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

1. Supercement for Annular Seal and Long-term Integrity in Deep, Hot Wells DE-FC26-02NT41836

2. Problem:Long Term Zone Isolation in HTHP Wells • High Temperature and Pressure • Deviation angles - Placement is difficult • High Density systems – 17 to 20 ppg well fluids • High Pressure Gas – Gas migration • Narrow Annuli – High Friction • Liners versus longstrings • Tie Backs and Expandable Liners • CO2 and H2S common

3. 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

4. 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”

5. Project Work Team • CSI Technologies LLC • Material Manufacturers • Steering Committee • Operators

6. 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

7. 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.

8. 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

9. Mechanical Integrity Issues - Solutions • Improve material properties relative to Portland Cements: • Higher Tensile Strength • Higher Ductility* • Lower Anelastic Strain • Higher Young’s Modulus • Correlate material properties with performance

10. 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

11. Potential HTHP Solutions • Multi-material solutions • Optimized sealing • Optimized strength • Placement methods • Enhanced Portland performance • Non-Portland materials • Hybrid Portland materials

12. 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

13. 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

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

15. 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

16. Material Evaluation Strategy • Conventional testing • Compressive Strength • Tensile Strength • Kinetics and Placement • Thickening time • Consistency

17. Material Evaluation Strategy • Non-traditional testing • Young’s Modulus • Anelastic Strain / Fatigue • Annular Seal performance under cyclic loading • Expansion • Shearbond

18. 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

19. 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

20. Material Evaluation Results

21. Material Evaluation Results

22. 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

23. 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)

24. 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

25. 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

26. 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

27. 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

28. 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

29. Testing Issues • Cannot measure tensile strength via Splitting Method for highly expansive cements • Cannot measure tensile Young’s 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

30. 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

31. Direct Tensile Strength Method • No industry-authorized method • Different methods give different results • Proposed method yields tensile YM

32. High Temperature Expansion • Utilize split sleeve • Expansion imposes forces on transducers • Continuous measurement of expansive forces

33. High Temperature Annular Seal • Test resistance for gas flow continuously at temperature and pressure • Different methods give different results • Proposed method yields tensile YM

34. Phase III – 2007-2008 • Evaluate Supercement in Field Applications • Cost / benefit analysis • Commericalization / Technology Transfer

35. 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)

36. 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