Application of a 3-D
Hybrid
Seismic
Inversion
on Mar’a Inés Oeste Field, Santa Cruz, Argentina
By
Marcelo Benabentos1, Subhashis Mallick1, Tarek Nafie2, Mario Sigismondi3, Juan soldo3
(1) WesternGeco, Houston, TX (2) WesternGeco, Cairo, Egypt (3) Perez Companc, Neuquén, Argentina
Application of a 3-D
hybrid
seismic
inversion
on Mar’a Inés Oeste field,
Santa Cruz, Argentina Marcelo Benabentos, Subhashis Mallick, WesternGeco,
Houston, Texas. Tarek Nafie*, WesternGeco, Cairo, Egypt. Mario Sigismondi and
Juan Soldo, PECOM de Pérez Companc S.A., Neuquén, Argentina.
Abstract In this paper, we apply hybrid seismic
inversion
on a
three-dimensional (3D)
seismic
data
set
from
Mar’a Inés Oeste, one of the major
oil and gas fields in Argentina. The Mar’a Inés sandstones are Paleocene in age,
the traps are mainly
structural
, and the reservoir is about 50 m thick,
containing either oil or gas. These oil/gas-bearing sands usually cause
anomalously high amplitude bright-spots on the stacked
seismic
data
. These
bright-spots were generally used as hydrocarbon indicators for this area.
Drilling through these bright-spots has resulted in pay, as well as some dry
wells.
Hybrid seismic
inversion
, a combination of prestack waveform
inversion
and
poststack inversions of some amplitude-variation-with-offset (AVO) attributes,
allowed us to demonstrate that the Poisson's ratio, obtained
from
this hybrid
inversion
was effective in fluid discrimination and provided successful drilling
locations. We also demonstrate that the Poisson's ratio contrast; obtainable
from
a standard AVO is not as effective in fluid discrimination as the one
from
hybrid
inversion
.