TCO has been using multiphase flowmeters (MPFMs) since early 2000 and has gained significant operational experience during this time. MPFM’s have replaced conventional separators because of higher operating ranges and they provide instantaneous measurements for operating decisions.
MPFMs from several manufactures are used in the Tengiz and Korolev fields and have several applications such as gas oil ratio monitoring on each well in the Sour Gas Injection Project pilot, at the metering stations for well testing which is used to calibrate the well performance models and production allocation, daily water production monitoring and well clean ups.
TCO has been working with vendors to improve flowmeter performance and reliability in a sour environment and extreme weather conditions. Several modifications were implemented to improve inline temperature measurements. To ensure MPFMs are operating properly and reliably requires a good understanding of the principles the manufacturer uses to calculate flowrates, meter components, operating envelopes, daily monitoring of key parameters, ability to trouble-shoot problems that do occur, regular maintenance and dedicated Production Engineers to manage the process. Getting accurate surface measurements is a challenge due to the wide range of well rates (1,600 to 25,000 BOPD), large seasonal temperature variation (from -40 °C to +50 °C) and high H2S content.
This paper provides an overview of MPFM usage in Tengiz and describes lessons learnt, best practices and challenges, from the perspective of a Production Engineer who is responsible for ensuring the MPFM’s are providing accurate and reliable data.