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Effective Sealing Operations

Effective Sealing Operations. Baroid Industrial Drilling Products.

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Effective Sealing Operations

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  1. Effective Sealing Operations

  2. Baroid Industrial Drilling Products This presentation contains technical information and data, and know-how that are confidential and properties of Baroid Industrial Drilling Products (IDP). Any unauthorized publication or disclosure of such information to any person, or any unauthorized use of such information, without the express written consent of Baroid IDP is strictly prohibited.

  3. Objective of Seal Placement • Replacement of Native Material with a product that meets and/or exceeds the sealing capability of the native formation • Maintain and Protect Water Quality • Sealing The Annular Space • Prevent Commingling of Aquifers • Prevents Surface Contamination • Provides Casing Support • Complies With Federal, State and Local Well Construction Codes • It’s The Law

  4. Sealing Materials • Sodium Bentonite • Pumpable Grouts • Chips • Pellets • Calcium Bentonite • Pumpable Grouts • Chips • Pellets • Cement • Portland Cement (ASTM Type I, API Class A) • Cement/Bentonite Mix • Specialty Cements

  5. Cement • Initially a true hydraulic fluid that transmits hydrostatic pressure • Cement slurry densities range From 15.6 - 12.0 lb/gal • Converts to a solid-set material with compressive strength • Considerable amounts of heat are generated from the curing process (Heat of Hydration) • Thicker sections of cement evolve more heat

  6. Cement(continued) • Bentonite addition • Reduces slurry density and increase slurry volume • Reduces resistance of cement to chemical attacks from formation water • Adequacy of annular seal is determined by hydraulic bonding • Hydraulic bonding of cement to formation is affected by the presence of thick filter cakes • Failure to remove drilling mud/filter cake is more detrimental to formation bonding than pipe bonding • Effective cementing has several requirements

  7. Cementing Requirements • Bore Hole Stability • Water Requirements • 5.2 - 6.0 gal/94 lb sack • Adequate Mixing • High shear • Filtration Control Additives • Mud & Filter Cake Removal • Centralization of casing • Pumping Rate • Rotation/Reciprocation

  8. Considerations For Cement Usage

  9. Why Use Bentonite For A Seal? • Ability To Hydrate And Expand • Low Permeability of Material • Hydration of Material Results In Expansion Pressure When Confined • Bentonite Seals Can Reconstitute • Results in A Flexible Seal • No “Heat of Hydration”

  10. Quality of Sealing Materials • Higher Quality Bentonite Materials Produce Higher Quality Seals • What Defines Quality of Bentonite • High Percentage of Sodium Montmorillonite • Results In Greater Liquid Limits, Increased Expansion Pressure • High Degree of Confidence In Seal

  11. Quality of Solidsvs.Quantity of Solids • Does Higher % Solids Insure a Quality Seal? • Define The Type and Quality of The Solid • Experience Shows That The Liquid Limit and % Sodium Montmorillonite of the Bentonite Are Good Indicators of Quality • The Resultant Hydration, Expansive Properties and Structural Integrity Make Solids of This Nature Superior • Bentonite Quality Is Determined From Analysis of Untreated Bentonite

  12. Calcium Mortmorillonite 9.6 Å 15.5 Å 15.5 Å Dry Maximum Hydration Normal State Sodium Mortmorillonite 9.6 Å 12 Å 40-100 Å Dry Normal State Hydrated

  13. Effective Bentonite Seal • Depends on four factors • Bore Hole Stability • Quality of Material • Placement of Bentonitic Material In The Annular Space In as Near “UN-Yielded Form” as Possible • Proper Emplacement

  14. Effective Placement • Bentonite grouts need to be placed in a manner that allows for “In-Situ Swelling” for optimum results • Do not shear or over-mix • Structure grouting procedure to allow for maximum volume and flow • Place grout into annulus under turbulence and high velocity • This helps insure complete filling of the annular space volume and reduces potential of channeling

  15. Effective Placement(continued) • In general, the larger the annular space the less problems encountered during grout placement (2”) • It is desirable to have the casing centralized in the bore hole to facilitate even grout distribution around the casing efficient displacement of drilling fluid • Casing in tension rather than compression • Know annular volume to insure adequate amounts are utilized • During placement of bentonite grout, the grout returning to the surface should be of the same consistency of that being pumped • Active pumping of the grout should continue as the tremie pipe is extracted from the annular space or open hole to insure effective displacement

  16. Formation & Casing Interaction

  17. Industry Products & Systems • Granular Bentonite • Granular Bentonite and Polymer Slurry • Polymer Coated Granular Bentonite • Chipped Bentonite (3/8" or 3/4") • BENTONITE PELLETS (1/4", 3/8",1/2") • 20 % pumpable grout • 30 % pumpable grout • Unsorted granular 100 to 16 mesh

  18. Granular • Sealing and Plugging Agent • Uniform, #8 mesh, granular material • For use in sealing and grouting wells and in reduction of soil permeability • Used in Heat-Loop installations • Sealant for leaking ponds, ditches and dams • ANSI/NSF Standard 60 Certified

  19. Granular Polymer Slurry • Sealing and Plugging System • 15% Total Active Solids • 1.2 x 10-8 cm/sec permeability • No Heat of Hydration • Flexible Seal • Utilize for sealing of casing, ground source heat loops and abandonment of bore holes • Do Not Use With Centrifugal Pumps • ANSI/NSF Standard 60 Certified

  20. Polymer Coated Granular • Single-Sack grouting and plugging material • Effective with Total Active Solids of 15%, 20%, 23% • 1.0 x 10-9 cm/sec permeability • No Heat of Hydration • Flexible Seal • Utilize for sealing of casing, ground source heat loops and abandonment of bore holes • Do Not Use With Centrifugal Pumps • ANSI/NSF Standard 60 Certified

  21. Bentonite Chips • Untreated, sized bentonite chips • Available in 3/8" and 3/4" • Utilized in well completion & abandonment • Excellent In-Situ swelling capabilities • 1.5 x 10-9 cm/sec permeability • No Heat of Hydration • Flexible Seal • Eliminate “fines” to avoid bridging • ANSI/NSF Standard 60 Certified

  22. Bentonite Pellets • Untreated, Compressed Bentonite • Used in well completion and bore hole abandonment • Available in 1/4”, 3/8” and 1/2” sizes • No Heat of Hydration • Flexible Seal • ANSI/NSF Standard 60 Certified

  23. 20 % Grout • Single-Sack grouting and plugging material • 20% Total Active Solids • 2.5 x 10-8 cm/sec permeability • No Heat of Hydration • Flexible Seal • Utilize for Monitor & Water Well completions and abandonment • Do Not Use With Centrifugal Pumps • ANSI/NSF Standard 60 Certified

  24. 30 % Grout • One-Sack Bore hole Grouting Material • 30% Total Active Solids • 3.0 x 10-8 cm/sec permeability • No Heat of Hydration, Flexible Seal • Designed for sealing annular spaces in monitor and water well applications • Do Not Use With Centrifugal Pumps • ANSI/NSF Standard 60 Certified

  25. Mixed Granular • Untreated random sized granular bentonite • Effective for reducing soil permeability • Random sized particles aid in sealing • Effective for bore hole abandonment • Utilized in casing driving operations • Sealant for leaking ponds, ditches and dams

  26. Closing Thoughts • The most common reason seals fail is due to improper placement • Match The Grout or Sealing Agent To The Job • Bentonite Seals Have Limitations, Don’t Ask The Material To Do Something It Is Not Capable Of • A Successful Seal Starts With The First Turn of The Bit • Focus On Quality

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