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SMS– Slide 1

Sand Management Services

Victor Chipana

Sand Control - SLB

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SMS– Slide 2

Outline• Process Management• Formation Characteristics• Factors & Causes of Sand Production• Reasons for Sand Control

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SMS– Slide 3

Fundamental Cause of Sand Production

• Destabilizing forces overcome formation strength – formation matrix fails– if sand is mobile - sand transport

(production) will occur– sand production is a function of rock

strength and/or fluid flow effectsStage 1 - Failure Stage 2 - Transportation

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SMS– Slide 4

General Formation CharacteristicsFive general types of sand producing

formation:

1. No sand – no fines– Competent formation

2. Fines migration– Generally acceptable– Must be manageable

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SMS– Slide 5

General Formation Characteristics3. Some sand production

– Unconsolidated formation.4. High sand production

– Loss of perforation tunnel and formation integrity.

5. Major sand production– Formation collapse, reservoir settling.

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SMS– Slide 6

Formation Hardness ClassificationDescription Sonic Travel

Time Brinell

Hardness Strength, Analogue

Unconsolidated >140 msec? <2 Near 0 psi. Similar to strength required for sand castles. Sonic travel times may not accurately predict this state.

Semi or marginally Consolidated

>120 msec 2 to 5 <300 psi, easily crushed with fingers.

Friable

>90<120 msec 5 to 10 300 to 1000 psi, crushed with forceps.

Consolidated

>50<90 msec 10 to 30 1000 to 5000 psi, stable, but may loose strength as rock dries.

Hard

<50 msec 30 to >100 5000 to over 35,000 psi, does not change significantly.

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SMS– Slide 7

UCS: Unconfined Compressive Strength• Rock with UCS below 1000 psi may need

sand control – although recent work has shown weak

formation that are reasonably stable

• Porosity indications: – <20% usually stronger formation– 20 to 30% - highly variable strength area– >30% - unconsolidated (except for

chalks)

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Factors for Sand Production

Formation or reservoir factors:• Rock mechanics

– overburden, intergranular friction, differential stresses

• Formation lithology– cementing material and degree of

consolidation– particle size, shape and distribution

• Reservoir fluid characteristics– viscosity, velocity and resultant drag forces

(friction)– changes in surface wetting

•Drag Forces •Cementing•Capillary•Overburden

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SMS– Slide 9

Factors for Sand Production

Production characteristics• Water breakthrough

– coning or injection breakthrough

• Structural weakening by reactive fluids– dissolution of cementing material

• Frequency of production shutdowns

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SMS– Slide 10

New Well - Formation Strength Factors• Poorly consolidated formation

– generally a “young sandstone problem”

Epoch Period Era Eon

Phanerozoic

Proterozoic

Cenozoic

Mesozoic

Paleozoic

RecentPleistocene

PlioceneMiocene

OligoceneEocene

Paleocene

Quaternary

Tertiary

CretaceousJ urassicTriassicPermian

CarboniferousDevonian

OrdovicianSilurian

Cambrian

00.011.65.324375766

144208245286360408438505570

Epoch Period Era Eon

Phanerozoic

Proterozoic

Cenozoic

Mesozoic

Paleozoic

RecentPleistocene

PlioceneMiocene

OligoceneEocene

Paleocene

Quaternary

Tertiary

CretaceousJ urassicTriassicPermian

CarboniferousDevonian

OrdovicianSilurian

Cambrian

00.011.65.324375766

144208245286360408438505570

Sand production difficulties most commonly are

associated with Tertiary

sandstones

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SMS– Slide 11

Old Well - Production Factors

• Increased water cut – water coning or injection break-through– reducing stability of perforation arch– higher drag forces

Water break through can effect the performance

of the formation cementing material or

change the flow characteristics which

destabilises the formation sand

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SMS– Slide 12

Old Well - Production Factors

Pressure depletion, rock failure and reservoir compaction

• Prior to depletion pore pressure supports the overburden

• fines retention(plugging) - permeability decrease

Formation stable against

overburdenDestabilized formation

compacted by overburden

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SMS– Slide 13

Causes of Sand Production

• Once the destabilizing forces overcome the formation strength, the rock will fail.

• Sand production will follow if sand can be transported.

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SMS– Slide 14

Sand Production or Fines Production

Fines migrate through matrix

Sand is the load bearing solids.

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SMS– Slide 15

Why Control Sand Production?Reasons for controlling sand production:• Produced sand disposal • Formation stability• Equipment erosion• Realizing full well productivity

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SMS– Slide 16

• Cumulative sand production– e.g., # lbm per well per day

= ?– plugs equipment or reduces

efficiency

• Production shut-down– routine separator cleaning

required– high-cost activity

• Sand clean-up required– oil removed before disposal

Reasons for Sand Control :Sand

Disposal

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SMS– Slide 17

Reasons for Sand Control: Casing /

Liner Collapse• Failure may occur

due to :– Non uniform lateral

loading as rock is produced.

– High axial compressive load due to slumping of the overlying casing-bearing formation.

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SMS– Slide 18

Reasons for Sand Control: Sand

Erosion• Sand production can cause erosion in both

surface and downhole equipment such as :

Downhole Surface

Blast Joints Chokes

Gas lift Equipment Elbows / Tees

Pumps Metering Devices

Safety Valves Flow line

Circulating sleeves Flanges

Nipples Wellhead

Tubular Valves

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SMS– Slide 19

Reasons for sand control :Well ProductivityAs a stimulation treatment option:

– Sandface completions can enable a well to produce at or near full potential while avoiding sanding problems.

A properly completed well will:– Enable higher production rates to be

safely achieved.– Retain formation stability at higher

drawdown pressures.

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Sanding MechanismsKey points:• Sandface completions relate to the control

of the load bearing solids within the formation structure– some fine production occurs from most wells– production of fines may not be a problem

• Sand production is a function of:– formation characteristics– fluid flow conditions (flow rate and

drawdown)– produced fluids

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SMS– Slide 21

What is Gravel Pack?

Consists of sized

particles placed in

the annular space

between an

unconsolidated

formation and a

centralized

screen.

Open ( EGP)or

cased hole ( IGP).

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SMS– Slide 22

Typical Gravel Pack Completion ( IGP)

Packer

Tubing

Blank Pipe

Sump Packer

Proppant(gravel)

Casing

Seal Assembly

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Horizontal Open Hole Gravel PackingTwo main placement techniques:• Water packing

– brine carrier, high rate, low concentration– sustained circulation required during job

• Alternate path– viscous carrier, low rate, high

concentration– sustained circulation not required

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SMS– Slide 24

Fracturing

StimPAC

Gravel Pack

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SMS– Slide 25

Gravel Placement Methods• Gravel Pack

– 1-5 BPM - pumping brine with low concentration gravel. Typically (1 to 2 PPA).

– Treatment pressure below fracture pressure.• High Rate Water Pack (HRWP) & GelPACs

– Treatment rate above 5 bpm • Pumping brine with low concentration gravel.

Typically (1 to 2 PPA).( HRWP’s) .• Pumping viscous fluid with high concentration gravel.

Typically (4 to 8 PPA).( GelPACKS) .– Treatment pressure may reach fracture pressure in lower

permeability or highly damaged wells.• Frac-n-Pack or StimPAC

– 5 to 40 BPM - pumping viscous fluid with “ramped” concentration gravel. Typically (0.5 - 15 PPA)

– High Rates Erosion, Burst , Collapse (Stronger Equipment Required).

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SMS– Slide 26

PPA

Pound of Proppant per gallon Added (PPA)

• Volume that the proppant occupies is given by:

• Total volume is given by: 1 gallon +: Absolute proppant

density [ppg]

=

+

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SMS– Slide 27

GP Equipment

SKID PUMP UNIT

WASP

HIGH PRESSURE LINE(Treating Iron)

SAND SILO

HYDRAULIC POWER UNIT

BLENDER for

Fluids or Brine

Mixing

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SMS– Slide 28

Sand Silo

HOSE FEEDING FLUID (4-in)

Two 4-in Hoses to Triplex

•4-in Manifold on TriplexHas a densitometer for gravel conc.•Max. Rate w/WASP’s C-PUMP ~ 5 bpm•1 Hose for recirculation if C-Pump is pumping at rates higher than treatment (Triplex) rate

Go to

Equipment

Set Up

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SMS– Slide 29

Water and Sand Proportioner (WASP)• Stainless Steel

construction• Accurate gravel

addition from 0.5 to 6 ppa.

• Simple design with min. moving parts.

• 1 bbl Stainless Steel Mixing Tub

Go to Equipment

Set Up

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SMS– Slide 30

WASP - Rig-Up

Water / BrineDownhole

Slurry

Gravel

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SMS– Slide 31

Barge Operations

35 BPM13,500 psi700K lbs Prop

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SMS– Slide 32

Slotted Pipe

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SMS– Slide 33

Slotted Pipe

• Applications :– Standalone screen for open hole

• Advantage :– Fixed gap– Cost

• Disadvantage :– Low open area– Erosion and plugging resistance

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SMS– Slide 34

Wire-wrap Screen

• A single wire rolled around a perforated base pipe with a fixed gap opening

• Slip-on type• Wrap on pipe type

Perforated base pipe

Wrap wire

Rib wire

Controlled gap

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SMS– Slide 35

Wire-wrap Screen

• Applications :– Cased and open hole gravel pack– Stand alone screen for open hole

• Advantage :– Fixed gap– Cost– Heavy duty application

• Disadvantage :– Plugging and erosion in standalone application

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SMS– Slide 36

Pre-pack Screen

• Two concentric wire wraps with gravel placed in the annular space

• The thickness of the gravel layer can be varied to meet special needs

• May be subject to plugging• Offers a redundant sand

retention method

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SMS– Slide 37

Pre-pack Screen

• Type of gravel :– Dry gravel (12/20, 20/40, 16/30,…)– Resin Coated Gravel

Outer jacket

Pre-packed gravel

Inner jacket

Perforated base pipe

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Plugging of PPS in unsupported wellbore

Screen FormationGravel Fines

Permeability reducing fines, which have been produced from wellbore collapse

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SMS– Slide 39

Pre-pack Screen

• Application :– Cased and open hole gravel pack– Standalone screen for open hole

• Advantage :– Redundancy for a void in gravel pack

• Disadvantage :– Plugging– Increased OD

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SMS– Slide 40

Mesh Type Screen

Woven Wire MeshPorous Metal Fiber Stainless Steel Wool Stabilization Bed

• Use a number of layers of woven wire mesh that form a filter designed to retain formation sand

• Size measured in micron (from 60 to 250 micron)

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SMS– Slide 41

MeshRite

Stainless Steel Wool

Stabilization Bed

The fibre mesh provides:• Large Effective Inflow Area • Broad pore size distribution 15 - 650

micron• Standard and High Compression

bed

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SMS– Slide 42

STAR Screen

• Final assembly is flush.• Cartridges are integral to base pipe.• Require thicker/heavier base pipe.

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SMS– Slide 43

Mesh Type Screen

• Application :– Open hole gravel pack– Stand alone screen for cased and open

hole

• Advantage :– Plugging resistance

• Disadvantage :– No fixed gap (requires high quality

control)

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SMS– Slide 44

Expandable Screen

ExpandableBase Pipe

Attach filtersonto base pipe

ExpandableBase Pipe

FiltrationMedia

ExpandableShroud

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SMS– Slide 45

Expandable Screen

• Applications :– Open hole– Cased Hole

• Advantage :– Increased OD/ID ratio– Wellbore stabilization

• Disadvantage :– Cost– Collapse resistance

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SMS– Slide 46

Features on Screen

• Alternate Path Technology :– Schlumberger has exclusive license

Transport tubes

Packing tubes

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SMS– Slide 47

Features on Screen

• Fiber Optics

• Inflow Control Device for long horizontal open hole completed with standalone screen

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SMS– Slide 48

Screen Considerations

• Inflow area (screen and base pipe)• Pack thickness• Gravel placement (O.D)• Clearance

– Fishing– Dogleg severity/Installation

• ID for logging, selective equipment or productivity

• Screen nominal size is the screen base pipe OD

• Thread type and screen mechanical properties

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SMS– Slide 49

Screen Failure

Erosion during pumping

Remedial TreatmentsFlapper not hold or poor filtration on Injection well

Incomplete Perforation Packing

Tensile failure

High drawdown and plugging

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SMS– Slide 50

Formation Sampling

The first step to select screen or gravel to retain the

sand

is to obtain representative samples of formation sand.

Full Core.- (If possible 2-3 ft within the

formation)

Side Wall Core (wireline)

Produced Sand (fine grains)

Bailed Sand (coarse grains)

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SMS– Slide 51

Sand Size AnalysisParticle Size Measurement

• Sieving

– Very fine particles can adhere to the larger particles and agglomerate underestimation of the fines in the analysis.

– Sieving analysis can only measure down to 44 microns.

– Result of sieving analysis is reported as the accumulative weight vs the particle size.

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SMS– Slide 52

Particle Size Measurement

• Laser Diffraction method

– Measures fractions of sand electronically.

– It can detect more fines in the sand since sand samples are suspended in a fluidized stream than the sieving.

– It can measure down to 0.5 micron.

– Result of laser analysis is reported as the accumulative volume vs the particle size which is equivalent to the results of sieving analysis.

Sand Size Analysis

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SMS– Slide 53

Cumulative Log Diagram (S-Plot)

or PSD Graph

US Sieve Weight Cumulative

number retained % %70 0.08 1.38 1.38100 0.43 7.43 8.81140 0.79 13.64 22.45

200 1.21 20.90 43.35270 1.29 22.29 65.64325 0.57 9.84 75.48400pan 1.42 24.52 100.00

Total 5.79 gr.

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SMS– Slide 54

Formation Analysis - Cumulative PSD

Cumulative Log Diagram

0%

20%

40%

60%

80%

100%

0.0010.0100.100Grain Diameter (inches)

Sample A Sample B

Cu

m.

% b

y W

eig

ht

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Cumulative Log Diagram (S-Plot)

100 90 80 70 60 50 40 30 20 10 0

8 12 16 20 30 40 50 70 100 140 200 270 325 400 pan

Grain Size (in)o

o

o

o

o

o

o

D 50

D 40

D 90

D 95

D 10

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SMS– Slide 56

Definitions on PSD

• From Tiffin et al., SPE 39437

• Fines are defined as < 325 mesh (44 m) particles

• Uniformity Coefficient = D40/D90

– Well-sorted formations have low values for D40/D90

• Very uniform sand: D40/D90 = 1.3 to 1.5

• Well-sorted formation: D40/D90 < 3

• Poorly-sorted formation: D40/D90 ~ 10

• Sorting Coefficient = D10/D95

– Very sensitive to fines content

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SMS– Slide 57

Formation Fines

• Small weight % of fines translates into an alarming number of particles

• Problems start with only 5% of fines in a typical formation

• Best candidates for SAS completions have a fines content ~ 2%

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SMS– Slide 58

Gravel Pack Sizing

Sand Gravel

•Gravel size(Dg50) vs Sand size(Ds50)

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SMS– Slide 59

Gravel / Sand Ratio < 6

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SMS– Slide 60

Gravel / Sand Ratio 6 - 10

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SMS– Slide 61

Gravel / Sand Ratio > 10

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SMS– Slide 62

Gravel Permeability Comparisons

In situ Gravel Permeability (Zero Closure Stress)

US Sieve Number Range

Description PermeabilityMillidarcies

50/70 Resieved Sand 30,000

40/60 Resieved Sand 45,000

30/50 Ceramic (“EconoProp”)

230,000

20/40 Resieved Sand 120,000

20/40 Ceramic (“EconoProp”)

340,000

20/40 Ceramic (“CarboLite”’)

540,000

Man made proppants have 300-500% more permeability

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SMS– Slide 63

Screen OD

• Cased Hole : 0.75” minimum clearance recommended– Gravel placement– Fishing

• Open hole :– 8.5” open hole

• Gravel pack : 5-1/2” screen

• Standalone screen : 5-1/2” or 6-5/8” screen

– 6.25” open hole• 4” screen

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Gravel Volumes

• Practical guidelines based strictly on experience :

• Use annular volume of screens and blank plus :

– New zones

Good clean formations 0.25 cu.ft/ ft. perfs

Dirty, low perm formations 0.25 - 0.5 cu.ft/ ft. perfs

– Re-completions 0.5 - 1.5 cuft / ft.

perfs

(zones have produced sand)

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SMS– Slide 65

Absolute and Bulk Density• Absolute density of a gravel is the density of the

grain and is given by:

I.e: Pacsan: SG = 2.65 , 22.1 ppgIsopac: SG = 1.60 , 13.3 ppg

• Bulk density of a gravel is the density of the bulk that includes the air between grains and is given by:

I.e: Pacsan: 13.3 -14.3 ppg = 99 - 107 #/ft3

Isopac: 7.6 - 8.6 ppg = 59 - 64 #/ft3

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SMS– Slide 66

PPA and Yield

Pound of Proppant per gallon Added (PPA)

• Volume that the proppant occupies is given by:

• Total volume is given by: 1 gallon +: Absolute proppant

density [ppg]

=

+

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SMS– Slide 67

Slurry Density

Then:

Where:: density of slurry: density of base fluid: Proppant concentration

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SMS– Slide 68

Slurry density calculation

Example:Calculate the slurry density in ppg when 8

pounds of Pacsan are added to 1 gal of 9.6 ppg brine.

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Gravel Pack Calculations

1. Blank / Casing annular volume [ft3]

100% or less of this volume may be considered as the

excess gravel. This ensures a complete screens / formation

coverage. BLANK / CASING ANNULAR VOLUMEV1

[in][ft]

[in]

V1 = [ft3]

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Gravel Pack Calculations

2. Screen / Casing annular volume [ft3]

This volume must be filled up with gravel

SCREEN / CASING

ANNULAR VOLUMEV2

[in]

[in]

[ft]

V2 = [ft3]

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Gravel Pack Calculations

3. Gravel Injected in perforations [ft3]

This is the volume of gravel require to pack the perforations

PERFORATIONSV3

[ft]

Where:

Cp = 0.25 to 1.5 [ft3 / ft] depending on formation characteristics

V3 = [ft3]

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Gravel Pack Calculations

Total Volume of Gravel: Vg = V1 (%) + V2 + V3

Weight of Gravel (Wg) :

Where: b : bulk density [ppg] Vg : gravel volume [gal]

Carrier fluid volume (VCF) :

%: filling percentage of the blank/casing area

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Gravel Pack Calculations

• Tables can be built with % of blank coverage, depending on the gravel type and concentration.

Pacsan

Isopac

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Gravel Pack Calculations

• We call slurry to any fluid that contains proppant.

• The relation between carrier fluid and slurry is given by:

In this equation the units of VSL will depend on the units of VCLF

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Gravel Pack Calculations

• Amount of gravel injected in the formation– This will respond to a mass balance

Wform= Wg- (W2+WRO+WSTL) [#]

Where:

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SMS– Slide 76

Gravel Pack Packer

Sump Packer

Gravel Pack Extension

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SMS– Slide 77

Cased & Perforated Completion Configurations

pjfc

fcpj

p jf c

f cp j

o o

pjfc pj

fc

fcpj fc

pj

Single SingleSelective

Dual

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SMS– Slide 78

DualSelective

DualSelectiveW/ Spacer

Packer

p jf c p j

f c

f cp j f c

p j

p jf c p j

f c

f cp j f c

p j

Cased & Perforated Completion Configurations

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SMS– Slide 79

pjfc

fcpj

oo

>1,000 Components

LocatorsSeal SystemsQuantum PackersCirculating HousingsShear SubsBlank PipeIsolation TubingMultizone Seal AssembliesFluid Loss Control EquipmentScreenSump Packers

Fit-for-purposeWell SpecificConfigurations

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SMS– Slide 80

Questions…