Interactive geological subsurface interpretation using well logs on a geophysical workstation - A case history

Conference · Tue May 01 00:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:6677668

Jones, G L; Mallon, K ^[1]

---

1. Landmark Graphics Corp., Houston, TX (USA)

This project involves loading well log data from a major oil and gas field into a geosphysical workstation, interpreting the data, and generating geological displays using procedures similar to those used when interpreting the two-dimensional and three-dimensional seismic. The well data includes four log traces per well from 261, as well as the depths of geological tops for each well. The well log curves were received in ASCII file format and loaded into the system along pseudoseismic lines created to fit the location information. The data consists of latitude and longitude information, reference elevations for well logs, gamma ray, acoustic, calculated porosity, and calculated permeability curves, as well as 13 tops for each of the 261 wells. The relationship of one well to another is shown realistically. The interpretation process started once location information was converted to x and ys and appropriately disguised. The operating procedure involved converting well locations to theoretical shot point locations on a 330-ft grid and loading log curves as seismic traces, forming a sparsely sampled three-dimensional grid. Lines of section were created, and well-to-well correlations were drawn on the sections. Strike and dip cross sections were constructed on the workstation screen. Formation and zone correlations were edited interactively. A series of color schemes were used for various log curve values, lithology, and porosity heterogeneity. The Vairfill feature caused correlative zones to be highlighted dramatically. Structural and isopach maps, with triangulated contours, were computed from input tops. These triangulated surfaces were written into a grid and smoothed by the geologist to provide structural contour maps on each of the 13 horizons. Inputting gas-oil contact depths for the field permitted calculation of closure for several formations with an easily drawn gas thickness isopach map.

• OSTI ID: 6677668
• Report Number(s): CONF-900605-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (USA), Vol. 74:5; Conference: Annual convention and exposition of the American Association of Petroleum Geologists, San Francisco, CA (USA), 3-6 Jun 1990; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
58 GEOSCIENCES
NATURAL GAS DEPOSITS
EXPLORATION
PETROLEUM DEPOSITS
WELL LOGGING
DATA ANALYSIS
COMPUTERS
PERMEABILITY
POROSITY
SEISMIC SURVEYS
THREE-DIMENSIONAL CALCULATIONS
GEOLOGIC DEPOSITS
GEOPHYSICAL SURVEYS
MINERAL RESOURCES
RESOURCES
SURVEYS
020200* - Petroleum- Reserves
Geology
& Exploration
580000 - Geosciences