency Fluid – complementary to cement

- Primary- Well plugging

5. Tergovis II Efficiency Fluid – barrier material?

Stay tuned for more great solutions to come!