Direct Reading Gas Meters For Production Applications
Authors: Laycock LeRoy C. 
Published: December 2007

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This paper is to be presented at the Eastern Regional Meeting to be held in Pittsburgh, Pa., on Nov. 5–6, 1964, 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 the 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
Operational and field test data are presented for rotary positive displacement direct-reading gas meter applications in the production field for G-O-R testing, as sales, gas lift injection, automatic well testing and others. The areas of application and limitations of this type meter are discussed and compared with more common types. Methods of obtaining digital totals in standard gas volumes of even highly fluctuating flows, either local or remote, without the need for charts, are discussed.

Introduction
This discussion is primarily directed to the application of rotary positive displacement (RPD) gas meters in the area of gas production measurement. RPD gas meters have been in use, primarily in the gas distribution field, for over 40 years and have built up an excellent performance record in this field. During the past five years, with the introduction of a more complete range of available capacities and pressure ratings, wide areas of application have been developed in all phases of the gas production and gas transmission field.
Because of their direct reading, their very wide range of capacity, their low maintenance and their corresponding very close degree of accuracy, RPD gas meters are finding application in practically all areas of gas measurement.
Special emphasis is placed on the RPD gas meter for application where automation is being employed because of the above mentioned features and because instrumentation can be economically installed to automatically compensate for pressure, temperature, and super compressibility, individually or in combination, and to read out of dials, record on charts or telemeter standard gas volumes, again, either individually or in any combination. Specific gravity is not a factor of measurement with RPD gas meters.

GENERAL DESCRIPTION
As shown pictorially in Figure 1 and by diagram in Figure 2, a RPD gas meter consists basically of two oppositely rotating impellers of two-lobe or "figure 8" contour, operating within a rigid casing having inlet and outlet gas connections on opposite sides. Impeller contours are mathematically developed and accurately produced, and are of such form that a continuous line seal without contact can be obtained between the impellers at all positions during rotation. To accomplish this, the correct relative impeller positions are established and maintained by timing gears.