Application of computer-processed well log data for geologic evaluation of Green River basin, Wyoming

Conference · Sun Apr 01 04:00:00 EST 1984 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:6523369

Prensky, S E; Dickinson, W W

As part of ongoing regional evaluation of tight gas sand resources, computer processing of well log data was used as a tool for revealing gross trends in stratigraphic and diagenetic characteristics. Log data for 20 wells in the northern Green River basin were processed using a DEC LSI-11/23 microprocessor. The processing technique involved the application of single or multiple logic tests for lithology discrimination and elimination of bad hole data. Resulting data for the entire length of the well are plotted vs. depth as x-y plots, thereby displaying large-scale trends that may be present. Cross sections constructed using these crossplots aid in regional evaluation. This technique has proved to be particularly useful for identifying the regional Cretaceous-Tertiary unconformity, which in many wells shows up as a dramatic shift in ..gamma..-ray response across the boundary from low (Cretaceous) to high (Tertiary). Possible zones of overpressuring are identified by means of shale conductivity crossplots. Porosity reduction trends as well as gas zones are revealed through plots of sandstone sonic travel time. The primary advantages of this method are that it (1) reduces the sampling bias that can occur with manual plotting and reduces the sensitivity of data trends to discriminator values due the large sample population; (2) reveals data trends that may not be apparent from viewing analog well log prints or that may be masked by the log response due to the presence of other lithologic characteristics; and (3) provides additional insight into problems related to stratigraphy, overpressuring, and porosity, for which other kinds of data are incomplete or absent.

• Research Organization: Geologic Survey, Denver, CO
• OSTI ID: 6523369
• Report Number(s): CONF-8405216-
• Conference Information: Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 68:4
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030200* -- Natural Gas-- Reserves
Geology
& Exploration
CENOZOIC ERA
COMPUTERS
CRETACEOUS PERIOD
DATA ANALYSIS
ELECTRONIC CIRCUITS
FEDERAL REGION VIII
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
MESOZOIC ERA
MICROELECTRONIC CIRCUITS
MICROPROCESSORS
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NORTH AMERICA
RESERVOIR ROCK
RESOURCES
SEDIMENTARY BASINS
TERTIARY PERIOD
USA
WELL LOGGING
WYOMING