erosion damage

Erosion Damage

• Erosion creates both wear of a surface due in part to impinging a slurry of particles, droplets, or bubbles in a fluid stream.

• The damage variables are related to: – The mass of the particles, – The velocity of the flowing fluid, – The distance to the target, –

• The most severe effects are from high speed gas flow carrying hard, angular materials such as formation sand, proppant, or similar debris, that strike the surface of equipment at an oblique angle.

8/25/2015 1 George E. King Engineering

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Sand production damage

in a surface connection –

the problem started with

a small leak, probably

interior erosion to the

point where a seal was

lost, then the expanding

gas made the problem

much more severe.

Erosion - Sand production damage

BP Canada 8/25/2015 2 George E. King Engineering

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Max Velocities for Particle Sizes

0

50

100

150

0 100 200 300

Particle size, u

ma

x v

el. f

/se

c

0.1 ft3/day

1 ft3/day

Maximum flowing fluid

velocity for increasing

particle diameters.

Although smaller

particles do less damage

than larger particles (less

mass), the sheer number

of small particles can

still do a significant

amount of damage.

Maximum velocity when solids are the the flow stream? Not much!


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Max Producing Velocity

0

0.5

1

1.5

2

2.5

3

3.5

4

0 1000 2000 3000

particle size, u

Ma

x V

elo

cit

y, fp

s

1 ft3/day

4” pipe

Direct

impingement

This data shows that

direct impingement is

much worse than flow

inside a pipe (flow

parallel to the pipe

wall).

Tubing flow with frac

fluid –high velocity and

high concentration of

sand – produces only

slight problems.

Problems start when the

angle of impingement is

changed.

The Impingement Angle


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Threshold

velocity for

screen like

clearances - 5

mpy limit in 316

Stainless. Gas

Flow.

0.00001 ft3/day

0

0.5

1

1.5

2

2.5

3

0 0.005 0.01 0.015

Flow Path Diameter, in

Th

res

ho

ld v

el. fp

s

"Tee"

Direct

0.00001 ft3/day

Potential for damage

from particles to

sand screen sized

openings.

Damage at the screen – sharp angle


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Wirewrap Screen Erosion w/ Air

SLIM-PAK™ 8 Gauge BAKERWELD®

Baker Tests

Note – the difference in the “life” or resistance of any screen to direct impingement of a sand slurry is measured in minutes – none are long lived.


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Multi-Layered Sintered Screen Erosion

Baker Tests

Surface damage of a steel shell may be minor or major, but the real damage is in the wire mesh – this is very rapid.


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Test Screen Erosion – but be careful of conclusions……

Vector Shroud Vector Weave

Baker Tests

Note – although it looks better – the test time of a few minutes is not meaningful in the life of a well – this screen will fail a few minutes after the others – not a significant improvement. 8/25/2015 8

George E. King Engineering GEKEngineering.com

Screen Damage from Trinidad

Trinidad

The damage to the exterior screen shows the type of damage that a high velocity gas flow containing sand.


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Erosion Screen Damage from Trinidad

Weave

Seam

Upper

shroud

removed

showing

Dutch

Twill

Weave

(DTW)

Screen.

Notice that

the major

damage is

on the

seam.

Trinidad 8/25/2015 10

George E. King Engineering GEKEngineering.com


Upper shroud and

support screen removed

showing base pipe.

Notice that the major

damage is at the center

hole.

Considerable erosion

from outside to inside is

seen here.

Due to handling, the

material blocking some

of the

holes has fallen out.

Plugged hole

Erosion


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Plugged hole showing gravel/formation fines.

Eroded center hole.


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Screen Plugging – usually the start of the failure

The plugging, which may

be from dope, scale, rust,

mud, cement, or sand can

quickly reduce the flow

area of the screen. Since

total flow area is usually

around 10%, any loss can

be severe, focusing flow

through a few remaining

open holes and increasing

erosion.


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Plugged screen – and resulting erosion

The hole in screen was probably produced by a high velocity flow

through one of the few remaining unplugged ports. 8/25/2015 14 George E. King Engineering

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Erosion holes in wash

pipe (and screen) – result

of using a large CaCO3

pill to control losses and

then circulating the OHGP

into place. Hot spots

amplified the flux

velocity.

Lawrence Ramnath,

Trinidad, 2002

Erosion – not just from produced solids….


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Erosion angle – any angle other than parallel (zero angle of impingement)


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Erosion – more severe at the surface

Choke body erosion at the surface from rapidly expanding gas and extremely high velocities.

Erosion most severe at angles – not in parallel flow.

Hard, angular particles are the most severe.


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Old equipment showing the effects of erosion following leak development.

The bone yard…..


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Severe erosion damage in a choke.


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Erosion Damage – exit of the choke

Erosion damage in the exit end – high velocity gas.


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Erosion – sand slurries continue to cut…..


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Erosion in a partly open plug valve.

Never use a valve to throttle any flow operation or venting of gas – use a choke.

Valves in the flow line should be fully shut or fully open.

A small leak through a valve will become worse (wash out) very quickly in most cases, particularly when solids are in the flow stream.


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Erosion in a fixed choke bean – Trinidad.


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Time to failure? A few minutes.

Notice the shape of the eroded opening?

Most probably from a perforating producing formation sand.


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Erosion – after breakthrough. The high velocity that develops after erosion breaks through creates much more serious erosion and much more damage. Repair leaks immediately and shut the well in until they can be repaired.


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OK – now both damage and a lot of cleanup……

Very fine sand carried through a small leak in a surface pipe by rapidly expanding gas.


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What remains of a rotary table on a drilling rig after release of solids laden mud at extremely high velocity.

The erosion will enlarge the opening until the velocity through the opening drops below the threshold for metal loss to the solids stream.

Erosion from Solids in the Mud


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erosion damage

Documents

erosion screen damage

erosion damage erosion

king engineering

real damage

type of damage

damage variables

test screen erosion

exterior screen