Direct Digital Laserlogging

This paper describes a newly developed, direct-digital system for monitored data acquisition, automatic computation and calibration of well log data with presentation on an entirely new Laser Beam graphic recorder. The new direct-digital system avoids the errors that are sometimes made by field engineers when faced with the multitide of switches, connectors, adjusting knobs and meter dials of conventional analog panels, as well as errors due to analog drift and nonlinearity. Many older systems have utilized a computer to "process" the data provided by the conventional analog panels, but processing by these hybrid systems does not avoid the errors that are inherent in the analog panels and in the adjustment of the analog knobs and dials during calibration and operation. The new system described in this paper, is digital from the start, avoids the knobs and dials and provides automatic calibration and quality control, resulting in precisely repeatable records. The Laser Beam photographic record is completely ready for use within a few seconds after the recorder receives the input data. The steps involved in reaching this degree of refinement are generally analogous to those experienced in seismic exploration operations during conversion to digital methods; digital processing of data from standard analog truck equipment only prefaced the present direct-digital field equipment, which has made vastly improved data processing possible.