900 likes | 1.07k Views
Overview of Utah Tomography and Modeling/Migration (UTAM). Chaiwoot B., T. Crosby, G. Jiang, R. He, G. Schuster, J. Sheng, J. Yu, M. Zhou and Xiang Xiao. 2004 UTAM Consortium. ($24 K/year). Aramco BP-Amoco BGP Geotomo Chevron-Texaco Conoco-Phillips. IMP INCO Sisimage Unocal
E N D
Overview of Utah Tomography and Modeling/Migration(UTAM) Chaiwoot B., T. Crosby, G. Jiang, R. He, G. Schuster, J. Sheng, J. Yu, M. Zhou and Xiang Xiao
2004 UTAM Consortium ($24 K/year) Aramco BP-Amoco BGP Geotomo Chevron-Texaco Conoco-Phillips IMP INCO Sisimage Unocal Veritas Western-Geco
UTAM • Started 1988 • Goal: Innovative Imaging/Modeling • 10-18 sponsors/year • $24,000/year membership • Benefits: Yearly meeting: Feb. 3-4 Annual+midyr Report Software
Interferometric Imaging below Salt And Overburden Jianhua Yu, Min Zhou Gerard T. Schuster University of Utah
Outline Motivation Interferometric Imaging Synthetic Data Conclusions
Outline Motivation Interferometric Imaging Synthetic & Field Data Conclusions
Salt v(x,y,z) not known Static errors ? Problems with VSP or CDP Salt Imaging Quality?
Outline Motivation Interferometric Imaging Synthetic & Field Data Conclusions
How do you remove kinematic effects of propagating through unintersting parts of medium? Uninteresting Part of Medium
Pick Direct Arrival Time T and shift all Traces by T T M { M M M
T M { Shifting Traces Removes Kinematic Effects Of Propagating through Uninteresting Parts of Medium M
Shifting Traces Removes Kinematic Effects Of Propagating through Uninteresting Parts of Medium M
Kirchhoff Migrate psuedo-shot gathers m(x) = (g, t + t ) gx gx Mx M g M Shifting Traces Removes Kinematic Effects Of Propagating through Uninteresting Parts of Medium. . Source Moved to Depth Can replace time-shifted traces by crosscorrelograms M
Kirchhoff Migrate psuedo-shot gathers m(x) = (g, t + t ) gx gx Mx M g M Can replace time-shifted traces by crosscorrelograms M
Kirchhoff Migrate psuedo-shot gathers m(x) = (g, t + t ) gx gx Mx M g M Can replace time-shifted traces by crosscorrelograms M
Kirchhoff Migrate psuedo-shot gathers m(x) = (g, t + t ) gx gx Mx M g M Can replace time-shifted traces by crosscorrelograms M
Kirchhoff Migrate psuedo-shot gathers m(x) = (g, t + t ) gx gx Mx M g M Can replace time-shifted traces by crosscorrelograms M
Kirchhoff Migrate psuedo-shot gathers m(x) = (g, t + t ) gx gx Mx M g M Can replace time-shifted traces by crosscorrelograms M
Kirchhoff Migrate psuedo-shot gathers m(x) = (g, t + t ) gx gx Mx M g M Can replace time-shifted traces by crosscorrelograms M
Eliminates source statics and uninteresting parts of the medium. Lower source to be near target. Interferometric Summary
Eliminates source+rec statics and uninteresting parts of the medium. Lower source+rec. to be near target. Interferometric Summary Reference layer
Outline Motivation Interferometric Imaging Synthetic CDP Data & Field Data Conclusions
X (km) 3 0 0 Depth (km) Shots: 280 Shot interval: 10 m Receivers: 300 Receiver interval: 10 m Temporal interval:1ms 1.8 Salt model
X (km) 0 3 0 Depth (km) 1.8 True velocity model
X (km) 0 3 0 Pick Traveltime Subsalt Reference Reflection Time (s) 3 CSG 100
X (km) 0 3 0 Depth (km) 1.8 Kirmig with inaccurate salt dome boundary
X (km) 0 3 0 Depth (km) 1.8 RT migration with inaccurate salt dome boundary
X (km) X (km) X (km) 3 3 3 0 0 0 0 Depth (km) 1.8 Standard mig Correct velocity Standard mig Incorrect velocity RT mig
Outline Motivation Interferometric Imaging Synthetic HSP Data & Field Data Conclusions
HSP Interferometric Imaging Salt Model HSP Shot Gather 0 km 0 km 1.2 km 1.2 s 0 km 5 km Mig. Image+Corr. Vel. 0 km 0 km 0 km 5 km 1.2 km 1.2 km 0 km 1.2 km 0 km 1.2 km
HSP Interferometric Imaging Salt Model HSP Shot Gather 0 km 0 km 1.2 km 1.2 s 0 km 5 km Mig. Image+Corr. Vel. 0 km 0 km 0 km HSP Interferometric Imaging 5 km 1.2 km 1.2 km 0 km 1.2 km 0 km 1.2 km
HSP Interferometric Imaging Salt Model HSP Shot Gather 0 km 0 km 1.2 km 1.2 s 0 km 5 km Mig. Image+Corr. Vel. HSP Image 0 km 0 km 0 km 5 km 1.2 km 1.2 km 0 km 1.2 km 0 km 1.2 km
HSP Interferometric Imaging Salt Model HSP Shot Gather 0 km 0 km 1.2 km 1.2 s 0 km 5 km Mig. Image+Corr. Vel. HSP Image SWI-HSP Image 0 km 0 km 0 km Garbage 5 km 1.2 km 1.2 km 0 km 1.2 km 0 km 1.2 km
HSP Interferometric Imaging Salt Model HSP Shot Gather 0 km 0 km 1.2 km 1.2 s 0 km 5 km Mig. Image+Corr. Vel. HSP Image SWI-HSP Image 0 km 0 km 0 km No Need for V Garbage 5 km 1.2 km 1.2 km 0 km 1.2 km 0 km 1.2 km
Outline Motivation Interferometric Imaging Synthetic VSP Data & Field Data Conclusions
VSP Data Image Below Salt Without Knowing Salt Velocity 0 km2 km 0 km 3 km
Interferometric Image X (m) 1000 1400 950 Depth (m) 1950
Well 256 Sources V = 1.5 - 3.0 km/s 0 Depth (km) SEG/EAGE Model 2 0 X (km) 3
X (km) 1.4 2.4 Xcross 60 X (km) 0 2.4 0 Time (s) CRG 60 3
Xcorr Mig (45) Xcorr. Mig(15’) Kirchh Mig (45) 0.5 Depth (km) 2.0 0.5 2.5 0.5 2.5 0.5 2.5 X (km)
Outline Motivation Interferometric Imaging Synthetic VSP Data & Field Data Conclusions
Depth (ft) 30 900 0 Raw Data(CRG15) Time (s) 0.3
Depth (ft) 30 900 0 Ghosts Time (s) 0.3
X (ft) X (ft) 0 400 0 400 200 Standard mig Xcorr. mig Depth (ft) 1300
Salt + Overburden SUMMARY • Interferometric Tomography • Interferometric Imaging: Kinematically equivalent to sources-receivers below datum • True wave equation statics w/o V(x,y,z) • HSP, VSP and CDP data
SUMMARY • Interferometric Tomography • Interferometric Imaging: Kinematically equivalent to sources-receivers below datum • True wave equation statics w/o V(x,y,z) • HSP, VSP and CDP data Salt + Overburden
Increased illumination coverage in the VSP image. VSP ->CDP Eliminate the static errors in the well No need to know source (RVSP) or receiver location (VSP) Half sensitivity to velocity migration errors than mult. migration by “mirrors”. Crosscorrelogram Migration Conclusions
Xcorr Kirchhoff Be careful about virtual multiple Ghost is weaker than primary Extra summation compared to KM vs Narrow Angle Wide Angle Conclusions Loss of some lateral resolution?
Outline Motivation Crosscorrelation Migration SEG/EAGE Model 2-D RVSP Field Data Conclusions
Well 256 Sources V = 1.5 - 3.0 km/s 0 Depth (km) SEG/EAGE Model 2 0 X (km) 3