Using Aspen HYSYS Upstream for Sizing and Scheduling of Gathering Systems
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This document discusses the use of Aspen HYSYS in modeling and scheduling gathering systems within the oil and gas industry, detailing various applications such as slug volume estimation and the development of dynamic model-based production systems. It highlights the challenges in modeling multiphase flow and offers solutions through automation and real-time data integration, alongside a comparison between HYSYS hydraulics and dynamics. The conclusions emphasize the importance of HYSYS in effectively sizing and scheduling pipelines, while also noting the advantages and considerations of using different modeling approaches.
Using Aspen HYSYS Upstream for Sizing and Scheduling of Gathering Systems
- 1. Authors: Francisco da Silva, James Holoboff, Ahad Sarraf Shirazi (Process Ecology Inc.) 30 June, 2015 Using Aspen HYSYS® Upstream for Sizing and Scheduling of Gathering Systems James Holoboff, Managing Partner, Process Ecology Inc.
- 2. © 2015 Aspen Technology, Inc. All rights reserved.2 Today’s Presenters Irina Rumyantseva Engineering Product Marketing, Aspen Technology James Holoboff Managing Partner, Process Ecology Inc.
- 3. © 2015 Aspen Technology, Inc. All rights reserved.3 Overview • Introduction – Applications for Hydraulics / Dynamics • Sizing and Scheduling of Gathering Systems – The Challenge – Approach to Solving Problem – Model Development – Automation – Results • Comparison - HYSYS Hydraulics vs. HYSYS Dynamics • Conclusions
- 4. © 2015 Aspen Technology, Inc. All rights reserved.4 Company Background – Process Ecology • Founded 2003, Calgary, AB • Key Competencies – Engineering consulting, process simulation – Process engineering & optimization – Air emissions estimation and management – Software development
- 5. © 2015 Aspen Technology, Inc. All rights reserved.5 We’ve come a long way … Disney’s Black Hole movie (1979) vs. Interstellar (2014) With Current Technology, We Can Accomplish Much More Released 1979 State-of-the art at the time, but … deemed the most scientifically inaccurate film of all time (the black hole is populated by drones in a burning landscape). Released 2014 Scientifically accurate, based on Einstein’s relativity equations Possible through modern computing technology
- 6. © 2015 Aspen Technology, Inc. All rights reserved.6 Hydraulics / Dynamics Applications • Estimation of Slug volume • Dynamic Model-Based Production System • Sizing / Scheduling of Gathering Systems
- 7. © 2015 Aspen Technology, Inc. All rights reserved.7 Application 1 – Estimation of Slug Volume • Background – Heavy fraction in natural gas condenses;; may result in slugs reaching facilities – Sizing the slug catcher requires estimation of slug volume and duration – Conventional Sizing methods may significantly oversize slug catcher • Slugging Types – Terrain –induced slugging – Caused by change of elevation in pipeline – Hydrodynamic slugging – Caused by formation of wave on liquid surface as a result of faster moving gas phase – Pig-Induced slugging – Caused by pigging operations in pipeline. Pig is designed to push most of the liquid contents to the outlet
- 8. © 2015 Aspen Technology, Inc. All rights reserved.8 Application 1 – Estimation of Slug Volume Elevation Profile
- 9. © 2015 Aspen Technology, Inc. All rights reserved.9 Application 1: Liquid Holdup Profile 0 0.0005 0.001 0.0015 0.002 0.0025 0 10000 20000 30000 40000 50000 60000 70000 80000 Liquid holdup Distance from Compressor1 discharge (m) Pipe 2 liquid holdup profile
- 10. © 2015 Aspen Technology, Inc. All rights reserved.10 Application 1: Estimation of Slug Volume 500 550 600 650 700 750 1440 2440 3440 4440 5440 6440 7440 8440 Pressure Drop (kPa) Elapsed Time (min) Pressure drop in Pipe 2b
- 11. © 2015 Aspen Technology, Inc. All rights reserved.11 Application 1: Estimation of Slug Volume - Peak of ~ 550 bbl/day - Most of the liquid is recovered within 1-2 hours
- 12. © 2015 Aspen Technology, Inc. All rights reserved.12 Application 2: Dynamic Model-Based Production System • Synchronized integration of a dynamic simulation model of the wells and production facilities with real-time online data obtained from production field • Accurate dynamic model of wells and production network • Online real-time application which transfers data between historian and simulation model
- 13. © 2015 Aspen Technology, Inc. All rights reserved.13 Application 2: Dynamic Model-Based Production System
- 14. © 2015 Aspen Technology, Inc. All rights reserved.14 Application 2: Dynamic Model-Based Production System
- 15. © 2015 Aspen Technology, Inc. All rights reserved.15 Application 2: Dynamic Model-Based Production System
- 16. © 2015 Aspen Technology, Inc. All rights reserved.16 Application 2: Dynamic Model-Based Production System • System acts as “virtual instrumentation” for key unmeasured variables such as well flow rates • Can monitor performance of specific equipment and support decisions to switch to production modes such as artificial lift • Can be run as a look-ahead tool • Can be used offline to run what-if scenarios • Real-time models that match field data improve understanding of the overall system • They provide the tools to translate data into decision support
- 17. © 2015 Aspen Technology, Inc. All rights reserved.17 Part II: Sizing and Scheduling of Gathering Systems • What is HYSYS Hydraulics? • What is the challenge? • What was the approach to solving the challenge? • What were the results and benefits?
- 18. © 2015 Aspen Technology, Inc. All rights reserved.18 What is HYSYS Hydraulics? • A solution for integrated upstream asset modeling • HYSYS Hydraulics can be run in steady-state and dynamic mode • Flow Assurance - predicts hydrate, wax, asphaltene formation • Can be used for slugging / pigging analysis • Network solver – flexible boundary conditions • Multiple phases, phase slip • Includes recent fluid flow correlations - TUFFP (Tulsa University) • Emulsion viscosity models
- 19. © 2015 Aspen Technology, Inc. All rights reserved.19 The Challenge: Network Sizing and Construction Scheduling • Challenges include: – Multiphase flow (condensate) – phase interaction, slip, flow patterns, pressure drop – Uncertainty in production data – Uncertainty in exact pipeline routes – Looping/networking of pipelines – Location of multiple processing facilities The Problem: What are the required pipeline sizes in the different segments of the gas gathering network, at various stages of the gathering system?
- 20. © 2015 Aspen Technology, Inc. All rights reserved.20 Network Schematic Plant A Plant B 32 wells, 2 plants Many looped lines Wells are being drilled over next 8 years Pipelines will be built as needed
- 21. © 2015 Aspen Technology, Inc. All rights reserved.21 Model Setup in HYSYS Hydraulics (Steady-State) • Rigorous multiphase pressure drop and heat transfer correlations • Rapid estimation of unknown profiles using Google Earth • Automation tool to transfer forecast data to the simulation model • Automation tool reports/interprets simulation results and identifies segments where constraints are violated
- 22. © 2015 Aspen Technology, Inc. All rights reserved.22 Model Setup • 32 wells, 2 plants, looped lines • All pipelines / wells (for all future times) modeled. Sections of model ignored depending on modeled year/quarter. • Well data imported from master spreadsheet, based on selected model year/quarter.
- 23. © 2015 Aspen Technology, Inc. All rights reserved.23 Automation Tool: Enable Quick Configuration of Model • Select Quarter/Year • Load HYSYS case / Transfer Data • Run • As system is analyzed, if flowrates change, they can easily be managed in master spreadsheet • Key assumptions (well temperatures, plant inlet pressures) can be managed in master spreadsheet
- 24. © 2015 Aspen Technology, Inc. All rights reserved.24 Model Constraints • Plant A limit of 50 MMSCFD – suction pressure calculated to limit this rate • Maximum pipe size – 12” (16” for short segments) • Ratio of velocity to erosional velocity not to exceed 55%
- 25. © 2015 Aspen Technology, Inc. All rights reserved.25 Model Calibration • 25-35 bbl/MMSCF liquids in produced gas • Selection of appropriate pressure drop correlation crucial • Calibration done for well- defined isolatable pipeline • Tulsa correlation gave the best match
- 26. © 2015 Aspen Technology, Inc. All rights reserved.26 System Analysis • Model/automation tool enabled quick analysis of the system at each quarter • Segments exceeding constraints could easily be identified, and modifications made • In the example below, in consultations with client, 16” pipe (instead of 10”) was installed to alleviate the high velocity
- 27. © 2015 Aspen Technology, Inc. All rights reserved.27 Results • A series of recommendations for each quarter from 2015-2022 – where to add pipelines and what size – i.e., the “drilling program” • This enables capital spending to be determined over the next few years of production • Trade-offs identified and reviewed: e.g., postpone capital spending with parallel lines
- 28. © 2015 Aspen Technology, Inc. All rights reserved.28 Benefits • Provided critical data for scheduling and budgeting purposes • Provided notifications regarding technical issues, such as potential reversal of flow direction in certain network segments • Model is now an asset for the client and can be used for future studies as conditions change Key Benefit: Projection was not a guess – sound science and engineering was efficiently used to develop the drilling program.
- 29. © 2015 Aspen Technology, Inc. All rights reserved.29 Are there advantages to using HYSYS Dynamics vs. HYSYS Hydraulics? Part III: HYSYS Hydraulics vs. HYSYS Dynamics • Why Consider HYSYS Dynamics? – It is beneficial to consider alternatives within HYSYS – HYSYS Steady-State cannot be used for this sort of analysis – HYSYS Dynamics is well-established and has been used for many applications
- 30. © 2015 Aspen Technology, Inc. All rights reserved.30 Hydraulics vs. Dynamics- Results • Plant A pressure – In Dynamics, plant pressure can be directly calculated by having a flowrate spec at plant A “sink”, while in Hydraulics estimating plant A pressure (with a flow constraint) is an iterative procedure • Flow rate and direction in two branches from Plant A: Parameter Name Unit Hydraulics Dynamics % Difference Plant A pressure kPag 1,688 1,612 4.5 “Branch 1” flowrate MMSCFD 5.5 5.3 3.6 “Branch 2” flowrate MMSCFD 21.5 21.7 0.9
- 31. © 2015 Aspen Technology, Inc. All rights reserved.31 Well Pressure Predictions – Hydraulics vs. Dynamics Well Pressure (kPa) Hydraulics Pressure (kPa) Dynamics % Difference b-74-A 1,338.6 1,303.6 2.6 c-51-A 1,218.5 1,212.5 1.0 c-54-A 1,423.1 1,348.3 5.3 c-17-H 1,634.3 1,482.9 9.3 15-1 1,820.1 1,468.9 19.1 c-64-H 1,936.0 1,473.2 23.9 The results are fairly close at some locations while they deviate 20% or more at others
- 32. © 2015 Aspen Technology, Inc. All rights reserved.32 • Taking a closer look at 15-1 lateral pipe: • Large elevation change over a few kilometers • Pipe is modelled in 3 segments in HYSYS: Well Pressure Predictions – Hydraulics vs. Dynamics Segment No. Length (m) Elevation change (m) 1 930 14 2 1190 -20 3 1150 35 15-1 lateral Hydaulics Dynamics Pressure drop 145 14
- 33. © 2015 Aspen Technology, Inc. All rights reserved.33 Well Pressure Predictions – Hydraulics vs. Dynamics • Liquid holdup profile in Hydraulics: • In Dynamics liquid holdup is proportional to liquid/vapour volume rates, and constant
- 34. © 2015 Aspen Technology, Inc. All rights reserved.34 Well Pressure Predictions – Hydraulics vs. Dynamics • Pipe segment calculations in Dynamics ignore phase slip and assumes both phases are moving with the same velocity • This can result in significant differences in pressure drop. • Conclusions – Using Dynamics for modeling gathering network can potentially be easier to set up and converge, but user must be extremely cautious when there is a large elevation change and significant liquid expected in the network 15-1 lateral Hydaulics pipe Pipe segment Dynamics Pipe segment steady-state Pressure drop 145 14 148
- 35. © 2015 Aspen Technology, Inc. All rights reserved.35 HYSYS Hydraulic Modeling of Gathering Systems • Initial convergence of the model is straightforward • Steady-state solution provides liquid hold-up profile in the pipes. Phase slip is considered in model. • Dynamic simulation of Hydraulic flowsheet provides ability to predict terrain-induced/pig-induced slug;; heat transfer rigorously modeled • Model is cumbersome to set up, as only two pressure nodes can be connected to each other • Only a few unit operations are available in the flowsheet • Objects inside Hydraulics flowsheet are not well-exposed in HYSYS API. • Solver takes more time to converge especially when there are multiple sinks. Advantages vs. HYSYS Dynamics Disadvantages vs. HYSYS Dynamics
- 36. © 2015 Aspen Technology, Inc. All rights reserved.36 HYSYS Dynamic Modeling of Gathering Systems • Takes into account equipment holdup (system accumulation) • More pressure drop correlations available in Aspen Dynamics • Quicker, easier transition to studying transient behaviour • Additional units operations: control valves, PSVs, pumps, compressors, etc. • Hydraulics flow assurance tools (erosion, corrosion, hydrates, deposit formation and slugging) are not available in dynamics • For steady-state analysis: step-time sensitive • Phase slip is not considered in model Advantages vs. HYSYS Hydraulics Disadvantages vs. HYSYS Hydraulics SS
- 37. © 2015 Aspen Technology, Inc. All rights reserved.37 Recommendations and Conclusions • HYSYS Hydraulics can be used to address the challenge of sizing and scheduling gathering systems • Automation can be used to improve the efficiency and flexibility in configuring the model • There are alternatives within HYSYS for large gathering system models • HYSYS Dynamics can be a feasible alternative, and there are some advantages. However, it must be used with caution for multi-phase systems.
- 38. © 2015 Aspen Technology, Inc. All rights reserved 38 Want to see similar results? http://training.aspentech.com Consider a training class from AspenTech
- 39. © 2015 Aspen Technology, Inc. All rights reserved 39 Aspen HYSYS: Process Modeling Training Aspen HYSYS: Process Modeling (EHY101) July 6, 2015 – Virtual-Americas July 13, 2015 – Frankfurt, Germany January 27, 2015 – Bedford, MA January 27, 2015 – Calgary, AB, Canada http://support.aspentech.com/supportpublictrain/CourseInfo.asp?course=EHY101 • Learn to build process simulations using Aspen HYSYS. • Discover how Aspen HYSYS allows rapid flowsheet construction and bi-directional calculations. • Investigate how templates and subflowsheets can streamline and organize simulation efforts. • Learn how to do preliminary cost estimation using Aspen Process Economic Analyzer from the Aspen HYSYS Environment.
- 40. © 2015 Aspen Technology, Inc. All rights reserved 40 Modeling Heavy Oil & Gas Production and Facilities Using Aspen HYSYS Upstream Modeling Heavy Oil & Gas Production and Facilities Using Aspen HYSYS Upstream (EHY2351) July 13, 2015 – Virtual-EMEA July 16, 2015 – Houston, TX July 20, 2015 – Virtual-Americas http://support.aspentech.com/supportpublictrain/CourseInfo.asp?course=EHY2351 • Use the new advanced capabilities of Aspen HYSYS to enable shared workflow between production modeling and facilities modeling. • Use the improved oil modeling tools in Aspen HYSYS for heavy oil models, hypothetical components from lab data, tune transport properties to match field data. • Use Aspen Hydraulics to perform hydraulic calculation and use Aspen HYSYS pipe segment for Flow assurance calculation
- 41. © 2015 Aspen Technology, Inc. All rights reserved.41 Visit the Process Ecology Website www.processecology.com Q&A James Holoboff james@processecology.com Irina Rumyantseva irina.rumyantseva@aspentech.com
- 42. Thank You