(18d) Discussions on Design of Deepwater Flow Assurance of LW3-1 Gas Field

With the increase of the water depth, the depth and length of subsea pipelines also increase. The hard circumstances of deepwater areas not only make harsh requirements for deepwater floating platforms, subsea production facilities and offshore operations, but also bring huge challenges for subsea pipelines from several kilometers to few hundreds kilometers, which tie subsea satellite wells, marginal fields to central processing systems. The complex of the gas oil and water multiphase flow, seabed hypsographic feature and operation activities etc., bring a series of problems to subsea transportation system, such as solid formation (hydrate, wax), severe slug flow in deep water riser, multiphase flow corrosions and solid particle’s erosion etc. These problems have seriously affected general running and safety of the subsea production oil fields, especially in the deepwater multiphase transportation systems, and accidents induced by these problems happen repeatedly. This paper summary the typical flow assurance problems related to the Chinese first deepwater gas field LW3-1. On this base, the flow assurance problems about the 79 Km multiphase flow along the slope and its design methods are presented.