Joseph Shen

Field Evaluation of a Multiphase Meter in Well Testing Operation

This paper describes the evaluation results on the measurement accuracy and long-term operation of a multiphase meter used for well testing. The test was conducted by Chevron at its Lost Hills Field in California. After many years of development work, several multiphase meter manufacturers have begun to offer their meters commercially for production operation. In this paper, commercial multiphase meters are first reviewed briefly based on the methods that those meters use to handle the fluid flow. The multiphase meter selected for this application was manufactured by Accuflow Inc. This commercial multiphase meter uses the compact separation approach in handling the oil/gas/water flow stream by first separating the gas from the liquid stream and then measuring the gas and oil/water separately. The Accuflow system was installed at a gauge station in January of 1996. It was designed to test wells that have productions ranging from about 100 to 400 barrels of fluid a day, high water cut (40% - 90%), and up to 200 MCFD of gas. For accuracy testing, the multiphase meter was piped in series with a test separator at the gauge station. Production from selected wells, covering a wide range of flow rates, water cuts, and gas volume fractions, flowed through the multiphase meter first and then the test separator, enabling comparison of the new meters performance and accuracy with an existing reference. Additional tests were also conducted to compare results with a test tank at the site. The paper also discusses other operational aspects of the multiphase meter such as equipment maintenance and sand accumulation. Overall, satisfactory performance of this multiphase meter was observed and additional units are being installed at Lost Hills Field.

Velocity Profile Survey in a 16-in. Custody-Transfer Orifice Meter for Natural Gas

Description of a research project conducted at Chevron USA Inc.s Venice, L.A., facility to ascertain that the flow condition inside a nominal 16-in; (406 mm) custody-transfer orifice meter was in compliance with American Gas Assn. (AGA) requirements. The test successfully demonstrated the techniques and equipment developed for determining actual flow distribution inside orifice meters in the field under normal operating conditions. This technology can be used to detect detrimental flow profiles and to verify compliance with AGA requirements on flow conditions in custody-transfer orifice meters.