Multiphase flow metering (MPFM) technology is gaining popularity and becoming the main well rate testing mechanism in some regions of the world. Yet, their application in measuring the flow rates of high gas-oil-ratio (GOR) and/or high gas volume fraction (GVF) wells has always been a challenge. A remote field located in the Southeastern part of Saudi Arabia commenced its production in the late 90's from a thin oil column lying between a large gas-cap and a water aquifer. Although, 84% of the thin-oil-column producing wells are horizontal and multilateral wells with extended reservoir contact, the gas-cap gas breakthrough and production from these wells have increased gradually; resulting in an increase in the wells GOR. Currently, 35% of the wells are producing at high GOR ranging between 2,000 and 6,000 SCF/STB with a GVF reaching as high as 98%.
The fluid flow rate tests of these wells are conducted through a test separator designed to handle a GOR of 2,500 SCF/STB; well below the current GOR of these wells. Such plans require identification of the most appropriate MPFMs that can operate successfully in such high GOR/GVF conditions.
This paper describes the field trial test of three MPFMs under high GOR/GVF conditions of dry and wet production. The meters' performance is compared to a portable test separator properly sized to accommodate the high gas and liquid flow rates of the producers of this field. The paper summarizes the results of this test and justifies the measurement errors in light of the operating principle of each meter. The paper also provides valuable guidelines for conducting such testing operations by building on the lessons learned from this trial test.