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non aqueous fluid
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5/21/2010
1
SCOMI OILTOOLS
Global Research & Technology Centre/ GRTC
Training Department
Non Non Aqueous FluidsAqueous FluidsNon Non Aqueous FluidsAqueous Fluids
SCOMI OILTOOLS
What is mud
LIQUID MUDSOLIDS
WATER
OIL
SALT
CHEMICALS
BARITE
BENTONITE/GEL
DRILL SOLIDS
WATER-BASE MUD
OIL-BASE MUD
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SCOMI OILTOOLS
Why is SBM the “ultimate” drilling fluid?
Oil is non-polar i.e. there is NO reaction with
water sensitive clays & shales.
Clay & shale formations remain stable in an
SBM environment provided that the salinity of
the SBM brine phase is higher than the
salinity of the “in-situ” shale pore fluid, ie
maintain osmotic backflow from the shale to
the SBM.
“No shale hydration” problems ☺☺☺☺
SCOMI OILTOOLS
Why is SBM the “ultimate” drilling fluid?
A very stable mud system over a wide range ofdrilling challenges & environments
Very low rates of invasion / minimal pore pressurepenetration
Very high temperature stability
High ROPs Minimal bit balling & accretion
Environment but can be managed at a cost!
Cost of managing discharges
Lubricity, ie low torque & drag
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SCOMI OILTOOLS
A mixture of two immiscible liquids in which oneliquid exists in the form of very small dropletsdispersed throughout the other liquid
Cease all shear input& the fluids will separate with time depending upon
the strength of the emulsion
Shear input creates a water in oil emulsion.
The emulsifiers stabilise that emulsion
water
oil
Natural state of two immiscible liquids
Interfacialtensionseparateswater and oil
oil
water
oil
water
What is an Emulsion?
SCOMI OILTOOLS
What is an Emulsion?
To obtain small droplet of uniform size, energy orwork must be applied in the form of shear.
Sufficient shear to form a stable emulsion in mudpits and LMP (Liquid Mud Plant)
Sufficient shear can be achieved through turbulentagitation by special high-shear devices of whencirculating through the bit jets, mud gun orwith some centrifugal pumps.
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SCOMI OILTOOLS
What is an Emulsion?
SBM in the mud tank
Centrifugal Pump
Drilling Bit
Mixing Hoper
Bit Nozzle
SCOMI OILTOOLS
Emulsifiers are chemicals that stabilise aphysical emulsion once it is formed
Emulsifier molecule:
Water solubleportion
Oil soluble portion
Hydrophilic“water loving”
Lipophilic“oil loving”
What is an Emulsifier?
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SCOMI OILTOOLS
An emulsifier stands on the boundary betweenthe continuous oil phase and the water dropletor solid particle
Waterdroplet
Hydrocarbonchains
Emulsifier molecules“coat” the waterdroplet giving itan “oil wet” surface
Oil phase
How does an Emulsifier Work?
SCOMI OILTOOLS
• Emulsifier molecules preferentially “oil wet” the face of the wellbore, drill cuttings and all the steel surfaces.
• Emulsifier molecules form a semi-permeable membrane at the face of the wellbore
Drill Cutting
Emulsifier
How does an Emulsifier Work?
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SCOMI OILTOOLS
Most oil based mud use a system of two emulsifiers to ensure a stable emulsion as the mud is contaminated by cuttings and formation fluids.
Primary emulsifiers include:• Fatty acids• Rosin acids and their derivatives
Secondary emulsifiers include:• Amines• Amides• Sulphonic acids, alcohols and related co-polymers
Secondary emulsifiers act to preferentially oil wet drill solids and barite. They also act to improve emulsion stability, particularly at high temperature
Primary and Secondary Emulsifier
SCOMI OILTOOLS
Fatty acid emulsifiers:
• Tall oils - complex mixtures of oxygenated hydrocarbons – anionic ( -)
• Tall oils require activation by a metal ion usually calcium derived from LIME to be saponifyed i.e. Fatty acid Calcium Soap
Imidazoline emulsifiers:
• Cationic (+) and anionic ( -)
• Anionic imidazolines require LIME for activation
• Thermal stability generally inferior
Different types of emulsifiers
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SCOMI OILTOOLS
Polyamide / Polyester emulsifiers:
• Non-ionic emulsifiers do not require LIME for activation
• Highly resistant to salt contamination
• High thermal stability
• Good oil wetting capability
Different types of emulsifiers
SCOMI OILTOOLS
HLB values (Hydrophile - Lipophile Balance)
Stabilisation of water in oil emulsion
(typically non-ionic)
Preferential oil wetting of solidsie wetting agents / thinners
(typically ionic)
Stabilisation of oil in water emulsion
3 4 5 6 7 8 9 10 11 12 13
Hydrophilicmolecule
Lipophilicmodule
Ratio by weight of the hydrophilicmolecule to the lipophilic molecule rises
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SCOMI OILTOOLS
What should a GOOD emulsifier package achieve?
• Establish a stable emulsion of water in oil
• Maintain a stable water in oil emulsion while tripping, logging and running casing, i.e. minimal coalescing of water droplets under static conditions leading an increase in fluid loss (i.e. invasion) & consequently filter cake thickness.
• Preferentially oil wet ALL particulate matter i.e. barite & drill solids.
SCOMI OILTOOLS
• Preferentially oil wet steel surfaces.
• Achieve good “oil wetting” characteristics without a significant impact on “low shear” rheology ie. thinning effect.
• Remain stable at anticipated bottom hole temperatures.
What should a GOOD emulsifier package achieve?
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SCOMI OILTOOLS
Impact of a stable vs unstable water-in-oil emulsion
Lower fluid loss properties Higher fluid loss properties
Dynamic conditions i.e. circulating mud system
Stable emulsion Unstable emulsion
SCOMI OILTOOLS
Lower static fluid loss
properties over short
term
Higher static fluid loss
properties over short
term
Static conditions, i.e. tripping, running casing & sustained logging programs
Impact of not sustaining a stable water-in-oil emulsion under static conditions
Stable emulsion Unstable emulsion
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SCOMI OILTOOLS
The role of organophilic clays in SBM:
• Primary viscosifier for synthetic oil based muds
• Untreated bentonitic clays will neither disperse noryield in SBM without first being treated withquaternary amine.
Organophillic Clays
SCOMI OILTOOLS
Role of Lime in SBM
• Saponification reaction with fatty acid type emulsifiers
• Converting some additives into oil soluble forms
• To maintain alkaline environment environment. This isespecially relevant to dealing with H2S
Role of black powders in SBM
Lignites will not disperse in SBM without first being reactedwith Quaternary Amines
• Minimise filtrate invasion
• Improve filter cake quality
The Role of Amine treated lignite and Lime
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SCOMI OILTOOLS
Brine is present in SBM to reduce the volume of oil and therefore the cost & to hydrate the organophilic clay viscosifier
Semi permeable membrane (skin) of emulsifier molecules formed on the face of the well bore does not impede the osmotic backflow of pore fluid from the shale to the higher salinity SBM brine phase.
Result = shale dehydration. Caution: Taken to extremes can cause bore hole collapse.
Shale SBM brine phase
“In situ” shale pore water
Shale / pore water
salinity lower
Dilute solution Concentrated solution
Brine phase
salinity higher
The Role of Salt (CaCl2, etc) in SBM
SCOMI OILTOOLS
Monitoring SBM Salinity
The only way to successfully monitor the salinity of a SBM in the field is to examine the condition of the cuttings coming over the shale shaker screens.
• Soft sticky cuttings indicate an immediate increase in the water phase salinity
• Very dry, dehydrated cuttings indicate an immediate decrease in the water phase salinity.
• Cuttings should be firm / discrete & travel smoothly over the shale shaker screens
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SCOMI OILTOOLS
Components of an Invert Emulsion Mud
1. Base oil or synthetic fluid2. Water
• Possibly with salts3. Emulsifiers
• Primary• Secondary
4. Wetting Agents5. Viscosifiers6. Fluid Loss Control Additives7. Weight Material8. Special Additives (Rheology modifiers, etc)
SCOMI OILTOOLS
Base Fluids
• OILS
• Diesel
• Low Toxic Mineral Oil Base Fluids
• LTOM– Escaid 110
• Synthetic Base Fluids• IO Internal Olefin C16 – C18
• LAO Linear Alpha Olefin • IP Iso Paraffin• LP Linear Paraffin• ESTER Ester derived from Palm Oil / Olefin etc.,• Blends of Ester & Synthetic (for deepwater)
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SCOMI OILTOOLS
Low toxicity mineral oil :
A refined mineral oil with it’s intrinsic toxicity reduced by the removal of aromaticcompounds, both mono and polynuclear aromatics.
Olefin
Any of the saturated aliphatic [as opposed to aromatic] hydrocarbons of themethane series, i.e. Alkanes –such as methane, ethane, propane, pentane,hexane, etc.
Olefin – A family of unsaturated, chemically active hydrocarbons with onecarbon-carbon double bond; includes ethylene and propylene & alkene.
Paraffin
EstersEsters occur in nature as lipids. Lipids are naturally occurring organic moleculesisolated from cells and tissues by extraction with nonpolar organic solvents. Mostcommon lipids are animal fats and vegetable oils.
Base oils currently used to build oil based mud
SCOMI OILTOOLS
Typical Base Oil & Properties
Flash Point Pour Point Aniline Point
oC
oC
oC
Sarapar 147 0.773 2.5 mm2/s 120 12 93
Saraline 98V 0.810 2.5 - 4.0 mm2/s >85 0 N/A
Saraline 185V 0.780 2.8 mm2/s 85 -30 +75
Saraline 200 0.783 3.0 -4.0 cSt 95 -18 88
Escaid 2000 0.811 3.12 cSt 128 0 87
Escaid 110 0.794 1.64 cSt 83 N/A 77
EDC95-11 0.815 3.5 cSt 118 -27 91
HDF 2000HF 0.813 3.5 cSt 117 -31 90
HDF 2000 0.808 3.3 cSt 105 -22 89
IO (16/18) 0.780 3.09 cSt 137 -24 81
LAO (16/18) 0.780 3.08 cSt 146 0 81
AQUAMUL 0.840 3.5 cSt > 135 <-60 N/A
LVT 200 0.800 2.0 - 3.0 cSt 100 -18 169
Ether 0.830 6.0 cSt 166 -10 40
Diesel 0.865 2.0 cSt 37.8 -17.7 66
Fluids
Kinematic
Viscosity (@
40oC)
Density
(SG)
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SCOMI OILTOOLS
Scomi Oiltools NAF System
CONFI-DRILL Invert Emulsion System for IO, LAO,
LMO, IP and LP
CONFI-DENSE HTHP Invert Emulsion System
CONFI-DEEP Deepwater Invert Emulsion System
EXTRA VERT Ester based NAF
OPTA-VERT NAF Drill-In Fluid
SCOMI OILTOOLS
Scomi Oiltools NAF Products
CONFI-MUL Emulsifier
CONFI-GEL Organophilic Bentonite
CONFI-WET Oil-wetting agent
CONFI-TROL Fluids loss control agent
CONFI-TEC Economical Primary Emulsifier
CONFI-THIN Thinner for SBM
CONFI-MOD Low-end rheology viscosifier