Horizontal Well Artificial Lift Simulation: Unconventional Oil & Gas Well Case Histories

Transcription

1 2018 Artificial Lift Strategies for Unconventional Wells Workshop Cox Convention Center, February 4 7, 2018 Horizontal Well Artificial Lift Simulation: Unconventional Oil & Gas Well Case Histories Dr. Anand S. Nagoo CEO, Pipe Fractional Flow pipefractionalflow.com Director, University of Texas ALAMO Artificial Lift Consortium tinyurl.com/alamo-invitation

2 Executive Summary Can predicting the multiphase flow behavior improve understanding? Whether production, reservoir, surveillance or artificial lift, predicting the flow behaviors under different equipment and conditions can help in better designing and optimizing wellbore multiphase flows Our basic approach = simplify and interconnect flow pattern behaviors and phase slippage using the analytical pipe fractional flow framework to rapidly simulate phase holdups and pressure gradients For more information/presentations/publications, visit pipefractionalflow.com/updates 2

3 Example Simulation Applications of PipeFractionalFlow Accurate downhole pressure from surface at low cost (THE PRIZE) - Minimize need (and huge costs) for permanent DHPG installs in new wells - Give reliable DHPG simulation in old wells with faulty/non-functioning gauges Transient real-time modeling for surveillance & optimization - Real-time drawdown management & reservoir monitoring - Fast simulations for closed loop optimization & reservoir model calibration Wellbore and pipeline flow rate calculations (virtual flow metering) - Local flow system modeling at discrete level (multi-segmented approach) - Minimize need (and huge costs) for multiple field flow meters & maintenance FOCUS Horizontal well artificial lift simulation for Unconventionals - Gas lift optimization, slugging flows, ESP PIP modeling, horizontal gas well liquids loading, plunger lift optimization, critical velocities and lift curves, etc. 3

4 Complementary points of view of AL Systems EXTERNAL VIEW (EQUIPMENT) Can I gain knowledge by case studies or trial-and-error how different equipment selections and operating conditions can change the multiphase flowing mixture behavior to what I want it to be? (e.g. to cause liquids lift, lower FBHP, change flow pattern) INTERNAL VIEW (MODELS) Can I better understand via reliable analytical predictive modeling how the multiphase flowing mixture behaves under different equipment selections and operating conditions? (e.g. to mitigate slug flow, to diagnose liquid loading long before) The well is the key component linking the reservoir and the surface in a hydrocarbon production system. Monitoring its performance and taking action to keep it operating at optimum condition ensures best production and financial results. It s the best lab and infrastructure we can control and measure! 4

5 How does analytical simulation impact AL in the field? Impact on well design - Influence of well trajectory on slugging, holdups, pressure gradients - Placement of EOT/equipment, lateral length optimization, flow obstructions Impact on well operations - Influence of well trajectory on loading behavior, loading/pip surveillance - Gas lift optimization, flow conditioning, FTHP-to-FBHP, DHPG simulation Impact on field-wide production optimization - Simulate flows in multiple well scenarios (1000 s of wells at a time) - Suited for IoT, virtual flow metering and real-time fast runs (1GB RAM RPi) 5

6 Benchmarking: Simulating Published Lab Data Cousins, Denton and Hewitt (1965) Exp. # 49, data also in Table 12.1 of Wallis s One Dimensional Flow textbook 6

7 Benchmarking: Simulating Published Lab Data 7

8 Benchmarking: Simulating Transient Gas Lift 8

9 Benchmarking: Simulating Transient Gas Lift 9

10 Big Technology Gaps in Wellbore Simulation Well J Well Case 6 10

11 Closing Technology Gaps in Wellbore Simulation 11

12 Slightly Up/Down Inclined Flow in Long Laterals Undulating trajectories will change the phase volume fractions and velocities behavior (flow patterns) resulting in liquids/gas blocks Phase volume fractions in slightly up- vs. down-inclined flows are very different from vertical/deviated flows, i.e. sharp phase holdup changes Long laterals is a combination problem, combining alwaysdeveloping flow through a segmented/perforated conduit system and sharp phase holdup changes e.g. liquids held up in up-flow and gas held up in down-flow 12

13 Many Field Observations of Extreme Slip Effects Source: Eriksen, S., Midttveit, O.: PLT - Overcoming changing multiphase flow behavior along horizontal sections, (2010), and at: 13

14 Many Field Observations of Extreme Slip Effects Baldauff, J., Runge, T., Cadenhead, J., Faur, M., Marcus, R., Mas., C., North, R., Oddie, G.: Profiling and quantifying complex multiphase flow, Schlumberger Oilfield Review, Autumn (2004) 14

15 Big Technology Gaps with Popular Tools! Horizontal, large-diameter Simpson, H. C., Rooney, D. H., Grattan, E., Al-Samarrae, F.: Flow pattern and pressure drop studies, Reports 1, 2 and 3, Research Contract RD/1065/014, Dept. of Mechanical Engineering, U. of Strathclyde (1976) +1 degs from horizontal Grollman, E., Fortuin, J. M. H.: Transient gas-liquid flow in upward sloping pipes, approaching the wavy-to-slug flow transition, Trans. ASME, FED-v. 225, Gas Liquid Flows, pp (1995) 15

16 Improved Understanding in Slight up/down Flows: Blind Test of PipeFractionalFlow against New Data! Fig. 8 of reference Fig. 9 of reference Brito, R., Pereyra, E., Sarica, C.: Stratified flow for downward highly viscous two-phase flow, 8th N. American Conf. Multiphase Tech., June 20-22, Banff, Alberta, Canada (2012) -2 degrees from horizontal 16

17 Improved Understanding in Obstructed Flows Obstructed flows are either fluid obstructions (cross-jet perforated pipe flow), or, solid obstructions (nozzles, chokes, valves, blockages, bends, branches) Flow must decelerate and then accelerate - the convective acceleration/deceleration pressure gradient will become the dominant pressure gradient term if cross-jet perforated conduit multiphase flows are considered 17

18 Improved Understanding in Obstructed Flows 18

19 Improved Understanding in Obstructed Flows Pougatch, K., Salcudean, M., Chan, E., Knapper, B.: Modeling of compressible gas-liquid flow in a convergentdivergent nozzle, Chem. Eng. Sci., v. 63, pp (2008) 19

20 Improved Understanding in Obstructed Flows Same scale! Multiple cases in the paper - lines are our predictions. Demonstrates the accuracy of our in-situ phase flow rate calculations. 20

21 Case History: Permian Gas-Condensate-Water HW PLT Flow scanner imager (FSI) prod. log run on Permian basin gas-condensatewater well (DEFT and GHOST probes); simulation starts from surface and all flow enforced to come only from toe Validation simulated severe impact of well trajectory correlative to data; ALL phase holdups & pressure predicted Significance of results horizontal wells are uniquely complex systems! Expected learning liquids held up in up-flow and gas held up in down-flow; demonstrates impact of well trajectory Unexpected learning extreme slip effects exist as long as up-flow and downflow exist and NOT on severity of wellbore trajectory curviness ; higher likelihood of terrain-induced slugging red = high water holdup blue = high gas holdup 21

22 Case History: Permian Gas-Condensate-Water HW PLT 22

23 Case History: Permian ESP HW PIP Simulation (2 ways) 23

24 Case History: Bakken HEAL System Simulation 24

25 Case History: Bakken HEAL System Simulation 25

26 Case History: WCSB HEAL System Simulations 26

27 Case History: WCSB HEAL System Simulations 27

28 Case History: Independent Confirmation of Beneficial Influence of Back Pressure in Conditioning the Flow Key Finding: Increasing backpressure leads to reduced amplitude of pressure fluctuations (or reduced oscillations) and reduced severe slugging (i.e. higher frequency, stable slug flow) 28

29 Case History: Improved Sand or Solids Erosion Simulation of Multiphase Flows in Chokes and Valves Camacho, C. A.: Comparison of correlations for predicting pressure losses in high gas-liquid ratio vertical wells, M.S. Thesis, U. of Tulsa (1970) 29

30 Case History: Improved Sand or Solids Erosion Simulation of Multiphase Flows in Chokes and Valves 30

31 Case History: HW Liquids Loading Simulation Static Column - Sutton et al. (2003) 2 7/8" Well "11" at 525 Mscf/d - Liquid Loaded 31

32 Case History: HW Liquids Loading Simulation Simulate published loaded gas well producing under a static liquid column (SLC) and compare against the reported downhole field data Significance of result: PFF can simulate liquids loaded gas well operations including well death prediction and changing liquid levels using only basic field data and average reservoir pressure Water holdup red = high blue = low 32

33 Case Studies: HW Liquids Loading Simulation Static Column - Sutton et al. (2003) 2 7/8" Well "11" at 525 Mscf/d - Liquid Loaded 33

34 HW Liquids Loading Case Histories using PFF s Simple, Analytical V g,crit Equation (New!) Case histories for field-level understanding: demonstrate liquid loading prediction and prevention long before in horizontal wells; demonstrate liquid loading effects on major variables such as WHP, tubing/casing diameters, fat casing in bend region, small diameter strings and End-of-Tubing placement optimization; simulation of onset of LL for VLP/Lift curves for quantifying lost liquids production! Permian Case (loading in bend only) Comprehensive field database: real horizontal liquid loaded wells in unconventionals, e.g. Permian, Eagle Ford, Marcellus, Barnett, lots more... 34

35 Case History: Permian DHPG Well History Simulation Fig. 200 of Simulation Workflows (pipefractionalflow.com/userguides): direct comparison of calculated vs. measured downhole gauge pressures at 9550 ft MD over Permian three-phase horizontal well history (BLIND TEST) 35

36 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 Artificial Lift Strategies for Unconventional Wells 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 Artificial Lift Strategies for Unconventional Wells Workshop where it was first presented. 36

37 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 Artificial Lift Strategies for Unconventional Wells Web Site. The Artificial Lift Research and Development Council and its officers and trustees, and the Artificial Lift Strategies for Unconventional Wells 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 Artificial Lift Strategies for Unconventional Wells 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, noninfringement of copyright or patent rights of others, merchantability, or fitness or suitability for any purpose. 37