Supercement for Annular Seal and Long-term Integrity in Deep, Hot Wells

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Supercement for Annular Seal and Long-term
Integrity in Deep, Hot Wells

• DE-FC26-02NT41836

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ProblemLong Term Zone Isolation in HTHP Wells

• Narrow Annuli High Friction
• Liners versus longstrings
• Tie Backs and Expandable Liners
• CO2 and H2S common

• High Temperature and Pressure
• Deviation angles - Placement is difficult
• High Density systems 17 to 20 ppg well fluids
• High Pressure Gas Gas migration

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Problem Well Intervention is Big Cost

• Survey 15 of all primary jobs require remedial
  cementing
• Estimate of 35 of HTHP primary jobs require
  remedial cementing
• Cost estimate
• On shore - 100k per squeeze (average 2 per)
• Off shore - 500k per squeeze (average 2 per)
• Bigger cost for Operators Long Term loss of
  production
• Interzonal flow
• Water influx

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Project Objectives

• Develop database of jobs for evaluation
• Determine the cement system properties that
  affects the ability of cementing materials to
  provide long term zone isolation under deep hot
  conditions
• Use recently developed laboratory methods to
  determine key properties
• Evaluate various materials to generate the key
  properties
• Develop Supercement systems!!!!
• Application for all wells including deep hot

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Project Work Team

• CSI Technologies LLC
• Material Manufacturers
• Steering Committee
• Operators

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HTHP Well Database

• Develop database for HTHP Cementing
• Determine critical well info and parameters
• Successful cementing/completion
• Unsuccessful cementing/completion
• Confidentially is important (all contributing
  members have access)
• Track industry practices and results
• Status rollout week of 10-31-05
• Update with outside data if possible

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Deep Trek Technical Interest Web-Site

• CSI/DOE develop web-site
• Clearing house for discussion, questions,
  concerning Deep Trek wells
• Focus mainly US but can include others
• Look for trends, new information, repeating
  issues, new technologies used etc.

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Mechanical Integrity Issues

• Flow of Fluids
• Around the Cement
• Bonding, Microannulus, Deformation
• Through the matrix of the Cement
• Cracking, Permeability changes
• Stress
• Pressure, Temperature
• Stress Cycling Conditions
• Mechanical shock

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Mechanical Integrity Issues - Solutions

• Improve material properties relative to Portland
  Cements
• Higher Tensile Strength
• Higher Ductility
• Lower Anelastic Strain
• Higher Youngs Modulus
• Correlate material properties with performance

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Anelastic Strain

• Definition Permanent Deformation resulting from
  Low-Intensity Stress Cycling
• Measured at 25 and 50 ultimate strength
• Tensile and Compressive may be very different
• All Portland cements exhibit behavior
• Measured by comparing ideal (completely
  elastic) behavior with actual
• Low-level stress can modify ultimate strength

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Potential HTHP Solutions

• Multi-material solutions
• Optimized sealing
• Optimized strength
• Placement methods
• Enhanced Portland performance
• Non-Portland materials
• Hybrid Portland materials

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Phase I Tasks

• Literature Search on Portland and Non-Portland
  Binders
• Evaluate materials at low temperatures
• Evaluate materials at high temperatures
• Evaluate materials with non-traditional testing

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Literature Search Strategy

• Emphasis on non-Portland binder research
• Emphasis on ceramic acid-base reactions
• Effects of unconventional additives on Portland
  cement properties
• Refractory cements
• Emphasis on non-oilfield binder applications

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Literature Search Results

• Chemically-reactive fibers
• Ceramic
• Kevlar
• Inorganic expansive additives
• Molybdenum
• High concentrations of MgO
• Ceramicrete (ANL)
• Calcium Aluminum Silicate
• High-temperature resins

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Material Evaluation Strategy

• Conduct screening laboratory tests to determine
  material properties
• Advanced material property and performance
  testing on best materials from screening tests
• Evaluate materials at low and high temps
• Correlate material properties and performance

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Material Evaluation Strategy

• Conventional testing
• Compressive Strength
• Tensile Strength
• Kinetics and Placement
• Thickening time
• Consistency

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Material Evaluation Strategy

• Non-traditional testing
• Youngs Modulus
• Anelastic Strain / Fatigue
• Annular Seal performance under cyclic loading
• Expansion
• Shearbond

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Material Evaluation Results

• Candidate Phase II Materials
• 9 formulations in 3 product categories
• Non-Portland
• High-temperature resin
• Calcium Aluminum Silicate
• Portland with Unconventional Additives
• MgO
• Molybdenum
• Reactive Fibers
• Modifier for other slurry systems

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Material Evaluation Results

• Best properties do not always mean best
  performance
• No single property is a reliable predictor of
  performance
• Performance based on Annular Seal model
• Preliminary numerical model relates energy
  application and resistance prior to loss of seal
  to cement properties
• When available, evaluate Single-Wall Carbon
  Nanotubes as performance-enhancing additive

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Material Evaluation Results
System Formula Recipe Water Density
Baseline 99 H 35 Silica Flour 5.16 16.6
Mod Baseline 77 H25 SBMC15 MFA2 Daxad 9 2.50 19.7
MgO 128 Baseline 77 20 MgO H 3.60 19.0
Moly 132 Baseline 99 0.5 Moly 5.19 16.6
Moly 133 Baseline 77 0.5 Moly 2.50 19.7
Resin 188 Resin Hardener Reactive Diluent N/A 9.0
Silicate 180 NaSiO3 CaOH AlOOH 24
Fiber 130 Baseline 99 1.0 Ceramic Fibers 5.21 16.6
Fiber 131 Baseline 99 1.4 Ceramic Fibers 5.24 16.6
Fiber 136 Baseline 77 0.5 Ceramic Fibers 2.50 19.6
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Material Evaluation Results
System Formula Comp Tensile AS 10-6 SB Ann Seal
Baseline 99 4,790 705 5.87 260 44,850
Mod Baseline 77 5,650 725 3.49 470 29.900
MgO 128 3,190 281 1850 Pend HT
Moly 132 4,280 1,083 1.55 308 1,325,360
Moly 133 6,680 1,366 0.85 570 349,900
Resin 188 5,550 3,690 18.23 1850 In Proc
Silicate 180 1,240 970 6.41 In Proc
Fiber 130 3,710 1,016 4.04 300 0
Fiber 131 3,020 1,149 3.10 190 8,250
Fiber 136 4,510 1,312 1.59 1,020 1,749,500
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High-Temperature Epoxy Resin

• Solves problems with Furan Resins
• Shrinkage
• Water intolerance
• Weighting / Lightening destroys properties
• Difficult to control kinetics
• High-Temperature Epoxy Resins
• Discovered as part of a different project
• Traditional usage HT winding insulation for
  electric motors
• Evaluation revealed controllable kinetics at high
  temps
• Material subjected to DeepTrek testing

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High-Temperature Epoxy Resin

• Properties
• Very high tensile and compressive strength
• High shearbond
• Rubber-like
• Absorbs large amount of energy without failure
• Difficult to test using conventional cement test
  protocols
• High anelastic strain over short time / Low
  anelastic strain over long time (deforms, then
  rebounds)

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High-Temperature Epoxy Resin

• Issues
• Liquid / liquid system
• Health issues with handling
• Highly exothermic must cure under pressure
• Can use conventional batch mixers
• Dedicated automatic-controlled continuous mixer
  feasible
• Requires different test protocols and equipment
  to adequately quantify properties and performance

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Modifications to Resin

• Combine with Cement
• Solids help with fluid loss
• Penetration of big voids with cement
• Filtrate of the fluid sets and consolidates
  formations
• Sealing and zone isloation not only in wellbore
  but in the formation itself

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Phase II Tasks

• Manufacture Supercement to specification
• Batch testing to confirm performance on large
  scale
• Large-scale mixing, shearing, and drillout,
  testing
• Field test, research test well

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Phase II Result to Date

• Phase II Tasks nearly complete for Epoxy Resin
• Field-scale mixing, shear, and drillout testing
• Large-scale manufacturing
• Field tests in low temperature (200 deg F) well
• Phase II Remaining Work
• Deep, Hot test well application
• Test well applications of other candidate systems

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Phase II Results to Date

• Continuing materials property and performance
  testing to refine formulations
• Epoxy Resin
• Calcium Aluminum Silicate
• MgO and Moly (performance)
• Hybrid Epoxy Resin / Portland Cement
• Interesting properties
• Fills matrix voids with strength and
  ductility-contributing material

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Testing Issues

• Cannot measure tensile strength via Splitting
  Method for highly expansive cements
• Cannot measure tensile Youngs Modulus with
  indirect Splitting method
• Ultimate Annular Seal test must be conducted at
  elevated temperatures
• Expansion of highly-expansive cements cannot be
  measured with current tests

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Testing Issues - Solution

• Design new test equipment, develop testing
  protocols, and perform validation tests
• Direct tensile strength test
• Expansion under elevated temperature and pressure
  conditions
• High temperature Annular Seal
• Phase II Extension Proposal to Develop apparatus,
  protocols, and validation

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Direct Tensile Strength Method

• No industry-authorized method
• Different methods give different results
• Proposed method yields tensile YM

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High Temperature Expansion

• Utilize split sleeve
• Expansion imposes forces on transducers
• Continuous measurement of expansive forces

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High Temperature Annular Seal

• Test resistance for gas flow continuously at
  temperature and pressure
• Different methods give different results
• Proposed method yields tensile YM

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Phase III 2007-2008

• Evaluate Supercement in Field Applications
• Cost / benefit analysis
• Commericalization / Technology Transfer

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Deep Star Project

• Determine current technology and gaps in
  cementing and zone isolation at HTHP wells
  primarily in deep water
• Considering leveraging Deep Trek for addressing
  key gap in cementing
• CO2 and H2S resistance at elevated T and P
• Estimated funding at 1million (non DOE funds)

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Summary

• Successful Phase I multiple candidate systems
  of interest
• Successful Phase II to date with Epoxy Resin
• Additional test apparatus and protocols required
  to evaluate candidate systems under HTHP
  conditions