Perspectives on the Latest Cold Flow Technology Developments

Abstract

This paper describes a flow assurance method known as "cold flow". The method is suitable for deepwater liquid dominated fields and reduces costs and carbon emissions compared to conventional flow assurance methods by letting hydrate and wax deposits travel as inert solids with the production stream to the host fascility (e.g. an FPSO). A compact subsea unit that utilizes the cold flow method is presented and an experimental test setup at SINTEF's Multiphase Flow Laboratory is described. The unit consists of a recycle stream that seeds dry particles to a place where the bulk flow temperature is close to the hydrate formation temperature (HFT) and the wax appearance temperature (WAT). Water droplets coat the dry particles and become a part of the particles absorbing free water in the flow. In addition to the seeding mechanism, a robot operated induction coil removes inner pipe wall deposits by heating the pipe locally. Results from the tests show no build-up of solids inside the cold flow unit itself or downstream the unit. The flow system is also robust in terms of shutdowns and the production flow is regained easily. Measurements also show that the unit is robust with respect to increasing water cut (WC).