Objectives/Scope: The increasing global importance of subsea production drives the need for betterrnaccuracy in subsea measurements to allow precise reservoir management while ensuring accurate royaltyrnassessment and production allocation. The work described here resulted from the previous RPSEA Projectrn1301, which showed that flow measurement errors of 10 to 20 percent were possible when meters werernsubject to scale or erosion. The objective of this work under RPSEA Project 4304 is to identify ways ofrndetecting fouling in multiphase and wet gas meters, so that corrective measures can be taken before largernerrors occur.rnMethods, Procedures, Process: The effort consisted of two major parts:rnTechnology Review: An examination of the state of the art in sensor and meter technology wasrnconducted for the purposes of detecting and/or quantifying meter fouling. A number of ideas werernconsidered.rn1. Measurement of the wall thickness of the meter, where an increase would indicate a scalerndeposition and a decrease would indicate erosion. Several methods were considered.rn2. Although sand monitors can indicate the presence of sand and possibly give an indication of sandrnquantity, they cannot detect erosion, but can warn of the possibility. Several sand monitors werernexamined.rn3. The Venturi meter is the most common component in multiphase meters. An additional pressurernmeasurement in the meter was investigated to detect fouling.rn4. The possibility of combining a physical meter and a virtual meter was evaluated to detect fouling.rn5. Since most multiphase meters have an abundance of diagnostics, the possibility of their being usedrnto detect fouling was considered.rnCandidate Selection: An evaluation of these and other technologies was performed to ultimately selectrnthe three most promising methods from the technology review. The criteria for choosing the mostrnpromising methods are discussed. The chosen methods were:rn1. Use of an additional pressure measurement in a Venturi meter.rn2. Use of multiphase flow meter diagnostics.rn3. Use of virtual metering and data reconciliation.rnThe results of these developments show promise, can be used in parallel and are discussed in the paper.
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