The Robert Gordon University, Aberdeen Condition Monitoring for Remedial Sand Control MSc Thesis by ILESANMI OLUMAKINDE Oil & Gas Engineering

The Robert Gordon University, Aberdeen. 9TH SEPT Subsea UK/OFFSHORE EUROPE 2 Problem Theme & Objectives 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. PROBLEM THEME A systematic approach to failure diagnosis in sand control completions using State-of-the-art tools for effective condition monitoring.

The Robert Gordon University, Aberdeen. 9TH SEPT 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?

The Robert Gordon University, Aberdeen. 9TH SEPT Subsea UK/OFFSHORE EUROPE 4 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. Tools for Condition Monitoring

The Robert Gordon University, Aberdeen. 9TH SEPT Subsea UK/OFFSHORE EUROPE 5 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, S w ).  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 ] Hard Tools for Condition Monitoring

The Robert Gordon University, Aberdeen. 9TH SEPT Subsea UK/OFFSHORE EUROPE 6 Government Research 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. [Barron R., 1996, Neale M., 1979]

The Robert Gordon University, Aberdeen. 9TH SEPT Subsea UK/OFFSHORE EUROPE 7 Hypothetical Case 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.  Deviated well, cased hole, unconsolidated formation, k V /k h =1, Multiphase fluid, 5000bopd.

The Robert Gordon University, Aberdeen. 9TH SEPT Subsea UK/OFFSHORE EUROPE 8 Hypothetical Case-Contd- Case 2  Routine monitoring of fluid samples & Optic fibre P/T sensors…pressure 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 upper region (7days).  Good production & No later problems.

The Robert Gordon University, Aberdeen. 9TH SEPT Subsea UK/OFFSHORE EUROPE 9 Is Conditioning Monitoring worth it? $ $ Pre-pack Screens $ Misc. $ $ Acid Treatment $ Sand cleaning & disposal $3 000 $0 NPT due to cleaning of separators (12hrs: 1ce a week), Production Logging (2day), Remedial Ops. (14days) $ $ $ days NPT for PL & remediation $ Option 1 Option 2 $ $ Squeeze Job $ Sand handling $1 000 $ 0 Cut back on Production. $ days $ 0 Option 1 Option 2 $ $ PLT (2days) $ $ water processing $1 000 $ 0 water 10% of production rates (21days) $ $0 Option 1 Option 2 TOTAL Remedial Expenses Processing, Handling & Disposal Expenses Lost Production $ $ Sum Totals Excluding safety hazards & later remedial expenses for Option 1

The Robert Gordon University, Aberdeen. 9TH SEPT 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.

The Robert Gordon University, Aberdeen. 9TH SEPT 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.

The Robert Gordon University, Aberdeen. 9TH SEPT Subsea UK/OFFSHORE EUROPE 12 Thank You Q & A