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

5/21/2010

2

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

5/21/2010

3

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.

5/21/2010

4

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?

5/21/2010

5

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?

5/21/2010

6

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

5/21/2010

7

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

5/21/2010

8

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?

5/21/2010

9

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

5/21/2010

10

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

5/21/2010

11

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

5/21/2010

12

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)

5/21/2010

13

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)

5/21/2010

14

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