Down-Hole Gas Separator Performance Simulation

Transcription

1 10 th Annual Sucker Rod Pumping Workshop Renaissance Hotel Oklahoma City, Oklahoma September 16-19, 2014 Down-Hole Gas Separator Performance Simulation Jim McCoy Ken Skinner, Lynn Rowlan - Echometer Company

2 Gas Separator Simulation Program The simulation program shows how a gas separator separates the liquid from the gas. Viewing the simulation should help operators understand how gas separators work and improve the results of the separators that they are running. Operators can analyze a particular separator configuration and view how the gas separator separates the liquid from the gas and also determine separator capacity Sucker Rod Pumping Workshop 2

3 Pump Video 2014 Sucker Rod Pumping Workshop 3

4 Echometer Gas Separator Simulation Program (Free)

5 Program from Studies Performed at UT Podio, Tony, J. N. McCoy, M. D. Woods, Hanne Nygard, and B. Drake, Field and Laboratory Testing of a Decentralized Continuous-Flow Gas Anchor, Proceedings of the 46th Annual Technical Meeting of the Petroleum Society of CIM, Guzman, M.: Downhole Gas Separator Performance in Sucker Rod Pumping System, (master s thesis, University of Texas at Austin, 2005). Lisigurski, O.: The Effect of Geometry on the Efficiency of Downhole Gas Separators, (master s thesis, University of Texas at Austin, 2004). Robles, J. and A. L. Podio, Effect of Free Gas and Downhole Gas Separation Efficiency on the Volumetric Efficiency of Sucker Rod Pumps and Progressing Cavity Pumps, Proceedings of the 43rd Annual Meeting of the SWPSC, R. Bohorquez, V. Ananaba, O. Alabi, A. L. Podio, O. Lisigurski, and M. Guzman, Laboratory Testing of Downhole Gas Separators, SPE Videos can be viewed at oleseparator 2014 Sucker Rod Pumping Workshop 5

6 Bubble Behavior Effect of Liquid Velocity 5 inch/sec 243 BPD 6 inch/sec 275 BPD 9 inch/sec 420 BPD 2014 Sucker Rod Pumping Workshop 6

7 Separator Downward Flow rate 243 BPD 5 in/sec Video Casing Separator Outer Barrel Dip Tube 2014 Sucker Rod Pumping Workshop 7

8 Separator Downward Flow rate 243 BPD 5 inches /Second 2014 Sucker Rod Pumping Workshop 8

9 Separator Downward Flow rate 275 BPD 6 inches /Second 2014 Sucker Rod Pumping Workshop 9

10 Separator Downward Flow rate 420 BPD 12 inches /Second 2014 Sucker Rod Pumping Workshop 10

11 Describe Variables and Display using Program 2014 Sucker Rod Pumping Workshop 11

12 Separator Liquid Inflow Profile, percent of Average Rate Net Pump Displacement Simulation Separator Liquid Flow Rate Profile Maximum Rate is 3.77 times Average Actual plunger movement of a beam pumping unit or RotaFlex or Hydraulic unit does not materially affect separator performance Profile selected from dynamometer data on higher volume wells. except slower units require longer dip tubes Average Production Rate 0 5 % 48% Time as % of stroke Period 100 % 2014 Sucker Rod Pumping Workshop 12

13 Dip Tube Length (Length Below Separator Ports) 13

14 Gas Movement All gas that is in the separator below the inlet ports at the beginning of the upstroke will eventually move into the pump chamber. The gas separator capacity should exceed the net pump displacement rate so that gas bubbles will not exist in the separator annulus at the beginning of the upstroke. A long dip tube that is in excess of the required net dip tube length does not increase the separation capacity of the separator. It often hurts pump fillage by restricting liquid flow into the pump chamber 2014 Sucker Rod Pumping Workshop 14

15 Maximum Gas Separator Capacity Performance Operating a gas separator with a net pump displacement in excess of gas separator capacity will cause gas to be pulled into the pump. Generally, the pump will be about % filled with liquid if the pump displacement exceeds the gas separator capacity excessively. The simulation program showns in the next slide the performance when net pump displacement is below, at and above gas separator capacity Sucker Rod Pumping Workshop 15

16 Maximum Capacity Behavior Run a 2 3/8 Poor boy at 80 and 96 and 120 BPD Pump Capacity

17 Operating a Separator Above its Capacity Franks #1 Tubing Anchor 10,471 Feet Pump and 10,530 Feet 2 3/8 poor boy Separator Casing Perforations10,621 SBHP = 1924 psi PBHP = 416 psi Pump Displacement = 141 BPD Separator Capacity = 96 BPD 17

18 Poor Boy Separator Franks # Effective Plunger Stroke with 34% Pump Fillage

19 Show: 2 3/8 Poor Boy Simulation and Capacity 2014 Sucker Rod Pumping Workshop 20

20 Run 2 3/8 Collar Size Simulator 2014 Sucker Rod Pumping Workshop 20

21 Collar Sized Gas Separator Franks #1 Production of 100 BPD with a Full Pump 2014 Sucker Rod Pumping Workshop 21

22 SPM Effect Slower Speed Needs Longer Dip Tube 2 3/8 collar size separator at 6 and 3 SPM at 242 BPD 22

23 Low Capacity Gas Separator Seating Nipple 6 foot 2 7/8 sub 6 foot 2 7/8 Perforated Sub 60 Foot 1 ¼ inch dip tube Tubing Plug 6 foot Perforated sub 2 7/8 inch Poor- Boy Separator with 60 foot dip tube What is capacity? Baker Latch Assembly 2014 Sucker Rod Pumping Workshop 23

24 RotaFlex Unit (Constant Plunger Speed) Stroke Length 306 Inches SPM 4 Casing Pressure 140 psi Separator 96 feet long 2 7/8 Poor Boy Separator OD Capacity is 147 BPD ID 2.5 Dip Tube 60 feet long Simulation program recommends OD 1.66 a minimum length of 27 inches. ID 1.38 Long dip tubes cause gas to be released from the oil. Pump Displacement 324 BPD Reported high fluid level no test Pump card shows high pump intake pressure that indicates high fluid level Sucker Rod Pumping Workshop 24

25 Separator Capacity 147 BPD Pump Displacement 324 BPD 2014 Sucker Rod Pumping Workshop 25

26 RotaFlex Unit 23 BOPD 3 BWPD Indicates high PIP Gas Free Liquid Fillage 2014 Sucker Rod Pumping Workshop 26

27 Phantom Poor Boy Separator Net Pump Displacement = 168 BPD 6.82 SPM 27

28 Modified Poor Boy Separator Net Pump Displacement 168 BPD 2014 Sucker Rod Pumping Workshop 28

29 Phantom Poor Boy Separator Net Pump Displacement = 140 BPD 6.14 SPM 2014 Sucker Rod Pumping Workshop 29

30 Simulation Program to Field Tests Comparison The simulation program predicts how a separator will perform in the field so that the proper gas separator and pump can be selected. Field tests will be compared to the simulation program to determine what bubble rise velocity should be used in that particular field. The industry uses 6 inches/second for the bubble rise velocity. Is this the correct rise velocity? 2014 Sucker Rod Pumping Workshop 30

31 Simulation Program and Field Tests Comparison Echometer plans to work with operators to obtain field data so the simulation program can be compared to field data. Most separator configurations can be input and saved into the program for simulation studies. The comparison studies will be distributed. Hopefully, the study will result in a standard separator that is efficient and predictable in its performance. Please contact us if interested Sucker Rod Pumping Workshop 31

32 Gas Separator Simulation Program The program and updates can be downloaded free from: Or requested from echometer.com Or on Echometer USB 2014 Sucker Rod Pumping Workshop 32

33 Final This presentation and other presentations in addition to downhole pump animations showing gas compression, pump chamber pressure and pump fillage and also descriptive papers on the different gas separators discussed are available from Echometer Company. Videos of gas/liquid separation in laboratory models can be obtained at the University of Texas website ownholeseparator Sucker Rod Pumping Workshop 33

34 Copyright Rights to this presentation are owned by the company(ies) and/or author(s) listed on the title page. By submitting this presentation to the Sucker Rod Pumping Workshop, they grant to the Workshop, the Artificial Lift Research and Development Council (ALRDC), and the Southwestern Petroleum Short Course (SWPSC), rights to: Display the presentation at the Workshop. Place it on the web site, with access to the site to be as directed by the Workshop Steering Committee. Place it on a CD for distribution and/or sale as directed by the Workshop Steering Committee. Other use of this presentation is prohibited without the expressed written permission of the author(s). The owner company(ies) and/or author(s) may publish this material in other journals or magazines if they refer to the Sucker Rod Pumping Workshop where it was first presented Sucker Rod Pumping Workshop 34

35 Disclaimer The following disclaimer shall 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 Sucker Rod Pumping Web Site. The Artificial Lift Research and Development Council and its officers and trustees, and the Sucker Rod Pumping Workshop Steering Committee members, and their supporting organizations and companies (here-in-after referred to as the Sponsoring Organizations), and the author(s) of this Technical Presentation or Continuing Education Training Course and their company(ies), provide this presentation and/or training material at the Sucker Rod Pumping 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. The views, opinions, and conclusions expressed in these presentations and/or training materials are those of the author and not necessarily those of the Sponsoring Organizations. The author is solely responsible for the content of the materials. The Sponsoring Organizations cannot and do not warrant the accuracy of these documents beyond the source documents, although we do make every attempt to work from authoritative sources. The Sponsoring Organizations provide these presentations and/or training materials as a service. The Sponsoring Organizations make no representations or warranties, express or implied, with respect to the presentations and/or training materials, or any part thereof, including any warrantees of title, non-infringement of copyright or patent rights of others, merchantability, or fitness or suitability for any purpose Sucker Rod Pumping Workshop 35