Sand Control.pdf

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Sand Prediction and Sa Sand Control Giuseppe Ripa

Junior Production Engineering/Sand Control

Map of Sand Producing Areas

Usually associated with younger Tertiary formations such as the Miocene or Pliocene Age Sands Approximately 70% of the world’s oil and gas reserves are contained in poorly consolidated reservoirs where solids production is likely to become a problem during the life of the field. [JPT October 1998, Page 80 ]


Sand Problems in ENI-E&P and Sand Completions

West Africa & GOM

On & Off-Shore Italy

On-Shore Italy

Sand

Thin Sand-Shale Sand-Shale Interbeds

Sand-Shale Sand-Shale Int erbeds

500-4800 m

600-3500 m

1200-1700 m

30-350 µm

20-150 µm

50-150 µm

200-8000 200-8000 mD mD

20-500 mD

200-2000 200-2000 mD mD Completion per year

Over 50% of the total production (~1700 BOED) is coming from reservoir requiring sand control

Cumulative Completions

120

1800

100

1500

80

1200

60

900

40

600

20

300

0

0 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004

Year Junior Production Engineering/Sand Control

Consequences of sand production • Wellbore fill • Equipment problems due to sand fill • Sand erosion of downhole and surface equipments • Sand accumulation on surface and Sand Disposal •

• Production Loss • Casing / Liner Collapse


Forces Aiding in Resisting Sand Production

• Intergranular frictional forces and bonding (cementation) help resist grain movement • Capillary Pressure adds further grain-to-grain bonding Water-Wet Grains Oil Flow


Forces Contributing to Sand Production

• Pore pressure relieves frictional forces • Production of wetting phase reduces capillary pressure forces

Oil and Water Flow


What causes sand production? •

Totally or weakly unconsolidated formations

•

Changing stresses in the near wellbore area

•

Water Production

•Overburden •Cementing •Capillary •Drag


Sand Production Mechanism

•

Primer:

– Rock shear collapse owing to in situ stress forming “shear band”

•

Sand Production:

– Erosion of perforation tunnel around “shear band” by the produced fluids


Detecting sand production • Erosion of Equipment • Acoustic Detectors • Sand Traps/Desanders

Fluenta Acoustic Sand Detector

Sand Probe Junior Production Engineering/Sand Control

Predicting sand production

• • • • • • •

Experience in the area Offset well production data Drilling data Core sample evaluation Sand Flow Test Logs Computer modeling


Predicting Sanding Potential SAND FLOW TEST RESULTS ) 220 2 m c / g 200 k ( E R U S S E R P E L O H M O T T O B

PERFS CLEAN-UP D50=40- 60 µm

180

FINES REMOVAL D50=3 - 7 µm

CONTINUOUS SAND INFLUX D50=18 µm

2/16"

160

3/16"

140

9/16"

6/16"

4/16"

S =

5/16" 10/16"

120 100

11/16" 12/16"

8/16"

CHOKE SIZE

S = 8 0

- 1 7

S = 0

80 0

50

100

150

200

250

300

GAS FLOW RATE (ksm3/d)

FORMATION SAND : D50 = 22 - 44 µ m Junior Production Engineering/Sand Control

What can be done about sand production? • Rate Exclusion

– Drawdown Control – Selective Perforations • Mechanical Methods – “ Downhole Filter”

– Slotted Liner and Screens – Gravel Pack • Chemical Methods

– Consolidation of the formation – Resin-Coated Sand


Drawdown control

• Reduction in production rate will reduce drag forces and drawdown to provide reduced risk of sand production • Procedure: – Slowly increase rate until sand production begins to increase – Sequentially reduce flow rate until the sand production declines to an acceptable level • Attempting to establish maximum flow rate in conjunction with stable arch


Selective Perforating Practices Once formation characteristics are known, perforating strategies can be evaluated.

If possible, only high strength intervals can be perforated.

Low Strength

For high rate wells this will require a high shot density to prevent additional pressure drop and associated sand production. However, high shot density lead to perforation interaction which also promotes sand production.

Sand

Higher Strength Sand

The appropriate compromise is key to success . Junior Production Engineering/Sand Control

Slotted Liner and Screens

Slotted Liner (3-6%)

Wire Wrap Screen (6-12%)

Dual Screen Prepack (3-6%)

Slim-Pak Screen (3-6%)

Wire Mesh Screen (15-30%)

Expandabl e Screen (15-30%) Junior Production Engineering/Sand Control

Gravel Pack Consists of sized particles

Gravel Pack Sand

Formation Sand

placed in the annular space between an unconsolidated formation and a centralized screen. Open or cased hole. Screen Junior Production Engineering/Sand Control

Chemical Methods

Consolidation of the Formation

Resin-Coated Sand Junior Production Engineering/Sand Control

Information for designing a sand control FORMATION CHARACTERISTICS

Types of Clays, Mineralogy & water-sensitivity Permeability, Heterogeneity, Height, SBHT & SBHP FORMATION GRAIN SIZING

Sieve Analysis for gravel size selection SLOT SIZING

Gravel Pack vs. FracPack Slotted Liners, Screen only (wire wrapped, prepacked, etc.) TYPE OF WELL

Producer, Injector Deviation & Size Off-shore, On-shore, sub-see


Sieve Analysis Indicates Uniform and Non-Uniform Formations 100 90

) % ( t h g i e W e v i t a l u m u C

80

Poorly Sorted Sand We ll Sorted Sand

70 60 50 40 30 20 10 0 0.1000

0.0100

0.0010

0.0001

G r a i n D i a m e t er ( in c h e s )

Uniformity coefficient:

C= D40/D90

Poorly Sorted Sand:

C> 5 Junior Production Engineering/Sand Control

Gravel Pack Impairment: Saucier’s Results 1. 2

o t i y ) t i k l i / f b ( k a t e i l i m r b e a P e l m a r n e i F P f l a o i t o i i n t I a R

1. 0

0. 8

0. 6

0. 4

0. 2

0. 0 0

2

4

6

8

10

12

14

16

Ratio of Median Gravel Pack Sand Diam eter to M e d i a n F o r m a t i o n S a n d D i a m e t e r (D 50 / d 50 )

GRAVEL PACK

Saucier 5-6 x D50

18

20

• D50 /d50 ≤ 6, good sand control, no formation sand invasion of gravel pack sand • 6 < D50 /d50 ≤ 13, good sand control, but restricted flow due to formation sand invasion of gravel pack sand • D50 /d50 > 13, no sand control, formation sand passes through gravel pack sand

FRACPACK One size larger than Saucier’s Criteria Junior Production Engineering/Sand Control

Commonly Available Gravel Sizes U.S. Mesh Size Range

Grain Diameter Range (inches)

Median Median Grain Diameter Grain Diameter (inches) (microns)

Permeability (darcies)

6-10

.1320 - .0787

.1054

2677

2703

8-12*

.0937 -.0661

.0799

2029

1969

10-20

.0787 - .0331

.0559

1420

652

12-20*

.0661 - .0331

.0496

1260

518

16-25

.0469 - .0280

.0388

986

391

16-30* 20-40*

.0469 - .0232 .0331 - .0165

.0351 .0248

892 630

398 136

30-40

.0232 - .0165

.0199

505

138

30-50

.0232 - .0117

.0175

445

100

40-60*

.0165 - .0098

.0132

335

61

50-70

.0117 - .0083

.0100

254

32

1

* stocked size

Mesh refers to the number of openings per linear inch Junior Production Engineering/Sand Control

Screen Selection Gravel pack and Prepack Screen

– The screen opening is typically between 50-70% of the smallest gravel diameter  For 20/40 mesh sand the smallest gravel is the 40 mesh which has a D50 of 0.0165”  0.0165” x 70% = 0.01155” or 0.012” opening (12 gauge) Screen Only and Slotted Liner

– Screen Opening is approximately equal to the D10 Screen Diameter

– Fishing (7” csg: IDmax= 4” screen; 9 5/8” csg: IDmax= 6” screen ...) – ID for logging and or selective equipment


Screen Length - Centralizers • Length normally 5’ above and below the perfs • Length needs to be considered for shipments (rig basket @ 30’, airplane @ 20’)

• Centralizer spacing to avoid any casing contact Open hole, Bow-Spring type Cased hole Weld-on Lug type

• Recommended centralizer OD clearance from casing ID to be 1/8” to 1/4”


Gravel and Screen Summary • Representative formation samples are required for gravel pack sand size design • Gravel pack sand is typically designed to be six times larger than the formation sand at the median grain size • Only gravel pack sand meeting API RP58 specifications should be used • Gravel pack sand substitutes are available for special applications • In a gravel pack the screen serves only to retain the gravel pack sand • Prepack screens offer “second line of defense”


Cased Hole Gravel Pack 1

Slurry is injected down the workstring

2

The slurry crosses over to the annulus below the packer, depositing sand adjacent to the screen

3

The carrier fluid leaks off through the screen and is carried back to the surface via the washpipe and crossover tool, crossing back over to the casingworkstring annulus just above the packer

MULTI-POSITION SERVICE TOOL GRAVEL PACK PACKER FLOW SUB OR CLOSING SLEEVE

BLA NK PIPE

SCREENS

O-RING SUB TELLTAL E SCREEN

SUMP PACKER


Quantum Packer Assembly Service Tool Quantum Packer Circulating Ports G.P. Extension Ball Seat Crossover Ports

Closing Sleeve Lower Seal Bore

Check Valve Indicating Collet Wash Pipe

Indicating Collar

Safety Shear Sub Blank Pipe

Perforations

Screen PBR

Sump Packer

Seal Assembly


Setting the Quantum Packer Service Tool 1. Packer at Set Depth - Drop Ball - Apply Pressure, set begins at 1,000 - 1,200 psi - Pressure Test Annulus and pull test to test set. 2. Release Service Tool - Apply 2,200 - 2,400 psi - Slack off 15K down - Pick up 3. Ball Seat Sti ll i n Place

Quantum Packer Set Position

Ball Seated on Ball Seat “Fluted” Crossover Sub


Service Tool Operations Blowing the Ball Seat (Openin g Crossover Port s) Pick up to t he reverse-out posit ion - Pressure Drill Pipe to 3,750 - 4,000 psi - Ball seat shifts and pressure is vented to the annulus. Formation is isolated from pressure spike.

Ball Seat is Shifted Open

- Fluids are spotted in this position. Collet Indicates at Upper Packer Seal Bore Shoulder Collet Drags the Port Closure Sleeve Into Closed Position


Service Tool Operations Circulating Position

To Reach Circul ating Posit ion - Pick up 18 inches at the tool or until collet indicator causes 15K increase in hook load

Circulating Ports are Open

- Circulating ports are now above packer bore. - All circulating fluids must flow through the screen, upwrd through the wash pipe and exit to the annulus.

Check Valve Allows Only Upward Flow


Service Tool Operations Reversing Out To Reverse Out: - Apply enough annular pressure to overcome hydrostatic in the pipe. Typically 500 psi. - Pick up service tool until pressure falls off. This occurs when crossover port clears the top of the upper packer bore. - Continue pumping

Check Valve Closed

- Check valve prevents slurry from entering the inside of the washpipe. - If annular fluid density is greater than the D.P. fluid density, 500 psi back pressure must be trapped on the tubing side to keep check valve closed.

Lower Set of Seals Still in Packer Bore Port Closure Sleeve Is Closed


ICGP – General Procedure

• • • • • • • • • •

Well site preparation Casing clean-up Fluid filtration Casing perforation Killing and fluid loss control Buttomhole clean-up Running and setting GP assembly Gravel placement Running and setting completion string Well clean-up


Casing Cleaning

• Prior to gravel packing the casing should be thoroughly cleaned with a bit and a scraper to remove any dirt or scale • Circulation of completion fluid, mud solvents, scouring material, acid, and caustic solutions may be required to fully remove these material • The casing should also be pressure tested for leaks on older wells

Brine Fresh or Seawater Gel pill Chemical Fresh or Seawater Caustic Fresh or Seawater Gel pill Drilling Mud


Casing Cleaning – when to stop?

well returns

U T N

irreducible minimum Injection fluid

Time (hrs)

• The irreducible minimum of solids is taken as the cleanliness value such that the level of cleanliness can only be increased marginally over lengthy circulating times Junior Production Engineering/Sand Control

Fluid Filtration • Clean completion, workover, injection, and treatment fluids are imperative to avoid formation damage and gravel’s permeability reduction. • Ideally, all solids larger than 1/6 of the average pore size of the productive formation should be removed from fluids.

•

Methods of determination

– – – •

From Kozeny: Dpore = √k From Coberly: Dpore = D50/6.5 SEM measurements of pore throat diameters from closely spaced core samples

Particle size and damage potential

– – –

Dpart > 0.33 Dpore 0.1 Dpore < Dpart < 0.33 Dpore Dpart < 0.1 Dpore

instant bridging of core invasion of core and deposition unrestricted passage


Filtration Systems

Maintaining the clarity of the completion fluid can be very expensive and time consuming. Diatomaceous earth filter in series with a downstream absolute rated filter have proved to be an effective and economical fluid cleaning system.


System Layout


Perforating • Each shaped shaped charge charge exer exerts ts up up to 4 milli million on psi psi on on the the reserv reservoir oir.. • This This force force crush crushes es and and compac compacts ts the the reserv reservoir oir rock rock and and perfo perforat rating ing debris can plug perforating tunnels.

Result:

Limited leakoff and poor injectivity


Clean Perforations Limit damage both within and surrounding perforations

Low debris/carrot free charge



Underbalanced perforating



Crushed zone removal



Limit use of fluid-loss control material in empty perforations



Damage Prevention is Also Critical


Perforation Cleaning • Underbalanced Pr Pressure – sele selected cted on form formatio ation n perme permeabi ability lity and Oil Wells Gas Wells

• Backflow – When perfo perforati rating ng is is perform performed ed overb overbalan alanced ced a period of backflow is sometimes used to clean up the perforations with a dedicated string


Perforating for Gravel Packs & Frac-Packs •

Numbe Numberr of perfo perforat ration ions s shou should ld be be suffi sufficie cient nt to to allow allow unimpa unimpaire ired d (flow (flow maximi maximize ze infl inflow ow area)

•

Larg Large e diam diamet eter er cha charg rges es rec recom omme mend nded ed whe when n grav gravel el pla place ced d in tun tunne nels ls

– Enha Enhanc nce e gra grave vell pla place ceme ment nt in tu tunn nnel elss – Enh nhan ance ce fl flow ow of pr prod oduc uced ed fl flui uids ds



Depth of pe p ene netration tration not cri critic tica al Various studies (SPE 71458, SPE 38633, SPE 68932) indicate that cavity is often not formed when perforating in unconsolidated un consolidated formations. “Disturbed” zone is filled with dilated formation material. Need to concentrate on tunnel through casing and cement


Perforating for Gravel Packing •

Entry holes less than 0.6 inches result in high pressure drops.

•

Benefits associated with maximized inflow area leads to need for high shot density.

•

Perforations must be fully packed to prevent excessive pressure drop, and screen plugging and/or erosion.

2

Linear Flow

20

Perfs diameter (in.)

1.6

r e t e m 1.2 a i D s 0.8 f r e P

Radial Flow

16

Effective shots per foot

12

8

0.4

f p s e v i t c e f f E

4

0

0 0

1

2

3

4

5

6

7

8

SKIN

9

10

11

12

13

14

15

Cement Casing Gravel Pack Sand Screen


High productivity requires: complete packing, large entry holes Pressure Drop (psi) Pack

Permeability

Flow Rate

3/8” Diameter

1/2” Diameter

3/4” Diameter

Material

(mD)

(bpd/perf)

Perforation

Perforation

Perforation

Formation

1,000

1

450

190

64

10

27,760

9,280

2,091

1

2

1

0.4

10

55

21

6

Sand 20/40 Mesh Gravel

119,000

0.888 L µ Q Q⎤ ⎡ 13 ∆P = + 9.1× 10 β L ρ ⎢ ⎥ KA ⎣ A ⎦

2

A= Perforation Cross-Sectional Area (ft 2) β= Inertia Coefficient (ft-1) ∆P= Differential Pressure (psi) K= Permeability (Darcies) L= Length Of Perforation (ft) µ= Viscosity (cp) Q= Flow Rate (bpd) ρ= Density Of Fluid (lb/ft3)


Use of Fluid Loss Control Material in Empty Perforations •

This should be avoided whenever possible.

Casing

•

Increased viscosity will decrease leakoff rate without halting it.

•

If leakoff completely stopped, perforations will not be able to be packed and it will be difficult to remove FLCM prior to prepacking.

•

Filtercake

Spearheading acid in front of prepack treatment may help re-establish initial leakoff rates.

Formation Cement


ICGP critical issue Ideal Wellbore

• Cased-Hole Gravel Packs still exhibit high skins • Improved Cased-Hole Gravel Packing methods have helped but have not solved problem • Implication is that perforations may not be completely filled with gravel and may not bypass the damaged zone

Damaged Zone

Actual Wellbore

Pumping Pressure < Fracture Pressure With Leakoff

Without Leakoff


Open Hole Gravel Pack – Slurry is injected down the workstring – The slurry crosses over to the annulus below the packer, depositing sand adjacent to the screen – The carrier fluid leaks off through the screen and is carried back to the surface via the washpipe and crossover tool, crossing back over to the casing-workstring annulus just above the packer


OHGP – General Procedure

• • • • • • • • •

Underreaming of the borehole Well site preparation Fluid filtration Killing and fluid loss control Bottomhole clean-up Running and setting GP assembly Gravel placement Running and setting completion string Well clean-up


Mechanism of Bore Hole Collapse Clay

Fluid Loss

Filter Cake

Pov

Sand Uncontroll ed Fluid Loss if BRINE or HEC (linear pol ymer) are used

Coll apse due to aqueous fluid - clay interactions

Controlled Fluid L oss improves Bore Hole stability

Modi fications of Rock Mechanical Prop erti es and Stress in-situ Equi lib riu m are responsib le for Bore Hole Collapse. Swelling alone does not explain the behavior of this kind of rock. Junior Production Engineering/Sand Control

OHGP vs. ICGP •

Due to its large flow area the OHGP has a better inflow performance than ICGP

•

The difference between the OHGP and the ICGP deliverability can be negligible at low rates but it becomes more marked at high rates

•

The difference between OHGP and ICGP deliverability increases as kh increases

•

The high deliverability of the OHGP can be wasted due to completion constraints (small tbg ID, high FTHP…): in this case ICGP can be more convenient

•

Pressure losses due to incomplete filling of perfs are negligible for high permeability formations whereas they are extremely high in low permeability formations


Important Factors for Gravel Placement • Washpipe size – Must keep area outside the screen larger than area inside the screen; especially in deviated wells where is much easier to create sand bridge • Return Flow Rate – Sufficient to keep an annular velocity of at least 1 ft/sec at end of screen (turbulence helps to suspend sand particles, annular velocity must kept less than 2.77 ft/sec to minimize turbulent effects) • Low-viscosity carrier fluids result in high-quality gravel pack in nearly all situations • For cased-hole completions, high fluid loss rates and prepacking both have positive effect


Gravel Pack Techniques

(I)

• Slurry Pack

– Cased or open hole completions – Typically used in very high permeability formations – The carrier fluid is viscosifed – Sand concentrations can range from 3 to 15 ppg • Water Pack – Cased or open hole completions, horizontal wells – Typically used in low permeability formations – Brine or slightly viscosifed brine – 2 bpm of Returns required – Lower sand concentrations required – Very good annular packing technique



(II)

• High Rate Water Pack

– Water or slightly viscosifed water – Higher rates required to fill perforations and create numerous mini-fracs into the formation in high permeability wells • Typically 5-10 bpm or 1 bpm per 10 ft of perforations – Sand concentrations 0.5-4 ppg – Additional Surface Equipment is required



(III)

Frac-Packing is a general term applied to the process of combining a hydraulic fracture with a gravel pack.

STANDARD

FRAC-PACK

GRAVEL PLACEMENT P
Kd

GRAVEL PLACEMENT P>Pfrac

The main purpose is to provide the optimum combination of productivity improvement through damage bypass, and well life improvement through effective sand control

Kf


FracPack Technique – Used to bypass damage in the near wellbore area – Mini-Frac used to gather data about the formation to fine-tune the Frac design – Short (10 < L < 100 ft), Wide Fracs – Tip Screen-out designed to widen the frac and allow a high sand concentration at the wellbore

The process of injecting a slurry of gravel (proppant) and a fluid into the formation, faster than the formation can accept it.


FracPack: Step Rate Test •

Preliminary Test: – Step Rate Test (generally with brine) • Fracturing pressure • Propagation pressure • Closure pressure

SRT

BHP

Frac Extended Frac Matrix Injection Rate

P

Break Down

P Ppropag

Frictions

PNET

ISIP

PBreakDown = 2 ( /(1- ))( o- p) + PBreakDown = 2 ( o- p) + p PClosure = ( /(1- ))( o- p) + p

Pclosure

p

values:

[ mud ] [ brine]

0.28 (average)

theoretical: from the lab: Adriatic Sea:

Time

o

0-0.5 0.22-0.33 0.25-0.35

= sigma overburden = sigma pore = Poisson’s coefficient

p


FracPack: PClosure e Leak Off •

Preliminary Test: – Injection Test (with carrier fluid) • leak off coefficient (from fall-off)


Tip Screen Out Hydraulic Fracturing

An advanced hydraulic fracturing process designed to intentionally deplete the pad and have the slurry bridge on the perimeter of the fracture, locking the fracture length and height.

Slurry injection is continued to balloon the fracture creating a very wide, (1”) highly conductive fracture to by-pass near wellbore damage in high permeability formations. Junior Production Engineering/Sand Control

FracPack Final Design and Execution • Frac model calibration by measured data from Step Rate Test and Injection Test (P frac, Pc, Ct) • Main Treatment: – Pumping of designed treatment • Changing of the pumping parameters if TSO is not achieved (pump rate reduction, open return flow) • Fall off to close the fracture • POOH workstring and RIH completion tubing string • Clean up


Barbara C 24 Liv ello Q HRWP Tbg Pressure

Annulus Pressure

Mix Ratio

Flow in

Return

2200

11

2000

10

1800

9

1600

8

1400

7

) i s p 1200 ( e n o i s s 1000 e r P

6 5

80 0

4

60 0

3

40 0

2

20 0

1 0

0 14.52.48

15.07.12

15.21.36

15.36.00

15.50.24

16.04.48

16.19.12

Time (hh:mm:ss)


16.33.36

ENI - DIVISIONE AGIP, Adriatic sea, Barbara C - Well 24 - level O-O1 Frac Pack

1200

12

1000

10

800

8

) i s p ( e n 600 o i s s e r P

6

400

4

200

2

0

0 1 4 : 1 2 : 7 0

9 0 : 3 2 : 7 0

7 3 : 4 2 : 7 0

5 0 : 6 2 : 7 0

3 3 : 7 2 : 7 0

1 0 : 9 2 : 7 0

9 2 : 0 3 : 7 0

7 5 : 1 3 : 7 0

5 2 : 3 3 : 7 0

3 5 : 4 3 : 7 0

1 2 : 6 3 : 7 0

9 4 : 7 3 : 7 0

7 1 : 9 3 : 7 0

5 4 : 0 4 : 7 0

3 1 : 2 4 : 7 0

1 4 : 3 4 : 7 0

9 0 : 5 4 : 7 0

7 3 : 6 4 : 7 0

5 0 : 8 4 : 7 0

3 3 : 9 4 : 7 0

1 0 : 1 5 : 7 0

9 2 : 2 5 : 7 0

7 5 : 3 5 : 7 0

5 2 : 5 5 : 7 0

3 5 : 6 5 : 7 0

1 2 : 8 5 : 7 0

9 4 : 9 5 : 7 0

7 1 : 1 0 : 8 0

5 4 : 2 0 : 8 0

3 1 : 4 0 : 8 0

1 4 : 5 0 : 8 0

9 0 : 7 0 : 8 0

7 3 : 8 0 : 8 0

5 0 : 0 1 : 8 0

3 3 : 1 1 : 8 0

1 0 : 3 1 : 8 0

9 2 : 4 1 : 8 0

7 5 : 5 1 : 8 0

5 2 : 7 1 : 8 0

3 5 : 8 1 : 8 0

1 2 : 0 2 : 8 0

9 4 : 1 2 : 8 0

7 1 : 3 2 : 8 0

5 4 : 4 2 : 8 0

3 1 : 6 2 : 8 0

1 4 : 7 2 : 8 0

Time (hh:mm:ss) Tbg pressure

Annulus pressure

Rate

Mix ratio


9 0 : 9 2 : 8 0

) a p p ( o i t a R x i M ; ) m p b ( e t a R

Points to Consider When Designing a Fracture Treatment • The purpose of a hydraulic fracture is different in hard, low-permeability formations than in soft high-permeability formations

– Low-perm formations require long fractures for stimulation – High-perm formations require short fractures for damage bypass • The goal of the fracture treatment must be considered early in the design • Fluid selection should match application


FLOW EFFICIENCY 100

Total 26

Total 25

Range

Range

80 % E60 F e g a r 40 e v A 20

70-114

Total 22

80-97

Range

20-90

0 FRAC-PACK

ICGP

OHGP Junior Production Engineering/Sand Control

Clean Times & Performances 1.2

CF 100%

ICGP FracPack 1.0

y a p t e n / I P o d u e s P

TCP

OHGP

0.8

CF=85-100% 0.6

ICGP 0.4

CF=30-50% 0.2

0.0 0

100

200

300

400

500

600

700

800

900

1000

1100

Flow period (dd) Junior Production Engineering/Sand Control

GRAVEL PACKING: Possible Alternatives •ICGP (Saucier’s Criteria for gravel size, better if even smaller) – suitable for high perm, homogenous sands – no damage inside tunnels and into formation sand

•OHGP

(Saucier’s Criteria)

– recommended for: • high productivity wells • laminated reservoir – requires DIF for drilling and underreaming (no damage) – requires stable boreholes

•ICGP-F&P (TSO, gravel selection with bigger sizes) – recommended for laminated reservoirs – suitable for deep damage by-pass – TSO recommended for maximum productivity, and LONGEVITY



(IV)

• Horizontal Gravel Packing

– – – – – – – – –

Pump Rate and Fluid Velocity (2-4 bpm, 1-3 ft/sec) Alpha and Beta Wave Progression Through Pack Sand Concentration (0.5 - 2 ppg) Placement Procedure and Tool Configurations Liner / Tailpipe Ratio (> 0.80 ratio) Screen / Casing Clearance Screen / Open Hole Clearance Perforation Phasing Shunt tube technique


Horizontal Gravel Packing 

Typically open hole



Must maintain adequate filter cake



Must have ability to remove filter cake after gravel placement

• • •

Dune Height /Hole ID = .65 - .85 Washpipe OD / Screen ID = .8 Superficial Velocity 1 ft/sec - Return Rate


Typical Well GP Configuration S. V. S. V.

S. V.

CSG size 7”

CSG size 9" 5/8

NO SAND CONTROL SHORT SELECTIVE STRING

ICGP

ICGP

ICGP

F V.C

SHORT STRING

ICGP CASING SHOE

OHGP

LONG SELECTIVE STRING

LONG STRING

ICGP

OHGP

CASING SHOE


Gravel Pack Stacked Completions RIH GUNS

PERFORATING

SCRAPER /

RIH AND SET "D" PKR

LAYER "A"

TAPER MILL

WITH TUBING / E-LINE


Gravel Pack Stacked Completions RIH GP ASSEMBLY

PERFORM HRWP

(cont)

RIH PKR PLUG

LEVEL "A"


Gravel Pack Stacked Completions SET PKR PLUG & PERFORM SAND PLUG

RIH GUNS

(cont)

PERFORATE LEVEL “B"


Gravel Pack Stacked Completions

(cont)

RIH RET.PKR PLUG and

RIH GP ASSY

SET PKR PLUG &

RETRIEVE IT

w PROD TBG FOR LEVEL A

PERFORM HRWP


Unconsolidated Sands Completion Criteria NEW WELLS SAND CONTROL DECISION TREE

YES

MULTI-ZONE COMPLETION NO

NO LOWEST ZONE COMPLETION

YES

YES

D50 FORMATION SIZE < 55 µm

NO

YES

YES RES. FLUID CONTACTS DEFINED

NO GEO-SECT. DEFINED

NO

FINES MIGRATION?

YES

NO

YES MULTYLAYERED NO NO

YES

ACTIVE SHALES

SHALES CAN BE ISOLATED OR STABILIZED

NO

YES NO PAY-ZONE > 25 ft vert YES

OPEN HOLE COMPLETION

CASED HOLE COMPLETION


Open Hole Sand Control Completion YES

YES

GAUGED HOLE

FORMATION GRAIN SIZE - D10> 150 microns

NO

NO

MAXIMISE

NO

COMPLETION ID

YES

ZONAL ISOLATION REQUIRED

NO

YES

YES NO

OPERATING WINDOW BETWEEN PORE PRESSURE AND Pfrac > 600 psi

CASING SHOE APPROPRIATELY SET

Available: •No damaging DIF •Effective matrix stimulation (back-up)

NO

YES

REMEDIAL J OB

EXPANDABLE SYSTEM

OPEN HOLE GRAVEL PACK


Cased Hole Sand Control Completion


Through Tubing Gravel Packs or Fracs Sanded up completion

Sand wash

Run Screen on Coil


Through Tubing Gravel Packs or Fracs (cont.) Release Screen from Coil

Fracture or GP Treatment

Sand wash


Through Tubing Gravel Packs or Fracs (cont.) Produce Well

>50’


Typical Screen Dimensions For 2 7/8” Tubing

For 2 3/8” Tubing

0.957” I.D. x 1.63” O.D. 1.38” I.D. x 2.16” O.D.


Flow Profiles Q

P

V

Rate (Q) BOPD

P Through Blank PSI 0.84

Velocity Through Pack Ft/Min 0.0016

144 288

2.83

V

Fluid

0.0055

P 432

5.80

0.0111

576

9.68

0.0185

720

14.4

0.0277

1440

49.8

0.0924

2160

103.4

0.196

For sand production, upward annular velocity must overcome sand settling velocity. Maximum upward velocity never exceeds 5% of this value in this case.

Q

40/60

µ = 1 cp

100’

Settling Velocity Ft / Min 20/40

12.6

40/60

4.0

7 5/8” Csg. Junior Production Engineering/Sand Control

Definition of Sand Consolidation •

Plastic Consolidation - is a method of stopping sand

production

by

artificially

bonding

the

formation sand grains into a consolidated mass. A liquid resin is pumped through the perforations and into the pore spaces of the formation sand. Excess resin is removed either by overflushing the resin or by phase separation. The resin coats the sand grains and then hardens to hold the sand in place. •

Typically utilized in wells that have not previously produced sand.


Conditions favoring consolidation • Short Interval • Lack of previous sand production • Upper zone of multiple completion • Limited sand production tendency • High reservoir pressure • Good sand quality with vertical permeability


Unconsolidated zone to be treated


Preflush Stage Preflush fluid is applied to condition the formation to accept resin .


Resin Stage Low viscosity resin with an affinity for silica surfaces coats each individual grain of sand.


Spacer / Overflush Stage A spacer fluid is pumped down to remove excess resin from sand, dilute the resin, and carry it into the formation.


Catalyst Stage

The hardening catalyst is pumped through the matrix of resin-wet sand, instantly beginning the hardening process.


Resin Coated Sand

• Single stage mechanical filter technique • Thermoset resin • Uses API specification gravel pack sand consolidated with resins • Filters out the formation sand in the perforation tunnels and behind casing


Application of Resin-Coated Sand Slurry Cement Sheath

Formation

Casing

Liquid Resin-Coated Proppant Entering Perforation and Filling Casing

Liquid Resin-Coated Proppant During Placement Junior Production Engineering/Sand Control

Sand Control.pdf

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