Seismic
Attribute
Analyses of Lower Permian
(Wolfcampian-Leonardian) Carbonate Buildups, SW
Midland Basin, Texas
C. C. Decalf
Texas A&M University, Dept. of Geology,
College Station, TX
A trend ofWolfcampian-Leonardian carbonate buildups is located in
the southwestern Midland Basin, Upton County, Texas. The buildup
trend is located east of the eastern faulted margin of the Central Basin
Platform and north of the Ozona Arch. Carbonate deposition began
during lowstand times, within or just below wave base. In the Southwestern
Midland Basin, the Wolfcampian-Leonardian carbonate interval
is lithologically heterogeneous due to the presence of abundant
lithoclastic debris that was shed from the uplifted Central Basin Platform.
The lithologic heterogeneity makes it difficult to identify the
buildups on seismic
profiles. Several inferred buildups have been
drilled in the past, but many boreholes only penetrated lithoclastic
facies, not true buildup facies.
Analyses of various seismic
attributes were conducted for the
Wolfcampian-Leonardian interval in the SW Midland Basin in an
attempt to improve the recognition and imaging of the carbonate
buildups. The objective was to identify a set of attributes that directly
indicate the buildup locations. After extensive trail of various attributes,
the variance
attribute
was selected as the optimum
seismic
attribute
.
The resultant 3-D variance volume was used to detect the
buildup locations, and some aspects of their internal stratigraphy, and
to establish the fault framework in the Amacker survey. The instantaneous
frequency
attribute
, combined with the variance
attribute
was also marginally useful for imaging the buildups.
AAPG Search and Discovery Article #90902©2001 AAPG Foundation Grants-in-Aid