Mixing theory

Question 1

Cement Mixing

Answer 1

Cement mixing is the process where a flow of pressurized water meets a flow of cement and a cement slurry is formed.

Question 2

Continuous Mixing

Answer 2

Mixing on FLY: mixing and pumping at the same time

Question 3

Batch Mixing

Answer 3

mixing required amount of cement in large tank before pumping

Question 4

Cement mixing actually comprises of two actions:

Answer 4

1. The accurate proportioning of cement solids
2. mix water Mixing energy

which homogenizes the mix by wetting and deflocculation of solids

Question 5

minimum and good Mixing Energy

Answer 5

.2 kj/kg y 2 kj/kg

Question 6

Deflocculation?

Answer 6

Deflocculation is the process by which a cement particle is wetted and forcibly separated from other particles clinging to it.

Question 7

Mixing Energy - Laboratory

Answer 7

• 15 sec-4,000 RPM
• 35 sec-12,000 RPM
• 5.90 kJ/kg

Question 8

COILED TUBING mixing energy

Answer 8

SME = 1.0 – 7.0

Question 9

Function of Jets in jet line

Answer 9

• Supply mix water
• Accelerate mix water
• Wet and disperse cement grains
• Create “venturi” effect
• Vacuum is created by water
• Pulls more cement in from hopper

Question 10

Batch Mixing Advantages and disadvantages

Answer 10

Advantages

• Good density control
• Good mixing energy

Disadvantages

• Small slurry volumes

Question 11

The Slurry Chief ADVANTAGES

Answer 11

• More accurate control of cement slurry
• More energy added by RA 56
• Gives a second chance to control density
• Can stop pumping downhole and mixing, leaving recirculating
• Low pressure mixing system
• Recirculating line from a tub goes back to mixing bowl
• Knife gate to control cement falling into mixing bowl 2 bypasses with jets

Question 12

what is a Vacuum Breaker in jet line

Answer 12

a check valve that lets air enter the system if the re-circulation circuit is open and cement valves are closed