Abstract: Depth-Calibrated Raster Images: A Revolution in Productivity for Oil and Gas Geologists

ROSS, William C.

For most geologists the primary tool for the investigation and interpretation of the subsurface is the paper well log. While most geologists are very comfortable using hard-copy well logs, a geologist's productivity is limited by the inefficiency of paper-based manipulation / interpretation techniques (e.g., manual tops picking and cross-section construction).

Ideally, the computerization of the geologist's work flow would involve a cost-effective, integrated software and data system which would provide the following: (1) The low-cost assembly of well-log data in digital format (including log images, well header and well spot data), and (2) Software with the ability to search for, manage and manipulate well-log images in depth (including onscreen log scrolling, tops picking, rescaling, and structural or stratigraphic cross section construction).

The "dream" of computerizing the geologist's work flow with well-log cross-section software has not been realized because of the high cost of converting well-log data into digital (LAS) format. New software technologies have been developed which allow geologists to work with inexpensive, depth-calibrated raster well logs. These technologies provide geologists with the ability to have cost-effective access to 100% of the log data in their project area. Freed up from the need to work with paper or microfiche well logs, geologists become more productive with the ability to acquire, archive, retrieve, view, scroll, correlate, and hang digital well logs structurally or stratigraphically. Proprietary tops databases can be imported and displayed on the wells, and the geologist can interactively pick new tops on the screen. All tops can be exported for use in any mapping package.

Fully functional raster-based cross-section technologies provide the ability to easily draw facies interpretations, channels, unconformities, correlation lines, and various truncation patterns. The PC-based software enables the user to instantly change from stratigraphic to structural cross-section perspectives. In addition, the user can pick faults and create desired breaks in the log images.

AAPG Search and Discovery Article #90946©1997 AAPG Rocky Mountain Section Meeting, Denver, Colorado