Oil spill leakage avoidance with real time seismic monitoring Helge Brandsæter, President OCTIO AS
Injection wells - Pitfalls Oseberg - Norway Frade Brazil Veslefrikk Norway Tordis - Norway
Challenges in Northern Norwegian waters From the Wisting field, Source: Halfdan Carstens, Geo635 Pockmarks, The Barents Sea, Source: Mareano project report
Drilling Hazards Particularly applicable for: Areas with shallow overburden with young or eroded sediments Northern Norwegian waters, Brazil, West Africa
Up to 25% of wells ends up as service or injection wells Challenge: Production and Environmental risk Injection systems raise the reservoir pressure Can cause cap rock integrity issues and subsequent failure Can result in potential environmental contamination 131 An estimated 25% of offshore wells in Europe can be considered service wells (water or waste injection) 1 Production loss and environmental risk / penalties ~15% of operational discharge injection wells in the NCS are shut in because of established or suspected leaks 2 391 European Offshore Wells Drilled Annually Predicted 1.8% annual increase 2010-2015 3 1 Simmons Market Intelligence 2 Norwegian Climate and Polution Agency (Klif) 3 Drilling and Production Outlook, 2010
System Objectives Ensure spill avoidance by: Monitoring of stress changes Real time monitoring of microseismic events Real time monitoring of failures in CapRock and flow barriers Most important: Provide alarms in the event that critical barriers are effected, so that appropriate actions can be taken
The ReM System
Ethernet on the seafloor: Open digital system Interfaces third party sensors Connects to subsea infrastructure Expandable, starting from a small focused system to a large full-field system =>The digital oil field becomes a reality!
Active and Passive operation Active mode On demand surveys for IOR or CapRock integrity monitoring Passive mode 24/7 passive monitoring for detection of microseismic events caused by: Fault reactivation CapRock failures and leaks to surface
Remotely operated 24/7 Data in real-time to client s office System operation and QC in client s office and/or OCTIO s operation room Unmanned system on the rig
The SWIM project
Oseberg area - Location OSC C-4 A Source : Statoil
Survey on Oseberg C after observation of subsea craters OMR C OMR B OMR A High concentration of EOM (Extracted Organic Material) Source: Statoil
Oseberg C, Seafloor changes Source: Statoil
Seismic Data across the old CRI well at Oseberg C Seismic data(1982) before outof-zone injection event Seismic data (2011) after outof-zone injection event Utsira Utsira Injection intervall Injection intervall Source: Statoil
The SWIM project principles Onshore for real time processing Detect fractures before they reach surface Source: Statoil
Perforation shot Vertical, 15-70 Hz Expected P Multiples: - P + 1.33 - P + 2.66 (just where S expected) Travel time curves shifted up, not to hide the signal
Fracking from water injection test
Operational Scenario Real time console Operational Team Baseline Microseismic Pressure Other activity Alert level Graded event notifications Sets alert levels Evaluates fracture positions and speed of fracture propagation Requests more detailed fracture analysis if needed If fracturing reaches critical levels appropriate actions will be instigated within 3 hours of notification
Cuttings Re-Injection or Transport Onshore? Transport onshore Re-injection Transportation costs scenario based on North Sea case (yearly cost): All inclusive transportation cost: USD 12 mill Lost drilling awaiting weather for transport: USD 6.5 mill Total: USD18.5 mill Yearly monitoring cost USD 2-3 mill Additional benefits: 2 years extension of life time of injection well Reinjection of sloop saving USD 50k per week Potentially less production downtime
Conclusions Focused well monitoring facilitates: Safer injection (for IOR) in case CapRock integrity is challenged Safe injection of cuttings and waste water Well integrity monitoring during drilling and production Most important focused monitoring improves the bottom line