Post on 23-Jun-2015
description
transcript
4. Drilling Fluids (Mud)
Habiburrohman abdullah
Mud
• Properties and measurements
• Types:
- Pneumatic-air, gas, mist. Foam
- Water based
- Oil based
What is a drilling fluid?
Drilling fluid is any fluid that is used in a drilling operation in which that fluid is circulated or pumped from the surface, down the drill string, through the bit and back to the surface via the annulus.
– A Fluid Can Either Be a Gas or a Liquid.• Air is a gaseous fluid.
• Foam is an aerated liquid.• Water is a liquid fluid.
• Oil is a liquid fluid. (Diesel and Mineral oils)• Synthetic Polymeric Liquids are also used as drilling fluids. (Olefins and
Esters)
Functions of Drilling Fluids
1. Remove cuttings from the well. 2. Control formation pressure.3. Suspend and release cuttings. 4. Seal permeable formations.5. Maintain well bore stability.6. Minimize reservoir damage.
7. Cool, lubricate and support the bit and drilling assembly.
8. Transmit hydraulic energy to tools and bit.
9. Ensure adequate formation evaluation.
10. Control corrosion.
11. Facilitate cementing and completion.
12. Minimize impact on environment.
13. Prevent gas hydrate formation.
Choice of Drilling Fluid
• Performance – choose the fluid that does the job
– Inhibition
– Rheology
– Fluid Loss
– Temperature
• Environment – damage to the environment should be avoided
• Safety – To all personnel
• Cost – Average DF Costs = 10% well costs
• Availability – Check first
• Storage – Can be easily forgotten
Choice of Drilling Fluid
Lubricity
Tolerance to Contaminants
Environmental Footprint
Drilling Performance
Corrosion Inhibition
Thermal Stability
Shale Inhibition
Formation Protection
Oil Based MudEster Based MudLAO SystemKCl/PHPAKCl/Glycol System
Operator’s Objectives
Environmental compliance
Lower cost / higher efficiency - focus on shale control
Better productivity - focus on formation damage
Mud Circulating System
Common Types of Drilling Fluids
Water Based Drilling Fluids
Invert Emulsion Drilling Fluids (NADF)
Oil Base Muds
Synthetic Base Muds
Water Base Drilling Fluids
COMPO NENTS O F W ATER BASE MUDS
SolubleChem icals
FreshWater
ChloridesCalcium
Magnesium
SeaWater
ChloridesCalcium
Potassium
Salt EnhancedWater
W ater
Com m ercial C laysPolym ers
Chem icals
Low Gravity
W eight Material
H igh Gravity
NecessarySolids
Sm ectite C laysContam inants
Reactive
MISC.
Inert
DrilledSolids
Solids
Oil/Synthetic Base Drilling Fluids
CO MPO NENTS O F NO N - AQ UEO US FLUIDS
SurfactantsR heo. M odifersL iq . Polymers
Thinners
O il SolubleL iquid A dditives
D iesel O ilM inera l O il
R efined LP 's
Oil BaseFluid
O lefinsEsters
Synthetic LP 's
SyntheticFluid
ExternalPhase
C a2+ and O H -from L im e
G lycolsC a2+ and M g2+
AcetatesN itra tes
N on-C hlorideA ctiv ity R educers
25% - 30%
CaCl2Activity =
0.747 - 0 .637
InternalPhase
O rganophyllic C layW eight Materia l
Salt (C aC l2)FLC Additives
NecessarySolids
MISC .
DrilledSolids
Solids
FLUIDS Technology DevelopmentFLUIDS Technology Development
Drilling Fluid Properties
The tests and reporting procedures for drilling fluids are documented in the API Specification 13 B.
Physical properties
• Density or mud weight – ppg or SG.
• Marsh Funnel Viscosity – seconds per quart.
• Plastic viscosity – centipoise.
• Yield point – lbs per 100 sq. ft or as pascal
• Gels – centipoise, 10 seconds & 10 minutes.
• Fluid loss or filtration rate - mls per 30 mins.
• HTHP filtration rate - mls per 30 mins.
Chemical properties
• pH
• Alkalinities, filtrate. –Pf/Mf.
• Alkalinity, mud. - Pm
• Total hardness – calcium and magnesium ions.
• Calcium concentration – calcium ion.
• Total chloride ion.
Solids analysis • % volume, oil.
• % volume, water.
• % volume, solids.
• % volume, solids corrected.
• Average specific gravity solids – as S.G.
• %, low gravity solids.
• %, high gravity solids.
• % sand content.
• % clay.
• MBT (CEC) gives the amount of clay in the mud expressed as ppb, equivalent clay.
Other analyses depending on mud
type.• %, KCl concentration. (KCl PHPA)
• Potassium chloride, ppb. (KCl PHPA)
• Excess polymer, ppb. (KCl PHPA)
• %, glycol. (KCl PHPA)
• Excess lime, ppb. (Lime muds)
• Oil / Water ratio. (SBM, OBM)
• Electrical stability, volts. (SBM, OBM)
END