Equinor and OneSubsea Processing have cooperated in developing and qualifying the world’s first subsea wet gas compression system which was installed at the Gullfaks field in the North Sea in late 2015. The system has been in continuous operation since July 2017. Early in the compressor technical qualification program it became obvious that subsea cooling was mandatory for the success of a subsea wet gas compression system. Development of a wet gas process cooler was essential and required focus on several aspects such as cooler performance, fluid distribution, pressure loss, sand accumulation, hydrate formation, and marine growth. Reliability, robustness, size and weight were of high priority, as marine interventions are costly, especially for large equipment. Three years after installation, and 1.5 years in operation have provided extensive operational experience for the process coolers in the Gullfaks subsea wet gas compression system. It is of high interest to evaluate and compare operational experience from field with test data and calculations. The purpose of this paper is to summarize the experience gained from field with respect to cooler performance and flow assurance issues and compare with initial calculations and assumptions.