What are the rheological properties of drilling mud?
Drilling fluids consist of many additives like bentonite, barite and hematite that are mixed in the mud to enhance rheological properties such as density, yield point, plastic viscosity and gel strength.
What are the properties of rheology?
The most common rheological properties are yield stress, relaxation times, viscosity and compliance. Rheological properties study the behavior of fluids under mechanical loading. The solid structure, having a defined shape, deforms and stresses when subjected to a load.
What are the characteristics of drilling fluid?
Properties of fluids
- Density. The correct drilling fluid density is dependent on the subsurface formation pressures.
- Viscosity. The flow properties of the mud depend on the depth of the hole and the annular viscosities.
- Fluid loss control.
- Chemical composition.
- Water-based muds.
- Oil-based muds.
- Air drilling.
What is the viscosity of drilling mud?
The minimum and maximum values of apparent viscosity for drilling mud with varying bentonite contents were 1.1 cP and 19.7 cP respectively and the mean, standard deviation and Cov (%) were 5.8 cP, 5.8 cP and 77.5% respectively as shown in Fig. 2. The average value of apparent viscosity was 7.4 cP.
What is rheology in drilling fluids?
The science and study of the deformation and flow of matter. The term is also used to indicate the properties of a given fluid, as in mud rheology. Rheology is an extremely important property of drilling muds, drill-in fluids, workover and completion fluids, cements and specialty fluids and pills.
How do you measure rheological properties?
To measure the rheological properties of a material, rheometers are used. They measure the torque and the deflection angle of the measuring bob. This means that in a viscosity measurement the rheometer presets a certain current that correlates to a defined torque.
Which property is not rheological property?
question. Option (c) Surface tension the physical property is not a rheological property. Explanation: Rheology is the department of physics that research how substances deform or flow in response to carried out forces or stresses.
What is PV and YP in drilling mud?
PV represents the viscosity of a mud when extrapolated to infinite shear rate on the basis of the mathematics of the Bingham model. (Yield point, YP, is the other parameter of that model.) A low PV indicates that the mud is capable of drilling rapidly because of the low viscosity of mud exiting at the bit.
What is the composition of drilling mud?
Drilling muds are traditionally based on water, either fresh water, seawater, naturally occurring brines, or prepared brines. Many muds are oil-based, using direct products of petroleum refining such as diesel oil or mineral oil as the fluid matrix.
Why is it important to study fluid rheology in drilling engineering?
The rheological properties of drilling fluid have an important impact on its performance as they affect many drilling parameters such as bit penetration rate, drill hole cleanliness, well hydraulics, filter cake formation and drilling fluid stability [20] .
What is the difference between viscosity and rheology?
Viscosity is a quantitative measurement that is useful in chemistry. These two terms are related to fluids such as liquids and gases. The key difference between rheology and viscosity is that rheology is the study of the flow of matter whereas viscosity is a measure of its resistance to deformation.
What are rheological properties of concrete?
The rheological properties of fresh concrete are related to cement hydration and chemical interactions in the cement paste system [1]. In addition, the rheological properties of concrete are also dependent on the shape and gradation of the aggregates (coarse and fine) contained in the mixture.
What is yield value in rheology?
Yield stress studies can help evaluate the product performance and processability and predict product’s long-term stability and shelf life1-5. A yield stress in rheology is defined as the applied stress at which irreversible plastic deformation is first observed across the sample. It is usually represented as σy.
What is pH in drilling mud?
Drilling fluid additives were developed to be mixed with water with a pH level from 8.5 to 10 in order for the required chemical reaction to occur and to provide a proper yield. Most water sources range from 5.5 to 7.5 which is too low.
What type of fluid is drilling mud?