INHIBITING WATER BASED MUDS
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
1
INTRODUCTION
Fluids classification :
Agip KCO
•
Calcium base
•
Salt base
•
Potassium base
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
2
CALCIUM BASED MUD • •
Lime Muds –Ca(OH)2 Gyp Muds -CaSO4.2H2O
FW/SW-LI FW/SW-GY
Calcium absorption from clays
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
3
CALCIUM BASED MUD
Reduction water hydration for sodium clay during base exchange with calcium.
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
4
CALCIUM BASED MUD
Effect of solids concentration on viscosity with calcium additions.
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
5
CALCIUM BASED MUD
Line A - Soluble calcium vs. lime concentration; Line B - Soluble calcium of 4 lb/bbl of lime added to caustic solutions.
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
6
CALCIUM BASED MUDS
Solubility of calcium vs. chlorides.
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
7
LIME BASED MUD Description and application
•
This system is used to drill in reactive shale formation, even at high temperature
•
It is a dispersed, lignosulfonate base fluid where lime is apporting source of Ca++.
•
Two basic formulations: low lime (5-8 kg/m3 – 1.75 – 2.8 ppb excess of lime) and high lime content (20 kg/m3 – 7 ppb excess of lime)
•
The tolerance to high solids is acceptable
•
It is possible to weight up to over 2.1 kg/l (17.5 ppg)
•
Low cost
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
8
LIME BASED MUDS
Limitations •
The system needs more dilution than other inhibitive systems.
•
The high value of the pH (up to 12) reduces the inhibitive action of the Ca++ due to the dispersing action.
•
At temperature over 120°C gelation problems may occur.
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
9
LIME MUD (FW/SW-LI)
Lime muds classification versus alkalinity values
Agip KCO
Low Lime
Intermediate
High Lime
PF
0.8 - 2
2-5
5 - 10
Pm
4-9
9 - 15
15 - 25
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
10
LIME MUD (FW/SW-LI) Lime Muds main additives Additive
Concentration, kg/mc
Function
Bentonite
60 - 80
Viscosity, filtrate control
Lignosulfonate
0,5- 1,5
Deflocculant
Lime Ca(OH)2
5 - 30
Soda or caustic potash
for pH 10.5 - 12.5
Inhibitor, alkalinity control pH Control
Lignite
0,5 – 1,2
Filtration Control
*(Starch)
0,6 – 1,2
Filtration Control
0.5 - 3
Filtration Control
PAC *Antifermentant treatment needed
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
11
LIME MUD (FW/SW-LI) Typical Properties of a Low and High Lime Mud Plastic Viscosit y (cPs)
Yield Point (gr/100 cm2)
Low Lime 1,20
15 - 18
3–5
0-1
0-2
5 - 10
High Lime 1,20
15 - 18
3-5
0-1
0- 2
12 - 18
Density (Kg/lt))
Agip KCO
Gels 10 sec/10 min (gr/100 cm2)
Well Area Operations Drilling Supervisors Training Course
pH
Eccess Lime (Kg/m3)
API Filtrate (cm3/3 0 min)
1-2
10.5 -12.5
3-6
6 - 12
5 - 10
12.0 -12.5
15 - 45
6 - 12
PM cc
PF cc
H2SO4
H2SO4
n/50
n/50
Drilling Muds
RPW2021A
12
LIME MUD (FW/SW-LI)
Filtrate alkalinity due to Caustic Soda additions (NaOH)
NaOH, lb/bbl
Kg/mc
PF, cm3 H2SO4 - N/50
1
2,8
1.0
2
5,6
3.0
3
7,8
5.0
4
11,3
7.0
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
13
LIME MUD (FW/SW-LI) Treatment Ranges for Lime Mud Conversions
Additive
Agip KCO
Concentration, lb/bbl Kg/mc
Soda/ Caustic potash
2–3
5–8
Lime
4–8
10 – 20
Thinning Agent
2–5
5 - 15
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
14
LIME MUD (FW/SW-LI) Lime Muds contaminants treatments Contaminants
Indicators
Treatments
Increase of solids in the mud
Increase in solids content in retort test. Increase in PV, Gels, MBT.
More dilution. Improve the solids removal. Centrifuges use.
Salt/Salt water
Chlorides, Visc.Marsh , yield point, gel 10” / 10’ , filtrate increase. PM, PF, pH decrease.
Increase density (if the level increases), to dilute with fresh water. Add fluidizing and caustic soda to control the rheology then treat with starch or PAC for the filtrate control. If salt presence is high, transform the system saturated with salt. Or replace with oil based mud.
Carbonates/CO2
MF, Gel10-min increase . PM, pH decrease. If the CO2 inlet is continuous, normal treatments with lime cause a thin solids increase (CaCO3).
Add lime for PM control and KOH for PF.control. Check solids content optimal conditions ( Low)
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
15
LIME MUD (FW/SW-LI) Contaminants
Indicators
Treatments
Low quality products
Packaging variations. Treatment quantities increasing. Mud properties anomalous state.
Shipping documents and specifications control. Organize sampling and analysis. Cooperation with the Supplier
Foam
Foam in the tanks. Trapped air . Decrease pressure pumps if possible
Add a non toxic antifoam. Detect the foaming causes and remove them
Gelation due temperature
Agip KCO
to
high Pressure peaks after round trip. Bottom cushion very viscous. High viscosity in the mud at the flow line
Well Area Operations Drilling Supervisors Training Course
Reduce Low Gravity solids. Add lignosulfonate if bottomhole temperature is <300°F (150°C). Add polymeric deflocculant for high temperature, for values higher than 150°C.
Drilling Muds
RPW2021A
16
GYPSUM MUD (FW-GY) Main Gypsum Mud additives Additives
Concentration,Kg/mc
Function
Bentonite
60 - 70
Viscosity, filtrate control
Lignosulfonate
10 - 25
Deflocculant
Gypsum
10 - 25
Inhibition, alkalinity control
Caustic Soda
pH 9.5 - 11.0
Alkalinity control,Inhib.I
Caustic Potash
pH 9,5 - 11
Inhibition
Tannin Sulphonated
5 - 10
Deflocculant
Starch
5 - 18
Filtrate Control
PAC
0.7 – 4,5
Viscosity, Filtrate control
Barite
Programmed Density
Weighting Material
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
17
GYPSUM MUD (FW-GY)
Gypsum mud typical characteristics API Filtrate (cm3/30 min)
Density (Kg/lt)
Plastic Viscosity (cPs)
Yield Point (gr 100 cm2)
Gels 10 sec/10 min (gr100 cm2
Exceeding Gypsum (Kg/mc)
PF
pH
1,08
12 - 15
3– 5
1-2
4- 6
30- 40
0.2 - 2.7
9.5 - 11.0
600-1200
8 - 12
1,44
15 - 20
1- 7,5
0 -2,5
1- 7,5
30- 40
2-3
11.0 12.0
200-600
6-8
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
Ca++ (mg/L)
RPW2021A
18
GYPSUM MUD (FW-GY) Advantages/Disadvantages of Gyp Mud Advantages
Disadvantages
Low Viscosity and Gel strengths.
High pressure peaks (pressure loss) during conversion can cause “Hole Damages”.
Solids content tolerance.
Gelation phenomena with temperature higher than 300°F (150°c)
Weighting facility up to 2,16 Kg/lt. It inhibits clay sands and clays hydration. It resists to contaminations: Cement, Anhydrite and Salt (Up to50000mg/lt Cl-) It stabilizes the hole (regular section)
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
19
GYPSUM MUD (FW-GY) Contaminant Treating of Gyp Muds Contaminant High content of gravity solid
Indicators low
Salt/Salt Water
Carbonates/CO2 problem for lime muds.)
Agip KCO
(no
Treatments
Values at Mud Still, PV,gel at 10-minute , MBT.
Higher dilution, improve solids discard, use the centrifuges to treat the mud
Chlorides, viscosity, yield point, Gel 10”/10’ and filtrate increase. PM, PF, pH decrease
Increase the density if water flows from well. Treat with deflocculant and soda for rheology, starch or PAC for the filtrate. Transform the mud saturated with salt or oil base mud, in presence of salt dome.
Increase MF,Gel 10-min . PM, pH decrease. To control the CO2 need Ca (OH)2 treatment- that causes thin solids increase (CaCO3)
Add lime for PM and KOH for PF control. Keep solids control to the lowest possible level
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
20
GYPSUM MUD (FW-GY) Contaminant
Indicators
Treatments
Low quality products
Different packing, minor product performance. Mud characteristics not conform to the programmed values
Supplier documents. Sample and analyse. Collaborate with the Supplier and detect the trouble (do not change the supplier)
Foam
Foam in the tanks, air incorporated Treat with non toxic antifoam. in the mud, irregular pump pressure Identify the foam origin and operate.
Temperature gelation
Agip KCO
Pressure peaks at the pump (when the circulation restarts) after the round trip. Very viscous bottom cushions and high viscosity mud at the flow line
Well Area Operations Drilling Supervisors Training Course
Reduce low gravity solids, treat with lignosulfonate if BHT<300°F Treat with polymeric deflocculant with temperature higher than 300°F (150°C).
Drilling Muds
RPW2021A
21
SALT BASED MUDS
•
Mainly used to drill salt formations. Sometimes also used as inhibitive fluid in shale formations. It’s better when saturated
•
It is possible to use the system with suitable viscosity as work-over fluid
•
Lower cost referred to other competitor system
•
The basic product, (NaCl) is readily available
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
22
SALT BASED MUDS
Agip KCO
Salt Muds Classification
NaCl, mg/L
Salt saturated (NaCl)
315,000
Sea Water
25,000-35,000
Brackish Water
10,000-25,000
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
23
SALT BASED MUDS Salt saturated mud The pH control, changes widely and it is not a fundamental function pf the system. Many low Solids Mud with starch are formulated without caustic soda. In other areas the pH=11 – 11,5 is maintained, with NaOH addition. The S.S. mud, needs a major quantity of soda to keep a high PH. To maintain the pH = 11 – 11,5 gives several advantages : •
More efficient fluidizing
•
Reduced Corrosion
•
To reduce the filtrate, minor quantities of additives, are needed when the solubility from Ca++ and Mg++ is reduced.
•
Minimizes foaming tendency
•
Mud is generally more stable
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
24
SALT BASED MUDS Principal Additives of Salt Saturated Muds Additive
Concentration, Kg/mc
Function
Pre-hydrated Bentonite
30 - 70
Viscosity, Filtrate control
STARCH
10 - 20
Filtrate control
Caustic Soda
pH 9.0 - 11.0
Soda Ash (Na2CO3) PAC
Salt (NaCl)
Agip KCO
3-8
Ca++ Removal
0.7 - 4.2
Filtrate control, Viscosity Inhibition, Weighting
350
Well Area Operations Drilling Supervisors Training Course
Alkalinity control
Drilling Muds
RPW2021A
25
SALT BASED MUDS Typical Properties of Salt Saturated Muds
Density (Kg/lt) (ppg)
Plastic Viscosity (cPs)
Yield Point (gr/100 cm2) (lbs/100 ft2)
1.26 – 10.5
8 - 12
4-6/8-12
2-4/4-8
6-8/12-16
8 - 12
2.1-17.5
45-50
10-14/20-28
3-5/6-10
15-18/30-36
6-8
Agip KCO
Gels 10 sec/10min (gr/100cm2) (lbs/100 ft2)
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
API Filtrate (cm3/30 min)
RPW2021A
pH
8.59. 5
26
SALT BASED MUDS Advantages/Disadvantages of Saturated salt Muds Advantages
Disadvantages
Inhibiting (clays)
Filtrate control more difficult (starches or polymers efficiency)
Contaminations resistant: cement, anhydrite, salt and salt water.
Foaming and air entrap tendence
Low solids content. The dissolved salt helps density.
Corrosive, with salinity lower than saturation
Good hole cleaning (cuttings transport).
Temperature max limit = 280°F (140°C).
Stabilizing action on-open hole.
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
27
SALT BASED MUDS
Contaminant Treating of Saturated Salt Muds Contaminant
High Solid Contents
Low Quality Products
Agip KCO
Indicators
Treatment
PV, YP, gels , viscosity, filtrate, MBT. Increases. Foaming, trapped air
Dilution. Use the centrifuges and improve solids removal
Lower material efficiency. Product Package change
Ask for data regarding package process. Sample and carry out efficiency test + complete analysis
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
28
SALT BASED MUDS Sea Water Muds
Principal Additives of Saltwater Muds Additives
Concentration, Kg/mc
Function
Pre-hydrated Bentonite
40 - 70
Control Filtrate, Viscosity
Soda /Caustic potash
1,5 – 4,5
Starch
9 – 18
Filtrate Control
PAC
1,5 – 3.0
Filtrate Control
Lignosulfonate
9 – 18
Deflocculant
Lignite
5 - 10
Filtr. Control HP/HT
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
Control alkalinity/corrosion
RPW2021A
29
SALT BASED MUDS Sea Water Based Mud Advantages and Disadvantages
Advantages/Disadvantages of Saltwater Muds Advantages
Disadvantages
Inhibiting Material (clay layer)
Increasing of the quantity of additives used because of lower performance
Reduced fresh water consumptions.
Difficult to control filtration
Contaminants negative aspects; anhydrite, cement, salt and layer salt water
Pre-hydrated bentonite is required
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
30
SALT BASED MUDS Problems and Contaminations – Sea Water Muds Contaminations are more evident compared to S.S. mud. The sea water mud has higher quantities of additives. The salinity and hardness range affect the fluid performances Contaminant Treating of Saltwater Muds Contaminants
Indicators
Treatments
High Solid Contents
Increase % solids , PV, YP, gel, viscous mud cushions from bottomhole to surface
Salt /Salt Water
Increase density in case of inlet from formation water. YP, Filtrate and chlorides Treat with fluidizing to control increase. the rheology. Control filtrated In case of formation water, loss of with starch or Pac. Add density and PH decrease caustic soda to repristinate correct PH
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Massive dilutions, use of centrifuges and other equipment to remove solids.
Drilling Muds
RPW2021A
31
SALT BASED MUDS Contaminant Treating of Saltwater Muds Contaminants
Indicators
Treatments
Increase the quantity of treating. Different packaging
Know the production methodology. Sample and analyse the product
Cement
PV, YP, pH, PM, PF, gel and filtrate increase. Ca++ increase.
Add sodium bicarbonate or SAPP. Dilute with water (fresh or sea). Treat with fluidizing, starch or PAC (Rheology and filtrate control)
Carbonates
Increase gels, YP. Rheology not correct. Bottom cushion with high viscosity.
Increase pH at 10.7 or more to convert the bicarbonate in carbonate, treat with lime or gypsum to remove carbonates.
Low quality product
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
32
SALT BASED MUDS
Brackish-Water Muds In many areas, for economical reasons or for fresh water shortage, Brackish waters are often used to prepare mud. They have a salinity (NaCl) between 10000 and 15000 mg/lt. These areas are near the sea a/o in marshy zones.
Main additives (Brackish-Water Muds) They are essentially the same additives of the sea water mud; they have lower salinity. Because of brackish-water (bacterium and organic products), the use of chemicals is always high to reduce the bacterium degradation
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
33
SALT BASED MUDS
Principal Additives of Brackish Water Muds
Additives
Concentration, Kg/mc
Pre-hydrated bentonite
40 - 70
Soda / Caustic potash
1,5 – 4,5
Function Viscosity and Filtrate, Control Pf corrosion control
Starch
9 – 18
Filtrate control
PAC
1,5 – 3
Filtrate control
Lignosulfonate
9 – 18
Deflocculant
Lignite
6 - 10
HP/HT Filtrate control.
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
34
SALT BASED MUDS Typical Properties of Brackish-Water Muds
Yield Gels Point Plastic 10 sec/10min Density Viscosity (gr/100 (gr/100cm2) (Kg/lt) 2 cm ) (cPs) Lbs/100ft2 2 lbs/100ft
pH
Chlorides mg/L
API Filtrate (cm3/30 min)
1,10
16
4–5 8 – 10
1–2 2–4
2–5 4-10
10.5 –11
10,000 -25,000
6 - 10
1,45
22
6–8 12 – 16
2–3 4–6
3–5 6 –10
10.5 - 11 10,000 -25,000
6-8
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
35
SALT BASED MUDS
Advantages/Disadvantages of Brackish-WaterMuds
Advantages
Give moderate inhibition degree
Reduced fresh water consumption (Brackish water is used).
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Disadvantages
Use of chemical products increasing, (because of minor efficiency)
Pre-hydrated bentonite (in fresh water) is required
Drilling Muds
RPW2021A
36
SALT BASED MUDS
Problems and Muds Contaminations - Brackish-Water Muds Contaminations and problems are the same of the sea water system
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
37
POTASSIUM MUDS – (FW/SW-KC)
There are three potassium based muds:
Agip KCO
•
KCl-Polimers (KCl-PHPA)
•
KOH-Lignite
•
KOH-Lime
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
38
POTASSIUM MUDS – (FW/SW-KC) KCl-Polimers (KCl-PHPA) =FW/SW-KC
Principal Additives of KCL-Polymer Muds Additive
Concentration,Kg/mc
Function
Pre-hydrated Bentonite
15 - 45
Control Visc. and filtrate
Potassium Chloride
15 - 170
Inhibiting source K+
Caustic Potash
0.7 – 2
Gives ions K+ and controls alkalinity
Starch
8 – 16
Filtrate control
PAC
1.5 – 3
Filtrate control
Lignosolfonate
8 - 16-
Fluidifizing
Lignite
5 - 10
Filtrate control HP/HT
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
39
POTASSIUM MUDS – (FW/SW-KC) Typical Properties of KCL-Polymer Muds Density (Kg/lt)
Plastic Viscosity (cPs)
Yield Point (gr/100cm2)
1,10-1,20
12 – 25
5 – 10
3–4
4 - 10
10 - 12
1,20–1,32
15 – 25
5 – 10
1–4
4–8
5–8
1,32–1,44
15 – 35
3–8
1–4
2–8
3–6
1,44–1,68
20 – 40
3–8
1–3
2–8
2–4
1,68–1,92
25 - 45
3–8
1–3
2–6
2–4
1,92-2,16
30 - 45
3-4
1-3
2-5
1-3
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Gels 10 sec/10min (gr/100cm2)
Drilling Muds
API Filtrate (cm3/30 min)
RPW2021A
40
POTASSIUM MUDS – (FW/SW-KC) Typical Material Concentrations for KCl-Polymer Muds CONCENTRATION , Kg/mc Density KG/Lt
Water (lt)
Bentonite
Caustic Potash
KCl
Xanthan
Gum LV
PAC
Reg Starch
Barite
PHPA Active
1,20
937
40
0,7
100
2,8
--
4
12
0
2,8
1,44
812
40
0,7
90
2,8
--
4
12
350
2,8
1,68
750
36
1,4
85
2,2
4
--
12
670
2,8
1,92
718
28
1,4
80
1,5
3
--
9
830
2,8
2,16
687
20
1,4
75
1,5
3
--
9
1080
2,8
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
41
POTASSIUM MUDS – (FW/SW-KC)
Contaminant Treating of Brackish-Water Muds Contaminants
Indicators
Treatments
Increase: solids, PV, YP, gels. Viscous bottom cushions after the round trip
Large dilutions. Use centrifuges and improve the efficiency of solids control equipment .
Cement
Increase: PM, PF, pH, YP, Filtrate, and Marsh viscosity
Minor dilution. To treat with bicarbonate a/o SAPP. When rheology becomes stable treat with starch or PAC to reduce filtrate.
Low-quality products
The product packaging changes. Higher quantity of the product used
Product documentation Supplier quality history. Sample and analyse.
High % solids
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
42
POTASSIUM MUDS – (FW/SW-KC)
Contaminant Treating of Brackish-Water Muds Contaminants
Indicators
Treatments
Salt Water/salt
Increase:Chlorides, Marsh viscosity, YP, Gels, Filtrate.
Increase density if the well flows salt water. Convert in a mud saturated with salt
Gypsum/ Anhydrite
Increase: Ca++, YP, gels, filtrate. Decrease: pH, PM, PF.
Treat with SAPP, soda ash or potassium carbonate. When necessary, treat with fluidizing
Carbonates
Increase: MF, YP, gels. Decrease: pH, PM, PF. Viscous bottom cushions and also high viscosity to the mud comes from flow Line
Carry out GGT analysis. Raise pH>10,7 with KOH. Add lime and guarantee the value of the solids within acceptable limits.
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
43
POTASSIUM MUDS – (FW/SW-KC) KOH-Lignite (system)
Principal Additives of KOH-Lignite Muds Additives
Concentrations, kg/mc
Functions
Bentonite
45 - 75
Viscosity and filtrate control.
Lignite
15 - 23
Fluidizing and filtrate control
Caustic Potash PAC/CMC Barite
Agip KCO
Alkalinity and K+ control
1,5 – 4,5 1,5 – 3
Viscosity and filtrate control
Add the amount needed to reach a programmed value of density
Well Area Operations Drilling Supervisors Training Course
Weighting material
Drilling Muds
RPW2021A
44
POTASSIUM MUDS – (FW/SW-KC)
Typical Properties of KOH-Lignite Muds
Density Kg/l
Plastic Viscosity (cPs)
Yield Point (gr/100 cm2)
1,08
12 - 14
4-6
1–2
1,44
16 - 20
5–9
1-3
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Gels 10 sec/10min (gr/100cm2)
pH
API Filtrate (cm3/30 min)
2–4
10.0
10 - 12
3-5
10.0
6–8
Drilling Muds
RPW2021A
45
POTASSIUM MUDS – (FW/SW-KC) Advantages/Disadvantages of KOH-Lignite Muds Advantages
Disadvantages
Inhibiting system
Contaminants intolerance such as, salt, Ca++, cement, carbonates and anhydrite
Economical. Control filtrate with lignite and bentonite
Clay solids (L.G.) must be kept very low
Simple. Limitated product numbers Thermic stability up to 400°F(240°C).
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
46
POTASSIUM MUDS – (FW/SW-KC) Contaminant Treating of KOH-Lignite Muds Contaminant High solid contents
Cement
Low quality product
Agip KCO
Indicators
Treatments
Increases:solids, PV, YP, and gels. Viscous bottom cushions. High additives consumption
Dilute and use centrifuge, improve solids removal.
Increases PM, PF, pH, YP, gel and filtrate.
Deflocculate with bicarbonate a/o SAPP. Dilute with water. Increase PF to limit the Ca++. Fluidify to reduce rheology. Transform in FW-LI if necessary.
Increases treatment quantity. (consumptions)
Production documents. Make sample and analysis. Pilot test with good quality materials. (comparison)
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
47
POTASSIUM MUDS – (FW/SW-KC) Contaminant Treating of KOH-Lignite Muds Contaminant
Salt Water/Salt
Anhydrite/Gypsum
Agip KCO
Indicators
Treatments
Well lows, viscosity, chlorides, YP, filtrate increases. Density decreases
Increase density, (Kill Flow) Treat with water and fluidizing for rheology control, then PAC/CMC for filtrate. Convert in mud SS when there’s much salt.
Change drilling speed (metres/hour) . Increases: Ca++ , Decrease: pH, PM, PF.
Increase pH with KOH to reduce Ca++. Treat with bicarbonate and soda Ash. Add fluidizing or convert in FWGY.
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
48
POTASSIUM MUDS – (FW/SW-KC)
Contaminant Treating of KOH-Lignite Muds Contaminant
Indicators
Treatments
Carbonates
Increase: MF, YP, gels. False rheological results. Decreases: pH, PM, PF. Viscous bottom cushions after round trips, high viscosity mud at the Flow line
Carry out GGT analysis. Raise the pH over 10,7 with KOH. Add lime a/o gypsum to settle carbonates (avoid overtreatments). Keep drilled solids contents (L.G.) within recommended limits
Gelation for High temperature
High pressure peaks at the pump to restart circulation after breaks. Bottomhole viscous cushions after trips.
Reduce L.G: E MBT solids. Use thermostable fluidizing. Analysis for carbonate contamination (GGT).
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
49
POTASSIUM MUDS – (FW/SW-KC) KOH-Lime Mud KOH-Lime Muds main additives Additives
Concentration,Kg/mc
Function
Bentonite
45 - 75
Control viscosity and filtrate
Lignosulfonate
12 - 24
Fluidizing and controls filtrate
Lime
12 - 30
High pH and Ca++ source
Caustic potash (KOH)
6-9
Pf control and K+ source
Tannin sulfonate
6-9
Deflocculant
PAC /Starch
3-6
Filtrate control
Barite
Agip KCO
Add the amount needed to reach a programmed value of density Well Area Operations Drilling Supervisors Training Course
Weighting material
Drilling Muds
RPW2021A
50
POTASSIUM MUDS– (FW/SW-KC)
Typical Properties of KOH-Lime Muds
Gels 10 sec/10.min (gr/100cm2)
API Filtrate (cm3/30 min)
Density (Kg/l)
Plastic Visc. (cPs)
Yield Point (gr/100 m2)
1,08
10 - 12
4–6
2–3
3-5
6-9
1,44
16 - 18
8 – 10
2-3
3–6
4-6
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
51
POTASSIUM MUDS – (FW/SW-KC)
Advantages/Disadvantages of KOH-Lime Muds Advantages
Disadvantages
Inhibiting (Ca++ e K+)
Non dispersed fluid
Solids Tolerance
Decreasing ROP in hard formation
Contaminations resistance : Anhydride, Cement, Carbonates and salt.
Complex, many additives Gelation at high temperature Bentonite must be pre-hydrated
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
52
POTASSIUM MUDS – (FW/SW-KC)
Contaminant Treating of KOH-Lime Muds Contaminants
Indicators
Treatments Strong dilution, use centrifuge and improve solids removal.
High solid contents
Increase: % solids, PV, YP, Gel 10’-
Salt and salt water
Increase Kill Flow denisty. Dilute with fresh water. Treat with fluidizing and KOH for Increase: Chlorides, Viscosity, YP, rheology and then PAC or gel and filtrate. Decreases: PM, PF, starch for the filtrate. With pH, and density (salt water). large quantities of salt, convert it in saturated salt or replace with oil base mud.
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
53
POTASSIUM MUDS – (FW/SW-KC)
Contaminant
Carbonates / CO2
Low quality products
Agip KCO
Contaminant Treating of KOH-Lime Muds Indicators Treatments Increase: MF, gels10’, rheology difficult to control. Decreases : Pm,PH
Add Ca(OH)2 for the PM e and KOH for PF.. Check clay solids at the planned range lower limit.
Package product changes. Product quantity increasing, to obtain the same results. Muds characteristics not reliable
Supplier documents on production mehtods and quality control. Sample and analyse through comparison with standard products as well.
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
54
POTASSIUM MUDS – (FW/SW-KC)
Contaminant Treating of KOH-Lime Muds Contaminant
Indicators
Treatments
Temperature Gelation
Viscous bottom cushion after round trip. Viscous mud at the flow line (not at the sump pit). Pressure peaks at the pump after a break.
Reduce L.G. solids. Increase lignosulfonate concentration if the temperature is lower than 160°C. If the temperature is higher, use high temperature deflocculant.
Foaming
Presence of foam to the tank and shaker The mud incorporates/absorbs air, pump pressure drop.
Treat with non toxic anti-foam. Detect the cause of the trouble and remove it.
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
55
POLYMERS FLUIDS
Low Solids PAC/CMC Muds: Main Additives Materials
Concentration Kg/mc
Bentonite
Viscosity and Filtrate control
15 - 30
Caustic Soda
Function
pH 9.0 – 9.5
Alkalinity
Ash Soda
0.75 – 1.5
Calcium removal
PAC/CMC Regular
1.5 – 4.5
Filtrate control
Barite
Agip KCO
Add the amount needed to reach a programmed value of density
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
Weighting material
RPW2021A
56
POLYMERS FLUIDS
Typical Properties of Low-Solids PAC/CMC Muds
Density (Kg/lt)
Plastic Viscosity (cPs)
Yield Point (gr/10 0 cm2)
1,08
4-6
4-6
Gels 10 sec/10min (gr/100cm2)
2-4
3-5
Chlorides mg/L
API Filtrate (cm3/30 min)
< 2000
10 – 12
pH
Hardnes s (mg/L)
< 200
9.0 – 9.5
< 200
9.0 – 9,5
6-8 1,44
8 - 10
Agip KCO
5-8
3-6
5-8
Well Area Operations Drilling Supervisors Training Course
< 2000
Drilling Muds
RPW2021A
57
POLYMERS FLUIDS Low Solids PHPA Muds (polyacrilamide partially hydrated)
Principal Additives of Low Solids PHPA Muds Materials
Concentration Kg/lt
Bentonite
Filtrate and Viscosity Control
3 - 40
Soda /Caustic Potash
pH 9,0 – 9,5
PHPA
Function
Alkalinity Control Solids encapsulation, Borehole stability, Viscosity control
2,85
SPA
0,75 – 1,5
Filtrate control
Ash Soda
0,75 – 2,15
To settle ions Ca++
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
58
POLYMERS FLUIDS
Typical Properties of Low-Solids PHPA Muds
Density (Kg/lt)
Plastic Viscosity (cPs)
Yield Point (gr/100 cm2)
1,08
4–6
5–7
2–4
3–5
10 - 12
1,44
8 - 10
6 – 10
4-6
5–8
6–8
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Gels 10 sec/10min (gr/100cm2)
Drilling Muds
API Filtrate (cm3/30 min)
RPW2021A
59
POLYMERS FLUIDS Advantages/Disadvantages of Non-Dispersed Polymer Muds Advantages
Disadvantages
High ROP (m/hour) in hard formations
Limited use
Pressure drop low values/ ECD
Polymers absorption on clays is irreversible
Good borehole cleaning (Transport Capacity)
Low stabilit at temperatures.
Easy maintenance
Solids increase is not tolerated.
Easily convertible in a deflocculated/dispersed system
They need higher dilutions compared to the deflocculate system
It doesn’t disperse solids (inhibited system).
Filtrate control is expensive More corrosive than deflocculate system. Contaminants sensible. Carbonates contamination difficult to be treated Weighting difficulty Not very inhibiting.
Agip KCO
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
60
POLYMERS FLUIDS Contaminant Treating of Non-Dispersed Polymer Muds Contaminant
High SolidContents
Cement
Agip KCO
Indicators
Treatment
Increases: solids %, PV, YP, gels, MBT. Viscous bottom cushions after round trip. High viscosity at the flow Line.
Higher dilution use the centrifuges To improve solids control
Marsh viscosity, pH, PM, PF, gels, filtrate increasing
Control (Ca++) contamination with bicarbonate a/o SAPP or Citric Acid Dilute with fresh water. Increase PF in order to limit the Ca++ solubility. Deflocculant could be necessary or convert mud into lime
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
61
POLYMERS FLUIDS
Contaminant Treating of Non-Dispersed Polymer Muds Contaminant
Salt water/Salt
Gypsum/Anhydrite
Agip KCO
Indicators
Treatment
Well flowing. Increases: Marsh viscosity, YP, Gels, Filtrate. Surface water separation. Decreases: pH, PM, PF.density.
Increase density (if the well flows). Dilute with fresh water to reduce chlorides. Treat with deflocculant for PAC contamination and for the filtrate control. If necessary transform in SS. mud
Increase:Ca++, YP, Gels, and filtrate Decrease: pH, Pm, Pf.
Treat for Ca++ with ash soda, Bicarbonate a/o SAPP. Add fresh water. Deflocculant treatment can be required.
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
62
POLYMERS FLUIDS
Contaminant Treating of Non-Dispersed Polymer Muds Contaminant
Carbonates / CO2 (Not very problematic)
Low quality products
Agip KCO
Indicators
Treatment
Increases: MF, gels 10’. Rheology difficult to be checked. Dercreases: PM, pH.
Add lime for the Pm and KOH for the Pf. Keep the content of clayey solids to the lowest possible value.
Treatment quantities increasing. Type of packaging changed. Poor results with standard treatments
Documentation of the productive process from supplier. Sample and analyze. Pilot test comparison with reliable products
Well Area Operations Drilling Supervisors Training Course
Drilling Muds
RPW2021A
63