2. Bentonite: Its Origin
 Large volumes in
western U.S.
 Formed during
Cretaceous Period
 Formed by volcanic
ash
http://www.webcamcruise.com/USA%20Map_fichiers/usa_map.jpg

3. Bentonite Mining

4. Wyoming Sodium Bentonite
 High swelling clay
 Ability to adsorb large
quantities of water
 Composed of many stacks of
platelets like a stack of cards
 Expands up to 20 times its
volume
 One inch3 covers 66 football
fields
 One inch high contains
between 35,000-40,000 layers
(stresses good mixing)

5. Venturi Style Mixing Hopper
Bentonite going into
hopper @ 200 mesh
(74 Microns)
Bentonite platelets (1/2 Micron)
mechanically separated by high
velocity fluid from jet hopper
Hopper Jet Venturi Pipe

6. Mixing System

7. Examples of Un-yielded Bentonite
This image shows a poorly This image shows the un-
mixed 40 Viscosity SUPER yielded bentonite on your
GEL-X poured over the hand when dipping it into
screen on a Marsh Funnel the mix tank

8. Make-Up Water
 Most important block of fluid system!
 Makes 95-99% of a drilling fluid!
 Bad Water = Bad Drilling Fluids

9. Do These Problems Sound Familiar?
 Bentonite does not mix like it should
 When we turn off the mixing equipment the
bentonite settles and leaves water on the surface
 It takes a lot more bentonite to get the same
viscosity
 The pump is making all kinds of noises when
pumping the slurry
 Polymer gets all stringy when we mix it

10. Make-Up Water
 Is there a problem with the Bentonite?
Probably not.
 Most likely the culprit is low pH (<9.5) and or
hardness (calcium)
 When contaminants are present, the stack of cards
does not want to separate and disperse

11. Effects of Soda Ash on Bentonite in Water
 Soda ash increases the negative charge on bentonite
 More water is adsorbed
 Dispersion of clay platelets increases
Na2CO
+ +
 Soda ash also promotes dispersion of the drill cuttings

12. Bentonite Settles and Leaves Water on the Surface
Bentonite settling due to calcium in water

13. What to Do?
 Check pH (7 is neutral)
 HYDRAUL-EZ and polymers like a pH of
approximately 9.5+
 Raise the pH with soda ash (sodium carbonate).
This also precipitates out calcium
 Normal treatment is ¼ to ½ pound per 100 gallons
of water

14. Check Mix Water pH with pH Strips

15. The pH Scale
H+ Concentration (Moles/Liter) pH Value
100 0 1 Molar Hydrochloric acid (HCI)
10-1 1 Stomach Acid, Lime Juice
10-2 2 Lemon Juice
Increasingly Acid (H+ >
10-3 3 “Acid Rain” (2.5-5.5), Vinegar, Cola
10-4 4 Beer
10-5 5 Black Coffee, Tea
OH-)
10-6 6 Normal Rain (5.6)
Bentonite 10-7 Neutral 7 Pure Water, Saliva, Blood, Sweat
(H+=
Mixing 10-8 OH-) 8 Seawater (7.8-8.3)
10-9 9 Baking Soda
Increasingly Basic (H+ <
10-10 10 Phosphate Detergents, Chorine Bleach
10-11 11 Household Ammonia
Reference: Audesirk,
10-12 12 Washing Soda T., Audesirk, G., &
Byers, B. 2003. Life On
Earth. Third Edition.
10-13 13 Oven Cleaner
OH-)
Prentice Hall. Upper
Saddle River
10-14 14 1-Molar Sodium Hydroxide (Na0H)

16. Functions of HYDRAUL-EZ Drilling Fluid
Cool bit & lubricate the
hole
Clean the hole, suspend
& transport cuttings
Hold the hole open,
stabilize the hole
Control fluid-loss, loss
circulation, and frac-outs
Reduce torque
associated with sticky
soil
Control sub-surface
pressure

17. Characteristics of HYDRAUL-EZ
Drilling Fluid
Viscosity
Gel Strength
Fluid Loss
Sand Content
Density,
Hydrostatic Head

18. Viscosity
 The resistance of a fluid to flow; the greater the
resistance, the greater the viscosity or thickness
 Measured with a marsh funnel and cup
 Viscosity only tells us the thickness of a fluid
 Two fluids with the same viscosity can be vastly
different in terms of its ability to clean the hole

19. Units for Bingham Plastic Fluids
We use the following units, typically, to describe the
rheological behavior of drilling fluids
 Plastic viscosity, PV (cp)
 Yield Point, YP (lb/100 ft2)
 Apparent Viscosity, AV (cp)
 Gel strengths (??)
How can this possibly make any sense?

20. Marsh Funnel and Cup - Viscosity

21. Viscosity & Pump Performance
 Higher viscosity fluids will reduce the flowability of
cuttings
 Higher viscosity fluids will drastically reduce pump
performance
 Higher viscosity fluids will increase pumping and
material costs

22. Viscosity & Pump Performance
Pump curves are based on clear water at sea level and
under ideal conditions
Example
40 gpm pump with clear water, 26 viscosity
 40 viscosity – 10-15% capacity = 34-36 gpm
 60 viscosity – 25-30% capacity = 28-30 gpm
 80 viscosity – 40-50% capacity = 20-24 gpm

23. Gel Strength
 Most important drilling fluid characteristic
 The ability of HYDRAUL-EZ to form gels and suspend
cuttings in borehole
 If drill cuttings are not suspended, they will pack off
borehole and cause pressure buildup, fracturing, and
stuck pipe

24. Gel Strength
Two methods to increase the gel strength of a drilling
fluid
1. Add more HYDRAUL-EZ, which also increases viscosity
(resistance to flow)
2. Add a gel strength enhancing polymer to HYDRAUL-EZ slurry
HYDRAUL-EZ/polymer system - HYDRAUL-EZ with
SUSPEND-IT is most desirable since it forms a high gel
strength, pump-able slurry

25. Gel Strength
 If cuttings are flowing out
of the hole, we know we 45
have an open hole 40
35
30
 If the hole is open, we don’t 25
get stuck 20
15
10
 HYDRAUL-EZ offers 5
0
superior gel strength 1 0 MIN GEL
S UPER GEL -X
HYDR AUL -EZ

26. One Minute Gel Strength @ 60 Viscosity
SUPER GEL-X HYDRAUL-EZ

27. Four Minute Gel Strength @ 60 Viscosity
SUPER GEL-X HYDRAUL-EZ

28. Ten Minute Gel Strength @ 60 Viscosity
SUPER GEL-X HYDRAUL-EZ

29. Gel Strength
 No viscosity increase
with HDD designed
drilling fluids
 Recommend
SUSPEND-IT when
coarse sands and gravel
are anticipated

30. Fluid Loss
 Measure of amount of drilling fluid lost through a
permeable formation
 Fluid loss can be measured with a filter press
 Bentonite platelets shingle off wall of the hole and
form a filter cake when slurry is pumped under
pressure
 This cuts off water to surrounding sand or gravel

31. Fluid Loss
Two methods to “tighten” or reduce amount of fluid
going into formation
 Add more HYDRAUL-EZ, which increases platelets but
increases viscosity (resistance to flow)
 Add fluid loss polymer to HYDRAUL-EZ slurry HYDRAUL-
EZ/polymer system – HYDRAUL-EZ with SUPER PAC or REL
PAC is most desirable since it forms a low solids pump-able
slurry

32. Bentonite Suspension
HYDRAUL-EZ Drilling Fluid Seals Borehole Sidewall
Hydrostatic
Pressure
Bentonite Particles
Soil Bentonite Filter Cake Formed by
Grains Clogging and Bridging

33. Fine to Medium Sand
Water percolating Total saturation
through sand

34. Fine to Medium Sand
HYDRAUL-EZ and REL- Water or drilling fluid with
PAC Drilling Fluid poor fluid loss
MINIMAL Fluid Loss HIGH Fluid Loss

35. Controlling Fluid Loss
Minimal Fluid Loss = Borehole Stability

36. Fluid Loss
 SUPER PAC and
REL-PAC enhance the
performance of
HYDRAUL-EZ
 A thick filter cake does not
translate to a reduction in
fluid loss

37. Modified Natural Polymer
Used in Coarse Non-Reactive Soils
 Manufactured in liquid and powdered form, cellulose polymers are
used primarily to control fluid loss and stabilize difficult holes
 REL-PAC and SUPER PAC – Dry and liquid cellulose polymers which
are added to HYDRAUL-EZ systems to create superior borehole
stability

38. Holding the Hole Open
Maintaining a stable hole while drilling through soil,
sand, gravel or other non-consolidated formations
Positive pressure of drilling fluid (filter cake,
circulating pressure, hydrostatic pressure)
 Similar to coffee grounds in a vacuum sealed can
Keys
 Filter cake
 Particle bridging character of the polymers in CETCO’s
formulations

39. Density/Hydrostatic Pressure of Boring Fluids

40. Borehole Stability
 Major function of HYDRAUL-EZ fluid is to keep the
hole open
 Hole is held open by hydrostatic pressure from a
HYDRAUL-EZ fluid pressing against a lower formation
pressure – across a filter cake
 The pressure difference need not be great, but must
always be positive

42. What Is Loss Circulation?
 Loss circulation refers to the total or partial seepage of
drilling fluid into the formation through crevices or
porous media
 Not to be confused with frac-outs which refer to fluid
breaking through the surface

43. Coarse Unconsolidated Formations
 Sand
 Gravel
 Partial and or gradual loss of return flow
may be experienced in coarse soil
conditions.
 Utilize a drilling fluid with good fluid-
loss control such as a HYDRAUL-EZ/PAC
polymer fluid (soda ash is also important
to get maximum yield out of HYDRAUL-
EZ)
 Reduce the mud weight as much as
possible by good solids control practices
and checking mud properties frequently

44. Driller-Created Loss Circulation Problems
High solids/high density drilling fluids increase
hydrostatic pressure on formations
Example:
Mud Weight X 0.052 X Depth = Hydrostatic Pressure
9.0 pound mud @ 200’ depth:
9.0 X 0.052 = 0.468 X 200’ = 93.6 PSI of Hydrostatic Pressure on the
Formation
14 pound mud @ 200’ depth:
14 X 0.052 = 0.728 X 200” = 145.6 PSI of Hydrostatic Pressure on the Formation

45. Driller-Created Loss Circulation Problems
 Failure to adequately transport
cuttings to the surface
 Inadequate gel strength and or
annular ascending velocity to
transport cutting to the surface,
and suspend cuttings when
circulation is stopped can result
in the bridging of drill cuttings
around the drill stem which can
block return flow, over pressure,
and fracture the formation

46. Driller-Created Loss Circulation Problems
 Failure to control the hydration
of reactive soils
 Reactive clays can swell up and
create blockages that prevent
return flow from exiting the
bore and over-pressure the
formation causing fractures and
loss circulation
 Utilize synthetic polymer for
controlling reactive soils

47. Driller-Created Loss Circulation Problems Hole Swabbing
 Thick, poorly-yielded
bentonite drilling fluids (not
using soda ash) along with a
failure to utilize modified
natural polymers (PAC
polymers) to control water-
loss can result in high fluid-
loss conditions
 A thick ineffective filter cake
can cause swabbing (suction)
of the hole, when downhole
tooling is pulled, resulting in
hole collapsing and loss
circulation problems

48. Barrel Yield
Describes the number of barrels of a given viscosity bentonite
slurry that can be made from a ton of clay
 SUPER GEL-X High Yield Bentonite = 200-220 bbls
 HYDRAUL-EZ HDD specialty bentonite = 165-185 bbls
 PREMIUM GEL API grade = 90 bbls
Examples
210 bbls x 42 gal = 8,820 gallons of slurry
185 bbls x 42 gal = 7,770 gallons of slurry
90 bbls x 42 gal = 3,780 gallons of slurry

49. Five Steps to a Successful Borehole
Soil
Volume
Identification
Successful
Borehole
Drilling
Planning
Fluids
Bits
& Reamers

50. PLAN for SUCCESS!
 Time is Money!
 Planning Phase Saves Time
 Jobsite Layout
 Needs:
 Manpower
 Equipment Needs (Tooling, Vacs, Recycling)
 Product Needs
 Jobsite Water Source (Fire Hydrant)
 Disposal Options

51. CETCO Online Calculation Guides

52. Why Use a Software Based Mud Program?
 Allows for more accurate bidding of jobs
 Ensure you have the correct products on the job-
site
 Ensure you have proper quantity of products on
the job
 Printed report can be used with your submission
 Engineers are using this to assist in specs

53. Sample Input Screen

56. Five Steps to a Successful Bore - Soil Identification
Coarse Soils
Sand, Gravel, Cobble, Rock, typically use bentonite or
bentonite/polymer system
Fine Soils
Clay and silts, typically use polymer or
bentonite/polymer system

57. Soil Identification
Reactive Non-Reactive
(Fine Soils) (Coarse Soils)
 Clay  Sand
 Shale  Gravel
 Cobble
 Rock

58. Five Steps to a Successful Bore -
Drilling Fluids
 There are no universal soils and there are no
universal drilling fluids
 Match the drilling fluid to the soil type
 Use bentonite as a base for all soil conditions
 Polymers & additives are added to bentonite
drilling fluids to match soil conditions

59. Polymer Additives
 Designed as additives for HYDRAUL-EZ & SUPER
GEL-X drilling fluids, not a replacement
 First used as drilling fluids in the late 1930’s
 Specifically designed for a particular drilling
situation
 Three basic categories; synthetic, modified
natural, and natural polymers

60. Synthetic Polymers - Used in
Reactive Soils
Manufactured in liquid and powdered form;
they can be tailor made to fit any function
Functions:
 Viscosifiers
 Clay and shale inhibitors
 Lubricants
 Borehole stabilizers
 Very shear sensitive

61. Synthetic Polymers
 ACCU-VIS and INSTA-VIS PLUS
– Liquid polymers to increase
viscosity and inhibit hydration
of clay and shale
 INSTA-VIS DRY – Dry polymer
for stabilizing borehole and
coating clay and shale

62. Clay & Water (Reactive Soils)
Mixing clay Polymer and Clay will hydrate Polymer coats clay
with water water causing sticking particles and
and swelling delays hydration

63. CLAY CUTTER
 A concentrated, non hazardous,
proprietary clay inhibitor that
can be used with either polymer
or HYDRAUL-EZ drilling fluid
systems
 An ideal additive for reactive
clay soils
 Will greatly reduce or eliminate
clay cuttings from sticking to
each other and to the drilling
tools. Swelling of the bore will
be reduced or eliminated
 Rotation and pullback pressures
will be significantly reduced
 Can be used in antifreeze tank
for easy spot treatment

64. CLAY CUTTER Breaks Down Reactive Soils
Adding CLAY CUTTER to granular Granular bentonite/reactive soils are
bentonite and water broken down (instead of being
encapsulated) and in a more flowable
state

65. Modified Natural Polymer (Used in Coarse
Non-Reactive Soils)
 Manufactured in liquid and powdered form,
cellulose polymers are used primarily to control
fluid loss and stabilize difficult holes
 REL-PAC and SUPER PAC – Dry and liquid
cellulose polymers which are added to HYDRAUL-
EZ systems to create superior borehole stability

66. Reducing Fluid Loss REL PAC
40 Viscosity 40 Viscosity
HYDRAUL-EZ fluid HYDRAUL-EZ fluid
with REL PAC

67. Natural, Biodegradable Polymers
 No viscosity increase
with HDD designed
drilling fluids
 Increases gel strength
 SUSPEND-IT is
recommended when
coarse sands and gravel
are anticipated

68. Example: Alternating Clay & Sand
Sand
Reactive Clay

69. Example: Difficult Conditions

71. Pilot Hole
 Use drilling fluids and additives both ways: if you
need it back-reaming, you will need it on the pilot hole
 Maintain an open bore path and steady flow
 Avoid over-steering

72. Avoid Creating Bottlenecks in the
Bore Path
Rotate the bit through sections where push-
steering corrections were performed to
maintain annular spacing

73. Five Steps to a Successful Bore
Bits & Reamers
 No universal soils Bits
Duckbill
 No universal drilling Roller Cone
fluids Geo-Head
 No universal bits & Reamers
reamers
Barrel/Packer
Spiral/Fluted
 Match downhole
tooling to the soil type Winged/Open
Roller Cone/Hole
Opener

74. Bit Selection – The Proper Bit is Critical for a Successful
Pilot Hole

75. Reamer Selection
 Reamer should always be a minimum of 1 ½ times
the diameter of the product line to prevent getting
stuck and frack outs.
 Reamer selection is critical for a successful bore
 Like fluids, reamers need to be matched to soil
types
 Reamers should not restrict the pump’s capacity or
annular flow

76. Spiral or Fluted Reamer
 Versatile type of
reamer
 Used in sand, silty
soils, and rocks &
cobbles
 Avoid using spiral or
fluted reamers in clay

77. Spiral Reamer In Clay

78. Winged or Open Reamer
 Used in reactive soil
conditions (i.e. clays)
 Minimal surface area for
clay to stick and cause
blockage of annular flow
 Good chopping action
(required in reactive soils)

79. Barrel Reamer or Packer
 Used in uniform soils
and loose sands
 Used with high
viscosity to maintain
borehole stability
Makes a great boat
anchor!

80. Frac-Outs and Bulging
Pavement
Drilling fluid has nowhere else to
go but into the formation
No space between formation and drill
pipe for drilling fluid to return
Reamers such as fluted and spiral ball up
with clay and restrict flow to exit side
Annular space is maintained through proper drilling
fluid additives and good drilling techniques
Open type of back reamers reduce balling of clays and provide
-
a chopping/mixing action while allowing for fluid to flow to the exit side

82. Preventing Frac-Outs
Frac-outs occur when the circulating pressure in
the wellbore exceeds the formation strength
 Build-up of solids in drilling fluid lead to really high
mud viscosities, low pump rates, and/or “out-running
mud”
 Solution is more drilling fluid and or higher circulation
rates to reduce solids content in returns

83. A Little Bit of Volume and Pressure Can
Cause a Lot of Damage

84. Damage Repair is Costly

85. Five Steps to a Successful Bore
Volume
 Provide sufficient volume to maintain a flowable
slurry
 Calculate drilling fluid volumes based on hole size
and soil type
 Determine backream time based on pump
capacity

86. Don’t Forget an Important Rule of
Thumb In HDD
Hole diameter must be at least 1 ½ times
the diameter of the product line

87. Calculating Drilling Fluid Volumes
Volume of hole = Diameter2 ÷ 24.52 = gals/ft
Example: 8” backream and 200 ft bore
8x8=64 ÷24.52=2.61 gals/ft
200 ft bore x 2.61 gals/ft = 522 gals (based on 1:1 ratio)
Requirements for different soils
Sands: 2-3 x volume of hole
Clays: 3-5 x volume of hole

88. Calculating Drilling Fluid Volumes
Estimating bore time based on pump capacity
Example: 200 ft bore x 8” hole; sandy soils
2.61 gals/ft x 2= 5.22 gals x 200 ft=1,044 gallons
Using 10 ft drill stem we need 52.2 gallons per stem:
 Pumping 20 gpm takes between 2.5 and 3 minutes per 10 ft. rod.
 Pumping 30 gpm takes between 1.5 and 2 minutes per 10 ft. rod.
 Pumping 40 gpm takes between 1 and 1.5 minutes per 10 ft. rod.
* Given above examples, reaming time should vary between 25 and 60
minutes.

89. HDD Pumping Volume Requirements
Hole dia. Gal/ Lin. Ft. Coarse Soils (Sands) Fine Soils (Clays)
(in.) = (dia2 ÷24.5) 2 to 3 X Vol. Of hole 3 to 5 X Vol. of Hole
2 0.16 0.32 to 0.48 0.48 to 0.8
4 0.65 1.3 to 1.95 1.95 to 3.25
5 1.02 2.04 to 3.06 3.06 to 5.10
6 1.47 2.94 to 4.41 4.41 to 7.35
7 2.00 4.0 to 6.0 6.0 to 10.0
8 2.61 5.22 to 7.83 7.83 to 13.05
9 3.30 6.60 to 9.90 9.90 to 16.5
10 4.08 8.16 to 12.24 12.24 to 20.4
12 5.87 11.47 to 17.61 17.61 to 29.35
14 8.0 16 to 24 24 to 40
16 10.44 20.88 to 31.32 31.32 to 52.2
18 13.22 26.44 to 39.66 39.66 to 66.10
20 16.32 32.64 to 48.96 48.96 to 81.6
24 23.49 46.98 to 70.47 70.47 to 117.45
30 36.73 73.467 to 110.19 110.19 to 183.65
36 52.88 105.76 to 158.64 158.64 to 264.4

90. Let the Exit Flow Be Your Guide

91. Five Steps to a Successful Borehole
Soil
Volume
Identification
Successful
Borehole
Drilling
Planning
Fluids
Bits
& Reamers

92. Up Your Odds for Success!
 Utilize drilling fluids as a tool to avoid trouble
instead of an aid to get you out of trouble
 Take advantage of the information available on the
CETCO website @ http://www.cetco.com/DPG/
 Utilize the CETCO HDD Estimator:
http://www.cetco.com/DPG/HDD.aspx

93. Putting it All Together
Functions of Drilling Fluid Characteristics of HYDRAUL-EZ
a Drilling Fluid
SUPER GEL-X
Cool bit & Lubricate the hole
SUSPEND-IT
Clean the hole Viscosity
(suspend & transport cuttings) SUPER PAC
Gel Strength REL-PAC
Hold the hole open SUPER PAC XTRA-
Fluid Loss LOW
(stabilize the hole)
REL-PAC XTRA-LOW
Sand Content INSTA-VIS PLUS
Control fluid loss, loss
circulation, and frac-outs INSTA-VIS DRY
Density,
Hydrostatic ACCU-VIS
Reduce torque associated with Head PROSHOT
sticky soil
CLAY CUTTER
CLAY CUTTER DRY
Control sub-surface pressure DRILL-TERGE