| Vol. 5 No. 4 Subject: Flow Measurement News Date: 4-7-03 From: McCrometer, "The Flow Measurement Specialists" ........ http://www.mccrometer.com ........ ******************************************* This newsletter is e-mailed by McCrometer monthly to subscribers worldwide. It consists of flow measurement information of interest for professionals in this field. For More information on our complete line of flowmeters go to: http://www.mccrometer.com ******************************************* McCrometer Newsletter - April 2003 Classification of Wet Gas Flow Meters In a very interesting article in the March 24th, Oil & Gas Journal of the 24th March, 2003, by Parviz Mehdizadeh, Jack Marreli and Frank Ting, Wet Gas is split into 3 Types: Types I, Type II and Type III which corresponds to increasing Lochart-Martinelli Numbers. Type I less than or equal to 0.02, Type II 0.02 to 0.30 and Type III greater than 0.3. This split is very useful for the classification of Wet Gas Flow Meters. Type I meters are generally standard gas meters, which may make a correction for the presence of liquid, but would not measure the liquid flow directly. If the liquid content was significant the operator may wish an estimate of the liquid flow rate as well as that of the gas and this could be done simply by a spot check of the liquid flow by a tracer technique. This involves injecting a tracer upstream of the flow meter and subsequently sampling the liquid downstream of the meter. If the tracer and the liquid is adequately mixed, the liquid flow rate can be estimated. Knowing the liquid content, a correction can then be made for the gas flow. This has been done for the combination of a Venturi and a tracer but could equally well be measured by a V-Cone replacing the Venturi. Type II meters require more than a single phase meter for the gas measurement. Often a differential pressure (DP) meter in conjunction with yet another DP device or another form of flow meter is used. The tracer technique described for the Type I meter could also be used for Type II metering. Type III meters are really multiphase meters and require expensive devices to cover the range of liquids and possibly more than simply one liquid e.g. oil and water as well as the gas. Roxar have developed such a meter and the V-Cone (or a Venturi) has been incorporated into their system to determine the bulk flow rate. The need for an accepted test protocol and procedure evaluating the performance and accuracy of these systems is currently needed. This would correspond to the approach taken by API to test DP devices in their publication: “Manual of Petroleum Measurement Standards Chapter 5.7 - Testing Protocol for Differential Pressure Flow Measurement Devices” To find out more about McCrometer's line of flow meters, including the V-Cone, Water Specialties Meter, Mc Propeller and Ultra Mag meters, please contact McCrometer at 951-652-6811 or visit our website at http://www.mccrometer.com. ****************************************** Copyright 2003 McCrometer If you have comments or suggestions for newsletter topics you would like to see, please address them to: Bob Peters or Richard Steven mailto:newscomment@mccrometer.com ********************************************************************************* Know anyone looking for a steady dose of flow measurement information? ********************************************************************************* To subscribe send e-mail to mailto:news-request@mccrometer.com with a keyword SUBSCRIBE in the subject field. To unsubscribe, send e-mail to mailto:news-request@mccrometer.com with a keyword REMOVE in the subject field. ********************************************************************************* To subscribe or unsubscribe online, please go to our website at: http://www.mccrometer.com/subscribe.htm ********************************************************************************* Distributed by McCrometer "The Flow Measurement Specialists" http://www.mccrometer.com |