Drilling Fluid Properties And Typs

Drilling  Fluid Properties And Typs

Drilling Fluid is the most important factor in drilling Drilling fluids process. is used to Remove cuttings ,cool and clean bit lubricate drill assembly, control formation pressure maintain
.well bore ,stability prevent lost circulation

Drilling Fluid Properties

Type of Drilling Fluid

Water base mud

Oil base mud

Salt saturated mud

Drilling Fluid properties

Mud weight or mud density

Gel strength and yield point


Viscosity and plastic viscosity

Fluid losses and filter cake

Gel strength and yield point

? The difference between gel strength and yield point

 Gel strength is the shear stress of drilling mud that is measured at a low shear rate after the drilling mud has been static for a certain
.period of time

  Gel strength is one of the most important drilling fluid properties because it demonstrates the ability of the drilling mud to suspend drill solid and weighting material when circulation is ceased

Gel strength : the ability of the fluid to suspend the cutting when at rest. And is the result of the viscosity and colloidal state of the fluid
Yield point : the resistance of the fluid to flow when start moving and is responsible of the cutting carrying 


Gel strength : its like ability of mud to suspending drilling cutting
.in static conditions
 Yield point : ability of mud to carry cutting to surface in dynamic
. conditions

Gel strength suspend cutting in Mud Yield point carry cutting to surface This property are very important in drilling

Yield point is the term used to measure the intersection of the shear stress axis by the relation between shear stress (t) and shear rate (g) 
.of a fluid (i.e., YP is the shear stress at zero shear rate

Yield point is the attractive force b/w the particles due to presence of +ve and -ve ions. where as Gel strength is the ability of mud to hold the cuttings at rest by attaining a gel stucture

Viscosity one of the most important properties for mud engineer because it measure and defined Resistance to flow of a fluid
and control the important factor in drilling hydrustatic pressure

you can use viscosity to overcome blow out because it used to kill the well during blow out

two type of viscosity Funnel Viscosity and Plastic Viscosity

viscosity depend on temperature and measured by viscometer and Marsh funnel

Important Notes

If you want increase mud weight to increase hydrostatic pressure -
 added barite to mud 

if you want increase viscosity or yield point added mud thickener -
to the mud such as cement and polymer

if you want decrease mud viscosity and yield point you must add -
mud thinner to the mud such as phosphates and chrome ligno sulfate