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AGIS – Karlsruhe Meeting 28/11/2012.
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AGIS – Karlsruhe Meeting 28/11/2012 Making the most of it: Combining seismic and electromagnetic observations in complex rock IESE MT Team – J.Peacock, P.Leary, E.Shalev, M.Hasting, J.Pogacnik, & P.MalinNORSAR MEQ Team -- J.Albaric, V.Oye, N.Langet, M.Hasting, I.Lecomte, K.Iranpour, M. Messeiller, & P.Reid
3 Part Outline: I. Complex rock a. Coromandel outcrop b. 3 Empirical rule for complex rock c. Well log and core evidence for complex rock d. THM coupling in complex rock – the movies II Combining seismic and electromagnetic observations in complex rock a. The event location conundrum at SAFOD b. The MT coil experiment – needs verification III MEQ and MT at the Paralana HSA site a. The MEQ event “cloud” b. The continuous and time-lapse MT effect
I. Coromandel NZ outcrop: why we need a new approach to thinking about/modeling fractures Graywacke reservoir exposure Coromandel New Zealand
3 Empirical rules for complex rock Coromandel Fractures The first rule relates spacing and properties Coromandel basement metasediments Expressed in terms of wavenumber Rule I S(k) ~ 1/k spaced this far apart volume v The second rule relates porosity and permeability D Compared to flaws this long (strong) flaws this long (strong) 2 m 2 m l d Expressed in terms of fluctuations Rule II δ~ δlog(k) L spaced this far apart The third rule relates fluid flow and Rules I & II Expressed in terms of a power law Rule III k ~ k010a(-0)
Rule I: reason to believe S(k) ~ 1/k from well logs S(k) ~ 1/k S(k) = fluctuation power at k Data from Roger Slatt k= spatial frequency
78% 92% 86% 69% 94% 87% 87% 94% 86% Rule II: reason to believe δ~ δlog(k) from well core porosity and permeability d(blue) dlog(k) (red) 78% 92% 86% 69% 94% 87% 87% • δ~ δlog(κ) /k ~ k010a(-0) Sample No. 1 2 3 4 5 6 7 Well No.
Rules III k ~ k010a(-0):aand injection well flow in complex rock a Perm Distribution Pressure Velocity small medium large
What are meant by an emergent phenomena? HEAT TRANSFER BY FLUID FLOW IN COMPLEX ROCK IS EMERGENT THE WATER COMES OUT HERE THE WATER COMES IN HERE THE WATER COMES IN HERE THE HEAT SOURCE IS DOWN HERE 1 KM 1 KM
II Combining seismic and electromagnetic observations in complex rock Earthquakes location: a lesson from SAFOD The problem: Define drilling target using best 3-D method Mag 2 repeating event ~ 10x10 m. Phase 1: 60 surface stations, 2 years, located within “100 m errors” Phase 2: add 32 levels borehole, 1 year, located within “50 m errors” moved 800 m Phase 3: add sensor 400 m from target, located within “20 m errors” moved 200 m
MEQ and MT: the first test – yet to be repeated (by us anyway)
Oct 1 2008 Event : Vel, Acc, MT Vel Pod 1 Acc Vel Pod 3 Acc Vel Acc Pod 5 Low gain Mid High – reversed polarity MT ?
Oct 1 2008 Event : Stacked Raw and Low Pass MT S-P 2 x S-P Sept 30 2008 Event : Stacked Raw and Low Pass MT S-P 2 x S-P
III MEQ and MT at the Paralana HSA site Seismic CMP profile MT profile 11 permanent MT 56 repeat MT profile 8 Borehole MEQ 4-6 Surface MEQ
Paralana: 3D MT, MEQ and Geology from Seismic Reflection 1km E 1km
Paralana: 3D MT and MEQ 1.Km ~NE N E
Paralana: Permanent MT station PB01 differences ~ a few hundred meters from well head Period of ~ 0.5-1 sec ~ 1 km; ~ 3-4 sec ~ 3-4 km Begin End
Permanent MT Map Day Period Impedance Tensor min/max ellipse NE directed change Max change ~ 3 – 4 km
Paralana: 3D MT, MEQ and Phase Tensors 1km 1km E N
Paralana: 3D MT and MEQ Possible Location Extraction Well N E
Fully coupled Hydro-Thermal-Mechanical model including shear stresses in complex rock