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Title: Comparison of petrophysical characteristics of selected carbonate rocks to their log response, Smackover Formation (Upper Jurassic)

Conference · · AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States)
OSTI ID:5787149

Recent advances in well-logging techniques have enabled geologists to increase their knowledge of petrophysical properties. Optimum use of porosity logs permits predictions of porosity parameters other than merely the porosity percent. Shallow-water carbonate rocks contain a wide variety of porosity types, and present a special problem to the geologist involved in subsurface work. The oolitic grainstone upper member of the Smackover Formation (Upper Jurassic) within the Gulf Coast region, contains numerous porosity types. Three major types (interparticle, intercrystalline, and oomoldic) were identified from petrographic analysis. With the use of computer generated crossplots of neutron-log values versus density-log values, it is possible to determine the amount of porosity types within a carbonate rock. The cementation exponent (m) from Archie's equation, as determined from Pickett Plots, is a reliable indicator of the tortuosity and permeability of carbonate units, whereas multivariate cluster analysis groups porosities solely by percent porosity and not by porosity type.

Research Organization:
Stephen F. Austin State Univ., Nacogdoches, TX
OSTI ID:
5787149
Report Number(s):
CONF-8710198-
Journal Information:
AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States), Vol. 71:9; Conference: Gulf-Coast Association of the Geological Society and Gulf-Coast Section SEPM meeting, San Antonio, TX, USA, 28 Oct 1987
Country of Publication:
United States
Language:
English