CVR System. Critical Velocity Reduction A Combination of Dead Strings, Capillary Injection Foamer and Plunger Lift

Transcription

1 CVR System Critical Velocity Reduction A Combination of Dead Strings, Capillary Injection Foamer and Plunger Lift Presented By: Scott Campbell - Weatherford - Denver, Colorado Petey Erwin Newfield Exploration - Tulsa, Oklahoma

2 Critical Flow Rates 4,000 Flow Rate (mcf/d) 3,500 3,000 2,500 2,000 1,500 1, "/0.826" 1.00-in. OD/0.826-in. ID CT 1.25"/1.076" 1.25-in. OD/1.076-in. ID CT 1.50"/1.310" 1.50-in. OD/1.310-in. ID CT 2.0"/1.78" 2.00-in. OD/1.780-in. ID CT 1.90/ in. OD/1.610-in. ID API Tubing 221/16"/1.75 1/16-in. OD/1.750-in. ID API Tubing 223/8"/ /8-in. OD/1.995-in. ID API Tubing 227/8"/ /8-in. OD/2.441-in. ID API Tubing 3.5"/ in. OD/2.867-in. ID API Tubing in., lb/ft Casing in., 20 lb/ft 20-lb/ft Casing 7.0" 7-in., 2626-lb/ft lb./ft Casing 4.5" 4.5-in. Casing Casing w / w/2 2 3/8" 7/8-in./ Tubing Tubing 5.5" 5.5-in. Casing Casing w / w/2 2 7/8" 7/8-in./ Tubing Tubing 7.0" 7.0-in. Casing Casing w / w/3 3 1/2" 1/2-in./ Tubing Tubing ,000 Wellhead Pressure (psi) 1

3 Typical Completion: 2 3/8 Production Tubing 4 ½ Casing 11.6# Casing Extended Perforation Interval 2

4 Typical Completion A B Production String: 2-3/8, 4.7 lb/ft 2 3/8 tubing Casing: 4-1/2, 11.6 lb.ft in. ID in. drift Flow area: in. 2 4 ½ casing Critical flow requirements assuming 200-psi WHBP(FTP): Extended perforation interval CFR for 2-3/8 = 406 mcf/d CFR for 4-1/2 = 1.63 MMcf/d 3

5 4 ½, 11.6-lb/ft Casing 2 3/8 Production Tubing with 2 7/8 Velocity Reduction String (Dead String) 4

6 4 ½ Casing, 2 7/8 Dead String Only 2 3/8 Tubing Production String: 2 3/8 4 ½ Casing Dead String: 2 7/8 ULTRA FLUSH NO couplings = 2 7/8 = OD Casing: 4-1/2, 11.6 lb/ft Flow area: in. 2 Annular flow area, 2-7/8 inside 4-1/2 Flow area: in /8 X-LOC nipple 2 3/8 Heavy Duty Flow Sub 36- ¾ holes 2 3/8 X-Nipple w/ retrv. plug Shear-Out Sub 2 3/8 X 2 7/8 Crossover CFR Assuming 200-psi WHBP: CFR for 2-3/8 = 406 mcf/d CFR for 4-1/2 x 2 7/8 Area = 790 mcf/d (was 1.63 MMcf/d with open 4 ½ casing) 2 7/8 Tubing Dead String 5

7 4 ½ Casing, 2 7/8 Tubing Casing Size O.D.= 4 ½ I.D. = 4.00 Tubing Size O.D.= 2 7/8 I.D. = Annulus Area, in

8 Top sub w/ WX LOC profile Heavy-Wall Flow Sub with Isolation Sleeve WX-LOK dogs Seal ring packing Kobe knockout equalization plug Isolation Sleeve OD = 1.75 ID = 0.98 Over 5 times the flow area of 2 3/8 tubing Heavy-Duty Flow Sub 2 3/8 tubing, 36 ¾ holes OD = ID = Seal ring packing polished bore 7

9 4 ½ Casing, 2 7/8 Dead String with Capillary String for Foamer Injection 2 3/8 Tubing Production String: 2-3/8 Dead String: 2 7/8 ULTRA FLUSH Casing: 4 ½, 11.6-lb/ft casing Flow area: in. 2 Annular Flow Area: 2-7/8 inside 4-1/2 Flow area: 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 ¼ Capillary Injection String 2 3/8 Heavy Duty Flow Sub 36- ¾ Holes 2 3/8 X-Nipple w/ retrv. Plug Injection Valve and Mandrel Shear-Out Sub 2 3/8 X 2 7/8 Crossover 2 7/8 Dead String (was 790 mcf/d without foam) (was 1.63 MMcf/d without Dead String) 4 ½ Casing 8

10 Same Assembly- Add Plunger Lift When Needed Three artificial lift solutions working together: Area Reduction (Dead String) 2 3/8 bumper spring with seating cups Surface Tension and Density Reduction Plunger Lift (Mechanical Interface) Perforation interval 9

11 Flowing Well Head Pressure = 200 PSI Flow Path Flow Area (ft 2 ) Flow Area (in. 2 ) CV with Water, (ft /sec) CV with Foam, (ft /sec) CFR with Water (mcf/d) CFR with Foam (mcf/d) 2 3/8, 4.7-lb/ft tubing /8, 6.5-lb/ft tubing ½, 9.20-lb/ft tubing ½, 11.6-lb/ft casing , ½, 17-lb/ft casing 2 3/8 tubing X 4 ½ casing , , , /8 tubing X 5 ½ casing , /8 tubing X 4 ½ casing /8 tubing X 5 ½ casing , ½ tubing X 5 ½ casing , CV = Critical velocity, ft/sec CFR = Critical flow rate, mcf/d Flowing surface temperature = 70 F Density of water = 8.4 lb/gal Z =

12 4 ½ Casing with 2 7/8 Dead String with 2 3/8 Production Tubing 11

13 Installation Photos 1. Installation Technician 2. Capillary Spooling Unit 3. Sheave in Derrick

14 Installation Photos 1. CVR Assembly in Elevators 2. ¼ Capillary Valve 3. Stainless Bands

15 Installation Photos 1. Ultra Flush Box 2. Ultra Flush Pin 3. Ultra Flush Connection 4. Extended Neck Tubing Hanger 5. Adapter Flange

16 Splicing the Externally Banded Capillary String 15

17 Mountain Front Wash Mid-Continent 16

18 4-1/2 Casing x 2-7/8 Dead String Mid-Continent 17

19 2-7/8 Dead String, No Cap String, Conventional Plunger, 300 mcfd Mid-Continent 18

20 2-7/8 Dead String, No Cap String, Conventional Plunger, < 300 mcfd Mid-Continent 19

21 2-7/8 Dead String, Capillary String, No Plunger, 300 mcfd Mid-Continent 20

22 5-1/2 Casing x 3-1/2 Dead String Mid-Continent 21

23 3-1/2 Dead String, Cap String, Conventional Plunger, 500 mcfd Mid-Continent 22

24 3-1/2 Dead String, Capillary String, CF Plunger, 500 mcfd Mid-Continent 23

25 3-1/2 Dead String, Capillary String, CF Plunger, > 500 mcfd Mid-Continent 24

26 Current Recommended Practice Prior to Installation Mid-Continent 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 25

27 ANY QUESTIONS? CVR System Critical Velocity Reduction A Combination of Dead Strings, Capillary Injection Foamer and Plunger Lift Presented By: Scott Campbell - Weatherford - Denver, Colorado Petey Erwin Newfield Exploration - Tulsa, Oklahoma 26

28 Liquid Loading: Turner Equation Surface Tension and Fluid Density Dependent Drag from flowing gas is tending to lift water droplet which is reacting to GRAVITY and trying to remain at bottom of a well. Water Droplet Gravity 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 Gas Flow V c = σ1/4 (ρliquid-ρgas) 1/4 ρgas 1/2 Turner Equation 27

29 Liquid Loading: Turner Equation Simplified with Oilfield Standard Values Vc Function of fluid type, Pressure, and Liquid Density Higher Pressures P>1,000 psi Water Droplet Gravity V c = σ1/4 (ρliquid-ρgas) 1/4 ρgas 1/2 Turner Equation Standard Assumptions that Simplify Turner Equation: 60 dynes/cm Surface Tension for Water 20 dynes/cm Surface Tension for Condensate 67 lbm/ft 3 Water Density 45 lbm/ft 3 Condensate Density 0.6 gas Gravity 120 o F Gas Temperature 20% Upward Adjustment Fit His Empirical Data Gas Flow V c = C (ρ Liquid p) 1/4 (0.0031p) 1/2 C = 5.321, water C= 4.043, condensate, p>=1,000 psi. Simplified Turner Equation 28

30 Liquid Loading: Coleman Equation Coleman Eliminates 20% adjustment Lower Pressures P<1,000 psi Standard Assumptions that Simplify the Turner Equation to the Coleman Equation: Water Droplet Gravity 60 dynes/cm Surface Tension for Water 20 dynes/cm Surface Tension for Condensate 67 lbm/ft 3 Water Density 45 lbm/ft 3 Condensate Density 0.6 gas Gravity 120 o F Gas Temperature 20% Upward Adjustment Fit His Empirical Data V c = C (ρliquid p) 1/4 (0.0031p) 1/2 C = 4.434, water C= 3.369, condensate, p<=1,000 psi. Gas Flow Simplified Coleman Equation 29

31 Liquid Loading: Coleman Equation - FOAM Lower Pressures FOAM CASE Simplified Coleman Equation V c = C (ρ Liquid p) 1/4 (0.0031p) 1/2 FOAM Droplet Cluster C = 4.434, water C= 3.369, condensate, C = 3.369, FOAM p<=1,000 psi. Gravity Surface Tension Condensate = +/- Surface Tension FOAM = +/- 20 dynes/cm So.Constant in Condensate Equation = Constant in FOAM Equation = 3.369, Coleman Equation Gas Flow Foam Cluster Apparent Density = 6 lbm/ft 3 (or less) Foam Cluster Water Surface Tension = 20 dynes/cm 30

32 Critical Flow Rate Critical Flow Rate can be calculated once we have Critical Velocity Q (MMCFPD) = 3.06PV c A Tz P Vc A T Z Flowing Tubing Pressure Critical Velocity X-Area Tubular Flow Path Flowing Temp o R Z Factor Critical Flow Rate Equation Critical Flow rate is the flowing gas rate necessary to maintain Critical Velocity 31

33 Table of Critical Velocities Coleman Equation - FOAM Lower Pressures FOAM CASE Q (MMCFPD) = 3.06PV c A Tz P Vc A T Z Flowing Tubing Pressure Critical Velocity X-Area Tubular Flow Path Flowing Temp o R Z Factor Critical Flow Rate Equation Vc --- reduces by factor of +/- 2.4 to 2.8 Depending Upon Pressure Conservative Rule of Thumb FOAMER REDUCES C V by a FACTOR of 3 Note: No Friction considered for additional foam viscosity 32

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