c03 --- presentation --- weatherford --- critical velocity ... i... · presented by: scott campbell...

Presented By:Scott Campbell - Weatherford - Denver, ColoradoPetey Erwin – Newfield Exploration - Tulsa, Oklahoma

CVR System

Critical Velocity Reduction

A Combination of Dead Strings, Capillary Injection Foamer and Plunger Lift

1© 2006 Weatherford. All rights reserved.

Critical Flow Rates

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

0 100 200 300 400 500 600 700 800 900 1,000

Wellhead Pressure (psi)

Flow

Rat

e (m

cf/d

)

1.00"/0.826"

1.25"/1.076"

1.50"/1.310"

2.0"/1.78"

1.90/1.61

2 1/16"/1.75

2 3/8"/1.995

2 7/8"/2.441

3.5"/2.867

4.5 11.6 lb/ft

5.5 20 lb/ft

7.0" 26 lb./ft

4.5" Casing w / 2 3/8" Tubing



1.00-in. OD/0.826-in. ID CT

1.25-in. OD/1.076-in. ID CT

1.50-in. OD/1.310-in. ID CT

2.00-in. OD/1.780-in. ID CT

1.90-in. OD/1.610-in. ID API Tubing

2 1/16-in. OD/1.750-in. ID API Tubing



3.50-in. OD/2.867-in. ID API Tubing

4.5-in., 11.6-lb/ft Casing

5.5-in., 20-lb/ft Casing

7-in., 26-lb/ft Casing

4.5-in. Casing w/2 7/8-in./ Tubing




Typical Completion:

2 3/8” Production Tubing

4 ½” Casing 11.6# Casing

Extended Perforation Interval


Critical flow requirements assuming 200-psi WHBP(FTP):

CFR for 2-3/8” = 406 mcf/dCFR for 4-1/2” = 1.63 MMcf/d

Typical Completion

• Production String: 2-3/8”, 4.7 lb/ft

• Casing: 4-1/2”, 11.6 lb.ft

– 4.000-in. ID– 3.875-in. drift– Flow area: 12.5683 in.2

2 3/8”tubing

Extended perforation interval

4 ½” casing

A B


4 ½”, 11.6-lb/ft Casing

2 3/8” Production Tubingwith

2 7/8” Velocity Reduction String(Dead String)


4 ½” Casing, 2 7/8” Dead String Only

2 3/8”X-LOC nipple

2 3/8” Heavy Duty Flow Sub

36- ¾” holes

2 3/8” X-Nipplew/ retrv. plug

2 3/8” X 2 7/8”Crossover

2 7/8” Tubing “Dead String”

2 3/8” Tubing

Shear-Out Sub

4 ½” Casing• Production String: 2 3/8”

• Dead String: 2 7/8” ULTRA FLUSH– NO couplings = 2 7/8” = 2.875” OD

• Casing: 4-1/2”, 11.6 lb/ft– Flow area: 12.5683 in.2

• Annular flow area, 2-7/8” inside 4-1/2”– Flow area: 6.0768 in.2

CFR Assuming 200-psi WHBP:

CFR for 2-3/8” = 406 mcf/dCFR for 4-1/2” x 2 7/8” Area = 790 mcf/d

(was 1.63 MMcf/d with open 4 ½” casing)


Casing SizeO.D.= 4 ½”I.D. = 4.00”

Tubing SizeO.D.= 2 7/8”I.D. = 2.441”

Annulus Area, in2

6.0768

4 ½” Casing, 2 7/8” Tubing


Heavy-Wall Flow Sub with Isolation

Sleeve

Kobe knockout equalization plug

Seal ring packing

WX-LOK dogs

Heavy-Duty Flow Sub2 3/8” tubing, 36 ¾” holes

OD = 3.063”

ID = 1.995”

Top sub w/ WX LOC 1.875”

profile

Over 5 times the flow area

of 2 3/8”tubing

1.875” polished bore

Isolation SleeveOD = 1.75”

ID = 0.98”

Seal ring packing


2 3/8” X 2 7/8”Crossover

2 3/8” Tubing

2 3/8” X-Nipplew/ retrv. Plug

¼” Capillary Injection String

Injection Valve and Mandrel

Shear-Out Sub

2 7/8” Dead String

4 ½” Casing

• Production String: 2-3/8”• Dead String: 2 7/8” ULTRA FLUSH• Casing: 4 ½”, 11.6-lb/ft casing

– Flow area: 12.5683 in.2

• Annular Flow Area: 2-7/8” inside 4-1/2”– Flow area: 6.0768 in.2

CFR assuming 200-psi WHBP:

2 3/8” = 168 mcf/d with foam(was 406 mcf/d without foam)

4 ½” x 2 7/8” = 327 mcf/d with foam

(was 790 mcf/d without foam)(was 1.63 MMcf/d without Dead String)

4 ½” Casing, 2 7/8” Dead Stringwith Capillary String for Foamer Injection

2 3/8” Heavy Duty Flow Sub

36- ¾” Holes


2 3/8” bumper spring with seating cups

Perforation interval

Same Assembly- Add Plunger LiftWhen Needed

• Three artificial lift solutions working together:

– Area Reduction (Dead String)

– Surface Tension and Density Reduction

– Plunger Lift (Mechanical Interface)


Flowing Well Head Pressure = 200 PSI

9.1757

12.3120

6.0768

14.3683

8.1360

18.7978

12.5683

7.0315

4.6800

3.1262

Flow Area(in.2 )

168.4406.70

6.5015.70

0.021712 3/8”, 4.7-lb/ft tubing

252.1608.800.032502 7/8”, 6.5-lb/ft tubing

378.8914.700.048833 ½”, 9.20-lb/ft tubing

676.91,634.900.087284 ½”, 11.6-lb/ft casing

1,012.52,445.400.130545 ½”, 17-lb/ft casing

494.21,193.700.063723 ½” tubing X 5 ½” casing

662.81,600.800.085502 7/8” tubing X 5 ½” casing

327.2790.300.042202 7/8” tubing X 4 ½” casing

773.91,869.000.099782 3/8” tubing X 5 ½” casing

438.31,058.500.056502 3/8” tubing X 4 ½” casing

CFR with Foam

(mcf/d)

CFR with Water

(mcf/d)

CV with Foam,

(ft /sec)

CV with Water,(ft /sec)Flow Area

(ft2)

Flow Path

CV = Critical velocity, ft/secCFR = Critical flow rate, mcf/dFlowing surface temperature = 70°FDensity of water = 8.4 lb/galZ = 0.97


4 ½” Casing with 2 7/8” Dead String with 2 3/8” Production Tubing


Installation Photos

1. Installation Technician2. Capillary Spooling Unit3. Sheave in Derrick

1 2 3


Installation Photos1. CVR Assembly in Elevators2. ¼” Capillary String @ Valve3. Stainless Bands

1 2 3


Installation Photos1. Ultra Flush Box2. Ultra Flush Pin3. Ultra Flush Connection4. Extended Neck Tubing Hanger5. Adapter Flange

1 3

4

52


Splicing the Externally Banded Capillary String


Mountain Front Wash

Mid-Continent


4-1/2” Casing x 2-7/8” Dead String

Mid-Continent


2-7/8” Dead String, No Cap String, Conventional Plunger, 300 mcfd

Mid-Continent


Mid-Continent

2-7/8” Dead String, No Cap String, Conventional Plunger, < 300 mcfd


Mid-Continent

2-7/8” Dead String, Capillary String, No Plunger, 300 mcfd


Mid-Continent

5-1/2” Casing x 3-1/2” Dead String


Mid-Continent

3-1/2” Dead String, Cap String, Conventional Plunger, 500 mcfd


Mid-Continent

3-1/2” Dead String, Capillary String, CF Plunger, 500 mcfd


Mid-Continent

3-1/2” Dead String, Capillary String, CF Plunger, > 500 mcfd


Mid-ContinentPrior to Installation• Obtain water analysis – pH, salinity, scaling tendencies, & SG

• Check for fill

• Acquire FBHP & T– extrapolate to proposed end of dead string

Lessons Learned• Run the largest size dead string possible for a given casing size

• Use Ultra-flush joint pipe for dead string

• Run cap string & plunger equipment with initial dead string installation

• Fill cap string and test valve every 1,000’ during installation

• Swab until soap returns are seen at surface or well kicks off

Current Recommended Practice


Presented By:Scott Campbell - Weatherford - Denver, ColoradoPetey Erwin – Newfield Exploration - Tulsa, Oklahoma

CVR System

Critical Velocity Reduction

A Combination of Dead Strings, Capillary Injection Foamer and Plunger Lift

ANY QUESTIONS?


Gravity

Gas Flow

Water Droplet

Drag from flowing gas is tending to lift water droplet which is reacting to GRAVITY and

trying to remain at bottom of a well.

Turner Equation: Calculates Flow Velocity that keeps “Liquid Drop” Stationary in flow stream;Calculate Critical Velocity necessary to maintain Drag Force.

VELOCITY OF FLOW IN THE TUBULAR CONFIGURATION THAT WILL CAUSE DROPLET

TO REMAIN STATIONARY

Vc = 1.593σ1/4(ρLiquid-ρGas)1/4

ρGas1/2

Turner Equation

Liquid Loading: Turner EquationSurface Tension and Fluid Density Dependent


Standard Assumptions that “Simplify”Turner Equation:

Vc = 1.593σ1/4(ρLiquid-ρGas)1/4

ρGas1/2

Turner Equation

60 dynes/cm Surface Tension for Water20 dynes/cm Surface Tension for Condensate67 lbm/ft3 Water Density45 lbm/ft3 Condensate Density0.6 gas Gravity120 oF Gas Temperature20% Upward Adjustment – Fit His Empirical Data

Vc = C(ρLiquid-0.0031p)1/4

(0.0031p)1/2

C = 5.321, water C= 4.043, condensate, p>=1,000 psi.

“Simplified” Turner Equation

Liquid Loading: Turner EquationSimplified with Oilfield “Standard” ValuesVc Function of fluid type, Pressure, and Liquid Density

Higher Pressures

P>1,000 psi

Gravity

Gas Flow

Water Droplet


Standard Assumptions that “Simplify” the Turner Equation to the Coleman Equation:


(0.0031p)1/2

C = 4.434, water C= 3.369, condensate, p<=1,000 psi.

“Simplified” Coleman Equation

60 dynes/cm Surface Tension for Water20 dynes/cm Surface Tension for Condensate67 lbm/ft3 Water Density45 lbm/ft3 Condensate Density0.6 gas Gravity120 oF Gas Temperature20% Upward Adjustment – Fit His Empirical Data

Liquid Loading: Coleman EquationColeman Eliminates 20% adjustment

Lower Pressures

P<1,000 psi

Gravity

Gas Flow

Water Droplet



(0.0031p)1/2

C = 4.434, water C= 3.369, condensate, C = 3.369, FOAMp<=1,000 psi.

“Simplified” Coleman Equation

Liquid Loading: Coleman Equation - FOAM

Lower Pressures

FOAM CASE

Gravity

Gas Flow

FOAM Droplet Cluster

Foam Cluster Apparent Density = 6 lbm/ft3 (or less)Foam Cluster Water Surface Tension = 20 dynes/cm

Surface Tension Condensate = +/- Surface Tension FOAM = +/- 20 dynes/cm

So….Constant in Condensate Equation = Constant in FOAM Equation

= 3.369, Coleman Equation


“Critical Flow Rate” can be calculated once we have “Critical Velocity”

Q(MMCFPD) = 3.06PVcA

Tz

P Flowing Tubing PressureVc Critical VelocityA X-Area Tubular Flow PathT Flowing Temp oRZ Z Factor

Critical Flow Rate Equation

Critical Flow rate is the flowing gas rate necessary to maintain Critical Velocity

Critical Flow Rate


Table of Critical VelocitiesColeman Equation - FOAM

Lower Pressures

FOAM CASE

Q(MMCFPD) = 3.06PVcA

Tz

P Flowing Tubing PressureVc Critical VelocityA X-Area Tubular Flow PathT Flowing Temp oRZ Z Factor

Critical Flow Rate Equation

Note: No Friction considered for additional foam viscosity

Vc --- reduces by factor of +/- 2.4 to 2.8 Depending Upon Pressure

Conservative Rule of ThumbFOAMER REDUCES CV by a FACTOR of 3


Disclaimer

The following disclaimer may be included as the last page of a Technical Presentation or Continuing Education Course. A similar disclaimer is included on the front page of the Gas Well Deliquification Web Site.

The Gas Well Deliquification Steering Committee Members, the Supporting Organizations and their companies, the author(s) of this Technical Presentation or Continuing Education Course, and their company(ies), provide this presentation and/or training at the Gas Well Deliquification Workshop "as is" without any warranty of any kind, express or implied, as to the accuracy of the information or the products or services referred to by any presenter (in so far as such warranties may be excluded under any relevant law) and these members and their companies will not be liable for unlawful actions and any losses or damage that may result from use of any presentation as a consequence of any inaccuracies in, or any omission from, the information which therein may be contained.

c03 --- presentation --- weatherford --- critical velocity ... i... · presented by: scott campbell...

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