Horizontally installed cone differential pressure meter wet gas flow performance

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.

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Wet Gas Flow Metering Based on Differential Pressure and BSS Techniques

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.383-390.4922 ◽

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.

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Using an Adjustable Cone Meter to Measure Wet Gas

10.2118/207505-ms ◽

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.

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Wet Gas Performance of Differential Pressure Flowmeters

Volume 2: Fora, Parts A and B ◽

10.1115/fedsm2007-37665 ◽

2007 ◽

Cited By ~ 3

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.

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

Sensors ◽

10.3390/s21072291 ◽

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.

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Wet Gas Measurement with Slotted Orifice Meter--Effect of Geometry of Slots and Pressure

Chemical Product and Process Modeling ◽

10.2202/1934-2659.1620 ◽

2011 ◽

Vol 6 (1) ◽

Author(s):

Perumal Kumar ◽

Boon Foo Chai ◽

Michael Wong Ming Bing

Keyword(s):

Gas Flow ◽

Oil And Gas ◽

Homogeneous Model ◽

Oil And Gas Industry ◽

Differential Pressure ◽

Pressure Recovery ◽

Cfd Modeling ◽

Flow Profile ◽

Wet Gas ◽

Gas Measurement

Wet gas metering by differential pressure flow meters is gaining prominence in the oil and gas industry, owing to their simple construction. Slotted orifice, a modified version of the standard orifice meter has been found promising by many researchers. This novel flow meter is shown to be insensitive to the upstream flow profile with lower head loss and faster pressure recovery compared to the standard orifice. In the present work, the effect of geometry of slots and pressure on the performance of the slotted orifice has been studied by CFD modeling of the wet gas flow. The performance of slotted orifice with rectangular perforations (1.5 ≤ l/w ≤ 3.0) and circular perforations has been compared with that of the standard orifice having same β-ratio of 0.40. Simulation results reveal that the shape of perforation of the slotted orifice has no effect on the differential pressure. However, the pressure recovery with the rectangular slots is found to increase with increasing aspect ratio. Moreover, at low pressure, slotted orifice is found to be more sensitive to liquid presence than the standard orifice. The relatively higher over reading values obtained in this work is consistent with the results of Geng et al (2006) that for slotted orifice, a low beta ratio is more sensitive to the liquid presence in the stream and hence is preferable for wet gas metering. Homogeneous model, Steven’s and De Leeuw’s correlations, are found to be better than orifice correlations for wet gas mass flow prediction.

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