Use of Integrated Modeling on Niger Delta Field - MICHAEL OWARUME

Use of Integrated Modeling on AN Onshore Niger Delta Field

CONTENTS

Presentation title - Place and Country - Date Month Day Year 2

●Introduction & Overview

●Objective

●Methodology

●Results

●Other tasks

●Conclusions

●Recommendations

Introduction & Overview


-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)



High resistivity, Low Gamma ray signatures



●Location Map of the OML fields showing major delineating faults

OBJECTIVE


●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

Methodology


METHODOLOGY – VERTICAL LIFT


●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

METHODOLOGY – VERTICAL LIFT


●Model Update

-FBHP ; Tubing flow behavior

• FBHP extraction

METHODOLOGY – INFLOW PERFORMANCE


●Model Update-Reservoir inflow behavior or IPR (Forchheimer reservoir model)

• Reservoir Pressure (SP tests)

• Forchheimer Reservoir model - (Pi

2 – Pwf2)/Qg Vs Qg

- Slope = Non-Darcy, Intercept = Darcy

METHODOLOGY – INFLOW PERFORMANCE


METHODOLOGY – ROUTINE TEST VALIDATION


Well test Model

Qgas (Mscfd) 0.987 0.963

Cond. (m3/d) 402 410

Water (m3/d) 18 17

METHODOLOGY – SURFACE NETWORK REPRESENTATION


Block flow diagram

Simplified PFD

Marked-up P&ID’s



Initial GAP representation

TVD Considerations



Gas condensate wells (Ibiwari)

Proposed new wells (Ubeji)

Treatment trains 1&2

MP Manifold

MP Gas compression on oil facility

Export LineGAS cap wells

METHODOLOGY – FINE TUNING & HISTORY MATCHING


●Factors considered include;

-Manifold pressure & WHP

-Well by well production rates

-Separator pressures

-Export line Pressures

-Constraints (Max train flow rate for example)



●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%



●Well by well production rates - Due to flash gas from condensate consideration;

WellsActual 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



●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 MODEL11.807 12.795 17,316 18,636



●Curtailed production-Reduction in condensate production as a result of ruptured pipeline

Wells

Actual reported Model EstimatedGas (Mscfd) Condensate (bbls) Gas (Mscfd) Condensate (bbls)

6.789 5,655 6.105 5,648Well Head Pressure / Status

Actual (WHP/Rates) Model (WHP/Rates)IBW 014/4 106.8 / 0.621 112 / 0.838IBW 018/5 S/I 152 / 0.838IBW 017 105.3 / 0.975 120 / 1.120OB 128/5 S/I S/IIBW 015 126 / 1.652 158 / 1.543OB 126/5 S/I S/I

IBW 019/5G S/I S/IIBW 020/5 S/I S/IIBW 02B S/I S/I

IBW 007/6 S/I 136 / 0.199OB 125/3 S/I S/IOB 129 175.3 / 776 211 / 0.340

Gas Cap Wells (Msm3/d)OB122 1.419 1.32OB105 1.526 S/I

Results

●Further Validation and Optimization


Condensate (bcpd)

Model Predicted Gas

(Mscfd)

Actual Gas Production Trend

(Mscfd)12,000 9.400 6.40 - 8.2914,000 10.850 7.60 - 10.0816,000 11.239 8.76 - 10.2718,000 11.899 10.18 - 11.51

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.


Results●Predictions

●Max Line Pressure


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 19,566Export 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 9211.52 92.54 92.83 8711.53 89.54 89.83 8411.54 85.54 85.83 8011.56 81.54 81.83 7611.57 75.54 75.83 70

August

11.78

12.086

97.54 97.83 9211.79 92.54 92.83 8711.80 89.54 89.83 8411.82 85.54 85.83 8011.83 81.54 81.83 7611.85 75.54 75.83 70

September

11.84

12.208

97.54 97.83 9211.88 92.54 92.83 8711.90 89.54 89.83 8411.92 85.54 85.83 8011.95 81.54 81.83 7611.97 75.54 75.83 70

Other tasks

●Gas Lift Optimization

●Restart & ramp-up

●Workover & Infill Studies


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


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.


THANK YOU


Documents

Use of Integrated Modeling on Niger Delta Field - MICHAEL OWARUME