Condition Monitoring for Remedial Sand Control

1. Condition Monitoring for Remedial Sand Control MSc Thesis by ILESANMI OLUMAKINDE Oil & Gas Engineering

2. Problem Theme & Objectives PROBLEM THEME • A systematic approach to failure diagnosis in sand control completions using • State-of-the-art tools for effective condition monitoring. OBJECTIVES • Adapt condition monitoring to sand management. • Define the failure mechanism of sand control completions. • Tools for failure diagnosis. • Options for remediation; risks, consequences and benefits. Subsea UK/OFFSHORE EUROPE

3. Fault/Failure Diagnosis • Faults & Failures? • Cause & Effect Analysis • A priori knowledge & • Search Technique[Venkatasubramanian V., ed., 2003] • primary & secondary failures [Peter Q.H., ed., 2004]. • Simultaneous failures [Wong G.K., ed., 2003] • Identification of faults & diagnosis of possible sand problems. • Considerations for the effects of production problems. • CM: Diagnosis or Simulation? Subsea UK/OFFSHORE EUROPE

4. Tools for Condition Monitoring • Soft & Hard Tools. • Integrated Approach! • Soft Tools • Description of well completion. • Reservoir characteristics & Lithology. • PVT data of fluids. • Production Parameters/History • Open-hole Logs/Offset data of typical failures. Subsea UK/OFFSHORE EUROPE

5. Hard Tools for Condition Monitoring • Application of Production Logging & Transience Tests [Wong G.K., ed., 2004, SPE 84497] using Wireline Testing Tool. • Magnetic Resonance Imager MRI or NMR (k, Φ, Sw). • Floscan Multiphase Flowmeter. • Electromagnetic Propagation Tool. • Permanent P/T monitoring [Acock A., ed., 2004 Slb oilfield review, Unneland T., ed., 1993 SPE Prod.& facilities ] • Fiber optics? • Sand Detection Devices (Acoustic probes). [Nisbet J.W.R., ed., 2003, SPE 84494] • Fluid Sampling at Surface (Microscopic analysis, sieve analysis). [Nisbet J.W.R., ed., 2003, SPE ] Subsea UK/OFFSHORE EUROPE

6. Government Research [Barron R., 1996, Neale M., 1979] • On the average, condition monitoring achieved savings of 1.2% on value-added output (i.e. total sales revenue minus cost of raw material and energy brought in). • Two-thirds (2/3) of savings were due to an increase in availability gained from improved shut-down performance. • There was a 75% decrease in unscheduled shutdown time. • One-thirds of savings were due to a decrease in maintenance costs gained from improved breakdown performance. • There was a 50% decrease in breakdown labour costs. Subsea UK/OFFSHORE EUROPE

7. Hypothetical Case • Deviated well, cased hole, unconsolidated formation, kV/kh=1, Multiphase fluid, 5000bopd. Case 1 • Reduced productivity, No sand...Increased drawdown? • Slight increase in water cut after 7days...No sand. • Transient sanding after 30days? Cut back on production! • Fair production rates…well sands continuously after 7days…rapid production decline. • Ran Production Logging Tools (2days). • Some perf. Collapsed & Poor primary cement job. • Well Shut-in, Squeeze job & pre-pack screen! (14days). • Good production with slight water cut due to fingering. • Subsequent gravel pack plugging. Subsea UK/OFFSHORE EUROPE

8. Hypothetical Case -Contd- Case 2 • Routine monitoring of fluid samples & Optic fibre P/T sensors…pressure spikes @ perf. & upper region? Normal temp. logs. • Production decline? No sand alarms…suspect perf./screen plugging, formation damage, possible channelling at upper region? • Run PL Tools (GR, MRI, Floscan, Noise Log, Spinner) (2days). • Formation damage due to fines migration. • Remedial Acid treatment, Cement & Squeeze job @ upper region (7days). • Good production & No later problems. Subsea UK/OFFSHORE EUROPE

9. Lost Production Processing, Handling & Disposal Expenses Remedial Expenses TOTAL Option 1 Option 2 water cut @ 10% of production rates (21days) $525 000 $0 water processing $1 000 $ 0 PLT (2days) $200 000 $400 000 $726 000 $400 000 Option 1 Option 2 Cut back on Production. $157 500 - 7days $ 0 Sand handling $1 000 $ 0 Squeeze Job $ 50 000 $ 50 000 $208 000 $ 50 000 Option 1 Option 2 NPT due to cleaning of separators (12hrs: 1ce a week), Production Logging (2day), Remedial Ops. (14days) $500 000 $500 000 $3 500 000 $4 500 000 9days NPT for PL & remediation $2 250 000 Sand cleaning & disposal $3 000 $0 Pre-pack Screens $ 80 000 Misc. $ 20 000 $ 100 000 Acid Treatment $ 50 000 $4 603 000 $2 300 000 Is Conditioning Monitoring worth it? $ 5 537 000 $ 2 750 000 Sum Totals Excluding safety hazards & later remedial expenses for Option 1 Subsea UK/OFFSHORE EUROPE

10. Risks, Consequences & Benefits • Risks & Consequences? • Benefits • Improved availability of downhole and surface equipments (less downtime, more production). • Improved reliability/safety of downhole and surface equipments. • Prolonged life of the reservoir for greater production-output by managing operational parameters. • Reduced workover and operational costs from catastrophic breakdown of well and/or reservoir. • Better well planning for remediation from cash flow. Subsea UK/OFFSHORE EUROPE

11. Conclusion • Sand Management technique. • Diagnose possible completion failures to “guarantee” economics & safety. • Cheap, effective technologies with better quality. • New technologies in Fibre Optics, NMR, Flow measurements, Acoustics, & computer-based diagnosis. Further research • Visual modelling of near-wellbore region. • Computer-based diagnosis e.g. neural networks, expert systems. Subsea UK/OFFSHORE EUROPE

12. Thank You Q & A Subsea UK/OFFSHORE EUROPE