Arid Continental Sand Bodies and Stratal Geometries
in the Haynesville Formation as Interpreted from Coherency
Processing
of a 3-D Seismic Data Cube, Monroe
County, Alabama
L. R. Baria
Jura-Search, Inc., Jackson, Mississippi
In an exploratory effort to extend the Frisco City Trend northward
and up-dip
of its original limits in central Monroe County, Alabama,
a twenty-four square mile 3-D seismic program was undertaken in
1998. Acquisition and
processing
parameters were established to
equal or exceed those of previous data sets. As a result, very good
imaging was accomplished for the Upper Jurassic targets in the 8,000
to 10,000 foot depth range.
The survey was acquired using deep hole (125’) pentalite with a
“triple-brick” 110x110 bin design. Throughout the central 80% of
the survey 24 to 30 fold data was attained. Following the initial processing
,
which included DMO pre-stack migration with noise suppression,
Coherency Cube
Processing
was applied to enhance sand
body shape, thickness and size recognition.
The basement massifs and inselbergs that underlie the Jurassic sediments
demonstrate several episodes of incised valley erosion and
subsequent onlapping deposition. Through interpretation, alluvial
fan, braided wadi, eolian dune, playa and pediment sand flat deposits
were delineated through variable amplitude horizon slice displays.
Valley fill Norphlet sand deposits and up-dip
Smackover strandline
facies were identified in addition to the Haynesville sand body
geometries.
The dunes appear to be best developed on the down-wind side of flat intermontane basins. Intermontane basin centers appear to be composed of flat lying, relatively high amplitude reflectors suggestive of playa evaporites. Low amplitude wadi sands, with their associated braided character, occur as packages of inclined valley fills and constructive, on-lapping bajada aprons.
AAPG Search and Discovery Article #90901©2001 GCAGS, Annual Meeting, Shreveport, Louisiana