DRILLING FLUIDS

Question 1

Continuous phase that carries other additives (e.g., water, seawater, oil, or compressed air).

Answer 1

Disperse Medium:

Question 2

Suspended particles, emulsions, or foams, including:

Clays (e.g., bentonite) for viscosity.
Weighting materials (e.g., barite) to control pressure.
Lost circulation materials (e.g., mica) to plug permeable zones.

Answer 2

Disperse Phase:

Question 3

Increase fluid viscosity.

Answer 3

Viscosifiers

Question 4

Prevent excessive viscosity

Answer 4

Thinners/Dispersants:

Question 5

Prevent clay swelling (e.g., KCl, glycol).

Answer 5

Shale Inhibitors

Question 6

Minimize fluid loss (e.g., PAC).

Answer 6

Filtration Control Agents

Question 7

Reduce friction.

Answer 7

Lubricants

Question 8

Prevent bacterial growth.

Answer 8

Biocides

Question 9

Types of WaterBasedMuds

Answer 9

Non-Inhibitive WBM: For stable formations.

Inhibitive WBM: Contains shale inhibitors (e.g., KCl).

Emulsion WBM: Contains emulsified oil droplets.

Foam WBM: Aerated for underbalanced drilling.

Advantages: Lower cost, environmentally friendly.
Limitations: Poor performance in reactive shales.

Question 10

Continuous phase is mineral oil (e.g., diesel).
Advantages: Excellent wellbore stability, lubrication.
Disadvantages: Toxicity, disposal challenges.

Answer 10

Oil-Based Muds (OBMs):

Question 11

Use synthetic oils (e.g., esters, olefins).
Advantages: Low toxicity, good stability, high biodegradability.
Suitable for: Environmentally sensitive areas, high-temperature wells.

Answer 11

Synthetic-Based Muds (SBMs):

Question 12

Determines hydrostatic pressure.
Measured using a mud balance.

Answer 12

Density:

Question 13

Resistance to flow.

Answer 13

Viscosity

Question 14

Initial resistance to flow

Answer 14

Plastic Viscosity (PV

Question 15

Ability to suspend solids.

Answer 15

Yield Point (YP)

Question 16

Suspension capacity at rest.

Answer 16

Gel Strength:

Question 17

Controls fluid loss into formations.
Measured using a filter press.

Answer 17

Filtration Control

Question 18

Quick viscosity indication (time-based).

Answer 18

Marsh Funnel:

Question 19

Measures PV, YP, and gel strength at various RPMs

Answer 19

Fann Viscometer

Question 20

Determines filtrate volume and filter cake thickness

Answer 20

Filter Press:

Question 21

Barite: Increases mud density.

Answer 21

Weighting Materials:

Question 22

Potassium Chloride (KCl): Prevents clay swelling.

Answer 22

Shale Inhibitors:

Question 23

PAC, Starch: Reduce fluid loss.

Answer 23

Filtration Control Agents:

Question 24

Enhance drill string movement, reduce torque and drag

Answer 24

Lubricants:

Question 25

Protect metal components (e.g., amines, phosphates).

Answer 25

Corrosion Inhibitors:

Question 26

Prevent bacterial degradation in WBMs.

Answer 26

Biocides: