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Abstract

Large volumes of digitized well logs can only be used efficiently if computer programs are available to assist in digitizing quality control, data editing, storage and retrieval, analysis and display. To date, the major industry effort has been directed toward improved analysis programs. This paper summarizes several of the more important applications of computers to well logs.

Introduction

The number of uses of digitized well logs is increasing in the mineral industries. Standard and exotic analysis programs are yielding more information from logs than was previously economical by hand methods. These previously economical by hand methods. These programs are applicable to one or several programs are applicable to one or several wells in reservoirs, fields or basins. The efficient use of these analysis programs for multiple wells demands other computer programs to quality-check and edit the digitized data, to store and retrieve it and to display the analysis in a form appropriate to the study in progress. Underlying all uses of digitized well logs, however, it the assumption that the digitized data faithfully represent the measurements made by the logging sonde.

Data Quality

Many applications of digitized logs depend as critically on the digitizing process as they do on the logging operation. Porosity calculations are sensitive to errors in the amplitudes of digitized logs, and certain log correlation and filtering methods may require curves digitized in equal increments of arc length rather than in equal increments of well bore depth.

The computer can assist in the editing and quality control of the log data. The most widely accepted method of checking data is a plotback and overlay technique. While this plotback and overlay technique. While this method is the most accurate when used by technical persons, it has two limitations: it assumes the source document is the most accurate basic information, and it does not take advantage of the computer's speed.

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