Slide 1

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.Malin NORSAR MEQ Team -- J.Albaric, V.Oye, N.Langet, M.Hasting, I.Lecomte, K.Iranpour, M. Messeiller, & P.Reid AGIS Karlsruhe Meeting 28/11/2012 Slide 2 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 Slide 3 I. Coromandel NZ outcrop: why we need a new approach to thinking about/modeling fractures Graywacke reservoir exposure Coromandel New Zealand Slide 4 Coromandel basement metasediments spaced this far apart d flaws this long (strong) l L D The first rule relates spacing and properties Expressed in terms of wavenumber Rule I S(k) ~ 1/k The second rule relates porosity and permeability Expressed in terms of fluctuations Rule II ~ log( ) The third rule relates fluid flow and Rules I & II 2 m Expressed in terms of a power law Rule III ~ 10 ( - 0 ) 3 Empirical rules for complex rock Coromandel Fractures Compared to flaws this long (strong) spaced this far apart 2 m volume v Slide 5 Data from Roger Slatt Rule I: reason to believe S(k) ~ 1/k from well logs S(k) = fluctuation power at k k = spatial frequency S(k) ~ 1/k Slide 6 (blue) log( ) (red) ~ log( ) / ~ 10 ( - 0 ) Sample No. Well No. 1 2 3 4 5 6 7 78% 92% 86% 69% 94% 87% 87% Rule II: reason to believe ~ log( ) from well core porosity and permeability Slide 7 Rules III ~ 10 ( - 0 ) : and injection well flow in complex rock Perm Distribution Pressure Velocity small medium large Slide 8 HEAT TRANSFER BY FLUID FLOW IN COMPLEX ROCK IS EMERGENT THE HEAT SOURCE IS DOWN HERE THE WATER COMES IN HERE THE WATER COMES IN HERE THE WATER COMES OUT HERE 1 KM What are meant by an emergent phenomena? Slide 9 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 II Combining seismic and electromagnetic observations in complex rock Earthquakes location: a lesson from SAFOD Slide 10 MEQ and MT: the first test yet to be repeated (by us anyway) Slide 11 ? Vel Acc Pod 1 Vel Acc Pod 3 Vel Acc Pod 5 MT Low gain Mid High reversed polarity Oct 1 2008 Event : Vel, Acc, MT Slide 12 S-P 2 x S-P S-P 2 x S-P Oct 1 2008 Event : Stacked Raw and Low Pass MT Sept 30 2008 Event : Stacked Raw and Low Pass MT Slide 13 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 Slide 14 Paralana: 3D MT, MEQ and Geology from Seismic Reflection E 1km Slide 15 Paralana: 3D MT and MEQ 1.Km ~NE 1.Km ~NE N E Slide 16 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 Slide 17 Permanent MT Map Day Period Impedance Tensor min/max ellipse NE directed change Max change ~ 3 4 km Slide 18 Paralana: 3D MT, MEQ and Phase Tensors NE 1km Slide 19 Paralana: 3D MT and MEQ N E Possible Location Extraction Well Possible Location Extraction Well Slide 20 Fully coupled Hydro-Thermal-Mechanical model including shear stresses in complex rock