MUD SYSTEMS, MUD DATA
&
HYDRAULICS
I- MUD SYSTEMS
A.
B.
C.
D.
Fresh Water Muds
Inhibited Muds
Water Base Emulsion
Oil Base & Synthetic Muds
A- Fresh water Base Mud
((is that mud with water as its continuous
phase.))
1- Spud mud.
2- Low solids mud.
3- Lignite mud.
4- Lignite surfactant systems.
5- Lignosulfonate mud.
6- Lignite/ Lignosulfonate mud.
B- Inhibited Mud
((Is that mud which repress the hydration
and subsequent dispersion of clay into
the mud)).
1- Lime mud.
2- Low lime mud.
3- Gypsum mud.
4- Sea water mud.
5- Saturated salt water mud.
6- K-plus mud.
B- Inhibited Mud (continue)
Advantages over conventional water base mud:1- will Telerate a higher concentration of clays before
developing high viscosity,
2- less drastic effects by contaminants such as cement,
anhydrite, ..
3- can be raised to a higher mud weights before developing
excessive viscosity,
4- less progressive gelling tendency.
C- Water Base Emulsion Mud
((Is that mud with oil & water being
emulsified together)).
Advantages over conventional water base mud:1- Reduction of pipe torque & drag.
2- Increased ROP & bit life.
3- Reduction of bit balling.
4- Alleviation of differential sticking.
5- Better filtration control & production zone.
D- Oil Base & Synthetic Mud
((Is that mud with oil as its continuous
phase with not more than 1 – 5% water)).
Advantages of oil base mud:1- protection of production horizon,
2- drill water sensitive formations; salt, clays..
3- allowing longer bit runs than water base mud of
the same weight.
4- less viscosity problems in deep hot holes.
Disadvantages
MUD CONTAMINATS
Water Base Mud
1- Shales.
2- Soluble Salts (cement).
3- Acid Gasses (H2S & CO2).
Oil Base Mud
1- Salt water.
2- Green cement.
3- Acid Gases (H2S & CO2).
II- MUD DATA
1- DENSITY
2- RHEOLOGY
1- DENSITY
((Any
accepted
terminology that
indicates the weight
per unit volume of
drilling fluid))
-Pounds per gallon (ppg).
-Pounds per cubic feet
(pcf).
-Gram per cubic centimeter
(g/cc).
-Kilogram per liter (kg/l).
2- RHEOLOGY
((The laboratory measured mud parameters))
a-Funnel Viscosity (vis)
b-Plastic Viscosity (PV)
c- Yield Point (YP)
d- Gel strength
e- ph
f- Filtration
g- Alkalinity
h- Chloride Content
i- Calcium
j- Retort
VISCOSITY
((Viscosity is a
measure of the
internal resistance
of a fluid to flow))
1- Funnel Viscosity
Apparent Viscosity (vis)
• is the measured times it
takes for one quart of
mud to gravity feed
through a hole of a
specific diameter.
viscosity
2- Multi Speed rheometr
•
relates viscosity to
shear rate and
shear stress.
i. Newtonian fluids
ii. Non Newtonian fluids
2- RHEOLOGY ((continue))
b-Plastic viscosity (Pv)
is that part of flow resistance in a mud caused
primarily by the friction between the suspended
particles and by the viscosity of the continuous
liquid phase. i.e. it is a representation of the
concentration, size and shape of the solid
particles.
c-Yield point (Yp)
is a measurement under flowing conditions of the
forces in the mud which cause gel structure to
develop when the mud is at rest.
Gel strength
• d-Gel strength (Gel)
is a measurement under static conditions of the
forces in the mud which cause gel structure to
develop when the mud is at rest.
2- RHEOLOGY ((continue))
e- pH
is a measure of acidity or alkalinity of drilling mud
as expressed in the hydrogen ion concentration .
It is used as an aid in determining for type of mud
treatment and as indication of contaminants such
as cement, gypsum .
f- Filtration (Wl)
is a measurement liquid filtrate of the drilling mud.
It measure the ability of the solid components to
form a thin, low permeability filter cake.
III- HYDRAULICS
((Deals with the behavior of mud with specific
Rheology in moving))
a- Flow PATTERN.
b- PRESSURE DROP.
c- ECD.
d- SLIP VELOCITY
d- SURGE & SWAP.
e- BIT HYDRAULICS.
a- Flow Pattern
((Refers to the relation between the different
layers to each other in moving))
1- Plug flow.
2- Laminar flow.
3- Turbulent flow.
This depends on the relation between the Fluid Velocity & the Critical
Velocity
i- Fluid Velocity.
ii- Critical Velocity.
b- Pressure Drop
((Refers to the pressure required to overcome
the friction between the drilling fluid and
specific system section))
1- Drill String Pressure Drop.
2- Annulus Pressure Drop.
3- Bit Pressure Drop.
1- Drill string pressure drop
((Refers to the pressure required to
overcome the friction between the
drilling fluid and drill pipe))
2- Annulus Pressure Drop
• ((Refers to the pressure required to
overcome the friction between the
drilling fluid and annulus))
• ECD (Equivalent Circulating Density):is the combined pressure being exerted
hydrostatically by the mud and the mud
pump when the system is circulating.
• Slip Velocity:is the rate at which cuttings fall back
toward bottom.
BINGHAM PLASTIC
((Reology in Bingham model concerned with
PV & YP))
PV = C 600 – C 300
YP = C 300 – PV
It is more accurate in Oil Base Mud than in Water base mud.
POWER LAW
• It allows for more plastic or pseudo – fluid
behavior.
• Power law slip velocity is generally less
than Bingham one. Calculating slip
velocity by Bingham provide adequate
hole cleaning
• More accurate in water base mud.
3- Swab & Surge Pressure
• Swap pressure is a negative value
produced by pipe movement up ward.
• Surge pressure is a positive value
produced by pipe movement down
ward.
4- Bit Hydraulics
•
•
•
•
Bit Pressure Drop.
Jet Velocity.
Hydraulic Horse Power.
Impact Force