Hydrate plug localization and characterization using guided waves

摘要

In some conditions of temperature and pressure, the exploitation of hydrocarbon deposits in deep waters can lead to the formation of hydrate plugs during shutdown operations. The operators try to decrease the use of chemical products necessary today to avoid the formation of such plugs. Technip is developing an active technology of pipe heating through the use of heating cables arranged around the pipe and protected by a second pipe around it (design called "Pipe in Pipe"). These cables can be used to avoid the formation of the plug and, if necessary, to dissolve it. In order to avoid catastrophic failures in case of uncontrolled plug melting (pocket of gaz which could lead to pipe explosion or sudden plug dissociation of the plug from the pipe due to the important upstream pressure), a non-destructive and non-intrusive technology is necessary to locate and to characterize the hydrate plug. Studies are therefore performed to determine the capabilities of guided wave technology to provide such information. In this paper, we present a feasibility program that encompasses numerical simulations using CIVA software and experimental tests on ice plugs that are supposed, in a first approximation, to be representative of an hydrate plug from an acoustical point of view.