Cement Slurry Flow Properties and Mud Displacement

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Assignment Cement job | Cement Slurry Flow Properties and Mud Displacement

Cement Job Design: Laminar and Turbulent Flow

You are evaluating an intermediate casing string for the Assignment well, and you want to determine the type of flow in the annulus.

The string is 9-5/8″ in a 12-1/4″ Open Hole, and you are using Class G neat cement (density 15.8 ppg).

In this size string, $1\ BPM = 0.298\tfrac{ft}{sec}$ .

Determine whether the flow is laminar, transitional, or turbulent at 1, 2, 3, 4 and 5 BPM.

Cement Job Design Laminar and Turbulent Flow, Cement Job, Cement additives in drilling, cement additives, Cement Slurry Flow Properties, Mud Displacement

Solution

$D_2\ - D_1 = 12.25\ - 9.625\ = 2.625\ in$

$r = 15.8\ ppg$

$n\ = 1,\ 2,\ 3,\ 4,\ and\ 5\ \tfrac{bbl}{min} \times 0.298 \tfrac{ft}{sec}$

$m\ =\$ taken from the provided graph

So the $Re = 757 \times 2.625 \times 15.8 \times 0.298 \times \tfrac{Flow\ Rate\ (BPM)}{Viscosity\ (cP)}$

$= 9356 \times \tfrac{Flow\ Rate\ (BPM)}{Viscosity\ (cP)}$

Flow Rate (BPM)	Viscocity (cP)	Equation	Re	Flow Regime
1	250	Re= 9356×1 / 250	37	Laminar
2	100	Re= 9356×2 / 100	187	Laminar
3	40	Re= 9356×3 / 40	701	Laminar
4	12	Re= 9356×4 / 12	3119	Transitional
5	6	Re= 9356×5 / 6	7797	Turbulent

Assessment “Cement job | Cement Slurry Flow Properties and Mud Displacement”

1. What is viscosity?

A .The ratio of pressure to depth
B .The ratio of mass to volume
C .The ratio of stress to strain
D .The ratio of shear stress to shear rate Correct

2. What describes a dilute mix of cement and water pumped ahead of the cement slurry in turbulent flow to help remove gelled mud and filter cake?

A .Cement scavenger slurry Correct
B .Viscosifiers
C .Spacer fluid

3. Which of these hole conditions would be considered favorable for obtaining an optimal cement job? (Select all that apply.)

A .Free of drill cuttings Correct
B .Increasing hole diameter with depth
C .Thick, protective mud cake
D .Consistent hole diameter Correct
E .Free of swelling shales Correct
F .Few doglegs or washouts Correct

4. Identify a characteristic of turbulent flow within the annular space.

A .Fluid moves uniformly as a homogeneous, relatively undisturbed, body.
B .There is no fluid motion transverse to the bulk flow direction.
C .Fluid particles swirl around in all directions. Correct

5. Knowing the ECD when pumping a cement slurry up a casing/wellbore annulus is primarily important to preventing ________.

A .lost circulation due to high wellbore pressure at the casing shoe Correct
B .premature setting up of the cement
C .excessive waiting on cement time

6. Rheological models are used to predict _________.

A .mud displacement Correct
B .compressive strength
C .setting time
D .thickening time

7. Identify examples of non-Newtonian flow models. (Select all that apply.)

A .Power Law Correct
B .Bingham Plastic Correct
C .Equivalent circulating density
D .Herschel-Bulkley Correct
E .Reynolds Law

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