Impact of Transient Simulations on Plunger Lift Operation
Rahel Yusuf, Schlumberger
Kees Veeken, Shell
Bin Hu, Schlumberger
Outline
• Introduction
• Candidate well and flow model
• Results and Discussion
• Conclusions
Slide 2
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
• Plunger lift is an artificial lift method mostly used to deliquify gas wells
• Plunger lift operation involves opening and closing of wellhead valveaccording to an optimum frequency to facilitate movement of plungerto surface alongwith liquid trapped above the plunger
• Low capital and maintenance cost
• Easy to install and operate
• Difficult to model as a transient modelling approach is required
Slide 3
Plunger Lift
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
Candidate Well
• Onshore gas well with inflow@ 2790 mAH
Slide 4
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
Transient Multiphase Flow Model
• A comprehensive transient multiphase simulator (OLGA) is used in the present work
• Simulator is based on three fluid model
• Solves five mass conservation equation and three momentum conservation equations
• Model has strong heat transfer calculations and solves a single energy balance for the fluid mixture
• Model extensively verified against laboratory and field data*
Slide 5
*Nossen, J., Shea, R. and Rasmussen J.: “New Developments in Flow Modeling and Field Data Verification”, 2nd North American Conference on Multiphase Technology, Banff, Canada, 21-23 June, 2000
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
Key Modeling Parameters
Slide 6
• 3.5” tubing to 2706 m, 7” liner to 2790 m
• Plunger between “launch” @ 2631m and “trap” @ 0
(Wellhead) and 93 m (SCSSV)
• A standing valve (SV) is placed at the plunger LAUNCH
position to prevent liquid escaping below the LAUNCH
position.
• Inflow @ 2790 , A=5.0 bara/(e3m3/d)
• Pres=15-18 bara, WGR=40-80 m3/e6m3,
• Wellhead pressure = 8 bara
• Plunger weight = 7.5 kg with zero leakage
• Plunger modelled as a PIG
• 10 plunger cycles with 2 hr flow, and1 hr shut-in
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
7
Temporal variation of different parameters for 10 plunger cycles
WGR=40, Pres=18, Trap @SCSSV
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
8
Temporal variation of different parameters for Cycle#9
WGR=40, Pres=18, Trap @SCSSV
Plunger Launched Plunger Trapped Well Shut-in
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
9
Profile plot of Tubing Holdup and Pressure@ 25.96 h
WGR=40, Pres=18, Trap @SCSSV
Standing Valve location
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
10
Profile plot of Tubing Holdup and Pressure@ 26.07 h
WGR=40, Pres=18, Trap @SCSSV
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
11
Profile plot of Tubing Holdup and Pressure@ 26.13 h
WGR=40, Pres=18, Trap @SCSSV
Standing Valve location
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
12
Profile plot of Tubing Holdup and Pressure@ 27.0 h
WGR=40, Pres=18, Trap @SCSSV
Standing Valve locationStanding Valve location
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
13
Profile plot of Tubing Holdup and Pressure@ 28.03 h
WGR=40, Pres=18, Trap @SCSSV
Standing Valve location
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
14
Profile plot of Tubing Holdup and Pressure@ 28.4h
WGR=40, Pres=18, Trap @SCSSV
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
15
Temporal variation of pressure at upstream and downstream of standing valve for
Cycle#9 with backpressure valve disabled
WGR=40, Pres=18, Trap @SCSSV
2.2bar
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
16
Temporal variation of gas rate and liquid content for different backpressure
threshold settings on backpressure valve: WGR=40, Pres=18, Trap @SCSSV
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
17
Zoomed in profile of tubing holdup at 28.9 h (cycle#9) with two
differential threshold pressure settings on backpressure valve
Standing Valve location
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
18
Temporal variation of different parameters for 10 plunger cycles
WGR=40, Pres=18, Trap @SCSSV
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
19
Temporal variation of different parameters for 10 plunger cycles
WGR=40, Pres=15, Trap @SCSSV
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
20
Temporal variation of different parameters for 10 plunger cycles
WGR=80, Pres=15, Trap @SCSSV
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
21
Temporal variation of different parameters for 10 plunger cycles
WGR=80, Pres=15, Trap @WH
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014
Conclusions
• Transient multi-phase flow model produces credible results andprovides valuable insight into influence of well parameters andbackpressure valve settings on plunger performance
• Plunger needs to travel to top of tubing to deliver maximumvalue i.e. liquid slug cannot bridge large “gap”
• Gas production during upward travel must deliver minimumplunger velocity and will diminish as slug size increases
• Further explore the influence of plunger launch position,wellbore (plus annulus) volume, inflow performance
Slide 22
Rahel Yusuf for 9th European Gas Well Deliquification Conference & Exhibition in Groningen (Netherlands) on 22-24 September 2014