Performance of Multiphase Flowmeter and Continuous Water-Cut Monitoring Devices in North Slope, Alaska

摘要

Alaska’s North Slope oil fields offer several different types of production environments that can prove challenging for effective production well testing with conventional gravity type test separators. The Prudhoe Bay field has mature production: high water cuts exceeding 90%, crudes with low 20s API gravity and gas-lifted wells with high gas volume fractions (GVF) >99.9%. The Milne Point field has viscous crude and light oil production and employs electrical submersible pumps (ESP), jet pumps and gas lift. This wide range of production methods and challenging fluid properties create challenges when analysing potential equipment and procedures to provide the critical production data needed to optimize overall production. Over the last several years, BP Exploration (Alaska) Inc. (BPXA), installed over 24 infrared water-cut sensors. Nineteen water-cut devices have been installed in three-phase flow regimes at the wellheads. Five water-cut units have been installed on the liquid legs of two phase test separators. During this period BPXA also installed seven in-line multiphase meters—five in use at production pads for testing wells and two on individual wellheads. This paper will discuss BPXA’s experience with these metering devices over two years of operation, and present the verification process used to qualify the devices and their performance data. Additionally, successes, challenges and lessons learned are discussed.