Orifice meter diagnostics laboratory tests & field tests (original) (raw)

Offshore Gas Well Flow and Orifice Metering System: An Overview

Innovative Energy & Research, 2017

This research presents a concise account of offshore surface well test from objective, organization, to practical approach and in relation to orifice metering system of natural gas; against the perspective of regulatory standards. With reference to reliability, availability, affordability and including control measures governing the design, the orifice meter sometimes called a head loss flow meter is chosen most often because of its reputation in the oil and gas industry. Alternative metering system of natural gas, including robust and cost effective innovations within the industry which addressed some key limitations of orifice meter was examined. The advanced flow computer with transducers suited for orifice measurement installations is a cost effective electronic flow real time measurement system. It has telemetry features and improved accuracy under fluctuating flow conditions based on functional differential pressure root mean squared volume calculation principles. These new developments and their capabilities have reduced the market share of the mechanical orifice chart meters. Except that Electronic flow meters has environmental limitations; thus, the proven mechanical orifice metering systems are still an effective solution for many flow measurement applications.

INCREASING TURNDOWN USING ORIFICE METER TECHNOLOGY

Well and pipeline flow rates are most often variable in nature. Shale wells can experience steep decline curves. Pad drilling can bring on new wells, increasing flow, followed by declining flows in the future. This paper describes a strategy that can be employed to increase the operational flow range over which an orifice meter may be used , thus lowering costs. Orifice meter flowrates and required turndown can be greater than is often assumed. Orifice plates used in natural gas custody transfer metering are subject to strict rules regarding flow rate ranges and differential pressures that are allowed per each plate thickness versus diameter. Flow rates per area ratio () are defined to make sure that orifice plate elements are not overstressed or damaged, during normal operation. Differential pressures (DP's) are described over specific ranges in all national and international measurement standards relating to orifice metering such as AGA, API, and ISO, to make sure that plate elements are kept from high DP distortion during flowing conditions. Orifice plate and carrier removal/replacement in orifice fitting designs usually performed by operating a mechanical crank handle and gear mechanism, is left to each individual manufacturing company generally built to allow plate changes during flowing conditions. Various orifice plate fitting manufacturers state in their technical bulletins and manuals that the flow rates (differential pressures) observed during custody measurement operations should be reduced for safety reasons during the plate extraction process, while other fitting manufacturers state that this is not required and claim a performance advantage.

Experimental research of single-hole and multi-hole orifice gas flow meters

Flow Measurement and Instrumentation, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Performance of an Orifice Meter Handling Two-Phase (Gas-Liquid) Flow.(Dept. M)

MEJ. Mansoura Engineering Journal, 2020

and mining transportation processes to measure the two-phase flow rates. Most of engineering systems have flow rate metering instruments, which mainly are affected by the properties of the two phases and the void fraction values. So, better understandings of the two-phase flow through systems are required to enhance the flow rate measurement accuracy and performance. In the present study, the orifice meter was selected due to its wide use in most engineering applications. The orifice meter is simple in design and construction, and is a limited maintenance metering device. Monni et al. [1] investigated experimentally the annular two-phase flow through a venturi flow meter in a vertical upward pipe (80 mm inner diameter). The experiments were performed at air void fraction values up to 0.97 to simulate nuclear accident cases. The value of the two-phase pressure drop between the venturi flow meter inlet section and throat section, and between inlet section and outlet section were dependent on the two-phase flow parameters (phase velocities, void fraction and dryness fraction). Also, new correlations were proposed to relate the flow rate as a function of the twophase pressure drop.

Fundamentals of Orifice Meter Measurement Fundamentals of Orifice Meter Measurement

Fluid meters are divided into two functional groups-One measures quantity (Positive Displacement); the other measures rate of flow (Inferential.) All fluid meters, however, consist of two distinct parts, each of which has different functions to perform. The first is the primary element, which is in contact with the fluid, resulting in some form of interaction. This interaction may be that of imparting motion to the primary element; the fluid may be accelerated etc. The second or secondary element translates the interaction between fluid and primary element into a signal that can be converted into volume, weights or rates of flow and indicates or records the results. For example, a weigher uses weighing tanks as its primary element and a counter for recording the number of fillings and dumpings as its secondary element. In an orifice meter, the orifice together with the adjacent part of the pipe and the pressure connections, constitute the primary element, while the secondary element consists of a differential pressure device together with some sort of mechanism for translating a pressure difference into a rate of flow and indicating the result, in some cases also recording it graphically and integrating with respect to the time. This same combination of primary and secondary elements will be observed in almost all other types of meters. Positive Displacement (Quantity Meters)-Some of the more common positive displacement meters are: Weighers, Reciprocating Piston, Rotating Piston, Nutating Disk, Sliding and Rotating Vanes, Gear and Lobed Impeller, and the meter most commonly used to sell small quantities of gas at relatively low flow rates, the Bellows meter. Inferential (Rate Meters)-(a) Orifice Plates-The most commonly used rate or inferential meter is the thin-plate, concentric orifice; a detailed discussion is covered in later paragraphs. (b) Flow Nozzles & Venturi Tubes-Flow Nozzles and Venturi Tubes are primary rate devices which will handle about 60% more flow than an orifice plate for the same bore under the same conditions, and can therefore handle higher velocity flows. If a differential limit is chosen, then a smaller bore nozzle or Venturi may be used to measure the same flow. They are more expensive to install and do not lend themselves to as easy size change or inspection as orifice plates. (c) Pitot Tubes-A Pitot or impact tube makes use of the difference between the static and kinetic pressures at a single point. A similar device which is in effect a multiple pitot tube, averages the flow profile. (d) Turbine Meters-A Turbine meter is one in which the primary element is kept in rotation by the linear velocity of the stream in which it is immersed. The number of revolutions the device makes is proportional to the rate of flow. (e) Swirlmeters, Vortex Shedding Meters, Rotometers, Mass Flow Meters, etc.-These are devices that have applications in flow measurement. The manufacturers should be contacted for detailed information. What is an Orifice Meter? An orifice meter is a conduit and a restriction to create a pressure drop. An hour glass is a form of orifice. A nozzle, venturi or thin sharp edged orifice can be used as the flow restriction. In order to use any of these devices for measurement it is necessary to empirically calibrate them. That is, pass a known volume through the meter and note the reading in order to provide a standard for measuring other quantities. Due to the ease of duplicating and the simple construction, the thin sharp edged orifice has been adopted as a standard and extensive calibration work has been done so that it is widely accepted as a standard means of measuring fluids. Provided the standard mechanics of construction are followed no further calibration is required. An orifice in a pipeline is shown in figure 1 with a manometer for measuring the drop in pressure (differential) as the fluid passes thru the orifice. The minimum cross sectional area of the jet is known as the "vena contracta." How does it work? As the fluid approaches the orifice the pressure increases slightly and then drops suddenly as the orifice is passed. It continues to drop until the "vena contracta" is reached and then gradually increases until at approximately 5 to 8 diameters downstream a maximum pressure point is reached that will be lower than the pressure upstream of the orifice. The decrease in pressure as the fluid passes thru the orifice is a result of the

Effects of Entrained Liquids on Orifice Measurement

2008

Orifice plate meters are one of the most widely used technologies in industry for gas flow metering. This is due to their relative simplicity, the extensive publicly available data sets that led to several orifice plate meter standards [1, 2, 3, and 4] and the fact that they are a relatively inexpensive method of gas metering. However, it is common in industry for gas meters to be installed in applications where the flows are actually wet gas flows, i.e., flows where there is some liquid entrainment in a predominantly gas flow. This is usually done out of economic necessity or due to the fact that the system designers were not aware at the conceptual design stage that the gas flow would have entrained liquid. Therefore, with the orifice plate meter being such a popular gas flow meter, it is by default possibly the most common wet gas flow meter.

Fundamentals of Orifice Meter Measurement

One measures quantity (Positive Displacement); the other measures rate of flow (Inferential.) All fluid meters, however, consist of two distinct parts, each of which has different functions to perform. The first is the primary element, which is in contact with the fluid, resulting in some form of interaction.