USING REAL TIME AUTOMATED OPTIMISATION AND DIAGNOSIS TO MANAGE AN ARTIFICALLY LIFTED RESERVOIR Julian Cudmore

Transcription

1 USING REAL TIME AUTOMATED OPTIMISATION AND DIAGNOSIS TO MANAGE AN ARTIFICALLY LIFTED RESERVOIR Julian Cudmore New Technology Manager Zenith Oilfield Technology 19 Sept Zenith Oilfield Technology Slide 1 of 46

2 KEY LEARNING OBJECTIVES 1. Understand the potential of real time digital processing when used on artificially lifted wells 2. See how automation shortens the time to optimised production and improves run life 3. Learn how draw down can be balanced using the lift system as a control to obtain best production 4. Listen to case studies illustrating how proactive data management has delivered significant profit for operators 19 Sept Zenith Oilfield Technology Slide 2 of 46

3 SECTION #1 TAKING THE HARD WORK OUT OF WELL SURVEILLANCE 19 Sept Zenith Oilfield Technology Slide 3 of 46

4 MORE OUTPUT / LESS INPUT A single well lifted by an ESP can have 20 or more key data streams associated with its operation which can be updating more than once per minute resulting in a potential overload of information. Manual analysis of this data can take days and becomes overwhelming with the high well counts of today s operations. Automated technology can gather data from the wells artificial lift system and perform automatic data analysis, diagnosis, optimisation and protection at the well site in real-time. With the automated system in place, operators can instantly recognise and prioritise wells requiring attention. 19 Sept Zenith Oilfield Technology Slide 4 of 46

5 SECTION #2 ARCHITECTURE OF THE AUTOMATED SYSTEM 19 Sept Zenith Oilfield Technology Slide 5 of 46

6 WELL SITE Well processor panel with downhole dual pressure ESP sensor Modbus interface to VSD and remote communication CLIENT OFFICE Communications server for remote data access and control ANY LOCATION Web based remote user interface and VSD control 19 Sept Zenith Oilfield Technology Slide 6 of 46

7 SYSTEM IMPLEMENTATION The intelligent surface panel is installed at the well site to locally process instrumented data into operational recommendations in real time All instrumented data, VSD data, and processed pump operational information is available at the well site, and transmitted to control rooms and office personnel where remote control of the VSD can be accessed WELL SITE OFFICE & CONTROL ROOM 19 Sept Zenith Oilfield Technology Slide 7 of 46

8 SECTION #3 SIMPLIFYING THE OPTIMISATION PROCESS 19 Sept Zenith Oilfield Technology Slide 8 of 46

9 FROM THIS TO THIS 19 Sept Zenith Oilfield Technology Slide 9 of 46

10 THE OLD WAY THE NEW WAY 1. Establish desired production rates for the reservoir 2. Test each well to establish current production rates 3. Production log the wells (if possible) to measure the inflow conditions and BHFP 4. Gather all the necessary data 5. Amalgamate the well test data with down hole gauge, log data, and ESP controller data 6. Perform sensitivity studies in software to assess the optimum frequency and WHP within the well draw down and ESP capabilities 7. Notify field operations to action the changes 8. Perform further well tests to verify the new production data 9. Analyse the new production data to ensure the ESP and well are running optimally and safely at the new set points 10. Continue the process to meet production targets 1. Establish safe target production rates for wells 2. Automated real time system suggests optimum frequency & WHP for each pump 3. Frequency adjusted by remote control 4. Results monitored using real time calculated well test data 19 Sept Zenith Oilfield Technology Slide 10 of 46

11 THE AUTOMATED REAL TIME OPTIMISATION PROCESS 1. Reservoir engineers provide the desired bottom hole flowing pressures for each well to appropriately manage overall drawdown. 2. This data is entered into the system as the target for optimising each well. 3. The automated optimisation calculations check if the target BHFP is achievable on the IPR curve, then calculate the potential rate increase. 4. The potential rate is automatically cross checked by the system against the ESPs operational capacity and operating limits to validate if the pumping system can safely deliver to target without effecting run life. 5. The system provides optimum operating frequency and well head pressure recommendations to achieve the target rate within the boundaries of each ESPs capability. 19 Sept Zenith Oilfield Technology Slide 11 of 46

12 Well Head Pressure Tubing Gradient Intake Pressure Discharge Pressure Well Potential Draw Down Target BHFP Current BHFP Reservoir Pressure 19 Sept Zenith Oilfield Technology Slide 12 of 46

13 Target BHFP Well Potential 19 Sept Zenith Oilfield Technology Slide 13 of 46

14 Current Operation ESP Maximum Rate Well Potential This well will benefit from a larger ESP! 19 Sept Zenith Oilfield Technology Slide 14 of 46

15 THE AUTOMATED REAL TIME OPTIMISATION PROCESS The process is simple basic petroleum engineering Performing the process manually over many wells takes time and continuous effort Automation of the process utilizes real time nodal analysis calibrated to instrument data When deployed across the field, draw down across the reservoir can be automatically controlled to maximize recovery 19 Sept Zenith Oilfield Technology Slide 15 of 46

16 SECTION #4 MANAGING RESERVOIR DRAWDOWN USING THE LIFT SYSTEM 19 Sept Zenith Oilfield Technology Slide 16 of 46

17 WELL 1 WELL 2 WELL 3 WELL 4 WELL 5 OIL GAS WATER TARGET BHFP CURRENT BHFP STATUS WELL psi 1500psi INCREASE ESP TO 58 HZ WELL psi 1400psi INCREASE ESP TO 56 HZ WELL psi 1250psi INCREASE ESP TO 57 HZ WELL 4 900psi 900psi HI WATER CUT ALARM WELL 5 850psi 850psi HI WATER CUT ALARM 19 Sept Zenith Oilfield Technology Slide 17 of 46

18 OIL PRODUCTION: 15,835 BOPD LOW WATER CUT WELLS WITH POTENTIAL FOR MORE PRODUCTION HIGH WATER CUT WELLS OIL GAS WATER TARGET BHFP CURRENT BHFP STATUS WELL psi 1500psi INCREASE ESP TO 58 HZ WELL psi 1400psi INCREASE ESP TO 56 HZ WELL psi 1250psi INCREASE ESP TO 57 HZ WELL 4 900psi 900psi HI WATER CUT ALARM WELL 5 850psi 850psi HI WATER CUT ALARM 19 Sept Zenith Oilfield Technology Slide 18 of 46

19 OIL PRODUCTION: 15,835 BOPD DECREASE TARGET DRAWDOWN TO MANAGE WATER PRODUCTION OIL GAS WATER TARGET BHFP CURRENT BHFP STATUS WELL psi 1500psi INCREASE ESP TO 58 HZ WELL psi 1400psi INCREASE ESP TO 56 HZ WELL psi 1250psi INCREASE ESP TO 57 HZ WELL psi 900psi HI WATER CUT ALARM WELL 5 900psi 850psi HI WATER CUT ALARM 19 Sept Zenith Oilfield Technology Slide 19 of 46

20 OIL PRODUCTION: 15,835 BOPD SYSTEM RECOMMENDS THE NEW ESP FREQUENCIES REQUIRED OIL GAS WATER TARGET BHFP CURRENT BHFP STATUS WELL psi 1500psi INCREASE ESP TO 58 HZ WELL psi 1400psi INCREASE ESP TO 56 HZ WELL psi 1250psi INCREASE ESP TO 57 HZ WELL psi 900psi DECREASE ESP 59 TO 55 HZ WELL 5 900psi 850psi DECREASE ESP 58 TO 56 HZ 19 Sept Zenith Oilfield Technology Slide 20 of 46

21 OIL PRODUCTION: 16,200 BOPD DECREASING DRAWDOWN TO CONTROL WATER PRODUCTION OIL GAS WATER TARGET BHFP CURRENT BHFP STATUS WELL psi 1500psi INCREASE ESP TO 58 HZ WELL psi 1400psi INCREASE ESP TO 56 HZ WELL psi 1250psi INCREASE ESP TO 57 HZ WELL psi 1000psi 55 HZ WELL OPTIMISED WELL 5 900psi 890psi DECREASE ESP 57 TO 56 HZ 19 Sept Zenith Oilfield Technology Slide 21 of 46

22 OIL PRODUCTION: 16,290 BOPD OPTIMISED WELLS OIL GAS WATER TARGET BHFP CURRENT BHFP STATUS WELL psi 1500psi INCREASE ESP TO 58 HZ WELL psi 1400psi INCREASE ESP TO 56 HZ WELL psi 1250psi INCREASE ESP TO 57 HZ WELL psi 1000psi WELL OPTIMISED WELL 5 900psi 900psi WELL OPTIMISED 19 Sept Zenith Oilfield Technology Slide 22 of 46

23 OIL PRODUCTION: 16,400 BOPD SYSTEM RECOMMENDS INCREASE HZ TO MEET BHFP TARGETS OPTIMISED WELLS OIL GAS WATER TARGET BHFP CURRENT BHFP STATUS WELL psi 1200psi INCREASE ESP TO 58 HZ WELL psi 1300psi INCREASE ESP TO 56 HZ WELL psi 1200psi WELL OPTIMISED WELL psi 1000psi WELL OPTIMISED WELL 5 900psi 900psi WELL OPTIMISED 19 Sept Zenith Oilfield Technology Slide 23 of 46

24 OIL PRODUCTION: 16,670 BOPD HIGH WATER CUT ALARM! REDUCE THE TARGET BHFP VALUE HIGH WATER CUT ALARM! REDUCE THE TARGET BHFP VALUE OIL GAS WATER TARGET BHFP CURRENT BHFP STATUS WELL psi 1100psi WELL OPTIMISED WELL psi 1200psi HI WATER CUT ALARM WELL psi 1200psi WELL OPTIMISED WELL psi 1000psi WELL OPTIMISED WELL 5 900psi 900psi HI WATER CUT ALARM 19 Sept Zenith Oilfield Technology Slide 24 of 46

25 OIL PRODUCTION: 16,670 BOPD NEW TARGET BHFP VALUES ASSIGNED: SYSTEM RECOMMENDS THE NEW FREQUENCIES AUTOMATICALLY OIL GAS WATER TARGET BHFP CURRENT BHFP STATUS WELL psi 1100psi WELL OPTIMISED WELL psi 1200psi DECREASE ESP TO 55HZ WELL psi 1200psi WELL OPTIMISED WELL psi 1000psi WELL OPTIMISED WELL 5 950psi 900psi DECREASE ESP TO 55HZ 19 Sept Zenith Oilfield Technology Slide 25 of 46

26 OIL PRODUCTION: 16,810 BOPD OPTIMISED WELLS OIL GAS WATER TARGET BHFP CURRENT BHFP STATUS WELL psi 1100psi WELL OPTIMISED WELL psi 1250psi WELL OPTIMISED WELL psi 1200psi WELL OPTIMISED WELL psi 1000psi WELL OPTIMISED WELL 5 950psi 950psi WELL OPTIMISED 19 Sept Zenith Oilfield Technology Slide 26 of 46

27 SECTION #5 AUTOMATION IN THE FIELD 19 Sept Zenith Oilfield Technology Slide 27 of 46

28 CASE STUDY #1: AN ALREADY OPTIMISED WELL? The production of the well was previously thought to be fully optimised to the limits of the ESP. The well was producing around 940 bfpd. After installation of the real time system, the automated analysis showed that the well was not achieving the target bottom hole flowing pressure, but was close to the upper range limit of the ESP whilst running at 55hz. The real time system predicted through automated sensitivity studies, that the frequency could be increased to 61.9Hz whilst keeping the ESP within its operational limits. 19 Sept Zenith Oilfield Technology Slide 28 of 46

29 CASE STUDY #1: AUTOMATED RECOMMENDATION The automated system relayed the following recommendation for the well optimization: AN ADDITIONAL 123 BFPD IS ACHIEVABLE BY INCREASING FREQUENCY TO 61.9HZ The VSD frequency was subsequently increased manually from 55 Hz to 56 Hz and then by remote control to 61Hz Adjustment was performed in 1 Hz steps to verify the system s recommendations and enable independent well tests to verify the results 19 Sept Zenith Oilfield Technology Slide 29 of 46

30 CASE STUDY #1: REAL TIME CALCULATED WELL TEST DATA The real time system calculations for flow and water cut were verified independently by well test during the optimization process: 55 HZ Well test total liquid flow at 55 Hz Virtual total liquid flow at 55 Hz Well test water cut at 55 Hz 22% Virtual water cut at 55 Hz 57 HZ Well test total liquid flow at 57 Hz Virtual total liquid flow at 57 Hz Well test water cut at 57 Hz 22% Virtual water cut at 57 Hz 935 stb/day 971 stb/day (+3.8% variance from well test) 19.5% (-2.5% variance from well test) 998 stb/day 1031 stb/day (+3.3% variance from well test) 19% (-2.5% variance from well test) 19 Sept Zenith Oilfield Technology Slide 30 of 46

31 CASE STUDY #1: RESULTS Oil production was increased by more than 71 bopd The overall increase in oil production in the 270 days since the automated system was initiated was: 19,400 BARRELS OR $1.82M 19 Sept Zenith Oilfield Technology Slide 31 of 46

32 CASE STUDY #2: OPTIMISING A WELL WITH EMULSION PROBLEMS A minimum bottom hole flowing pressure limitation of 370 psi was specified The ESP was running at 43 Hz but not achieving the target draw down. The automated optimisation immediately highlighted that optimum frequency of the ESP was 47.1Hz The automated pump performance diagnosis showed that the head performance of the ESP was unstable, dropping intermittently by up to 22% The reduction of head performance was thought to be due to formation of emulsions 19 Sept Zenith Oilfield Technology Slide 32 of 46

33 CASE STUDY #2: OPTIMISING WELL DRAWDOWN USING FREQUENCY Frequency was increased in small steps from 43Hz to 47Hz while monitoring the effect of the emulsions on the pump head performance The first optimisation step from 43hz to 44hz The final optimisation step from 45hz to 47hz 19 Sept Zenith Oilfield Technology Slide 33 of 46

34 CASE STUDY #2: REDUCED HEAD DUE TO EMULSION The pump operating point at 47Hz is shown to fall below the pump curve due to reduced head performance of the ESP whilst emulsions were forming. The ESP design was slightly oversized to compensate. 19 Sept Zenith Oilfield Technology Slide 34 of 46

35 CASE STUDY #2: THE OPTIMISED WELL The gradient plot taken at 47Hz shows bottom hole flowing pressure has achieved the target of 370psi The live IPR Plot shows the BHFP operating point on the well inflow curve 19 Sept Zenith Oilfield Technology Slide 35 of 46

36 CASE STUDY #2: RESULTS The VSD frequency was increased from 43Hz to 47Hz over the course of optimisation Correspondingly the production rate was increased from 570 stb/day to 671 stb/day With water cut averaging 73% this equated to a 27 bopd increase in production: APPROX $2,500 PER DAY ADDITIONAL REVENUE The ESP was shown to be within range, and sized to compensate the reduced head performance of approx 22% 19 Sept Zenith Oilfield Technology Slide 36 of 46

37 CASE STUDY #3: AN UNDERPERFORMING & UNDERSIZED ESP The target BHFP was set at 1131 psi The automated ESP diagnosis highlighted that the ESP was underperforming by 30% The system recommended that the ESP frequency could be safely increased from 42Hz to 46.7Hz The system automatically showed that 46.7Hz was still not sufficient to achieve the target draw down, because further increases of frequency were limited by the ESP sizing (pump range) Target BHFP Current BHFP Reservoir Press 19 Sept Zenith Oilfield Technology Slide 37 of 46

38 CASE STUDY #3: AN UNDERPERFORMING & UNDERSIZED ESP The bottom hole flowing pressure stabilised at 1267 psi with a liquid rate of 2720 stb/day The target bottom hole flowing pressure provided scope for an additional 1142 stb of fluid (PI 8.4 stb/d/psi ) The ESP installed was not capable of providing this additional flow rate In January 2012 the ESP was resized based on the recommendations of the real time system and draw down was optimised to the target bottom hole flowing pressure Flow rate was increased to 4027 stb/d 19 Sept Zenith Oilfield Technology Slide 38 of 46

39 CASE STUDY #3: RESULTS Automated diagnosis and frequency optimisation of the underperforming ESP provided an additional 73,000 barrels of oil ($7.15 Million) in the 334 days of operation with the real time system The ESP under performance issue was highlighted immediately the automated system was implemented on the well Further increase in rate was limited by the upper flow range of the ESP Resizing of the ESP in January 2012 resulted in: 562 BOPD OR $55,070 PER DAY ADDITIONAL PRODUCTION 19 Sept Zenith Oilfield Technology Slide 39 of 46

40 THANK YOU Julian Cudmore Zenith Oilfield Technology 19 Sept Zenith Oilfield Technology Slide 40 of 46