N. R. Carlson and J. C. Bamette
Atlas Wireline Services, Western Atlas International, Houston, TX
ABSTRACT
The continuous spinner flowmeter is widely used to establish a profile of flow velocity in a well, and numerous papers have been published on methods relating the spinner’s rotational speed during logging to the velocity profile. However, little attention. has been devoted to techniques for judging the quality of the spinner flowmeter log.
All the following techniques and guidelines related to the quality of spinner flowmeter logs in production (or injection) wells are discussed in the paper:
• A method of determining log applicability before logging. As an increasing percentage of the total flowrate can be quantitatively allocated by log analysis to the producing (or injection) intervals, the applicability increases. This determination requires knowledge of the logging system’s resolution, which the service company should specify.
• Plots and guidelines for judging operational reliability based on flowmeter performance in stagnant fluid downhole. The guidelines require certain data, which are enumerated in the body of the paper.
• A standard of determining suitable wireline speeds for calibrating the flowmeter downhole. The accuracy of the velocity profile is enhanced by use of suitable logging speeds,
• A technique for a reliable calibration of the flowmeter at a chosen depth. On preliminary review, the logged data may appear too scattered for such use as a result of flowrate variations during logging, but the technique successfully accomplishes the calibration.
The information in this paper is valuable to practitioners who use the continuous spinner flowmeter log and provides insight to an often neglected area of importance.