Collett, Timothy S. (1998): Well log evaluation of gas hydrate saturations

Leg/Site/Hole:
DSDP 84
DSDP 84 570
Identifier:
1999-051433
georefid

Creator:
Collett, Timothy S.
U. S. Geological Survey, Denver, CO, United States
author

Identification:
Well log evaluation of gas hydrate saturations
1998
In: Anonymous, Transactions of the SPWLA thirty-ninth annual logging symposium
Society of Professional Well Log Analysts, Houston, TX, United States
39
MM
The amount of gas sequestered in gas hydrates is probably enormous, but estimates are highly speculative due to the lack of previous quantitative studies. Gas volumes that may be attributed to a gas hydrate accumulation within a given geologic setting are dependent on a number of reservoir parameters; one of which, gas-hydrate saturation, can be assessed with data obtained from downhole well logging devices. The primary objective of this study was to develop quantitative well-log evaluation techniques which will permit the calculation of gas-hydrate saturations in gas-hydrate-bearing sedimentary units. The "standard" and "quick look" Archie relations (resistivity log data) yielded accurate gas-hydrate and free-gas saturations within all of the gas hydrate accumulations assessed in the field verification phase of the study. Compressional wave acoustic log data have been used along with the Timur, modified Wood, and the Lee weighted average acoustic equations to calculate accurate gas-hydrate saturations in all of the gas hydrate accumulations assessed in this study. The well log derived gas-hydrate saturations calculated in the field verification phase of this study, which range from as low as 2% to as high as 97%, confirm that gas hydrates represent a potentially important source of natural gas.
English
Coverage:Geographic coordinates:
North:17.4500
West:-92.1500East: -88.1500
South:13.1707

Economic geology, geology of energy sources; Applied geophysics; Central America; Deep Sea Drilling Project; DSDP Site 570; East Pacific; electrical logging; formation evaluation; gas hydrates; Guatemala; interpretation; IPOD; Leg 84; mathematical models; Middle America Trench; natural gas; North Pacific; North Slope; Northeast Pacific; Pacific Coast; Pacific Ocean; petroleum; petroleum exploration; reservoir rocks; sedimentary rocks; well-logging;

.