University-of-Oklahoma-Summary-Presentation-10-12-18

Research and Development on Critical (Sonic) Flow of Multiphase Fluids through Wellbores in Support of Worst-Case-Discharge Analysis for Offshore Wells Project Overview and Deliverable Status Saeed Salehi, PhD Principal Investigator Friday, October 12th 2018 Introduction Slide sonic velocity flow limitations Slide Objectives Slide University of Oklahoma Study Goals • Prevailing WCD models lack an accurate pressure drop prediction at sonic and supersonic conditions ‒ Models don’t account for flow regime development of two-phase flow that may attain sonic condition at the wellbore exist due to the dramatic pressure drop ‒ Lack of theoretical models and experimental data of two-phase flow at high Mach number (Ma > 0.3) ‒ Subsonic/supersonic conditions lead to the generation of shock waves in the system, which was not included in past studies • Goal is to develop a mechanistic model to predict two-phase flow characteristics for different WCD scenarios in the wellbore at high Mach number • Goal is to also provide a computational tool that predicts WCD rate under various operational conditions Slide University of Oklahoma Team Saeed Salehi, PI Rida Elgaddafi Post-Doc Associate Raj Kiran PhD Candidate Ramadan Ahmed, Co-PI Olawale Taye Post-Doc Associate Jeff McCaskill Technician and Equipment Specialist Slide Deliverable Milestone Slide Slide Progress Deliverables Literature Review and Theoretical Studies Report CFD Simulation/WCD Model Technical Reports Technical Report for Laboratory Results Completion of WCD Model and Computational Tool Final Report Due January 5th, 2018 March 24th, 2018 April 24th, 2018 October 12, 2018 October 3, 2018 • Kick off meeting, October 24th , 2017 Methodology and Scope Literature Review Review preceding experimental and theoretical studies Computational Fluid Dynamics Develop a simulation model for predicting TP characteristics Experimental study Measuring two-phase characteristics under a wide range of fluid velocity WCD Computational Tool Two-phase flow mechanistic model, PVT model and Nodal Analysis University of Oklahoma (OU) : High Velocity Experimental Setup • A new flow loop has been developed to perform high-velocity two-phase flow loop Slide 41 Comparative study Case study Parameters Oil Gravity Gas specific gravity Bubble point pressure Reservoir pressure Gas oil ratio Value 28 0.6 1404 7500 235 Unit oAPI psi psi scf/STB Slide 42 Comparative study VLP Curves 8000 Bottom Hole Pressure HB FB BB DR PE IPR MB PE 6000 • HB: Hagedorn Brown • BB: Beggs and Brill • PE: Petroleum Experts • MB: Mukherjee Brill • FB: Fancher Brown 4000 • DR: Duns and Ros • PE 2: Petroleum Experts 2000 0 5000 10000 15000 Liquid Rate (STB/day) 20000 25000 Each method gives distinct discharge rate Slide 43 Comparative study Case study: under subsonic conditions Case Oil Gravity Gas specific gravity Bubble Point Pressure Reservoir Pressure GOR (psi) 7500 scf/STB 235 oAPI 28 0.6 (psi) 1403.6 35 0.8 2000 3000 650 45 0.8 2165 3000 865 55 0.82 2560 3000 1376 Slide 44 Comparative study Case study: under subsonic conditions WCD Rate Diff OU Model Prosper % STB/day STB/day 14796.5 19886 46094 91598 14567 20368.4 56980.4 81442 Case WCD Rate 1.6 -2.4 -19.1 12.5 Slide 45 Comparative study Case study: under sonic conditions Case Oil Gravity Gas specific gravity oAPI Bubble Point Pressure Reservoir Pressure GOR WCD Rate WCD Rate Prosper STB/day % 15.3 17.6 (psi) (psi) scf/STB OU Model STB/day 50 0.8 3250 7500 1600 99597.26 86376 55 0.8 5000 3000 2586 134563.8 114368 Diff Slide 46 Comparative study Case study: GoM Reservoir Properties Reservoir temperature Reservoir permeability Drainage area Dietz shape factor Reservoir thickness Reservoir pressure Value 210 246 5894 31.6 106 11305 Unit oF mD Acres ft psi Well Properties Well type Measured Depth Casing inner diameter Liner inner diameter Open hole diameter Casing shoe depth Length of open hole section Case Oil Gravity Bubble Point Pressure oAPI (psi) 35 5500 45 6900 Value Vertical 16726 13.375 10.75 8.375 8850 5076 Unit ft in in in ft ft Slide 47 Comparative study Case study: GoM Case WCD Rate OU Model STB/day 302783 275248 WCD Rate Prosper STB/day 284519 264912 Diff % 6.4 3.9 Conservative Slide 48 Sensitivity Analysis Change in Permeability 1200 1000 300000 800 200000 600 400 100000 WCD Rate Gas Rate 0 200 400 600 Permeability (mD) 800 1000 200 1200 Gas Rate (MMscf/day) WCD RATE (STB/day) 400000 Slide 49 Sensitivity Analysis Change in Payzone Bottom Depth 400000 Change in Payzone Height 1000 400000 1200 600 200000 400 100000 200 1000 300000 WCD Rate Gas Rate 200000 800 600 400 100000 200 0 10000 20000 30000 Payzone bottom depth (ft) 40000 0 1000 2000 Payzone Height (ft) 3000 Gas Rate (MMscf/day) 300000 800 WCD RATE (STB/day) Gas Rate Gas Rate (MMscf/day) WCD RATE (STB/day) WCD Rate Slide 50 Sensitivity Analysis Change in Skin Change in Reservoir Pressure 1400 400000 1000 WCD Rate 300000 800 600 200000 400 100000 WCD RATE (STB/day) WCD RATE (STB/day) 1000 Gas Rate (MMscf/day) Gas Rate 400000 WCD Rate 1200 800 Gas Rate 300000 600 200000 400 100000 200 200 0 5000 10000 15000 Reservoir Pressure (psi) 20000 0 20 40 Skin 60 Gas Rate (MMscf/day) 500000 Conclusion • CFD Modeling:  Used in setting-up experimental facility  Predicting the experimental condition required for sonic flow  Mechanistic model validation • Calculated sonic velocity is in reasonable agreement with experimental data • WCD Computational Tool:  New approach for sonic modeling for WCD calculation Slide 51 Conclusion • WCD Computational Tool:  The tool integrates the reservoir and well model and works simultaneously  Fluid properties are updated based on the input parameters while running the calculation  Distinct IPR curves and discharge points for each layers of reservoir  Comparative study of the new tool with Prosper software shows good agreement  Sensitivity analysis shows the expected trends with respect to different well and reservoir properties Slide 52 Future Recommendation     Investigation of larger diameter with high velocity with experiments Implementation of transient reservoir model Including heat transfer model Broadening the scope of WCD model to simulate the production scenarios Acknowledgement • Project Sponsor: US Department of the Interior, Bureau of Ocean Energy Management (BOEM) • Jeff McCaskill Thank you !!!