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oa Risking Vertical Fault and Top Seal Using Gas Chimneys
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 2nd EAGE International Conference on Fault and Top Seals - From Pore to Basin Scale 2009, Sep 2009, cp-136-00062
- ISBN: 978-90-73781-69-6
Abstract
Gas chimneys and related hydrocarbon migration pathways have been highlighted in seismic data using a supervised neural network, to visualize them in 3D and map their morphology. Using this information on over 125 fields and dry holes (containing effective reservoir)traps were divided into top seal and fault traps.Fault traps have been divided into three classes. Fault Flank Trap where the fault is involved in charging the trap from the flank are low risk high integrity traps. Fault Seal Traps show clear evidence of chimneys related to deep seated faults which terminate at the reservoir interval. They are high integrity traps. Fault Leak Traps have fault related chimneys observed at the crest of the structure. They are moderate to low integrity traps (LIT-MIT), and represent higher risk for vertical seal integrity. Top seal traps have been divided into four classes based on the nomenclature of Cartwright et. al. Gas Cloud Traps are low risk, but moderate integrity traps. Seepage Pipe Traps, Blowout Pipe Traps, and Mud Volcano Traps have increasing risk of seal failure, but can hold economic quantities of hydrocarbons, if buried or being recharged.