Sand Control Techniques
Screen Completion Fundamentals
No sand production
(no erosion)
Minimal plugging of
downhole assemblies
Avoid flow restricting
deposits of fines
Retention of
erosive particles
outside production
string
Silicate/quartz
Particle sizes are often
above 100µ (4/1000“)
Erosive particles
are often hard
silicate / quartz
compounds
Accept production of
fines with well fluids
Fines are
soft silt
particles
Particle sizes of
fines are often below
50µ (2/1000”)
Adjustable
Largest
possible
tubing ID
Safe, long term,
low maintenance,
high well performance
Flow
Control
Fixed
Minimize
mechanical
skin
Fluid compatibility
Appropriate
inflow area
Optimal production
or injectivity
Avoid Plugging
Minimize
formation
skin
Minimal formation
“disturbance”
Avoid Sand Production
Optimize Productivity / Injectivity
Sand Control Completion Methods
Low complexity
Low cost
High complexity
High cost
Completion Method Evaluation Parameters
Design
Complexity
Sanding
Risk
Installation
Complexity
Erosion
Risk
Mechanical
Robustness
Plugging
Risk
Well
Productivity
Total
Cost
Different Screen Types Behave Differently
Screen Comparison
230 μ Mesh Screen
225 μ Reslink screen
Screen Comparison
110 μ Mesh Screen
225 μ Reslink screen
Screen Comparison
60 Mesh (250 μ) Shaker Screen
225 μ Reslink screen
Six Critical Questions
1. Does the selected screen act as surface
filter(Y), or depth filter(N)?
2. Does the screen construction and/or completion
allow production of fines?
3. Are the selected screens difficult to plug and
easy to clean?
4. Are the screens mechanically strong?
5. Does the completion type allow self cleaning
and formation de-stressing/relaxation?
6. Does the completion type control annular flow?
Surface Filter / Depth Filter
Surface Filter
Shroud
Screen wire
Axial support wire
Protective screen
Mesh Layer 1
Mesh Layer 2
Depth Filter
Solids
Deposits
Solids Deposits
Perforated Base pipe
Premium Screens
Single Wire Wrap
Mesh 1: 250 µ
Mesh 2: 250 µ
250 µ
Slot opening
Combined
Mesh
Opening?
• Premium mesh screens and wire wrap screens behave differently.
• Slot opening on single wire wrap screens can easily be measured.
Fines Must be Produced
Allowing Production of Fines
Wire Wrap Screen
Formation
When properly engineered,
the completion:
• Allows non load bearing fines (2)
to be produced
• Plugging is prevented
(SPE 38187, 38638)
2
3
1
• Retained sand (3) create a
natural sand pack on the screen
surface, with higher porosity and
perm than the formation (1)
Formation relaxation/de-stressing:
(SPE 56813, 36419. 71673)
• Increased formation stress from
depletion can result in reduced
permeability
• Barefoot and SAS completions
allow formation to de-stress or
relax
• Fines are produced, while coarse
sand is retained by the screen
• The annulus is shrinking
• Slot opening precision and screen robustness essential
Trapping Fines – “Premium Screens”
Depth filter screens are:
• Pre-packed screens
• Porous Metal Membrane Screens
• Premium Mesh Screens
WW screen
Layered Mesh
Shroud
2
1
By design, ‘depth filter’ screens have
significantly reduced filter opening:
• Fines get trapped
• Over time these screens get plugged
(SPE 38638)
• Self cleaning is almost impossible
• Back washing or acid washing has
limited effect.
Formation relaxation/de-stressing:
(SPE 56813, 36419. 71673)
• Increased formation stress from
depletion can result in reduced
permeability
• Barefoot and SAS completions allow
formation to de-stress or relax
• Fines are produced, while coarse
sand is retained by the screen
• The annulus is shrinking
However, With a plugged screen,
formation relaxation/de-stressing has
no value.
Trapping Fines – Gravel Pack
Formation
GP sand
2
Wire Wrap
Screen
• GP sand is (by design) 5-6
times larger than formation
sand d50.
• GP’ing does not alter
screen behavior.
• GP’ing will restrict annular
flow, i.e. transport of
moveable material.
• GP screen must allow
production of fines,
otherwise completion will
plug.
• Pore throat of most GP
sands will restrict
production of fines.
• GP’ing will arrest/trap
formation filter cake on the
formation surface.
• GP’ing will not allow
formation to relax/de-stress.
Single Wire Wrapped Screens – Measurable Slot Opening
• Photometric slot opening QC
(ResGauge™)
• Measures all slot openings (±3,000 per
joint vs. 15 – 200 per joint with feeler
gauge)
• Resolution; 1 µ (vs. feeler gauge 25 µ)
• Accuracy; ± 5 µ
-1.5G
-2G -38µ
-1G
-30µ
-50µ
-3G
75µ
Max 1.25%
Actual Data
0.42%
Slot Opening
‘So’
1G
-10µ
0
10µ
Minimum 97.5 % of all
measurement points
99.36%
1.5G
38µ 2G
30µ
50µ
75µ
Max 1.25%
0.233%
0.0014%
Mesh Screens – Effective Opening …
Mesh screen (Squares)
1
Ideal mesh stacking:
Bridging
Particle Diameter
=
Wire wrap screen (Slot)
Mesh Size
2.5 – 3
2
Realistic mesh stacking:
Bridging
Particle Diameter
=
Mesh Size
5-6
A wire wrap slot is
an accurate gap.
3
Worst case mesh stacking:
Bridging
Particle Diameter
=
Mesh Size
7.5 - 9
Bridging
Particle
Diameter
=
Slot Width
2 – 2.5
• Experiments performed with well sorted, spherical river bed sand
• The effective opening of layered mesh screen is reduced
• Mesh screens will trap fines that would pass through slots in a wire
wrap screen
Particle Retention Comparison
Screen construction determines particle bridging behavior
• Identically sized screens (wire wrap and mesh) retain particles of very different size
• Multi-layered mesh screens retain much smaller particles than wire wrap screens
Screen
Type
Screen
Type
Retained
Retained
Particle
Particle
size factor*
size (µ)
Wire wrap
screen
250 µ
slot opening*
Single layer
mesh screen
250 µ
mesh opening
Double layer
mesh screen
250 µ
mesh opening
Triple layer
mesh screen
250 µ
mesh opening
Produced
Produced
Particle
Particle
size factor*
size (µ)
2
2.5
>125
>100
2.5
3
<100
<83
2.5
3
>100
>83
3
3.5
<83
<71
5
6
>50
>42
6
7
<42
<35
8
9
>32
>28
9
10
<28
<25
Bridging theory according to Coberly and Penberthy
* Slot opening = Particle size x factor
Drill-in fluids and drilled
solids particle sizes.
Screen Plugging and Cleaning
Screen plugging theory according to Lau & Davies
Sand
C
M
Clay
Silt
F
VF
C
M
F
VF
Depth filters plug easily:
• Pre-packed screens
• Porous Metal Membrane Screens
• Premium Mesh Screens
16 micron
110 u screen
250 u screen
1000
36 micron
100
7 x d50
Cum
%
90
Micron (µ)
80
The 1/7th rule:
60
Screen plugging is
linked to screen slot or
pore opening,
according to the 1/7th
rule. A DIF containing
solids with D50 larger
than 1/7th the screen
slot opening will plug
the screen
D 50
10
7 x d50
The 1/7th rule [Lau & Davies. SPE 38638]
40
20
10
1
Screen Plugging and Cleaning
Example of
severe
screen
plugging
Depth filters are:
• Pre-packed screens
• Porous Metal
Membrane Screens
• “Premium” Mesh
Screens
Screen Strength
Screen with welded end connection
LineSlot™ Shrink Fit Wrap-on-pipe screen
All forces transferred through end connections
All forces transferred to the base pipe, and
screen and base pipe behave as one unit
Jacket to
Base pipe
weld
Reslink tension
test with welded
end connections;
Total Loss of
Sand Control
Reslink tension test with wrapon-pipe screen construction;
End connections
and screen jacket
intact –
No loss of sand
control
Self Cleaning / De-Stressing
Barefoot
Screen only
‘k’ - apparent
permeability
‘k’ - apparent
permeability
~s - effective stress*
~s - effective stress*
pressure - p
pressure - p
Distance f rom well bore
Improved PI
with time
PI
Time
Self cleans
and relaxes
CCP*
Distance f rom well bore
Improved PI
with time
PI
Time
Self cleans¤
and relaxes
OH GP
CCP GP
‘k’ - apparent
permeability
‘k’ - apparent
permeability
‘k’ - apparent
permeability
~s - effective stress*
~s - effective stress*
~s - effective stress*
pressure - p
pressure - p
pressure - p
Distance f rom well bore
Improved PI
with time
PI
Time
Self cleans
Partly relaxation
Distance f rom well bore
Declining PI
with time
PI
Time
No self cleaning
No relaxation
Distance f rom well bore
Declining PI
with time
PI
Time
No self cleaning
No relaxation
Depletion > Compaction > Crushing > Stress > K *Effective stress = Weight of overburden – pore pressure
SPE 71673: J.Tronvoll, M.B. Dusseault, F. Sanfilippo, and F.J. Santarelli
SPE 56813: J.P. Davies, SPE, Chevron USA Inc., and D.K. Davies, SPE, David K. Davies & Associates, Inc.
SPE 36419: A.P, Kooijman, P.J. van den Hoek, Ph. de Bree, C.J. Kenter, Shell, Z. Zheng, and M. Khodaverdian, TerraTek Inc.
¤Depends on type of screen
SPE 27360
*CCP= Cased, Cemented and Perforated
Annular Flow Control
9 ⅝” Casing
Functionality:
Sand control and zonal isolation
5 ½” Tubing
PBR Seal
9 ⅝” x 6”
Packer
6 ⅝” Screens
(7 ½” OD)
Swell Packer™
Sand control objectives:
• Sustained well performance
• Reliable, long term completion
• No plugging or sand production
• Simple to install
• Avoid pumping services to achieve objectives
8 ½” Open Hole
Zonal isolation objectives:
• Reservoir
compartmentalization
• Eliminate annular flow
Comparison
Desirable features
1. Screens are NOT susceptible to plugging
2. Screens act as surface filter, not depth filter
3. Screens are mechanically strong, well suited
for long horizontal OH completions
4. Screen construction/completion allows
production of fines
5. Completion type allows formation destressing/ relaxation
6. Completion type controls annular flow
Undesirable features
1. Screens ARE susceptible to plugging
2. Screens act as depth filter, NOT surface filter
3. Screens are mechanically weak(er), NOT
suited for long horizontal OH completions
4. Screen construction/completion does NOT
allow production of fines
5. Completion does NOT allow formation destressing/ relaxation
6. Completion type does NOT control annular flow
Completion Types
StandAloneScreens
(1) Pre-Packed ww screen
(2) mesh screen
(3) porous metal membrane screens
Reslink LineSlot™ Single Wire wrap design
w/ Swell PackerTM
Expandable Screens
Gravel
Packed
w/ Single wire wrap screen
(1) Pre-Packed ww screen
w/ (2) mesh screen
(3) porous metal membrane screens
1
2
3
4
5
6
ResScreen™ & Swell Packer Score Card
Design
Complexity
Installation
Complexity
Mechanical
Robustness
Sanding
Risk
Plugging
Risk
Erosion
Risk
Well
Productivity
Total
Cost
Low
Low
High
Low
Low
Low
High
Low
Yes
No
1. Does the selected screens act surface
filter(Y) or depth filter (N)?
ResScreenTM
2. Does the screen construction and/or
completion allow production of fines?
ResScreenTM
in Open Hole
3. Are the selected screens difficult to
plug and easy to clean?
ResScreen™
4. Are the screens mechanically strong?
ResScreen™
5. Does the completion type allow self
cleaning and formation de-stressing/
relaxation?
ResScreenTM
in Open Hole
6. Does the completion type control
annular flow?
Swell Packer TM
in Open Hole
Particle Management
Critical factors affecting particle management
Drilling Fluid
– Carrier fluid chemistry and compatibility
– Selection and PSD of weighting agent solids
Surface solids handling system
– Shaker screen (capacity, sizing, selection)
– Centrifuges (capacity, sizing, selection)
Formation sand analysis
– Laser PSD vs. Dry Sieve PSD
– Selection of sand screens and GP sand based on formation PSD
Gravel Pack Sand
– Selection (re-sieved sand vs. man-made proppant
– Sorting, strength, cleanliness
Sand Screens
– Function and Selection, (Wire wrap, mesh, pre-packed, expandable)
Completion fluids
– Types and function
– DF/CF Interaction and compatibility
Data for Sand Screen Design
Sieve Curves
100
90
80
70
60
50
40
30
20
10
0
1
10
100
Gr ain Siz e ( micr o ns)
1000
Laser versus Dry Sieve
The basis for evaluation and selection of screen slot opening and gravel
pack sand is the formation sand particle size distribution (PSD).
There are two methods currently utilized for analysis of particle size
distribution:
• Dry Sieve Analysis
• Laser Light Scattering
These two methods are used individually or in combination.
It is evident from industry experience and from the literature that the two
methods yield dramatically different results.
The Laser Light Scattering technique is limited to a sample size of
maximum 1 gram (0.035 ounce). Due to the small sample size this
technique can not provide a representative particle size distribution of a
given formation.
Reslink recommends the use of Dry Sieve Analysis
data for screen slot opening selection.
Particle Size Analysis Guide
Laser: sample size too small !
Dry Sieve: particle size range and
sample size are acceptable !
Laser Light Scattering Technique not Acceptable
Derry D. Sparlin and
Raymond W. Hagen, Jr.
“Sand Control Manual”
International
Completions
Consultants Inc.
Comparison Laser / Dry Sieve
Dramatic difference between the two analysis types !
Slot Selection Evolution
1938 Coberly:
– Screen slot opening: 2 x d10 formation sand
1974 Saucier:
– Gravel design: 6 x d50 formation sand; screen slot opening: ½ the
smallest gravel size from line through this point with C  = 1.5
1996 Markestad et al. (SPE 31087)
– Fractal Particle Size Distribution (PSD)
• Screen selection cannot be based on one single point on PSD
curve.
• Absolute particle size: d10, d40,d50 and d90
• Content and distribution of fine particles
– SAND software
Stand Alone Screens or Gravel Packing
SAS: (SPE 65140)
– Uc: (d40/d90) < 5
– Fines (< 44 ųm): < 5%
GP:
– Uc: (d40/d90) > 5
– Fines: > 5%
Slot Opening Selection
Sieve Curves
1,000µ
1 mm
500µ
100µ
Sieve Analysis data from
various measured
depths along open hole
section are input in
software program “Sand™”
– results presented
in graph.
100
90
80
70
60
50
40
30
20
10
0
1
10µ
10
100
Grain Siz e ( micro ns)
Smallest slot opening where
continuous sand production
is expected to occur
“Safe” slot width range
Largest slot opening where
sand production is not expected
to occur
Smallest slot opening
where no plugging
is expected to occur
Largest slot opening
where severe plugging
is expected to be frequent
1000
Reslink SandTM Slot Opening Design
Steps for running Sand TM Program:
1. Organize sieve data and review sieve curves
2. Set up Sand .prj file for well
3. Input sieve data into Sand program under created .prj file
4. Set up Excel spreadsheet and import results of Sand to it
5. Graph results -- Depth vs. Slot Opening (micron size) of d--,
d-, d+ and d++
6. On graph draw a straight line at best fit slot opening size.
Input Sieve Data
Output
Particle Size Distribution Model Parameters
Definitions of parameters related to the
particle size distribution model:
f1
the fractal dimension of the
finer sand fraction; slope of the
line of the finer fraction
f2
the fractal dimension of the
coarser sand fraction; slope the
line of the coarser fraction
Int1 the intercept between the two
straight lines in microns
Int2 the mass percentage of
particles larger than Int1
Excel Table with Data
Graph Results
Slot opening (microns)
Dry samples
(<50um produced)
600
550
500
450
400
350
300
250
200
150
100
50
0
d-dd+
d++
95
78
00
79
12
79
27
79
.8
.9
58
09
9
0
7
8
20
80
58
82
Sample
99
82
08
83
.6
93
3
8
10
84
bt
21
bs
21
Fines vs Permeability
Well No.
Sample Depth Permeability % fines(Laser) Poss. Sand Prod.
(Ft)
(mD)
<50 microns
Laser/ Dry
7877.2
% fines(Dry)
<50 microns
37.11
7892.00
183
29.24
9.68
7895.00
2950
8.6
2.14
7900.00
59.4
5.81
1.17
7912.00
4610
2.59
0.30
7927.00
3130
5.82
2.21
7958.80
5190
8.42
1.12
7963.00
190
6.72
3.19
8009.90
10580
6.12
0.57
8020.00
155
6.8
1.14
8053.00
44.1
11.1
1.66
8067.30
543
31.38
8.42
No Data
8258.00
19140
3.02
0.37
8299.00
8340
5.05
0.76
8308.00
39600
2.37
0.59
8334.00
25.78
8393.60
18600
5.02
0.95
8410.00
4650
4.61
0.55
8420.10
26.94
8427.10
23.73
21BT
2450
14.42
3.31
21BS
4.06
15.45
2.68
Often an advantage to consider fines content and permeability.
Assume that Fines are Produced
A2 Pink S1 Sand
350.00
Slot opening (microns)
300.00
250.00
d--
200.00
dd+
150.00
Plot with complete
sample (including
fines).
d++
100.00
50.00
0.00
19300.00 19305.00 19310.00 19315.00 19320.00 19325.00 19330.00 19335.00 19340.00
Depth(Ft)
A-2 Pink S1(<53microns produced)
450
Slot Opening (microns)
400
350
300
d-250
d-
200
d+
d++
150
100
50
0
19300
19305
19310
19315
19320
Depth (Ft)
19325
19330
19335
19340
Plot with data set
without particles
under 53 micron.
Laser vs Dry Sieve
600
550
500
450
400
350
300
250
200
150
100
50
0
Laser: 200-250µ
d-dd+
21BS
21BT
8427.1
8420.1
8410
8334
8299
8258
8067.3
8053
8020
7963
7958.8
7927
7912
7900
7895
7892
d++
7877.2
Slot opening (microns)
Well A Laser analysis data
(< 50 um particles produced)
Sam ple
Dry Sieve: 275-325µ
Slot opening (microns)
Well A Dry samples
(<53um produced)
600
550
500
450
400
350
300
250
200
150
100
50
0
d-dd+
d++
95
78
00
79
12
79
27
79
.8
.9
58
09
79
80
20
80
58
82
99
82
08
83
.6
93
83
10
84
bt
21
bs
21
Sample
Too small slot opening may result in plugging !
SAND™ Conclusions
• Provides fractal data analysis (i.e. number of particles)
rather than mass
• Fractal analysis provides improved description of smaller
particles (which tend to cause screen plugging)
• Multiple parameters are used for calculating the fractal
particle size distribution (d90, d50, d40, d10,Uc, fractal
dimensions of fine and coarse particles)
• Graphically illustrates which sand types that may cause
problems for the selected screen slot size
• Identifies which sand types that are well suited for stanalone-screens, and which sand types where a GP is
recommended
• Significantly improved selection process compared with
single point PSD selection
• Graphically quantifies the risk of plugging/sanding
Summary
There are several key issues to consider when designing screen slot
width, when manufacturing and controlling screen quality and when
installing sand screens in the wellbore:
• Thorough analysis of formation sands and fines with Dry Sieve Analysis and SEM
What is the size range of fines and what is the smallest sand particle size?
• Avoid the use of particle size distribution from Laser analysis for designing
screen slot opening.
The laser data is based on such a small sample that it is not representative for the formation
sand.
• Accept fines to be produced with well fluids to avoid downhole plugging
It is more cost effective to be prepared for, and deal with fines on surface than risking
downhole plugging and costly remedial work.
• Design slot opening to retain abrasive sand particles and avoid erosion
Focus on high risk abrasive sand production issues.
• Establish clearly understood quality criteria
Set criteria with basis in desired sand control and fines handling functionality.
• Quantifiable and accurate quality control
Slot opening of wire wrapped screens can be measured accurately and with a higher density
than in the past.
• Screen robustness to enable installation without compromising slot opening
A well designed screen will not be effective if it can not handle mechanical exposure during
installation.