THE Original DRILLING FLUIDS COMPANY © Copyright 2001 Baroid, a Halliburton PSL 1 Effective Sealing Operations

THE Original DRILLING FLUIDS COMPANY

© Copyright 2001 Baroid, a Halliburton PSL1

Effective Sealing Operations

© Copyright 2001 Baroid, a Halliburton PSL

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.


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


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


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


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


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

Interface

Drilling Mud

Cement

Formation

Casing

Micro Annulus

Filter Cake

Considerations For Cement Usage


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”


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


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


Water intake of HOLEPLUG (3/8") verse Chips from Brand X (3/8") to reach full hydration.

11

14

0

2

4

6

8

10

12

14

16

Brand X 3/8 11 HOLEPLUG(3/8")

Gal

lon

per

50

lb s

ack


Comparison Shear Strength of HOLEPLUG (3/8') and Brand X (3/8") w ith addition of 11 gallons of water per one 50 lb-sack product.

1007.09

2041.18

0

500

1000

1500

2000

2500

Brand X 3/8 1007.8 HOLEPLUG(3/8")

Gro

ut

Sh

ear

Str

eng

th, l

b/1

00 f

t

fully hydrated

T h in k A b o u t T h is

Liquid Limit

Expansion Pressure

Water In Solids Solids In Water

Hydrostatic Head

Plastic/Paste Slurry/Liquid

Increase In Volume Due To Addition of WaterTrue Expansion

G r o u t /P lu g

D r i l l in g F lu i dw /d e f in i t ep r o p e r t ie s

M u d d y W a t e rw i t h n o

p r o p e r t ie s

D r y B e n t o n i t e

A d d i t io n o f W a t e r

Dry

Dry Normal State

Normal State Maximum Hydration

Hydrated

Sodium Mortmorillonite

Calcium Mortmorillonite

9.6 Å

9.6 Å15.5 Å

12 Å

40-100 Å

15.5 Å


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


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


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

Interface

Drilling Mud

Formation

CasingFilter Cake

Bentonite Grout

Formation & Casing Interaction


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


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


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


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


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


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


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


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


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


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

Documents

THE Original DRILLING FLUIDS COMPANY © Copyright 2001 Baroid, a Halliburton PSL 1 Effective Sealing Operations