seismic inversion.pptx

8/17/2019 seismic inversion.pptx

1/14

Seismic Inversion The Best Tool for Enhanced Interpretation and Reservoir

Characterization

by

Kunal RathodB.Tech in Petroleum Engineering !chool of Petroleum Technology" P#P$%&.Tech in E'ploration (eophysics #ibrugarh $niversity%

)


2/14

Problem: 1 Interpret theseismic section

Fig. 1 This seismic section is from Mehsana-Ahmedabad block of Cambay Basin, India. The area was de osited!nder deltaic en"ironment. Horizon H1 and H2 has sandstone interbedded with shale but that signature isdifficult to identify in seismic data.

T*TT in s%

+

,) top

,+ top

,- top


3/14

Example: 2

Fig. # This seismic section is from so!theast Asia and re resents a se$!ence of sands and shales. The Yellowhorizon interpretation has not been completed. It is made diffic!lt by the close ro%imity of e"ents and thestr!ct!re. &e%am le from 'endrel (., )*eismic In"ersion + The Best Tool for eser"oir Characteri ation /

T*TT in s%

-


4/14

Constrains in interpretationwith seismic amplitude

!eismic doubleto direct relation to the physical

property of the roc/so lithological identi0cation&oreover" they are bandlimited )1to 21,z%

3


5/14

What is Seismic In ersion!

Seismic In ersion is the re erse of "orward#odeling

$efore understanding seismic in ersion it is firstimportant to understand the Forward and Reversemethod .

2


6/14

"orward %pproach

In sim le terms its

'hysicalModel

0ata Fig. 1 Forward Model4

Fig . Forward A roach 2 3


7/14

&e erse %pproach

Its e%actly o osite to forwardmodel

0ata

Model

Fig. 4 In"erse A roach 2 3

5


8/14

In ersion "low

I P$T for Post6!tac/ !eismic

Inversion

!onic"densitylogs 7

8ormation Tops

P!T&7

horizon

9!Pdata

*ell Correlation7

Calibration

Inversion:lgorithm

Initial Impedance&odel

8inal InvertedImpedance

9olume

;


9/14

'efinition( Seismic In ersion

It can be defined as “the technique forcreating a model of the earth in the form of

acoustic impedance using the seismic data asinput is called seismic inversion.” [2]

<


10/14

Seismic In ersion Types

Based on the nat!re of ty e of *eismic 0ata &i.e. if ost-stack or re-stack gather/seismic in"ersion can be erformed in # ways5

1. 'ost-*tack *eismic In"ersionBandlimited *eismic In"ersionModel Based *eismic In"ersion* arse-* ike *eismic In"ersionColored *eismic In"ersion

#. 're-*tack *eismic In"ersion6lastic In"ersionInde endent In"ersion*im!ltaneo!s In"ersion7amda-M!-rho In"ersion

)1


11/14

Example 1

Fig. 8 Colored based in"ersion o!t !t of the seismic section shown in Fig. 1. The high

im edance shale are $!ite clearly obser"ed in the section and are interbedded with mid-im edance shaly sandstones. ))


12/14

Example 2

Fig. 9 * arse s ike in"ersion of the data in Fig!re #. It is a m!ch sim ler section d!e to theatten!ation of wa"elet sidelobes. The com letion of the :ellow hori on is now easy. Thelow im edance region abo"e the :ellow, in the middle of the fig!re has been inter reted to

be a "alley fill.&e%am le from 'endrel (., )*eismic In"ersion + The Best Tool for eser"oirCharacteri ation /

:ellow ;ori oncan now becom leted

T*TT in s%

)+


13/14

References

1. 'endrel (., )*eismic In"ersion + The Best Tool for eser"oir Characteri ation , (ason>1, ->

#. !ssell B.;., )Introd!ction to *eismic In"ersion Methods , Co!rse ?otes *eries, ?o. # *. ?.0omenico, *eries 6ditor, 1@ , -1-#

. C


14/14

Than !ou:ny =ueries or =uestions >

)3

seismic inversion.pptx

Documents