2. CONTENTS
Presentation title - Place and Country - Date Month Day Year 2
● Introduction & Overview
● Objective
● Methodology
● Results
● Other tasks
● Conclusions
● Recommendations
3. Introduction & Overview
Presentation title - Place and Country - Date Month Day Year 3
-Oil and Gas fields
-Vertically stacked sand bodies, clay intercalations.
-Prograding Delta (Marine – transitional - Continental)
-Traps ; Synsedimentary gravitational growth faults & rollover anticlines
-Oil Kitchen; Marine and interbedded shales below continuous shale
bodies
-Migration; Post dates structural deformation of megaunits (accumulation)
5. Introduction & Overview
Presentation title - Place and Country - Date Month Day Year 5
● Location Map of the OML fields showing major delineating faults
6. OBJECTIVE
Presentation title - Place and Country - Date Month Day Year 6
● Development of an integrated model (Prosper + GAP) to optimize
production from gas condensate wells on the field and for production
forecasting
PROSPER GAP+
2 PART INTEGRATED NETWORK MODEL
8. METHODOLOGY – VERTICAL LIFT
Presentation title - Place and Country - Date Month Day Year 8
● Model Update
-FBHP ; Tubing flow behavior or VLP
• Measured Gauge pressure with depth
• Correlation selection or matching
(gravity & friction terms)
Gravity controlled
Tubing friction controlled
9. METHODOLOGY – VERTICAL LIFT
Presentation title - Place and Country - Date Month Day Year 9
● Model Update
-FBHP ; Tubing flow behavior
• FBHP extraction
10. METHODOLOGY – INFLOW PERFORMANCE
Presentation title - Place and Country - Date Month Day Year 10
● Model Update
-Reservoir inflow behavior or IPR (Forchheimer reservoir model)
• Reservoir Pressure (SP tests)
• Forchheimer Reservoir model
- (Pi
2
– Pwf
2
)/Qg Vs Qg
- Slope = Non-Darcy, Intercept = Darcy
11. METHODOLOGY – INFLOW PERFORMANCE
Presentation title - Place and Country - Date Month Day Year 11
12. METHODOLOGY – ROUTINE TEST VALIDATION
Presentation title - Place and Country - Date Month Day Year 12
Well test Model
Qgas (Mscfd) 0.987 0.963
Cond. (m3/d) 402 410
Water (m3
/d) 18 17
13. METHODOLOGY – SURFACE NETWORK
REPRESENTATION
Presentation title - Place and Country - Date Month Day Year 13
Block flow diagram
Simplified PFD
Marked-up P&ID’s
14. METHODOLOGY – SURFACE NETWORK
REPRESENTATION
Presentation title - Place and Country - Date Month Day Year 14
Initial GAP representation
TVD Considerations
15. METHODOLOGY – SURFACE NETWORK
REPRESENTATION
Presentation title - Place and Country - Date Month Day Year 15
Gas condensate wells (Ibiwari)
Proposed new wells (Ubeji)
Treatment trains 1&2
MP Manifold
MP Gas compression on oil facility
Export Line
GAS cap wells
16. METHODOLOGY – FINE TUNING & HISTORY MATCHING
Presentation title - Place and Country - Date Month Day Year 16
● Factors considered include;
-Manifold pressure & WHP
-Well by well production rates
-Separator pressures
-Export line Pressures
-Constraints (Max train flow rate for example)
17. METHODOLOGY – FINE TUNING & HISTORY MATCHING
Presentation title - Place and Country - Date Month Day Year 17
● Manifold pressure & WHP
971.0 1000Sm3/d (actual)
123.9 Bara (actual)
Ibewa Wells Actual WHP Model WHP % Diff
IBW 014/4 108.1 108.1 0.00%
IBW 018/5 115.6 117.19 1.38%
IBW 017 121.4 123.11 1.41%
OB 128/5 147.3 149.06 1.19%
IBW 015 127 127.13 0.10%
OB 126/5 157.7 159.6 1.20%
IBW 019/5G 171.2 173.25 1.20%
IBW 020/5 241 242.96 0.81%
IBW 02B 123.9 123.97 0.06%
IBW 007/6 126.9 124.82 1.64%
OB 125/3 170 170.01 0.01%
OB 129 197.3 197.4 0.05%
Average 0.75%
18. METHODOLOGY – FINE TUNING & HISTORY MATCHING
Presentation title - Place and Country - Date Month Day Year 18
● Well by well production rates - Due to flash gas from condensate consideration;
Wells
Actual test /Simulation
GCR
(m3/m3)
Model GCR
(Sm3/Sm3)
IBW020/5 1,487 2,118
IBW019/4 2,307 3,314
OB126/5 3,561 3,561
OB128/5 3,003 4,500
IBW015/5 3,200 4,628
IBW017/5 4,501 6,399
IBW018/5 5,000 6,999
OB129/5 5,403 7,416
IBW014/4 4,501 6,508
OB125/3 1,591 2,377
IBW02B/5 2,200 3,250
IBW007/6 2,664 2,664
19. METHODOLOGY – FINE TUNING & HISTORY MATCHING
Presentation title - Place and Country - Date Month Day Year 19
● Well by well production rates
Ibewa Wells
Allocated Gas
rates (Msm3/d)
Model Gas
rates
(Msm3/d)
% Diff
IBW 014/4 0.780 0.894 14.66%
IBW 018/5 1.289 1.373 6.52%
IBW 017 0.876 1.043 19.01%
OB 128/5 0.225 0.279 24.08%
IBW 015 2.126 2.314 8.89%
OB 126/5 1.013 1.165 15.02%
IBW 019/5G 0.748 0.839 12.16%
IBW 020/5 0.652 0.782 19.94%
IBW 02B 0.897 0.970 8.07%
IBW 007/6 0.293 0.292 0.36%
OB 125/3 0.892 0.703 21.22%
OB 129 0.642 0.726 13.00%
Average 13.58%
● Separator & Export line pressures
● Constraints (Max train flow rates)
GAS (Mscm/d) COND (bcpd)
ACTUAL MODEL ACTUAL MODEL
11.807 12.795 17,316 18,636
20. METHODOLOGY – FINE TUNING & HISTORY MATCHING
Presentation title - Place and Country - Date Month Day Year 20
● Curtailed production
-Reduction in condensate production as a result of ruptured pipeline
Wells
Actual reported Model Estimated
Gas (Mscfd) Condensate (bbls) Gas (Mscfd) Condensate (bbls)
6.789 5,655 6.105 5,648
Well Head Pressure / Status
Actual (WHP/Rates) Model (WHP/Rates)
IBW 014/4 106.8 / 0.621 112 / 0.838
IBW 018/5 S/I 152 / 0.838
IBW 017 105.3 / 0.975 120 / 1.120
OB 128/5 S/I S/I
IBW 015 126 / 1.652 158 / 1.543
OB 126/5 S/I S/I
IBW 019/5G S/I S/I
IBW 020/5 S/I S/I
IBW 02B S/I S/I
IBW 007/6 S/I 136 / 0.199
OB 125/3 S/I S/I
OB 129 175.3 / 776 211 / 0.340
Gas Cap Wells (Msm3/d)
OB122 1.419 1.32
OB105 1.526 S/I
21. Results
● Further Validation and Optimization
Presentation title - Place and Country - Date Month Day Year 21
Condensate
(bcpd)
Model
Predicted Gas
(Mscfd)
Actual Gas
Production Trend
(Mscfd)
12,000 9.400 6.40 - 8.29
14,000 10.850 7.60 - 10.08
16,000 11.239 8.76 - 10.27
18,000 11.899 10.18 - 11.51
22. RESULTS – OPTIMIZATION PROCEDURE
● Ensure all PROSPER models are updated with as much recent and reliable data as possible. Must be
crosschecked with valid well tests.
● Re-link PROSPER files to GAP models, regenerate VLP and run model validation to estimate
discrepancies between the measurements and estimated results.
● Input constraints and targets at different relevant nodes. For eg; Gas nomination rates, maximum
condensate requirement as specified by OFS etc. Control wells by inputting maximum DD as would have
been previously determined from the PROSPER models alone.
● Ensure that the GCR section (GOR in the GAP model) has actual values. i.e, dividing Potential gas by
potential condensates and not values from well tests or from the Well Instructions Sheet (WIS)
● Run network model solver to optimize with all constraints after inputting separator conditions (if values on
existing model seem to be non-representative).
● Crosscheck that all constraints and targets are met.
● Extract DD from well results. These are to be followed on site.
Presentation title - Place and Country - Date Month Day Year 22
23. Results
● Predictions
● Max Line Pressure
Presentation title - Place and Country - Date Month Day Year 23
Period
MPG-Model (PDC09) PG-Model
Gas
(Msm3/d)
Cond. (bcpd) Gas (Msm3/d) Cond. (bcpd)
Nov '15 13.31 18,663 13.30 19,951
Dec '15 12.94 17,718 13.33 19,566
Export Line Validation
Month
PG Model Rates
(Msm3/d)
Monthly
Potential
(Msm3/d)
HP Sep Pres
(Train #1)
HP Sep Pres
(Train #2)
Export Sep
(Bar)
July
11.50
11.809
97.54 97.83 92
11.52 92.54 92.83 87
11.53 89.54 89.83 84
11.54 85.54 85.83 80
11.56 81.54 81.83 76
11.57 75.54 75.83 70
August
11.78
12.086
97.54 97.83 92
11.79 92.54 92.83 87
11.80 89.54 89.83 84
11.82 85.54 85.83 80
11.83 81.54 81.83 76
11.85 75.54 75.83 70
September
11.84
12.208
97.54 97.83 92
11.88 92.54 92.83 87
11.90 89.54 89.83 84
11.92 85.54 85.83 80
11.95 81.54 81.83 76
11.97 75.54 75.83 70
24. Other tasks
● Gas Lift Optimization
● Restart & ramp-up
● Workover & Infill Studies
Presentation title - Place and Country - Date Month Day Year 24
25. conclusion
● Flexibility for monthly production predictions, hence proper planning
can be done.
● For unwanted constraints and/limitations to be spotted as the piping
network is more representative than the MPG model.
● Well test analysis and validations are now possible and more
automated via IFM
Presentation title - Place and Country - Date Month Day Year 25
26. Recommendations/improvements
● Update PROSPER Models
● A full field site survey can be conducted for accurate line
dimensioning.
● An MBAL model can be integrated into the network which will
account for reservoir pressure decline and thus unlocking the
prediction setting.
● Compositional PVT descriptions should be provided as inputs to
PROSPER. This will account for the interplay between the vapor and
the liquid phases.
● During well test validation, deviation from model should be
monitored so model update can be planned.
Presentation title - Place and Country - Date Month Day Year 26
Source Rock and Oil Kitchen; It has been assumed that the most effective source rocks are the marine shales and the shales interbedded with the paraUc sandstones, particularly
in the lower part of the parahc sequence where the shales are at least volumetrically more important. Where the "kitchen" lies well below
the top of the continuous shales, any oil generated is considered to have only a remote chance of finding its way into the overlying reservoirs, as the faults at depth within the shales are not considered to provide effective migration paths. It is of importance, therefore, to know the facies at and directly above the "kitchen."