Using an Adjustable Cone Meter to Measure Wet Gas

2021 ◽  
Author(s):  
Sakethraman Mahalingam ◽  
Gavin Munro ◽  
Muhammad Arsalan ◽  
Victor Gawski
Keyword(s):  
Pressure Measurement ◽  
Gas Flow ◽  
Liquid Fraction ◽  
Pressure Sensors ◽  
Differential Pressure ◽  
Design Development ◽  
Flow Conditions ◽  
Estimation Model ◽  
Flow Rates ◽  
Wet Gas

Abstract A traditional fixed size Venturi meter has a turndown of about 8:1 under dry gas conditions that may drop to as low as 3:1 under wet-gas flow. When the well conditions change, a replacement of the original Venturi meter with one of a different size is needed. In this paper, we present the design, development and testing of an Adjustable cone meter that has the ability to adapt itself to the flow conditions automatically and provide a turndown of as much as a 54:1 under dry gas conditions and as much as 20:1 under wet-gas conditions. The patented feature of the Adjustable cone meter is the adjustable sleeve that moves over the cone when the flow rate decreases below a preset value causing an increase in the differential pressure across the meter. In addition, traditional Venturi meters have only one differential pressure measurement and the sensor tends to overestimate the flow when there is liquid present in the flow (wet-gas). The Adjustable cone meter has two differential pressure sensors and the second measurement is used to estimate the liquid content in wet-gas. Two meters were manufactured and tested at the National Engineering Laboratory in East Kilbride, Scotland under gas flow rates of up to 18 MMscfd. Based on the differential pressure measurements under varying flow conditions, algorithms were developed to measure the dry gas and liquid fraction. An over-reading model of the meter and a liquid fraction estimation model based on the pressure loss ratio was derived from an additional differential pressure measurement. The model was used to not only to quantify the gas and liquid flow rates but also the estimated error in each measurement. The measurements show that the Adjustable Cone meter is able to provide low uncertainty in both dry and wet gas conditions and met the conditions outlined in ISO 5167-5. The Adjustable cone meter is a much needed innovation in the area of differential pressure measurement.

Using an Adjustable Cone Meter to Measure Wet Gas

2021 ◽  
Author(s):  
Sakethraman Mahalingam ◽  
Gavin Munro ◽  
Muhammad Arsalan ◽  
Victor Gawski
Keyword(s):  
Flow Rate ◽  
Pressure Measurement ◽  
Gas Flow ◽  
Flow Line ◽  
Liquid Fraction ◽  
Differential Pressure ◽  
Low Flow ◽  
Liquid Density ◽  
Estimation Model ◽  
Wet Gas

Abstract When the gas flow rate of a well significantly changes, the flow rate can fall below that of the operating range of a traditional fixed size Venturi meter, necessitating the replacement of the original meter with one of a smaller size. However, with an adjustable cone meter, the internal reconfiguration feature allows it to automatically switch from high operating flow range to low operating flow range and there is no requirement to disassemble the meter from the flow line assembly. Adjustable cone meters were designed, developed and tested at the wet-gas flow loop at National Engineering Laboratory in East Kilbride, Scotland. After calibrating the meter with dry nitrogen gas, the meter was tested with increasing amounts of liquid being injected into the flowline, upstream of the meter. The liquid caused the differential pressure measurement on the meter to over-read. Based on the differential pressure measurements under varying flow conditions, algorithms were developed to measure the dry gas and liquid fraction. The data obtained from the tests such as differential pressure, pressure, temperature, liquid density were used to build an over-reading model of the meter and a liquid fraction estimation model based on pressure loss ratio derived from an additional differential pressure measurement. The model was used to not only to quantify the gas and liquid flow rates but also the estimated error in each measurement. The measurements show that the Adjustable Cone meter is able to provide low uncertainty in both dry and wet gas conditions and offers a turndown ratio of up to 54:1 in dry gas conditions. In addition, the automatic adjustment of the meter from high flow to low flow positions avoids the need for manual intervention that involves additional risk and cost.

scholarly journals A Correction Method for Wet Gas Flow Metering Using a Standard Orifice and Slotted Orifices

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2291
Author(s):  
Barbara Tomaszewska-Wach ◽  
Mariusz Rzasa
Keyword(s):  
Gas Flow ◽  
Dynamic Pressure ◽  
Air Flow ◽  
Continuous Phase ◽  
Differential Pressure ◽  
Flow Measurements ◽  
Phase Form ◽  
Flow Rates ◽  
Flow Metering ◽  
Wet Gas

Flow measurements that utilize differential pressure meters are commonly applied in industry. In such conditions, gas flow is often accompanied by liquid condensation. For this reason, errors occur in the metering process that can be attributed to the fluctuations in continuous phase parameters in the flow. Furthermore, the occurrence of a dispersed phase results in flow disturbance and dynamic pressure pulsations. For the above reasons, new methods and tools are sought with the purpose of performing measurements of gas-liquid flows providing measurement results that can be considered as fairly accurate in the cases when flow involves a liquid phase form. The paper reports the results of a study involving measurement of wet gas flow using differential pressure flowmeters. The experiments were conducted for three constant mass air flow rates equal to 0.06, 0.078 and 0.086 kg/s. After stabilization of the air flow rates, water was fed into the pipe with flow rates in the range from 0.01 to 0.16 kg/s. The research involved a standard orifice and three types of slotted orifices with various slot arrangements and geometries. The analysis focused on the effect of orifice geometry on the flow metering results. On the basis of the results, it was found that the slotted orifice generates smaller differential pressure values compared to the standard orifice. The water mass fraction in the gas leads to overestimated results of measurements across the flowmeter. Regardless of the type of the orifice, is necessary to undertake a correction of the results. The paper proposes a method of gas mass flow correction. The results were compared with the common over-reading correction models available in the literature.

Wet Gas Flow Metering Based on Differential Pressure and BSS Techniques

2011 ◽  
Vol 383-390 ◽  
pp. 4922-4927
Author(s):  
Peng Xia Xu ◽  
Yan Feng Geng
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Differential Pressure ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Metering ◽  
Wet Gas

Wet gas flow is a typical two-phase flow with low liquid fractions. As differential pressure signal contains rich information of flow parameters in two-phase flow metering, a new method is proposed for wet gas flow metering based on differential pressure (DP) and blind source separation (BSS) techniques. DP signals are from a couple of slotted orifices and the BSS method is based on time-frequency analysis. A good relationship between the liquid flow rate and the characteristic quantity of the separated signal is established, and a differential pressure correlation for slotted orifice is applied to calculate the gas flow rate. The calculation results are good with 90% relative errors less than ±10%. The results also show that BSS is an effective method to extract liquid flow rate from DP signals of wet gas flow, and to analysis different interactions among the total DP readings.

High-Accuracy Wet-Gas Multiphase Well Testing and Production Metering

SPE Journal ◽  
2006 ◽  
Vol 11 (02) ◽  
pp. 199-205 ◽  
Author(s):  
David I. Atkinson ◽  
Oyvind Reksten ◽  
Gerald Smith ◽  
Helge Moe
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Volume Fraction ◽  
Well Testing ◽  
Gas Flow Rate ◽  
Flow Rates ◽  
Wet Gas ◽  
New Interpretation ◽  
Interpretation Model

Summary Dedicated wet-gas flowmeters are now commercially available for the measurement of gas and liquid flow rates and offer a more compact measurement solution than does the traditional separator approach. The interpretation models of traditional multiphase flowmeters emphasize the liquid rate measurements and have been used to well test and meter mostly liquid-rich flow streams. These models were not developed for the measurement of gas flow rates, particularly those of wet gas. A new interpretation is described that allows a traditional multiphase flowmeter to operate in a dual mode either as a multiphase meter or as a wet-gas meter in 90 to 100% gas. The new interpretation model was developed for a commercially available multiphase flowmeter consisting of a venturi and a dual-energy composition meter. This combination results in excellent predictions of the gas flow rate; the liquid rate prediction is made with acceptable accuracy and no additional measurements. The wet gas and low-liquid-volume-fraction interpretation model is described together with the multiphase flowmeter. Examples of applying this model to data collected on flow loops are presented, with comparison to reference flow rates. The data from the Sintef and NEL flow loops show an error (including the reference meter error) in the gas flow rate, better than ± 2% reading (95% confidence interval), at line conditions; the absolute error (including the reference meter error) in the measured total liquid flow rate at line conditions was better than ± 2 m3/h (< ± 300 B/D: 95% confidence interval). This new interpretation model offers a significant advance in the metering of wet-gas multiphase flows and yields the possibility of high accuracies to meet the needs of gas-well testing and production allocation applications without the use of separators. Introduction There has been considerable focus in recent years on the development of new flow-measurement techniques for application to surface well testing and flow-measurement allocation in multiphase conditions without separating the phases. This has resulted in new technology from the industry for both gas and oil production. Today, there are wet-gas flowmeters, dedicated to the metering of wet-gas flows, and multiphase meters, for the metering of multiphase liquid flows. The common approach to wet-gas measurement relates gas and liquid flows to a "pseudo-gas flow rate" calculated from the standard single-phase equations. This addresses the need for gas measurement in the presence of liquids and can be applied to a limit of liquid flow [or gas volume fraction, (GVF)], though the accuracy of this approach decreases with decreasing GVF. The accurate determination of liquid rates by wet-gas meters is restricted in range. The application and performance of multiphase meters has been well documented through technical papers and industry forums, and after several years of development is maturing (Scheers 2004). Some multiphase measurement techniques can perform better, and the meters provide a more compact solution, than the traditional separation approach. It is not surprising that the use of multiphase flowmeters has grown significantly, the worldwide number doubling in little over a 2-year period (Mehdizadeh et al. 2002). Multiphase-flowmeter interpretation emphasizes the liquid rate measurement, and the application of multiphase flowmeters has been predominantly for liquid-rich flow stream allocation and well testing.

Axial and Radial Investigation of Hydrodynamics in a Bubble Column; Influence of Fluids Flow Rates and Sparger Type

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
Hélène Chaumat ◽  
Anne-Marie Billet ◽  
Henri Delmas
Keyword(s):  
Liquid Flow ◽  
Gas Flow ◽  
Bubble Column ◽  
Bubble Diameter ◽  
Pressure Sensors ◽  
Operating Conditions ◽  
Batch Mode ◽  
Flow Rates ◽  
Wide Range ◽  
Injection Zone

A detailed investigation of local hydrodynamics in a pilot plant bubble column has been performed using various techniques, exploring both axial and radial variations of the gas hold-up, bubble average diameter and frequency, surface area. A wide range of operating conditions has been explored up to large gas and liquid flow rates, with two sparger types. Two main complementary techniques were used: a quasi local measurement of gas hold-up via series of differential pressure sensors to get the axial variation and a double optic probe giving radial variations of gad hold-up, bubble average size and frequency and surface area.According to axial evolutions, three zones, where radial evolutions have been detailed, have been separated: at the bottom the gas injection zone, the large central region or column bulk and the disengagement zone at the column top. It was found that significant axial and radial variations of the two phase flow characteristics do exist even in the so called homogeneous regime. The normalized profiles of bubble frequency appear sparger and gas velocity independent contrary to bubble diameter, gas hold-up and interfacial area normalized profiles. In any case bubbles are larger in the sparger zone than elsewhere.The main result of this work is the very strong effect of liquid flow on bubble column hydrodynamics at low gas flow rate. First the flow regime map observed in batch mode is dramatically modified with a drastic reduction of the homogeneous regime region, up to a complete heterogeneous regime in the working conditions (uG> 0.02 m/s). On the contrary, liquid flow has limited effects at very high gas flow rates.A large data bank is provided to be used for example in detailed comparison with CFD calculations.

scholarly journals Determination of void fraction in wet-gas vertical flows via differential pressure measurement

2021 ◽  
pp. 102080
Author(s):  
Paul Tait ◽  
Yuan Chen ◽  
Wataru Senjyu ◽  
Toru Watanabe ◽  
Yasuo Inamura ◽  
...  
Keyword(s):  
Void Fraction ◽  
Pressure Measurement ◽  
Differential Pressure ◽  
Wet Gas

Evaluation of a symmetrically disposed Pitot tube flowmeter for measuring gas flow during exercise

1994 ◽  
Vol 77 (6) ◽  
pp. 2659-2665 ◽  
Author(s):  
J. Porszasz ◽  
T. J. Barstow ◽  
K. Wasserman
Keyword(s):  
Tidal Volume ◽  
Pressure Measurement ◽  
Gas Flow ◽  
Minute Ventilation ◽  
Target Volume ◽  
Volume Measurement ◽  
Differential Pressure ◽  
Gas Composition ◽  
Gas Density ◽  
Pump Assembly

We evaluated the effect of airflow and gas composition on the linearity of measurement of airflow by a new disposable flowmeter. The flowmeter is based on the principle of differential pressure measurement across two symmetrically disposed Pitot tubes. Nonlinearities arising from the pressure-to-airflow relationship and sensitivity to changes in gas density were linearized with appropriate software and monitoring of the gas composition. With room air used as the respired gas, the measured tidal volume from a piston pump assembly was consistently within 1–2% of the target tidal volume for each of five flowmeters tested across physiological ranges of flow. Changing gas densities by varying concentrations of O2, CO2, and N2 led to errors in tidal volume measurement that ranged up to 6–8%. However, because the errors were predictable, they were corrected by software to within 0.6% of the target volume. Measurement of minute ventilation during exercise was within 1–2% of that determined from bag collections. We conclude that this type of flowmeter can accurately measure exercise minute ventilation and has advantages over some other flowmeters because of its ruggedness, reproducibility, and ease of sterilization or replacement compared with other flowmeters.

Wet Gas Performance of Differential Pressure Flowmeters

2007 ◽  
Author(s):  
Russell Evans ◽  
Stephen A. Ifft
Keyword(s):  
Flow Measurement ◽  
Gas Flow ◽  
Process Management ◽  
Gas Production ◽  
Differential Pressure ◽  
Liquid Volume ◽  
Gas Flows ◽  
Wet Gas ◽  
Separation Equipment ◽  
Process Measurements

Wet gas flow measurement is becoming vital to the natural gas production industry. New wells with marginal outputs cannot justify gas-liquid separation equipment and must transfer gas which contains some liquid volume. The flow measurement device on each well dictates the allocation earnings and must therefore provide gas flow measurement as accurately as possible. Several types of differential pressure based flowmeters are currently being used in wet gas flow measurement. DP based flowmeters share many performance characteristics in wet gas applications. However, studies have also found that there can be significant differences in the correlations between meter over reading and liquid content depending of the type of DP meter being tested. Emerson Process Management conducted a series of wet gas tests on a standard orifice plate, a V-Cone, a Venturi and two Rosemount conditioning orifice plates at the National Engineering Laboratory in Scotland (NEL). Previously, tests of conditioning orifice plates in wet gas were conducted at the Colorado Engineering Experiment Station, Inc. (CEESI). The work described in this paper is aimed at investigating the similarities and differences in the performance of these meter types in wet gas flows. Comparisons of these data to those from previous studies on the meter types tested are presented. Also, as a result of these studies, a general method for correcting the over-reading of DP-based, wet gas flowmeters using process measurements and the flow computing capabilities of modern multivariable DP transmitters was developed and is presented.

Gas-Liquid Two-Phase Flow in Hot Embossed Square Microchannels

2007 ◽  
Author(s):  
Namwon Kim ◽  
Estelle T. Evans ◽  
Daniel S. Park ◽  
Dimitris E. Nikitopoulos ◽  
Steven A. Soper ◽  
...  
Keyword(s):  
Weber Number ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Liquid Fraction ◽  
Scaling Law ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Rates ◽  
Homogeneous Liquid ◽  
Bubble Length

An experimental study was conducted to investigate the characteristics of gas-liquid two-phase flow in 200 μm square microchannels thermoformed in polymer chips. Polymer microfluidic chips were replicated using hot embossing of poly(methyl methacrylate) (PMMA) with micromachined brass mold inserts. The thermoformed microchannels in polymer chips typically had greater surface roughnesses compared to microchannels etched in the silicon substrate. Two more different polymer chips, a direct micromachined PMMA chip and a chip hot embossed with a LIGA nickel mold insert, were fabricated to compare surface characteristics of the sidewalls and bottoms of fabricated microchannels. Deionized water and dry air were injected separately into the chips at superficial velocities of jL = 0.005 – 0.11 m/s for the liquid and jG = 0.003 – 16.67 m/s for the gas. Capillary bubbly, plug, plug-annular, annular, and dry flows were observed in the microchannels. Two-phase flow pattern maps and transitions between flow regimes were determined for fixed values of the homogeneous liquid fraction defined as βL = QL/(QL + QG) where QL and QG are the liquid and gas flow rates, and the liquid Weber number fraction defined as γL = WeL/(WeL + WeG) where WeL and WeG are the liquid and gas Weber number. The surface roughness in submicron range showed minor effect in comparison with the previous work in terms of the gas-liquid two-phase flow patterns and transitions between flow regimes. Dimensionless bubble sizes scaled by the width of observation microchannel were plotted against the homogeneous liquid fraction (βL). A scaling law for the bubble length developed for the previous work with T-junctions was applicable to the present work used the cross junction for generation of segmented flow. With a fixed value of the fitting parameter, scaling law showed a good agreement with the experimental data. Deviation of the scaled bubble length from predicted bubble length line and irregularity of bubble length with a fixed homogeneous liquid fraction increased with higher gas flow rates.

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