Interpreter-assisted Tracking of Subsurface Structures within Migrated Seismic Volumes using Active Contour Muhammad Amir Shafiq and Ghassan AlRegib

Transcription

1 Interpreter-assisted Tracking of Subsurface Structures within Migrated Seismic Volumes using Active Contour Muhammad Amir Shafiq and Ghassan AlRegib Center for Energy and Geo Processing (CeGP) at Georgia Tech and KFUPM School of Electrical and Computer Engineering Georgia Institute of Technology, Atlanta, GA, , USA.

2 Outline Introduction Active Contour Formulation Level set evolution Active Contour Tracking Experimental Results Subjective Evaluation Objective Evaluation Conclusions 2

3 Outline Introduction Active Contour Formulation Level set evolution Active Contour Tracking Experimental Results Subjective Evaluation Objective Evaluation Conclusions 3

4 Introduction Seismic Interpretation Impermeable Exploration Planning Drilling Layout Delineation Methods Edge based Methods Texture based Methods Graph Cut based Methods 2D vs 3D Methods Active Contours 4

5 Outline Introduction Active Contour Formulation Level set evolution Active Contour Tracking Experimental Results Subjective Evaluation Objective Evaluation Conclusions 5

6 Active Contour An active contour is an energy minimizing, deformable curves that are governed by two energies External energy Internal energy Penalty on curve length Smoothness Energy minimization Main types include edge and region based active contours. Edge-based geodesic active contour with an arc length penalty 6

7 Outline Introduction Active Contour Formulation Level set evolution Active Contour Tracking Experimental Results Subjective Evaluation Objective Evaluation Conclusions 7

8 PDE Formulation Energy function External Energy Internal Energy Energy Minimization using gradient descent Edge Function design The Edge function should be chosen such that the energy is minimum when active contour lie accurately on the salt dome boundary. 8

9 Outline Introduction Active Contour Formulation Level set evolution Active Contour Tracking Experimental Results Subjective Evaluation Objective Evaluation Conclusions 9

10 Level Set Evolution and Implementation The implicit level set evolution of the curve is computed as follows We have used the upwind forward time difference scheme for numerical implementation 10

11 Edge Function Seismic Section Inline #369 Edge Function Inline #369 11

12 Level set evolution Seismic Section # 369 Blue: Initial Curve Red: Curve after level set evolution 12

13 Outline Introduction Active Contour Formulation Level set evolution Active Contour Tracking Experimental Results Subjective Evaluation Objective Evaluation Conclusions 13

14 Proposed Method Overview Time Inline # n+2 Inline # n+1 Crossline Inline # n Inline # n-1 Inline # n-2 Inline Projected boundary from inline # n-1 Salt dome boundary at inline # n-2 Tracking in +ve and -ve Inline direction 14

15 depth Tracking using Active Contour 3D Seismic Volume crossline 15

16 depth Tracking using Active Contour 3D Seismic Volume crossline Select an inline within seismic volume Track salt domes in +ve inline direction Initialize the Active Contour 16

17 depth Tracking using Active Contour 3D Seismic Volume crossline 17

18 depth Tracking using Active Contour 3D Seismic Volume crossline 18

19 depth Tracking using Active Contour 3D Seismic Volume crossline Select an inline within seismic volume Track salt domes in -ve inline direction 19

20 Outline Introduction Active Contour Formulation Level set evolution Active Contour Tracking Experimental Results Subjective Evaluation Objective Evaluation Conclusions 20

21 Real Seismic Dataset 21

22 Outline Introduction Active Contour Formulation Level set evolution Active Contour Tracking Experimental Results Subjective Evaluation Objective Evaluation Conclusions 22

23 Experimental results The experimental results of salt dome delineation on different seismic sections. Green: Ground Truth Magenta: Aqrawi et al. Yellow: Berthelot et al. Blue: Shafiq et al. Red: Proposed Method Seismic inline section #349 Seismic inline section #369 Seismic inline section #387 Seismic inline section #392 23

24 Outline Introduction Active Contour Formulation Level set evolution Active Contour Tracking Experimental Results Subjective Evaluation Objective Evaluation Conclusions 24

25 Comparison: Objective Evaluation SalSIM: Frechet distance-based similarity index Inline #334 Inline #369 25

26 SalSIM 26

27 CSI: Salt-dome 27

28 CSI: Salt-dome 28

29 CSI: Salt-dome 29

30 CSI: Salt-dome 30

31 Outline Introduction Active Contour Formulation Level set evolution Active Contour Tracking Experimental Results Subjective Evaluation Objective Evaluation Conclusions 31

32 Conclusions Geodesic Active contour based method for salt dome delineation. Active Contour Tracking Speed up Local Minima Eliminates need of initialization at every step Very good tracking even after 40 inlines Interactive interpretation Curve penalty or iteration Re-initialization Experimental results 32

33 References Zhen Wang, Tamir Hegazy, Zhiling Long, and Ghassan AlRegib, Noise-robust detection and tracking of salt domes in postmigrated volumes using texture, tensors, and subspace learning, Geophysics, Ahmed Adnan Aqrawi, Trond Hellem Boe, and Sergio Barros, Detecting salt domes using a dip guided 3D Sobel seismic attribute, in Expanded Abstracts of the SEG 81st Annual Meeting. Society of Exploration Geophysicists, 2011, pp Angelique Berthelot, Anne HS Solberg, and Leiv J. Gelius, Texture attributes for detection of salt, Journal of Applied Geophysics, vol. 88, pp , Muhammad A. Shafiq, Zhen Wang, Asjad Amin, Tamir Hegazy, Mohamed Deriche, and Ghassan AlRegib, Detection of saltdome boundary surfaces in migrated seismic volumes using gradient of textures, in 2015 SEG 85th Annual Meeting, New Orleans, Louisiana, Oct , dgb Earth Sciences B.V., The Netherlands Offshore, The North Sea, F3 Block - Complete,

34 Thank You Questions!