Very
little direct information is currently available on permeability
of the Miocene sands beneath the Texas City area. Most permeability
estimates are generated from geophysical logs of oil and gas wells
or from outcrops in the coastal plain to the east. A major drawback
of using geophysical logs for permeability estimates is that a number
of assumptions must be made (pore-water chemistry, formation mineralogy).
Drawbacks of using permeability information from outcrop studies
are primarily because these outcropping deposits were deposited
in more fluvial environments that the coastal deposits beneath Texas
City (Galloway and others, 1986). The permeability data from Kreitler
and others (1988) were used for the GIS because it is the most comprehensive
and systematic study of permeability of the Miocene interval that
is currently available. Kreitler and others (1988) used a combination
of data from brine-injection well reports and from pressure data
from petroleum wells and reported intrinsic permeability in millidarcys.
2 Map:
2
Reference:
Galloway,
W. E., Jirik, L. A., Morton, R. A., and Dubar, J. R., 1986, Lower
Miocene (Fleming) depositional episode of the Texas coastal plain
and continental shelf: structural framework, facies, and hydrocarbon
resources: The University of Texas at Austin, Bureau of Economic
Geology Report of Investigations No. 150, 50 p.
Kreitler,
C. W., Akhter, M. S., Donnelly, A. C. A, and Wood, W. T., 1988,
Hydrogeology of formations used for deep-well injection, Texas Gulf
Coast: The University of Texas at Austin, Bureau of Economic Geology,
open-file report prepared for U.S. Environmental Protection Agency
under Cooperative Agreement ID No. CR812786-01, 204 p.
