Polymers for HPHT applications

Ramanan Krishnamoorti

Oct 15, 2015

1

Nomenclature - Definition

• Schlumberger HPHT Classification Scheme

• Bottom Hole Temperature (BHT)

• Bottom Hole Pressure (BHP)

• Either BHT or BHP defines the category of well

2

Most Significant HPHT Challenges

• Fluids: – Can the fluid be prepared and properly placed in the

well? – Will the fluid be sufficiently stable? – Testing protocols include: rheology, filtration,

corrosion and mechanical-property evaluations • Electronic Components & Sensors:

– Stable packaging materials (plastic or composite) for structural integrity and insulation

– Operational time and temperature limit under downhole conditions.

3

Most Significant HPHT Challenges Cont’d

• Mechanical Devices including Seals, Screens, Packers, Shafts, Pistons, Valves, Pumps … – HPHT Exposure under high static and dynamic loads – Hazard exposure including mechanical shocks,

hydrogen sulfide, carbon dioxide and erosive particle based dispersions and fluids.

– Harsh Environments: • Drilling and production environments are increasingly

becoming harsher • Greater depths & new extractions methods increase

temperature and pressure • Material solutions limited

4

Materials Features Required

5

Current State of High Performance Non-Metallics

• Technical demand and application space for new materials is outpacing the rate of commercialization of viable products

• Demand for non-metallic solutions is growing in most market sector & utilize non-commodity materials

• Engineering risk is somewhat higher because materials are placed into applications without basic understanding of long term or service condition performance

• Standards and qualification criteria in critical service or environmentally risk prone areas is weak

• Fundamental science and engineering not conducted at scale

6

Demand for Engineering Plastics

http://www.valvemagazine.com/index.php/web-only/categories/technical-topics/5830-high-performance-polymers-the-gap-between-need-and-science 7

Materials Selection

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9

Imidized Plastics Key Characteristics

• Very high cost per pound • Excellent properties

above 204°C/400°F • Excellent electrical

properties • Excellent dimensional

stability • Low coefficient of friction

(COF)

• Polyimide (PI)

• Polyamide Imide (PAI)

• Polybenzimidazole (PBI)

10

Amorphous High Performance Thermoplastics

Thermal stability Cost effective high-performance materials Toughness High heat deflection temperatures Good chemical resistance Transparency Hot water and steam resistance Good radiation stability FDA compliant grades available

Polysulfone (PSU)

Polyetherimide (PEI)

Polyether Sulfone (PES)

Polyaryl Sulfone (PAS)

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Semi-Crystalline High Performance Thermoplastics

• High cost • High temperature

resistance • High strength • Good electrical

properties and toughness • Outstanding chemical

resistance • Low COF

• Polyphenylene sulfide (PPS)

• Polyetheretherketone (PEEK)

• Fluoropolymers – Fluorinated ethylene propylene (FEP) – Ethylene chlorotrifluoroethylene

(ECTFE) – Ethylene tetrafluoroethylene (ETFE) – Polychlorotrifluoroethylene (PCTFE) – Polytetrafluoroethylene (PTFE) – Polyvinylidene fluoride (PVDF) – Perfluoroalkoxy (PFA)

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Polyetheretherketone (PEEK)

• Transportation • Industrial • Medical • Food contact • Semiconductor products

• Excellent environmental resistance

• Excellent wear resistance

• Excellent creep, fatigue and modulus

• Radiation resistance • Low flammability • Low smoke emission • Low toxic gas

emission • Tribological grade

available

13

PAEK Material Comparison

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Modulus Retention is strongly correlated to Tg. What is the role of pressure?

PEEK & PAEK Properties Under Realistic Conditions

Glass Transition Temperature of PEEK with Pressure

Mechanical Properties with Temp.

What is the role of Pressure on Melting Temperature & Heat Deflection Temperature?

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High T Extrusion Creep of PAEK

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Chemical Resistance of PAEK

Sour gas conditioning: Studied at different temperatures Impact on

Mechanical Properties

Not Studied at

Pressures of Interest and is a significant Testing Challenge Aging in Seawater at Temperature Gets More Realistic

Impact of Pressure & Hydrocarbons?

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Role of Pressure

• Pressure can significantly change thermal transition temperatures in polymers – Glass Transition Temperature

• ~ 40 oC / 15000 PSI

– Heat Deflection Temperature – Melting / Crystallization Temperature

18

PVT Measurements

0.95

1.00

1.05

1.10

1.15

1.20

1.25

20 60 100 140 180

10 MPa50 MPa100 MPa150 MPa200 MPa

Spe

cific

Vol

ume

(g-1

cm

3 )

Temperature ( 0C )

90

100

110

120

130

140

150

0 50 100 150 200 250

Cry

stal

lizat

ion

Tem

pera

ture

(o C

)

Pressure (MPa)

D08

dTcryst

/ dP ~ 19 ± 4 K (k Bar)-1

Measurements in collaboration with Greg Dee. Verified using Light Scattering

V TH

VS

dTdP

∆∆

=∆∆

=

Ethylene Copolymer

PSI 15000C 123

dPdT o

LS

crys ±=

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Why Filled Polymers? Composite Materials: Properties

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Carbon Fiber Composites

21

Manufacturing Techniques for CFRP

22

Composite Molding Process

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PVDF – High Performance Materials

• Remote actuation based is crucial for many down-hole applications – Need strong environmental resistance – Need high temperature capability

• Polyvinylidene Fluoride (PVDF) based nanocomposites

– Relatively Inert and corrosion resistance can be improved by addition of nano-layers

– High Melting Point

• Can Nanoscale Fillers Provide Unique Improvements to PVDF & Other High Performance Polymers?

24

PVDF – SWNT Nanocomposites

Y (GPa) Strain

PVDF 1.30 0.2

PVDF + 0.5 wt % SWNT 2.02 1.25

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PVDF Nanocomposites: Electromechanical Actuation

0.5wt% SWNT-PVDF un-poled, random β−phase Bending Displacement

converted to deformation along length ∆L Strain=∆L/L

Mechanically reinforced; Electromechanical Actuation 26

Current Research & Development Directions

• Understand and quantify the role of fillers in altering fundamental property changes of High Performance Polymers:

– Strategies to Develop Materials with Properties better than Requirements

• Testing Methods & Protocols for Realistic Testing under T, P & Environmental Conditions

– With Accelerated Testing Protocols

• Collaboration with H. J. Sue & Mike Mullins (TAMU) in conjunction with their activities with the APPEAL Consortium

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