2014 SPE European Artificial Lift Forum (EuALF) Aberdeen, Scotland th June, Production optimization of ESP wells in Iraq Rumaila oilfield

Transcription

1 2014 SPE European Artificial Lift Forum (EuALF) Aberdeen, Scotland 17 18th June, 2014 Production optimization of ESP wells in Iraq Rumaila oilfield Presenter - Peter O. Oyewole, SPE, BP (Subsurface ESP Team Leader)

2 Presentation Objectives To introduce Rumaila ESP application and the unconventional optimization strategy, workflow process and case history To share knowledge, lesson learnt and results (that might be valuable for other operators) To obtain any feedback for further improvement

3 Content Introduction ESP Optimization Challenge in Rumaila ESP Optimization Strategy & Workflow Process Constant Pressure Control Mode (PID loop) Case Histories & Examples Results The Future - Real Time Data Application on Rumaila ESP Discussion, Questions & Comments 3

4 Rumaila Field JV (BP, CNPC, SOMO) = Rumaila Operating Organization in 2009 ~ 1000 Wells (Active/Non- Active Producer & Injectors) 4

5 Rumaila Field Simple Single Anticline 3 Main Reservoirs (Main Pay; Upper Shale; Mishrif) Early cretaceous deltaics system (series of stacked sandstone interbedded the lower cretaceous carbonate System Field Area Coverage = 70km X 14km Rumaila/W.Qurna Structure --- >100Billion bbl STOIIP 5

6 Reservoir & Fluid Properties ESP Perfect Application 6 High Rate (1-10mbd) Low to No Solid Production Low to Moderate GOR ( SCF/STB) Oil Gravity (27-34 API) Low Viscous Fluid (< 2cp) Reservoir depth ( m) Water Cut (0-60%) Moderate (Mishrif) to High Permeability(Main Pay)

7 ESP Current Overview Currently >230 mbd (~20%) of Total Field Production (25%) of Active Producer Wells Growing # of ESP and ESP Oil Production 7

8 ESP Optimization & Operations Strategy High Range Operating Envelop (managing uncertainty) Operate in Downthrust (if required) No Upthrust Bias - Fully Open Choke (where applicable) - Low frequency operation - Low Motor Loading (50-80%) Motor Loading Range % - Managing Gas in Low PI wells GS, AGH/GPU, HZ, Choke, Stages - Moderate Over-stage

9 ESP Optimization Challenge in Rumaila Flow Rate & Water Cut (WC) Measurement availability and frequency?? Flow Rate & Water Cut Measurement Accuracy?? Common Industrial Practice - Flow Rate & WC is known and use to perform ESP Optimization and Intervention How do you perform ESP Optimization and Intervention without known flow rate & WC? How will you understand well and ESP performance? How do you perform monitoring and troubleshooting? Additional requirement to provide accurate ESP well rate into Production Allocation

10 ESP Optimization Strategy & Workflow Process Effective ESP Well Performance Modelling - Nodal Analysis (SubPump & PROSPER) Flow Test & Fluid Sample Calibrated Models (subject to availability) Trouble shooting and understanding discrepancy Accurate Input Data Timely Data Acquisition (Weekly Update) Data Quantity Control Data Quality Control Perform Trend Analysis (Short Term & Long Term Trends) (See flow chart on the next slide)

11 ESP Monitoring & Optimization Workflow Process New WT Data & Wkly OPS Monitoring Report 1. Weekly Monitoring Field Data 4. Data Variation Check 5. ESP Optimization Master Sheet Update 6. Run ESP Performance Model Update of Daily Entry/Ops report (Wellwork) Derived Rate & Estim. WC 2. Weekly Datalog Download Vendor Field Ops Emerson data 3. Short Term Trend Analysis OFM 7. Yellow-Flag Trouble Wells 8. Long Term Trend Analysis Optimisation Choke Change 11. ESP Well Allocation (SS Prod. Opt.) 10. Weekly ESP Summary Report 9. Evaluation & Analysis (with Vendor) Freq. Change PID Loop (Parameter Change) Surveillance 14. Update Optimization Tracking (+ Gain/Loss) 13. Perform Optimization (Ops ESP Coordinator) 12. Optimization Request (to Ops ESP Coord.) WT Request Sample Request PBU Request Yellow Flag Active Monitoring

12 Constant Pressure Control Mode (PID loop) ESP Wells VSD Control Modes - 3 Modes Value of Constant Pressure Control Mode in Rumaila ESP Application Managing BHFP near Saturation Pressure Maximize optimization gain Reduce wellsite visit and intervention (safety) Reduce human error Timely response to reservoir inflow performance Function High speed clamp Low speed clamp Target PIP Low threshold Operating Value 45 Hz 40 Hz 1900 PSI 1650 PSI Proportional 3.00% Derivative 0.00% Integral 3.00% THP (WHP) 220 PSI Choke Setting Size 24

13 Case 1 : Performance vs SOR estimation Case SBHP (psi) PI (bpd/psi) WC (%) THP (psi) Fr. (Hz) Intake Press (psi) Flow rate (bpd) Motor Load (%) Expected case Stable Performance Pump Curves (Design) Pump Curves (Actual) 13

14 THP/psig FLP/psig Case 1- PID Loop (Constant Pressure Mode) Choke//64 Constant BHFP PIP/psi Pd/psi Tm/ Freq./Hz MA/amps 14

15 Case 2- Hole in Tubing

16 Case 3 Pre & Post Optimization PIP b4 Optz PIP after Optz

17 Case 4- Decreasing PIP & Norm FG

18 Case 5- Increasing Norm. FG & WC

19 Realtime data from RTU (Rumaila Future) The Future - Real Time Data Application on Rumaila ESP 19 Before and after optimization (stable flow)

20 2012 ESP Optimization Skin 12 MBD Annualized Rate 52 Optimization Interventions

21 Questions Comments? Feedback? Input? Discussion? What else? QUESTIONS

22 Acknowledgement Rumaila (ROO) ESP Subsurface & Operations team Rumaila (ROO) Subsurface Team Management BP