Vol.3 No.7 Subject: Flow Measurement News Date: 12-14-01 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 December 2001 Newsletter PROBLEMS WITH WET GAS METERING This topic is currently one of the subjects most discussed at flow measurement conferences today. Flow metering to a high level of accuracy has traditionally meant metering a single phase flow, either as a liquid or as a gas. However, flow measurement engineers are under increasing pressure to solve the problems associated with measuring more than one phase, that is, gas with a liquid present, also known as "wet gas" or liquids with gas and solids present known as "multiphase" metering. The biggest problem is measurement accuracy. Adding liquid into the flow changes several of the flow characteristics, such as density and differential pressure. But, because meters are calibrated with dry gas data, they inaccurately record the flow rate of wet gas, unless compensation is made for these changes. The degree of mixing between the gas and liquid also affects the meter: Are the two mixed intimately or does fluid tend to accumulate on the pipe walls? The effect on accuracy differs in each case. Wet gas is typically defined as the flow of a gas with the addition of a liquid between 0 and 5% fraction by volume. Many field applications fall into this category, particularly in the oil and gas industry. Examples include: water or condensate present in natural gas production; gas with oil or water present from the production well in oil and gas extraction; liquid water associated with gaseous steam in steam plants; wet gases at petrochemical, chemical and refinery plants; water and gas coming from the coalfield in coal bed methane applications; and in sewage plants, methane gas with moisture carry over. Over the next six months, we will address some of the questions concerning wet gas metering - How wet is wet? What are the problems in different applications? and What meters may be used to make the measurement? If there is another topic you wish to raise, or you would like more information about McCrometer's products for metering wet gas, please contact McCrometer at 951-652-6811 or visit our web-site at www.mccrometer.com. ******************************************* Copyright 2001 McCrometer ******************************************* Know anyone looking for a steady dose of flow measurement information? ****************************************** To subscribe send e-mail to <mailto:news-request@mccrometer.com>news-request@mccrometer.com with a keyword SUBSCRIBE in the subject field. To unsubscribe, send e-mail to <mailto:news-request@mccrometer.com>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