Log Quality Control And Operational Efficiency Check
Authors: Millard Frank S. 
Published: December 2007

MILLARD, FRANK S., Member AIME, Humble Oil and Refining Co., Tulsa, Okla.
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This paper is to be presented at the 38th Annual Fall Meeting of the Society of Petroleum Engineers of AIME in New Orleans, La., on October 6–9, 1963, and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of JOURNAL OF PETROLEUM TECHNOLOGY or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper.
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Abstract
Since the early days of well logging, operating and service companies have recognized the problem of log quality control. This problem becomes more critical when the well logs are used for formation evaluation. It is essential to obtain technically correct well logs along with all of their associated information if they are to be used effectively for formation evaluation.
A simple check list has been designed which permits the well site geologist or engineer to exercise systematic control over the logging operation. An operational efficiency check is also made by the well site geologist for each logging operation. This includes a notation of logging equipment failures and the lost rig time associated with the failures.
Results over a seventeen month test period in the Humble Oil and Refining Co.'s Central Region indicates that a decided improvement in the technical quality of the logs and in the operational efficiency has taken place.

Introduction
Log quality control is of particular interest to the geologist and engineer using well logs for formation evaluation and geologic subsurface studies. Technically correct logs and the necessary associated information must be obtained at the well site if full advantage is to be taken of the logs. Logging systems must be operating properly, correctly calibrated and scaled, and mud measurements and other pertinent information reported at the time of logging. It is the responsibility of the service company to present technically correct well logs and the other information needed to complete a logging operation. It is also the responsibility of the well site geologist or engineer to see that the well logs meet certain minimum standards.
In the past, Humble's Central Region had some problems in getting well logs of the desired quality. Standing instructions and special memorandums were not always followed.
In an effort to improve the situation, a simple check list was designed which provides a control on the log quality and assures the presentation of all necessary information on the logging operation.

LOG QUALITY CONTROL CHECK LIST
The log quality control check list (See Fig. 1) is relatively simple and for the most part is self-explanatory. It includes information concerning the failure of logging equipment, lost rig time due to equipment failure, and the overall rating of the logging service.
The heading is filled out by the well site geologist, and the check list is then given to the service company logging engineer, who follows the instructions pertinent to the particular logging operation.