Отправлено: 28.01.14 07:40. Заголовок: NURMI, ROY D. Diagenetic Effects and Pore System Evolution

NURMI, ROY D., Schlumberger-Doll Research, Ridgefield,CT
Diagenetic Effects and Pore System Evolution
Permeability/porosity relations obtained from core measurements and well logs from numerous sandstone
pear 10 have accumulated largely from submarine cementation of products of in-silu origin, in a setting of slower currents and possibly reduced oxygen levels on a bottom that may have been shallow enough to extend at times into the lower photic zone.
NEWTON. CATHRYN R., Univ. California at Santa Cruz, Sama Cruz, CA, and HENRY T. MULLINS, Moss Landing Marine Laboratories and San Jose State Univ., Moss Landing, CA
Fauna! Succession Within Deep-Water Coral Mounds North of Little Bahama Bank
Deep-water coral mounds of 5 to 40 m relief occur at depths of 1,000 to 1,300 mover a 2,500 sq km area of the lower slope north of Little Bahama Bank. These coral/gorgonian buildups, apparently unlithificd, have yielded radiocarbon ages of 860 ± 50 and 940 ± 40 years for the best preserved corals and gorgonians, and preliminary dales of 22,100 years for the most intensively bored corals, the youngest deep-water coral mounds ever reported. Eight genera of deep-water coral represent the highest diversity recorded from a single locality. These ahermatypes arc predominantly solitary, although branching and weakly branched forms are also present. The col-
above the medial limestone. Conglomeratic lenses {Rock Canyon Conglomerate) derived from the west and southwest arc equivalent lo both the Permian and Triassic sediments representing a major eroslonal cycle after the last retreat of the Permian seas and the advance of the Middle Triassic seas. The Timpoweap Member, Moenkopi Formation, was deposited on top of the underlying limestones and conglomerates developing a horizontal plane. It thins :o a featheredge west of the Hurricane Cliffs and cast of the Utah-Arizona state line suggesting that a positive area was present west of the Hurricane Cliffs during the Early Triassic. Thinning of the lower Red Member of the Moenkopi Formation also occurs west of the Hurricane Cliffs but in places it is absent, reflecting the topographic nature of the Permian and Triassic boundary'- 1' was not until the deposition of the Virgin Limestone member of ;he Moenkopi Formation that Triassic seas covered the western pari of Utah.
NURMI, ROY D„ Schlumberger-Doll Research, Ridgefield, CT
Diagenetic Effects and Pore System Evolution
Permeability/porosity relations obtained from core measurements and well logs from numerous sandstone
hydrocarbon reservoirs in North America were used lo quantitatively study diagenetic alterations of pore systems.
Results were most favorable for rocks in which no early cementation or secondary replacement occurred and
for which the pore system could be characterized sedimentologically.
Geologic modeling of permeability/porosity crossplots may reveal secondary permeability that results from microstruc-lural damage,
fracturing, and/or directional dissolution. Secondary permeability type may be determined from examination of the core or porecasls.
Analyses of permeability/porosity crossplois may establish the relative timing of the various diagenetic modifications.


AAPG Bulletin Volume: 65 (1981)
Issue: 5. (May)
pp.965-966
Title: Diagenetic Effects and Pore System Evolution: ABSTRACT
Author(s): Roy D. Nurmi
Article Type: Meeting abstract
Abstract:
Previous HitPermeabilityNext Hit/Previous HitporosityNext Hit relations obtained from core measurements and well logs from numerous sandstone
hydrocarbon reservoirs in North America were used to quantitatively study diagenetic alterations of pore systems. Results were most favorable for rocks in which no early cementation or secondary replacement occurred and for which the pore system could be characterized sedimentologically.
Geologic modeling of Previous HitpermeabilityNext Hit/Previous HitporosityNext Hit crossplots may reveal secondary Previous HitpermeabilityNext Hit that results from microstructural damage, fracturing, and/or directional dissolution. Secondary Previous HitpermeabilityNext Hit type may be determined from examination of the core or porecasts. Analyses of Previous HitpermeabilityNext Hit/Previous HitporosityTop crossplots may establish the relative timing of the various diagenetic modifications.
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