Velocity calibration and wavefield Overview decomposition for - PowerPoint PPT Presentation

CRS Operator for arbitrary geometry � 2 � τ 0 + sin β S ∆ x S − cos β S ∆ z S + sin β G ∆ x G − cos β G τ 2 = ∆ z G hyp v S v S v G v G τ 0 AB − 1 ( ∆ x S − ∆ z S tan β S ) 2 + τ 0 DB − 1 ( ∆ x G − ∆ z G tan β G ) 2 + 2 τ 0 B − 1 ( ∆ x S − ∆ z S tan β S ) ( ∆ x G − ∆ z G tan β G ) . −

CRS Operator for arbitrary geometry � 2 � τ 0 + sin β S ∆ x S − cos β S ∆ z S + sin β G ∆ x G − cos β G τ 2 = ∆ z G hyp v S v S v G v G τ 0 AB − 1 ( ∆ x S − ∆ z S tan β S ) 2 + τ 0 DB − 1 ( ∆ x G − ∆ z G tan β G ) 2 + 2 τ 0 B − 1 ( ∆ x S − ∆ z S tan β S ) ( ∆ x G − ∆ z G tan β G ) . − ◮ τ 0 : traveltime of central FO ray

CRS Operator for arbitrary geometry � 2 � τ 0 + sin β S ∆ x S − cos β S ∆ z S + sin β G ∆ x G − cos β G τ 2 = ∆ z G hyp v S v S v G v G τ 0 AB − 1 ( ∆ x S − ∆ z S tan β S ) 2 + τ 0 DB − 1 ( ∆ x G − ∆ z G tan β G ) 2 + 2 τ 0 B − 1 ( ∆ x S − ∆ z S tan β S ) ( ∆ x G − ∆ z G tan β G ) . − ◮ τ 0 : traveltime of central FO ray ◮ ∆ x S , ∆ z S , ∆ x G , ∆ z G : horizontal and vertical offsets

CRS Operator for arbitrary geometry � 2 � τ 0 + sin β S ∆ x S − cos β S ∆ z S + sin β G ∆ x G − cos β G τ 2 = ∆ z G hyp v S v S v G v G τ 0 AB − 1 ( ∆ x S − ∆ z S tan β S ) 2 + τ 0 DB − 1 ( ∆ x G − ∆ z G tan β G ) 2 + 2 τ 0 B − 1 ( ∆ x S − ∆ z S tan β S ) ( ∆ x G − ∆ z G tan β G ) . − ◮ τ 0 : traveltime of central FO ray ◮ ∆ x S , ∆ z S , ∆ x G , ∆ z G : horizontal and vertical offsets ◮ v S , v G : velocities in the vicinity of � x S and � x G

CRS Operator for arbitrary geometry � 2 � τ 0 + sin β S ∆ x S − cos β S ∆ z S + sin β G ∆ x G − cos β G τ 2 = ∆ z G hyp v S v S v G v G τ 0 AB − 1 ( ∆ x S − ∆ z S tan β S ) 2 + τ 0 DB − 1 ( ∆ x G − ∆ z G tan β G ) 2 + 2 τ 0 B − 1 ( ∆ x S − ∆ z S tan β S ) ( ∆ x G − ∆ z G tan β G ) . − ◮ τ 0 : traveltime of central FO ray ◮ ∆ x S , ∆ z S , ∆ x G , ∆ z G : horizontal and vertical offsets ◮ v S , v G : velocities in the vicinity of � x S and � x G ◮ β S , β G : emergence angles of central ray

CRS Operator for arbitrary geometry � 2 � τ 0 + sin β S ∆ x S − cos β S ∆ z S + sin β G ∆ x G − cos β G τ 2 = ∆ z G hyp v S v S v G v G τ 0 AB − 1 ( ∆ x S − ∆ z S tan β S ) 2 + τ 0 DB − 1 ( ∆ x G − ∆ z G tan β G ) 2 + 2 τ 0 B − 1 ( ∆ x S − ∆ z S tan β S ) ( ∆ x G − ∆ z G tan β G ) . − ◮ τ 0 : traveltime of central FO ray ◮ ∆ x S , ∆ z S , ∆ x G , ∆ z G : horizontal and vertical offsets ◮ v S , v G : velocities in the vicinity of � x S and � x G ◮ β S , β G : emergence angles of central ray ◮ DB − 1 , AB − 1 , B − 1 : composites of elements of ray-propagator matrix

Velocity calibration A look at multi-coverage walkover data and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration A look at multi-coverage walkover data and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP CR FO CRS-Operator Calibration method Data example Survey description CS Velocity calibration qCO Decomposition Conclusions & outlook * W I T

Velocity calibration Calibration of CRS attributes and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Calibration of CRS attributes and wavefield decomposition M. von Steht & J. Mann Stacking parameters are converted to wavefield Overview Theory attributes by using tuned velocities. CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Calibration of CRS attributes and wavefield decomposition M. von Steht & J. Mann Stacking parameters are converted to wavefield Overview Theory attributes by using tuned velocities. CRS stack for VSP FO CRS-Operator ◮ inaccurate velocities ⇔ incorrect attributes Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Calibration of CRS attributes and wavefield decomposition M. von Steht & J. Mann Stacking parameters are converted to wavefield Overview Theory attributes by using tuned velocities. CRS stack for VSP FO CRS-Operator ◮ inaccurate velocities ⇔ incorrect attributes Calibration method Data example ◮ conventional way: checkshot inversion Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Calibration of CRS attributes and wavefield decomposition M. von Steht & J. Mann Stacking parameters are converted to wavefield Overview Theory attributes by using tuned velocities. CRS stack for VSP FO CRS-Operator ◮ inaccurate velocities ⇔ incorrect attributes Calibration method Data example ◮ conventional way: checkshot inversion Survey description Velocity calibration often too inaccurate! Decomposition Conclusions & outlook W I T

Velocity calibration Calibration of CRS attributes and wavefield decomposition M. von Steht & J. Mann Stacking parameters are converted to wavefield Overview Theory attributes by using tuned velocities. CRS stack for VSP FO CRS-Operator ◮ inaccurate velocities ⇔ incorrect attributes Calibration method Data example ◮ conventional way: checkshot inversion Survey description Velocity calibration often too inaccurate! Decomposition ◮ alternatively: CRS analysis of downgoing waves Conclusions & outlook W I T

Velocity calibration Calibration of CRS attributes and wavefield decomposition M. von Steht & J. Mann Stacking parameters are converted to wavefield Overview Theory attributes by using tuned velocities. CRS stack for VSP FO CRS-Operator ◮ inaccurate velocities ⇔ incorrect attributes Calibration method Data example ◮ conventional way: checkshot inversion Survey description Velocity calibration often too inaccurate! Decomposition ◮ alternatively: CRS analysis of downgoing waves Conclusions & outlook Assumption: W I T

Velocity calibration Calibration of CRS attributes and wavefield decomposition M. von Steht & J. Mann Stacking parameters are converted to wavefield Overview Theory attributes by using tuned velocities. CRS stack for VSP FO CRS-Operator ◮ inaccurate velocities ⇔ incorrect attributes Calibration method Data example ◮ conventional way: checkshot inversion Survey description Velocity calibration often too inaccurate! Decomposition ◮ alternatively: CRS analysis of downgoing waves Conclusions & outlook Assumption: ◮ velocities virtually constant within paraxial vicinity W I T

Velocity calibration Calibration of CRS attributes and wavefield decomposition M. von Steht & J. Mann Stacking parameters are converted to wavefield Overview Theory attributes by using tuned velocities. CRS stack for VSP FO CRS-Operator ◮ inaccurate velocities ⇔ incorrect attributes Calibration method Data example ◮ conventional way: checkshot inversion Survey description Velocity calibration often too inaccurate! Decomposition ◮ alternatively: CRS analysis of downgoing waves Conclusions & outlook Assumption: ◮ velocities virtually constant within paraxial vicinity (already inherent assumption of CRS method) W I T

Velocity calibration Calibration of CRS attributes and wavefield decomposition M. von Steht & J. Mann Stacking parameters are converted to wavefield Overview Theory attributes by using tuned velocities. CRS stack for VSP FO CRS-Operator ◮ inaccurate velocities ⇔ incorrect attributes Calibration method Data example ◮ conventional way: checkshot inversion Survey description Velocity calibration often too inaccurate! Decomposition ◮ alternatively: CRS analysis of downgoing waves Conclusions & outlook Assumption: ◮ velocities virtually constant within paraxial vicinity (already inherent assumption of CRS method) � independent of � � � � ➥ length of slowness vector p incidence angle W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann ◮ VSP data provides only one slowness component: Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann ◮ VSP data provides only one slowness component: Overview Theory slowness component p t tangent to well CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann ◮ VSP data provides only one slowness component: Overview Theory slowness component p t tangent to well CRS stack for VSP � � ➥ in general insufficient to determine � � p FO CRS-Operator � Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann ◮ VSP data provides only one slowness component: Overview Theory slowness component p t tangent to well CRS stack for VSP � � ➥ in general insufficient to determine � � p FO CRS-Operator � Calibration method ◮ special case: walkover VSP Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann ◮ VSP data provides only one slowness component: Overview Theory slowness component p t tangent to well CRS stack for VSP � � ➥ in general insufficient to determine � � p FO CRS-Operator � Calibration method ◮ special case: walkover VSP Data example Survey description ◮ p t of downgoing rays varies with source position � x S Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann ◮ VSP data provides only one slowness component: Overview Theory slowness component p t tangent to well CRS stack for VSP � � ➥ in general insufficient to determine � � p FO CRS-Operator � Calibration method ◮ special case: walkover VSP Data example Survey description ◮ p t of downgoing rays varies with source position � x S Velocity calibration Decomposition ◮ a ray tangent to well at receiver � x G is very likely Conclusions & outlook W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann ◮ VSP data provides only one slowness component: Overview Theory slowness component p t tangent to well CRS stack for VSP � � ➥ in general insufficient to determine � � p FO CRS-Operator � Calibration method ◮ special case: walkover VSP Data example Survey description ◮ p t of downgoing rays varies with source position � x S Velocity calibration Decomposition ◮ a ray tangent to well at receiver � x G is very likely Conclusions & outlook � � � � there: naturally p t ≡ p � W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann ◮ VSP data provides only one slowness component: Overview Theory slowness component p t tangent to well CRS stack for VSP � � ➥ in general insufficient to determine � � p FO CRS-Operator � Calibration method ◮ special case: walkover VSP Data example Survey description ◮ p t of downgoing rays varies with source position � x S Velocity calibration Decomposition ◮ a ray tangent to well at receiver � x G is very likely Conclusions & outlook � � � � there: naturally p t ≡ p � ◮ Strategy W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann ◮ VSP data provides only one slowness component: Overview Theory slowness component p t tangent to well CRS stack for VSP � � ➥ in general insufficient to determine � � p FO CRS-Operator � Calibration method ◮ special case: walkover VSP Data example Survey description ◮ p t of downgoing rays varies with source position � x S Velocity calibration Decomposition ◮ a ray tangent to well at receiver � x G is very likely Conclusions & outlook � � � � there: naturally p t ≡ p � ◮ Strategy ◮ identify downgoing direct P and/or S arrivals W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann ◮ VSP data provides only one slowness component: Overview Theory slowness component p t tangent to well CRS stack for VSP � � ➥ in general insufficient to determine � � p FO CRS-Operator � Calibration method ◮ special case: walkover VSP Data example Survey description ◮ p t of downgoing rays varies with source position � x S Velocity calibration Decomposition ◮ a ray tangent to well at receiver � x G is very likely Conclusions & outlook � � � � there: naturally p t ≡ p � ◮ Strategy ◮ identify downgoing direct P and/or S arrivals ◮ calculate p t � � x S ,� � x G ∀ sources S and receivers G W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann ◮ VSP data provides only one slowness component: Overview Theory slowness component p t tangent to well CRS stack for VSP � � ➥ in general insufficient to determine � � p FO CRS-Operator � Calibration method ◮ special case: walkover VSP Data example Survey description ◮ p t of downgoing rays varies with source position � x S Velocity calibration Decomposition ◮ a ray tangent to well at receiver � x G is very likely Conclusions & outlook � � � � there: naturally p t ≡ p � ◮ Strategy ◮ identify downgoing direct P and/or S arrivals ◮ calculate p t � � x S ,� � x G ∀ sources S and receivers G ◮ for each G , search maximum of p t � � � x S ,� x G = const W I T

Velocity calibration Calibration strategy and wavefield decomposition M. von Steht & J. Mann ◮ VSP data provides only one slowness component: Overview Theory slowness component p t tangent to well CRS stack for VSP � � ➥ in general insufficient to determine � � p FO CRS-Operator � Calibration method ◮ special case: walkover VSP Data example Survey description ◮ p t of downgoing rays varies with source position � x S Velocity calibration Decomposition ◮ a ray tangent to well at receiver � x G is very likely Conclusions & outlook � � � � there: naturally p t ≡ p � ◮ Strategy ◮ identify downgoing direct P and/or S arrivals ◮ calculate p t � � x S ,� � x G ∀ sources S and receivers G ◮ for each G , search maximum of p t � � � x S ,� x G = const �� − 1 � � � � � � x S ; � searched-for velocity v x G = max p t x G ➥ W I T

Velocity calibration surface and wavefield decomposition well M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration surface and wavefield decomposition well M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method downgoing ray Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration surface and wavefield decomposition well M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method downgoing ray Data example Survey description Velocity calibration Decomposition Conclusions & outlook searched−for { observable: slowness tangent vector slowness W I T component ?

Velocity calibration surface and wavefield decomposition well M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration surface and wavefield decomposition well M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration surface and wavefield decomposition well M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook tangent length of = slowness slowness W I T component vector

Velocity calibration surface and wavefield decomposition well M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview ◮ separate calibration for P- and S-waves Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview ◮ separate calibration for P- and S-waves Theory CRS stack for VSP ◮ velocity v G is property of receiver position FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview ◮ separate calibration for P- and S-waves Theory CRS stack for VSP ◮ velocity v G is property of receiver position FO CRS-Operator Calibration method ➥ applicable to also calibrate reflected waves Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview ◮ separate calibration for P- and S-waves Theory CRS stack for VSP ◮ velocity v G is property of receiver position FO CRS-Operator Calibration method ➥ applicable to also calibrate reflected waves Data example Survey description ◮ Geometric interpretation provides Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview ◮ separate calibration for P- and S-waves Theory CRS stack for VSP ◮ velocity v G is property of receiver position FO CRS-Operator Calibration method ➥ applicable to also calibrate reflected waves Data example Survey description ◮ Geometric interpretation provides Velocity calibration ◮ emergence angles Decomposition Conclusions & outlook W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview ◮ separate calibration for P- and S-waves Theory CRS stack for VSP ◮ velocity v G is property of receiver position FO CRS-Operator Calibration method ➥ applicable to also calibrate reflected waves Data example Survey description ◮ Geometric interpretation provides Velocity calibration ◮ emergence angles Decomposition ◮ wavefront curvatures Conclusions & outlook W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview ◮ separate calibration for P- and S-waves Theory CRS stack for VSP ◮ velocity v G is property of receiver position FO CRS-Operator Calibration method ➥ applicable to also calibrate reflected waves Data example Survey description ◮ Geometric interpretation provides Velocity calibration ◮ emergence angles Decomposition ◮ wavefront curvatures Conclusions & outlook ◮ suited for W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview ◮ separate calibration for P- and S-waves Theory CRS stack for VSP ◮ velocity v G is property of receiver position FO CRS-Operator Calibration method ➥ applicable to also calibrate reflected waves Data example Survey description ◮ Geometric interpretation provides Velocity calibration ◮ emergence angles Decomposition ◮ wavefront curvatures Conclusions & outlook ◮ suited for ◮ wavefield decomposition W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview ◮ separate calibration for P- and S-waves Theory CRS stack for VSP ◮ velocity v G is property of receiver position FO CRS-Operator Calibration method ➥ applicable to also calibrate reflected waves Data example Survey description ◮ Geometric interpretation provides Velocity calibration ◮ emergence angles Decomposition ◮ wavefront curvatures Conclusions & outlook ◮ suited for ◮ wavefield decomposition ➥ data example W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview ◮ separate calibration for P- and S-waves Theory CRS stack for VSP ◮ velocity v G is property of receiver position FO CRS-Operator Calibration method ➥ applicable to also calibrate reflected waves Data example Survey description ◮ Geometric interpretation provides Velocity calibration ◮ emergence angles Decomposition ◮ wavefront curvatures Conclusions & outlook ◮ suited for ◮ wavefield decomposition ➥ data example ◮ redatuming W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview ◮ separate calibration for P- and S-waves Theory CRS stack for VSP ◮ velocity v G is property of receiver position FO CRS-Operator Calibration method ➥ applicable to also calibrate reflected waves Data example Survey description ◮ Geometric interpretation provides Velocity calibration ◮ emergence angles Decomposition ◮ wavefront curvatures Conclusions & outlook ◮ suited for ◮ wavefield decomposition ➥ data example ◮ redatuming ◮ inversion W I T

Velocity calibration Application of tuned velocities and wavefield decomposition M. von Steht & J. Mann Overview ◮ separate calibration for P- and S-waves Theory CRS stack for VSP ◮ velocity v G is property of receiver position FO CRS-Operator Calibration method ➥ applicable to also calibrate reflected waves Data example Survey description ◮ Geometric interpretation provides Velocity calibration ◮ emergence angles Decomposition ◮ wavefront curvatures Conclusions & outlook ◮ suited for ◮ wavefield decomposition ➥ data example ◮ redatuming ◮ inversion ◮ strategy also suited for deviated wells W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T P-wave velocity [km/s]

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP Modeling: FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP Modeling: FO CRS-Operator Calibration method ◮ wavefront construction method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP Modeling: FO CRS-Operator Calibration method ◮ wavefront construction method Data example Survey description ◮ direct P , reflected PP & SS, converted PS Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP Modeling: FO CRS-Operator Calibration method ◮ wavefront construction method Data example Survey description ◮ direct P , reflected PP & SS, converted PS Velocity calibration Decomposition ◮ 3D wave propagation Conclusions & outlook W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP Modeling: FO CRS-Operator Calibration method ◮ wavefront construction method Data example Survey description ◮ direct P , reflected PP & SS, converted PS Velocity calibration Decomposition ◮ 3D wave propagation Conclusions & outlook ◮ two walkover lines, 100 shots each W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP Modeling: FO CRS-Operator Calibration method ◮ wavefront construction method Data example Survey description ◮ direct P , reflected PP & SS, converted PS Velocity calibration Decomposition ◮ 3D wave propagation Conclusions & outlook ◮ two walkover lines, 100 shots each ◮ 40 three-component receiver levels W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP Modeling: FO CRS-Operator Calibration method ◮ wavefront construction method Data example Survey description ◮ direct P , reflected PP & SS, converted PS Velocity calibration Decomposition ◮ 3D wave propagation Conclusions & outlook ◮ two walkover lines, 100 shots each ◮ 40 three-component receiver levels ◮ 2D approach sufficiently accurate for calibration W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory convenient CRS parameter: emergence angle CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory convenient CRS parameter: emergence angle CRS stack for VSP ➥ tangency ≡ zero angle FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory convenient CRS parameter: emergence angle CRS stack for VSP ➥ tangency ≡ zero angle FO CRS-Operator Calibration method Data example Expected behavior: Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory convenient CRS parameter: emergence angle CRS stack for VSP ➥ tangency ≡ zero angle FO CRS-Operator Calibration method Data example Expected behavior: Survey description Velocity calibration ◮ over-estimated velocity Decomposition Conclusions & outlook W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory convenient CRS parameter: emergence angle CRS stack for VSP ➥ tangency ≡ zero angle FO CRS-Operator Calibration method Data example Expected behavior: Survey description Velocity calibration ◮ over-estimated velocity Decomposition Conclusions & outlook zero angle smeared over large offset range W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory convenient CRS parameter: emergence angle CRS stack for VSP ➥ tangency ≡ zero angle FO CRS-Operator Calibration method Data example Expected behavior: Survey description Velocity calibration ◮ over-estimated velocity Decomposition Conclusions & outlook zero angle smeared over large offset range ◮ under-estimated velocity W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory convenient CRS parameter: emergence angle CRS stack for VSP ➥ tangency ≡ zero angle FO CRS-Operator Calibration method Data example Expected behavior: Survey description Velocity calibration ◮ over-estimated velocity Decomposition Conclusions & outlook zero angle smeared over large offset range ◮ under-estimated velocity zero angle never occurs W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory convenient CRS parameter: emergence angle CRS stack for VSP ➥ tangency ≡ zero angle FO CRS-Operator Calibration method Data example Expected behavior: Survey description Velocity calibration ◮ over-estimated velocity Decomposition Conclusions & outlook zero angle smeared over large offset range ◮ under-estimated velocity zero angle never occurs ◮ correct velocity W I T

Velocity calibration Model and survey geometry and wavefield decomposition M. von Steht & J. Mann Overview Theory convenient CRS parameter: emergence angle CRS stack for VSP ➥ tangency ≡ zero angle FO CRS-Operator Calibration method Data example Expected behavior: Survey description Velocity calibration ◮ over-estimated velocity Decomposition Conclusions & outlook zero angle smeared over large offset range ◮ under-estimated velocity zero angle never occurs ◮ correct velocity well-localized minimum at zero angle W I T

Velocity calibration Calibration using checkshot inversion and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration Calibration using checkshot inversion and wavefield decomposition M. von Steht & J. Mann shot index 20 40 60 80 100 Overview Theory CRS stack for VSP 5 FO CRS-Operator Calibration method 7 15 10 Data example Survey description Velocity calibration receiver index 15 15 Decomposition 7 7 Conclusions & outlook 20 15 7 25 15 7 30 15 35 7 60 30 60 40 isoclines of emergence angle [ ◦ ] W I T

Velocity calibration Calibration with initial model and wavefield decomposition M. von Steht & J. Mann shot index 20 40 60 80 100 Overview Theory CRS stack for VSP 5 FO CRS-Operator Calibration method 10 Data example Survey description Velocity calibration receiver index 15 Decomposition 7 Conclusions & outlook 20 25 7 30 7 35 15 60 30 15 30 60 40 isoclines of emergence angle [ ◦ ] W I T

Velocity calibration Calibration with corrected model and wavefield decomposition M. von Steht & J. Mann shot index 20 40 60 80 100 Overview Theory CRS stack for VSP 5 FO CRS-Operator Calibration method 10 Data example Survey description Velocity calibration receiver index 15 Decomposition Conclusions & outlook 20 25 30 15 35 15 60 30 7 7 30 60 40 isoclines of emergence angle [ ◦ ] W I T

Velocity calibration Forward-modeled angles and wavefield decomposition M. von Steht & J. Mann shot index 20 40 60 80 100 Overview Theory CRS stack for VSP 5 FO CRS-Operator Calibration method 10 Data example Survey description Velocity calibration receiver index 15 Decomposition Conclusions & outlook 20 25 30 35 60 60 30 15 7 15 30 40 isoclines of emergence angle [ ◦ ] W I T

Velocity calibration 1D velocity curves along well and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration 1D velocity curves along well and wavefield decomposition M. von Steht & J. Mann 3000 Overview Inverted Model Initial Model Theory Calibrated Model CRS stack for VSP 2800 FO CRS-Operator Calibration method 2600 Data example Survey description Velocity calibration P-wave velocity [m/s] 2400 Decomposition Conclusions & outlook 2200 2000 1800 1600 1400 200 300 400 500 600 700 800 900 W I T depth [m]

Velocity calibration CRS-based wavefield decomposition and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T

Velocity calibration CRS-based wavefield decomposition and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook W I T Components (V,H) prior to rotation

Velocity calibration CRS-based wavefield decomposition and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook Components (R,T) after rotation by β P W I T G – R is strong

Velocity calibration CRS-based wavefield decomposition and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook Components (R,T) after rotation by β S W I T G – T is strong

Velocity calibration Five CS gathers prior to rotation and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook vertical component W I T

Velocity calibration Five CS gathers prior to rotation and wavefield decomposition M. von Steht & J. Mann Overview Theory CRS stack for VSP FO CRS-Operator Calibration method Data example Survey description Velocity calibration Decomposition Conclusions & outlook horizontal component W I T